Patent Description:
With the increasing prominence of environmental issues, a low carbon economy has become the mainstay of future economic development. An increasingly severe air situation has also further fueled the emergence and development of an energy storage device. The energy storage device with high energy density, high power density, a large number of recycling use times, and long storage duration becomes a key to addressing global problems such as energy crisis and environmental pollution.

The energy storage device typically includes an electrode assembly, a connector, a welding protection sheet, and a pole. The electrode assembly is provided with a tab. The tab is located between the connector and the welding protection sheet. The connector is welded to the pole. However, the existing welding protection sheet suffers from low alignment efficiency and poor alignment precision when being welded to the tab, resulting in low efficiency and poor reliability of the energy storage device.

The relevant prior art can be found in <CIT>, <CIT>, <CIT> and <CIT>.

Embodiments of the present disclosure provide an energy storage device and an electric device, to solve the problems of low alignment efficiency and poor alignment precision between a welding protection sheet and a tab.

In a first aspect, embodiments of the present disclosure provide an energy storage device, according to the independent claim <NUM>.

The energy storage device includes a connector, a tab, and a welding protection sheet. The tab is connected to the connector. The welding protection sheet abuts against a surface of the tab facing away from the connector. The welding protection sheet includes a body, a first bent connection portion, and a first extending portion. Each of the body and the first extending portion extends in a first direction. The first bent connection portion is connected between the first extending portion and the body. The first extending portion is foldable relative to the body to face towards the body. Each of two opposite ends of an end portion of the first extending portion away from the first bent connection portion in the first direction has a first notch, and the first notch has a width in a second direction less than a width of the first extending portion in the second direction. The second direction is perpendicular to the first direction. Two first corners are formed at connections between two end portions of the first extending portion in the first direction and the end portion of the first extending portion away from the first bent connection portion. A distance between the two first corners in the first direction is less than a length of the body in the first direction.

In the energy storage device according to the embodiments of the present disclosure, the first bent connection portion is connected between the first extending portion and the body, and the first extending portion is foldable relative to the body to face towards the body. Each of the two opposite ends of the end portion of the first extending portion away from the first bent connection portion in the first direction has the first notch. The width of the first notch in the second direction is less than the width of the first extending portion in the second direction. Further, the distance between the two first corners in the first direction is less than the length of the body in the first direction. In this way, on the one hand, a robotic arm can reach to the first notch to clamp the welding protection sheet, thereby stably clamping the welding protection sheet. In addition, it is possible to allow for rapid and accurate placement of the welding protection sheet at a specified position on the tab. Therefore, alignment efficiency and precision between the welding protection sheet and the tab can be improved, thereby improving production efficiency and product reliability of the energy storage device. Meanwhile, displacement of the welding protection sheet on the tab can be avoided, thereby avoiding problems such as solder false and solder leakage between the welding protection sheet and the tab. On the other hand, the first notch at the first extending portion can allow the first corner to be shrunk inwards relative to the body in the first direction to reduce contact between the first corner and the tab, thereby effectively preventing the tab from being damaged by the first corner. Therefore, reliability and service life of the energy storage device can be improved. Further, the shrinking of the first corners relative to the body in the first direction can also reduce the possibility of the first corners coming into contact with other objects, which can prevent the first corners from upwarping away from the body due to an external force. Therefore, it is possible to prevent the first corners from being formed into sharp portions that could pierce or scratch the tab.

In combination with the first aspect, in some implementations of the first aspect, the welding protection sheet further includes a second bent connection portion and a second extending portion. The second extending portion extends in the first direction. The second bent connection portion is connected to an end of the body away from the first bent connection portion. The second bent connection portion is connected between the second extending portion and the body. The second extending portion is foldable relative to the body to face towards the body. The second extending portion is located at a side of the body facing towards the first extending portion. Each of two opposite ends of an end portion of the second extending portion away from the second bent connection portion in the first direction has a second notch, and a width of the second notch in the second direction is less than a width of the second extending portion in the second direction. The second extending portion has two second corners formed at connections between two end portions of the second extending portion in the first direction and the end portion of the second extending portion away from the second bent connection portion. A distance between the two second corners in the first direction is less than the length of the body in the first direction. In this way, on the one hand, the robotic arm may simultaneously reach the first notch and the second notch to clamp the welding protection sheet. The first notch and the second notch can provide the robotic arm with several clamping positions to increase an acting point of the robotic arm. Therefore, the robotic arm can clamp the welding protection sheet more steadily and allows for the rapid and accurate placement of the welding protection sheet at the specified position of the tab. Therefore, the alignment efficiency and precision between the welding protection sheet and the tab can be improved, which in turn improves the production efficiency and the product reliability of the energy storage device. Meanwhile, the displacement of the welding protection sheet on the tab can be avoided, thereby avoiding the problems such as solder false and solder leakage between the welding protection sheet and the tab. On the other hand, the second notch at the second extending portion can allow the second corner to be shrunk inwards relative to the body in the first direction to reduce contact between the second corner and the tab, thereby effectively preventing the tab from being damaged by the second corner. Therefore, reliability and service life of the energy storage device can be improved. Further, the shrinking of the second corners relative to the body in the first direction can also reduce the possibility of the second corners coming into contact with other objects, which can prevent the second corners from upwarping away from the body due to an external force. Therefore, it is possible to prevent the second corners from being formed into sharp portions that could pierce or scratch the tab.

In combination with the first aspect, in some implementations of the first aspect, the first extending portion has two first side walls opposite to each other in the first direction and a second side wall located at a side of the first extending portion away from the first bent connection portion. The first notch has a first notch wall connected to the two first side walls and a second notch wall connected to the second side wall. Rounded transitions are achieved between the first side walls and the first notch wall, between the second side wall and the second notch wall, and between the first notch wall and the second notch wall. The second extending portion has two third side walls opposite to each other in the first direction and a fourth side wall located at a side of the second extending portion away from the second bent connection portion. The second notch has a third notch wall connected to the two third side walls and a fourth notch wall connected to the fourth side wall. Rounded transitions are achieved between the third side walls and the third notch wall, between the fourth side walls and the fourth notch wall, and between the third notch wall and the fourth notch wall. Therefore, sharp corners are prevented from being formed at the first extending portion and the second extending portion, thereby avoiding any damage to the tab by the first extending portion and the second extending portion. Therefore, the reliability and service life of the energy storage device can be improved.

In combination with the first aspect, in some implementations of the first aspect, an obtuse angle or a right angle is formed between the first notch wall and the second notch wall. An obtuse angle or a right angle is formed between the third notch wall and the fourth notch wall. By forming the obtuse angle between the first notch wall and the second notch wall and forming the obtuse angle between the third notch wall and the fourth notch wall, a transition between the first notch wall and the second notch wall and a transition between the third notch wall and the fourth notch wall become smoother, thereby reducing internal stress of the first extending portion near the corresponding first notch after stamping the first notch and internal stress of the second extending portion near the corresponding second notch after stamping the second notch. Consequently, a problem such as the upwarp of the first corners and the second corners after stamping can be further avoided, thus preventing the tab from being scratched by the first corner and the second corner. Therefore, the reliability of the energy storage device can be improved and the service life of the energy storage device can be prolonged. By forming the right angle between the first notch wall and the second notch wall and forming the right angle between the third notch wall and the fourth notch wall, it is possible to improve sharpness of a stamping die head, thereby reducing the difficulty in stamping the first notch and the second notch.

In combination with the first aspect, in some implementations of the first aspect, the width of the first notch in the second direction ranges from <NUM> to <NUM>, and a length of the first notch in the first direction ranges from <NUM> to <NUM>. In addition, the width of the second notch in the second direction ranges from <NUM> to <NUM>, and a length of the second notch in the first direction ranges from <NUM> to <NUM>. In this way, the first corner and the second corner are sufficiently shrunk relative to the body, thereby reducing the contact between the first corner and the tab and the contact between the second corner and the tab. Therefore, it is possible to prevent the tab from being damaged by the first corner and the second corner. In a case where the first notch has a width less than <NUM> and a length less than <NUM>, and the second notch has a width less than <NUM> and a length less than <NUM>, on the one hand, after the robotic arm reaches the first notch and the second notch, a clamped area of the welding protection sheet by the robotic arm is insufficient, resulting in unstable clamping of the welding protection sheet by the robotic arm. As a result, the welding protection sheet is prone to falling, thereby lowering the production efficiency of the energy storage device. On the other hand, insufficient inward shrinking of the first corner and the second corner relative to the body leads to easy contact between the first corner and the tab as well as easy contact between the second corner and the tab, which would easily result in damage to the tab. Further, the insufficient inward shrinking may also easily cause the first corner and the second corner to be in contact with other objects, resulting in upwarp of the first corner and the second corner away from the body due to an external force, and such an upwarp would pierce or scratch the tab. In a case where the first notch has a width greater than <NUM> and a length greater than <NUM>, and the second notch has a width greater than <NUM> and a length greater than <NUM>, on the one hand, after placing the welding protection sheet on the tab, the robotic arm would easily move the welding protection sheet when releasing the welding protection sheet, which affects the alignment precision between the welding protection sheet and the tab, thereby lowering the reliability of the energy storage device. On the other hand, in a case where the first notch and second notch has too large size, a connection area between the welding protection sheet and the tab would be reduced, leading to adverse effects on strength and stability of the connection between the welding protection sheet and the tab after welding the welding protection sheet to the tab.

In combination with the first aspect, in some implementations of the first aspect, a length of the first extending portion in the first direction ranges from <NUM> to <NUM>, and the width of the first extending portion in the second direction ranges from <NUM> to <NUM>. In addition, a length of the second extending portion in the first direction ranges from <NUM> to <NUM>, and the width of the second extending portion in the second direction ranges from <NUM> to <NUM>. In this way, the welding protection sheet has enough welding areas at positions respectively corresponding to the first extending portion and the second extending portion when being welded to the tab, thereby ensuring the sufficient connection strength between the welding protection sheet and the tab. Therefore, it is possible to improve the safety and reliability of the energy storage device. In addition, in a case where the first extending portion has a length less than <NUM> and a width less than <NUM>, and the second extending portion has a length less than <NUM> and a width less than <NUM>, there is too small welding area between the welding protection sheet and the tab, leading to an inadequate connection strength between the welding protection sheet and the tab, which may affect the reliability and service life of the energy storage device. In addition, in a case where the first extending portion has a length greater than <NUM> and a width greater than <NUM>, and the second extending portion has a length greater than <NUM> and a width greater than <NUM>, the energy storage device may not have a compact design, resulting in a low energy density of the energy storage device.

In combination with the first aspect, in some implementations of the first aspect, the first extending portion and the second extending portion are located between the tab and the body, allowing a side of the first extending portion away from the first bent connection portion to be in contact with the tab to increase a friction surface between the first extending portion and the tab, and allowing a side of the second extending portion away from the second bent connection portion to be in contact with the tab to increase a friction surface between the second extending portion and the tab. Therefore, it is possible to increase a friction surface and a friction force between the welding protection sheet and the tab, which in turn avoids displacement of the welding protection sheet relative to the tab. Further, a resistance increasing region with a predetermined roughness may be formed at a corresponding position on the welding protection sheet between the first extending portion and the second extending portion. In this way, the resistance increasing region can increase a friction coefficient between the welding protection sheet and the tab and the friction force between the welding protection sheet and the tab. Therefore, it is possible to avoid sideslip or displacement between the welding protection sheet and the tab during the pressing and assembling therebetween, thereby avoiding solder false or incorrect welding during welding between the welding protection sheet and the tab. Therefore, the reliability of the energy storage device can be further improved, and the service life of the energy storage device can be further prolonged.

In combination with the first aspect, in some implementations of the first aspect, a distance between the second side wall and the fourth side wall in the first direction ranges from <NUM> to <NUM>. In this way, on the one hand, the side of the first extending portion away from the first bent connection portion is allowed to be in contact with the tab, and the side of the second extending portion away from the second bent connection portion is allowed to be in contact with the tab, thereby increasing the friction surface and friction force between the welding protection sheet and the tab, which in turn avoids the slippage between the welding protection sheet and the tab. As a result, the solder false or incorrect welding during the welding between the welding protection sheet and the tab can be avoided, which further improves the reliability of the energy storage device and prolong service life of the energy storage device. On the other hand, such a design can provide a more compact structure for the welding protection sheet, and welding protection sheet has a uniform thickness. Therefore, uniform welding between the welding protection sheet and the tab can be realized, thereby strengthening the connection strength therebetween. In addition, the solder false or solder leakage between the welding protection sheet and the tab can be avoided, which in turn improves the reliability of the energy storage device and prolongs service life of the energy storage device. In addition, in a case where the distance between the second side wall and the fourth side wall is greater than <NUM>, a corresponding part of the body between the first extending portion and the second extending portion is easy to be burned in a case where the welding protection sheet is welded to the tab, result in damage to the tab, which would affect the production efficiency, the product reliability, and the service life of the energy storage device.

In combination with the first aspect, in some implementations of the first aspect, the first extending portion and the second extending portion are attached to the body, respectively. In this way, it is possible to prevent dust or foreign matter from enter between the first extending portion and the body and between the second extending portion and the body, which would result in solder falser between the welding protection sheet and the tab.

In combination with the first aspect, in some implementations of the first aspect, the welding protection sheet further includes a stop portion connected to end portions of the body in the first direction. The body, the first extending portion, and the second extending portion enclose an avoidance space at a position corresponding to the first notch and the second notch. The stop portion is bent relative to the body and extends into the avoidance space. The stop portion may serve as a stop or shield for the first corner at the first extending portion and the second corner at the second extending portion in the first direction, thereby reducing the contact between the first corner and the tab and the contact between the second corner and the tab. In addition, it is possible to prevent the first corner and the second corner from upwarping away from the body due to an external force, thereby avoiding any damage to the tab by the first corner and the second corner.

In combination with the first aspect, in some implementations of the first aspect, the stop portion is spaced apart from each of the first extending portion and the second extending portion in the first direction, to form a stop space between the stop portion and the first extending portion and a stop space between the stop portion and the second extending portion. In this way, the stop portion can further provide the first corner and the second corner with stopping or shielding, to reduce the contact between the first corner and the tab as well as the contact between the second corner and the tab. Therefore, it is possible to prevent the first corner and the second corner from upwarping away from the body due to the external force. Further, it is possible to prevent the first extending portion and the second extending portion from interfering with the stop portion during bending.

In combination with the first aspect, in some implementations of the first aspect, the first extending portion has a first surface located at a side of the first extending portion away from the body, and the stop portion has a second surface located at a side of the stop portion away from the body. The second extending portion has a third surface located at a side of the second extending portion away from the body. The second surface is coplanar with the first surface and/or the third surface. In this way, it is possible to avoid the upwarp of the first corner and the second corner away from the body due to the external force, thereby avoiding any damage to the tab by the first corner and the second corner.

In combination with the first aspect, in some implementations of the first aspect, a width of an end of the stop portion close to the body in the second direction is greater than or equal to a width of an end of the stop portion away from the body in the second direction. In this way, it is possible to reduce sharpness of the end of the stop portion away from the body, thereby avoid the damage to the tab by the stop portion. In addition, a smoother transition can be achieved between the stop portion and the body. Therefore, it is possible to reduce an internal stress at the connection between the stop portion and the body after the stop portion is stamped, thereby avoiding cracks between the stop portion and the body.

In combination with the first aspect, in some implementations of the first aspect, a width of the stop portion in the second direction ranges from <NUM> to <NUM>, and a height of the stop portion in a third direction perpendicular to both the first direction and the second direction ranges from <NUM> to <NUM>. On the one hand, it is possible to prevent the stop portion from affecting the clamping of the welding protection sheet by the robotic arm. On the other hand, the stop portion can effectively stop or shield the first corner and the second corner, thereby reducing the contact of each of the first corner and the second corner with the tab. In addition, it is possible to avoid the upwarp of the first corner and the second corner away from the body due to the external force. Further, it is possible to prevent the stop portion from protruding relative to the first extending portion and the second extending portion to damage the tab. In a case where the stop portion has a width less than <NUM> and a height less than <NUM>, the stop portion cannot effectively stop or shield the first corner and the second corner, resulting in the unwrap of the first corner and the second corner away from the body due to the external force. In a case where the stop portion has a width greater than <NUM> and a height greater than <NUM>, on the one hand, the stop portion can easily stop the robotic arm, causing the robotic arm to be difficultly reach the first notch and the second notch, thereby affecting the clamping of the welding protection sheet by the robotic arm. On the other hand, in a case where the first extending portion and the second extending portion are bent relative to the body, the stop portion can easily interfere with the first extending portion and the second extending portion. Further, the stop portion is easy to protrude from the first extending portion or the second extending portion in the third direction, resulting in damage to the tab.

In combination with the first aspect, in some implementations of the first aspect, the first extending portion and the second extending portion are located at a side of the body facing away from the tab. In this way, it is possible to improve an attachment degree between the welding protection sheet and the tab, thereby enhancing a welding strength between the welding protection sheet and the tab. Consequently, the problems such as solder false, incorrect welding, or solder leakage between the welding protection sheet and the tab can be avoided, thereby increasing welding reliability between the welding protection sheet and the tab, as well as use safety of the energy storage device.

In combination with the first aspect, in some implementations of the first aspect, the welding protection sheet has a welding region. A plurality of welding spots is formed in welding region. An orthographic projection of at least one of the plurality of welding spots on the body in a third direction overlaps with an orthographic projection of each of the first extending portion and the second extending portion on the body in the third direction. The third direction is perpendicular to both the first direction and the second direction. In this way, after the welding protection sheet is welded to the tab, the first extending portion and the second extending portion are connected to each other through fusion welding. Therefore, the welding protection sheet is uniformly welded to the tab. Thus, the connection strength between the welding protection sheet and the tab is enhanced. In addition, the problem such as the solder false between the welding protection sheet and the tab can be avoided.

In a second aspect, embodiments of the present disclosure provide an electric device, according to the independent claim <NUM>. The electric device includes the energy storage device according to any one of the above embodiments. The energy storage device is configured to supply electric energy to the electric device, thereby prolonging a service life of the electric device.

In order to clearly explain technical solutions according to the embodiments of the present disclosure, drawings used in the description of the embodiments are briefly described below. Obviously, the drawings described below are merely some embodiments of the present disclosure. Based on these drawings, other drawings can be obtained by those skilled in the art without creative effort.

Reference numerals in the drawings are described below. load device-<NUM>; electric energy conversion device-<NUM>; street lamp-<NUM>; household appliance-<NUM>; battery pack <NUM>; case body-<NUM>; case cover-<NUM>; energy storage device-<NUM>; housing-<NUM>; end cover-<NUM>; pole-<NUM>; electrode assembly <NUM>; tab-<NUM>; first tab portion-<NUM>; second tab portion-<NUM>; connector-<NUM>; welding protection sheet-<NUM>; body-<NUM>; first bent connection portion-<NUM>; second bent connection portion-<NUM>; first extending portion-<NUM>; first side wall-<NUM>; second side wall-<NUM>; first surface-<NUM>; first corner-<NUM>; second extending portion-<NUM>; third side wall-<NUM>; fourth side wall-<NUM>; third surface-<NUM>; second corner-<NUM>; first notch-<NUM>; first notch wall-<NUM>; second notch wall-<NUM>; second notch-<NUM>; third notch wall-<NUM>; fourth notch wall-<NUM>; avoidance space-<NUM>; resistance increasing region-<NUM>; stop portion-<NUM>; second surface-<NUM>; bent notch-<NUM>; welding region-<NUM>; welding spot-<NUM>.

The present disclosure is further described according to the following specific implementations in combination with the accompanying drawings.

Technical solutions according to embodiments of the present disclosure will be described below in combination with accompanying drawings of the embodiments of the present disclosure. Obviously, the embodiments described below are only a part, rather than all, of the embodiments of the present disclosure.

In the present disclosure, reference to "embodiment" or "implementation" means that a particular feature, structure, or characteristic described in conjunction with the embodiment or implementation may be included in at least one embodiment of the present disclosure. The presence of the term at each place in the specification does not necessarily refer to the same embodiment, nor does it refer to a separate or alternative embodiment that is mutually exclusive of other embodiments. It should be understood by those skilled in the art, both explicitly and implicitly, that the embodiments described herein may be combined with other embodiments.

It should be noted that terms used in the specification and claims of the present disclosure and the accompanying drawings are only for describing specific embodiments, and are not intended to limit the present disclosure. It should be noted that terms "first" and "second" in the specification and claims of the present disclosure and the accompanying drawings are used to distinguish different objects, rather than to describe a specific sequence. It should also be understood that the term "and/or" as used in the specification and claims of the present disclosure refers to and may include inclusion of any or all possible combinations of one or more associated listed items.

Since energy demands for users have strong temporal and spatial properties. In order for rational utilization of energy and an improvement in a utilization rate of energy, it is needed to employ a medium or device to store energy of one form or of another form converted from one form and then release the stored energy in a specific form of energy based on the demands of forthcoming applications. It is common knowledge that, in order to achieve the ambitious goal of carbon neutrality, a principal pathway for generating green electric energy currently is to develop green electric energy such as photovoltaic energy, wind power, and the like to replace fossil energy. Currently, the generation of green electric energy is often dependent on photovoltaic energy, wind power, potential energy of water, and the like. However, wind energy and solar energy generally pose challenges due to their intermittent nature and great fluctuating nature, which would result in grid instability, with insufficient electricity during peak demand and electricity excess during off-peak periods. In addition, unstable voltage may also cause damage to the power system. Therefore, insufficient electricity demand or inadequate grid capacity may lead to the problem of "Forced Abandonment of Wind and Light". To address these challenges, energy storage is crucial, i.e., the electric energy is stored by converting the electric energy into other forms of energy through physical or chemical means and released when needed by converting it back into the electric energy. In a nutshell, energy storage can be likened to a large-scale "power bank" that stores the electric energy during times when photovoltaics and wind power are abundant, and releases the stored electricity when needed.

By taking electrochemical energy storage as an example, embodiments of the present disclosure provide an energy storage device <NUM> internally provided with a chemical battery that mainly utilizes chemical elements within it as an energy storage medium, accompanied by chemical reactions or transformations of the storage medium during charging and discharging of the battery. In simple terms, electric energy generated by wind energy and solar energy is stored in the chemical battery. In a case where the use of external electric energy reaches a peak, the stored electric energy is released for use or is transferred to a place where the electric quantity is scarce for use.

Currently, energy storage (i.e., energy storage) finds extensive applications in various scenes, including power-generation-side energy storage, grid-side energy storage, renewable energy grid-connected energy storage, and user-side storage. The corresponding energy storage device <NUM> includes types as described below.

According to embodiments of the present disclosure, a household energy storage scene in the user-side energy storage is taken as an example for description. <FIG> is a view of a household energy storage scene of an energy storage device <NUM> according to an embodiment of the present disclosure. The energy storage device <NUM> in the present disclosure is not limited to the household energy storage scene.

Embodiments of the present disclosure provide a household energy storage system including an electric energy conversion device <NUM>, a user load, and an energy storage device <NUM>. The electric energy conversion device <NUM> may be a photovoltaic panel. The user load is a load device <NUM> that needs to be powered. The energy storage device <NUM> can supply electric energy to the electric device. The load device <NUM> may be a street lamp <NUM>, a household appliance <NUM>, or the like. The energy storage device <NUM> is a small energy storage box, which can be mounted at an outdoor wall in a wall-mounted manner. In an exemplary, the photovoltaic panel can convert the solar energy into the electric energy in the valley period of electricity charges. The energy storage device <NUM> is used for storing the electric energy and supplying the electric energy to the street lamp <NUM> and the household appliance <NUM> for use in a case where the electricity price peak occurs or supplying power in the event of power grid outages or blackouts.

It can be understood that the energy storage devices <NUM> may include, but are not limited to, a single battery, a battery module, a battery pack, a battery system, and the like. In a case where the energy storage device <NUM> is the single battery, the energy storage device <NUM> may be of a square shape.

In the present disclosure, for clear description, an X-axis direction is defined as a first direction, a Y-axis direction is defined as a second direction, and a Z-axis direction is defined as a third direction. Two of the first direction X, the second direction Y, and the third direction Z are perpendicular to each other.

<FIG> is an exploded view of a battery pack <NUM> according to an embodiment of the present disclosure. Referring to <FIG>, the battery pack <NUM> includes a case body <NUM>, a case cover <NUM>, and an energy storage device <NUM>. The energy storage device <NUM> is accommodated in the case body <NUM>, and the case cover <NUM> coves and seals the case body <NUM>. An accommodation space is enclosed between the case body <NUM> and the case cover <NUM>, and the energy storage device <NUM> is accommodated in the accommodation space. A plurality of energy storage devices <NUM> may be provided and connected in parallel or series.

<FIG> is an exploded view of an energy storage device <NUM> according to an embodiment of the present disclosure. Referring to <FIG>, the energy storage device <NUM> includes a housing <NUM>, an end cover <NUM>, an electrode assembly <NUM>, and a connector <NUM>. An accommodation space is enclosed between the housing <NUM> and the end cover <NUM>, and the electrode assembly <NUM> is accommodated in the accommodation space. A plurality of electrode assemblies <NUM> may be provided and is stacked together. The end cover <NUM> is also provided with a pole <NUM>. The electrode assembly <NUM> is electrically connected to the pole <NUM> through the connector <NUM> to allow the energy storage device <NUM> to output electric energy through the pole <NUM>.

<FIG> is a schematic structural view of an energy storage device <NUM> according to an embodiment of the present disclosure. <FIG> is an enlarged view of a part I of <FIG>. <FIG> is a schematic structural view of a welding protection sheet <NUM> according to an embodiment of the present disclosure a first direction. <FIG> is a schematic structural view of a welding protection sheet <NUM> according to an embodiment of the present disclosure in a second direction. <FIG> is an enlarged view of a part II of <FIG>. Referring to <FIG>, the electrode assembly <NUM> is provided with a tab <NUM> to be connected to the connector <NUM>. The connector <NUM> is connected to the pole <NUM> and the tab <NUM>, respectively. The welding protection sheet <NUM> abuts against a surface of a side of the tab <NUM> facing away from the connector <NUM>. The welding protection sheet <NUM> is configured to prevent the tab <NUM> from being welding penetrated by a welding die head in a case where the tab <NUM> is welded to the connector <NUM> and to enhance strength of a connection between the tab <NUM> and the connector <NUM> after welding. In an exemplary embodiment of the present disclosure, the tab <NUM> includes a first tab portion <NUM> and a second tab portion <NUM> connected to the first tab portion <NUM>. The first tab portion <NUM> is located between the welding protection sheet <NUM> and the connector <NUM>. The second tab portion <NUM> is bent relative to the first tab portion <NUM> away from the connector <NUM>. The second tab portion <NUM> is connected to the electrode assembly <NUM>.

The welding protection sheet <NUM> includes a body <NUM>, a first bent connection portion <NUM>, and a first extending portion <NUM>. The body <NUM> and the first extending portion <NUM> extend in a first direction X, respectively. A length L1 of the body <NUM> in the first direction X is same as a length L2 of the first extending portion <NUM> in the first direction X. The first bent connection portion <NUM> is connected between the first extending portion <NUM> and the body <NUM>. The first extending portion <NUM> is foldable relative to the body <NUM> to face towards the body <NUM>. In this way, the welding protection sheet <NUM> has a double-layer structure, thereby improving overall strength of the welding protection sheet <NUM>. As a result, it is possible to prevent the welding protection sheet <NUM> from being bent during transportation or mounting, and strength of a connection between the welding protection sheet <NUM> and the tab <NUM> is improved. Therefore, it is possible to allow the connector <NUM>, the tab <NUM>, and the welding protection sheet <NUM> to be welded together more stably, thereby improving reliability of the energy storage device <NUM>.

The body <NUM>, the first bent connection portion <NUM>, and the first extending portion <NUM> may be integrally formed. The welding protection sheet <NUM> may be manufactured through stamping, folding, and other processes. The integrated structure can simplify the manufacturing processes of the welding protection sheet <NUM> without additional connection structures, thereby lowering manufacturing cost of the welding protection sheet <NUM>. The first extending portion <NUM> is foldable relative to the body <NUM> to face towards the body <NUM>. The first bent connection portion <NUM> is formed at a bending between the first extending portion <NUM> and the body <NUM>. The first bent connection portion <NUM> may be in a C shape. The first bent connection portion <NUM> is located at a side of the body <NUM> close to the second tab portion <NUM>. After the first extending portion <NUM> is bent relative to the body <NUM>, a rounded transition is naturally achieved at the first bent connection portion <NUM>, ensuring no burrs on the first bent connection portion <NUM>. Therefore, the second tab portion <NUM> would not be punctured or pierced by the burrs when being bent relative to the first tab portion <NUM>, thereby improving the reliability of the energy storage device <NUM>.

Each of two opposite ends of an end portion of the first extending portion <NUM> away from the first bent connection portion <NUM> in the first direction X has a first notch <NUM>. An edge part of the body <NUM> is exposed through the notch <NUM>. A width W1 of the first notch <NUM> in a second direction Y is less than a width W2 of the first extending portion <NUM> in the second direction Y. the second direction Y is perpendicular to the first direction X. Two first corners <NUM> are formed at connections between two end portions of the first extending portion <NUM> in the first direction X and the end portion of the first extending portion <NUM> away from the first bent connection portion <NUM>. A distance D1 between the two first corners <NUM> in the first direction X is less than a length L1 of the body <NUM> in the first direction X. In this embodiment, the first extending portion <NUM> is foldable relative to the body <NUM> to face towards the body <NUM>. In addition, the end of the first extending portion <NUM> away from the first bent connection portion <NUM> has the first notch <NUM>. The distance D1 of the two first corners <NUM> in the first direction X is less than the length L1 of the body <NUM> in the first direction X. In this way, on the one hand, a robotic arm may reach the first notch <NUM> and clamp the welding protection sheet <NUM>, thereby stably clamping the welding protection sheet <NUM>. The first notch <NUM> may also provide positioning for robotic arm to allow a position of the robotic arm to keep relatively consistent with a position of the welding protection sheet <NUM>. Therefore, it is possible to allow for rapid and accurate placement of the welding protection sheet <NUM> at a specified position on the tab <NUM> by the robotic arm. As a result, alignment efficiency and precision between the welding protection sheet <NUM> and the tab <NUM> can be improved, thereby improving production efficiency and product reliability of the energy storage device <NUM>. Meanwhile, displacement of the welding protection sheet <NUM> on the tab <NUM> can be avoided, thus avoiding problems such as solder false and leakage of solder between the welding protection sheet <NUM> and the tab <NUM>. On the other hand, the first notch <NUM> can allow an edge part of each of the two ends of the body <NUM> in the first direction X to be exposed relative to the first extending portion <NUM>, i.e., the first notch <NUM> can allow the first corner <NUM> to shrink inwards relative to the body <NUM> in the first direction X to reduce contact between the first corner <NUM> and the tab <NUM>, thereby effectively preventing the tab <NUM> from being damaged by the first corner <NUM>. Therefore, reliability of the energy storage device <NUM> can be improved, and a service life of the energy storage device <NUM> can be prolonged. Further, the inward shrinking of the first corners <NUM> relative to the body <NUM> in the first direction X can also reduce the possibility of the first corners <NUM> coming into contact with other objects, which can avoid the upwarp of the first corners <NUM> away from the body <NUM> due to an external force. Therefore, it is possible to prevent the first corners <NUM> from being formed into sharp portions that could pierce or scratch the tab <NUM>. In addition, the robotic arm can clamp the welding protection sheet <NUM> in the first direction X to facilitate releasing the welding protection sheet <NUM> after placing the welding protection sheet <NUM> onto the tab <NUM>. In this embodiment, the welding protection sheet <NUM> is clamped and placed at the specified position on the tab <NUM> by the robotic arm. Compared with manual placement, placement efficiency and precision of the welding protection sheet <NUM> are significantly improved, thus greatly improving the production efficiency of the energy storage device <NUM> and lowering production costs.

A length L2 of the first extending portion <NUM> in the first direction X ranges from <NUM> to <NUM>, and the width W2 of the first extending portion <NUM> in the second direction Y ranges from <NUM> to <NUM>. therefore, it is possible to allow for sufficient welding area between the welding protection sheet <NUM> and the tab <NUM> at a position corresponding to the first extending portion <NUM>, thus ensuring that the welding protection sheet <NUM> and the tab <NUM> have sufficient connection strength, to improve safety and reliability of the energy storage device <NUM>. For example, the length L2 of the first extending portion <NUM> may be <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or the like. The width W2 of the first extending portion <NUM> may be <NUM>, <NUM>, <NUM>, <NUM>, or the like. The first extending portion <NUM> has a length L2 less than <NUM> and a width W2 less than <NUM>, which easily results in a small welding area between the welding protection sheet <NUM> and the tab <NUM>, leading to insufficient strength of the connection between the welding protection sheet <NUM> and the tab <NUM>, thereby impacting the reliability and service life of the energy storage device <NUM>. The first extending portion <NUM> has a length L2 greater than <NUM> and a width W2 greater than <NUM>, which is unfavorable for the compact design of the energy storage device <NUM>, resulting in a low energy density of the energy storage device <NUM>.

In this embodiment, the welding protection sheet <NUM> further includes a second bent connection portion <NUM> and a second extending portion <NUM>. The second extending portion <NUM> extends in the first direction X. A length L3 of the second extending portion <NUM> in the first direction X is the same as the length L1 of the body <NUM> in the first direction X. The second bent connection portion <NUM> is connected to an end of the body <NUM> away from the first bent connection portion <NUM>. The second bent connection portion <NUM> is connected between the second extending portion <NUM> and the body <NUM>. The second extending portion <NUM> is foldable relative to the body <NUM> to face towards the body <NUM>. In addition, the second extending portion <NUM> is located at a side of the body <NUM> facing towards the first extending portion <NUM>. In this way, the welding protection sheet <NUM> is formed into a double-layer structure, thereby improving the overall strength of the welding protection sheet <NUM>. In addition, it is possible to prevent the welding protection sheet <NUM> from being bent during transportation or installation, and the strength of the connection between the welding protection sheet <NUM> and the tab <NUM> is improved, which enables the connector <NUM>, the tab <NUM>, and the welding protection sheet <NUM> to be more stably welded together, thereby improving the reliability of the energy storage device <NUM>.

Here, the body <NUM>, the second bent connection portion <NUM>, and the second extending portion <NUM> may be integrally formed, to simplify the manufacturing processes of the welding protection sheet <NUM>, thus lowering the manufacturing cost of the welding protection sheet <NUM>. The second extending portion <NUM> faces towards the body <NUM> after being folded relative to the body <NUM>. The second bent connection portion <NUM> is formed at a bending between the second extending portion <NUM> and the body <NUM>. The second bent connection portion <NUM> may be in a C shape. After the second extending portion <NUM> is bent relative to the body <NUM>, a rounded transition is naturally achieved at the position of the second bent connection portion <NUM>, ensuring no burrs on the second bent connection portion <NUM>. Therefore, no damage is caused to the tab <NUM>, thereby improving the reliability of the energy storage device <NUM>.

Each of two opposite ends of an end portion of the second extending portion <NUM> away from the second bent connection portion <NUM> in the first direction X has a second notch <NUM>. The second notch <NUM> faces towards the first notch <NUM> in the second direction Y. A width W3 of the second notch <NUM> in a second direction Y is less than a width W4 of the second extending portion <NUM> in the second direction Y. The the second extending portion <NUM> has two second corners <NUM>. The two second corners <NUM> are formed at connections between two end portions of the second extending portion <NUM> in the first direction X and the end portion of the second extending portion <NUM> away from the second bent connection portion <NUM>. A distance D2 between the two second corners <NUM> in the first direction X is less than a length L1 of the body <NUM> in the first direction X. In this embodiment, the second extending portion <NUM> is foldable relative to the body <NUM> to face towards the body <NUM>. In addition, an end of the second extending portion <NUM> away from the second bent connection portion <NUM> has the second notch <NUM>. The distance D2 of the two second corners <NUM> in the first direction X is less than the length L1 of the body <NUM> in the first direction X. In this way, on the one hand, when clamping the welding protection sheet <NUM>, the robotic arm can simultaneously reach the first notch <NUM> and the second notch <NUM> to clamp the welding protection sheet <NUM>. The first notch <NUM> and the second notch <NUM> can provide the robotic arm with several clamping positions, to increase an acting point of the robotic arm. Therefore, the robotic arm can clamp the welding protection sheet <NUM> more steadily. The first notch <NUM> and the second notch <NUM> can also provide the robotic arm with positioning, allowing a position of the robotic arm to keep relatively consistent with the position of the welding protection sheet <NUM>. In this way, it is possible to allow for rapid and accurate placement of the welding protection sheet <NUM> onto the specified position of the tab <NUM> by the robotic arm. Therefore, the alignment efficiency and precision between the welding protection sheet <NUM> and the tab <NUM> can be improved, which in turn improves the production efficiency and the product reliability of the energy storage device <NUM>. Meanwhile, the displacement of the welding protection sheet <NUM> above the tab <NUM> can be avoided, thus avoiding the problems solder false and solder leakage between the welding protection sheet <NUM> and the tab <NUM>. On the other hand, the second notch <NUM> can allow the body <NUM> to be exposed at an edge part of each of the two ends of the second notch <NUM> in the first direction X relative to the second extending portion <NUM>, i.e., the second notch <NUM> can allow the second corner <NUM> to shrink inwards relative to the body <NUM> in the first direction X, to reduce contact between the second corner <NUM> and the tab <NUM>, thereby effectively preventing the tab <NUM> from being damaged by the second corner <NUM> and further improving the reliability of the energy storage device <NUM> and prolonging the service life of the energy storage device <NUM>. Further, the inward shrinking of the second corners <NUM> relative to the body <NUM> in the first direction X can also reduce the possibility of the second corners <NUM> coming into contact with other objects, which avoids the upwarp of the second corner <NUM> away from the body <NUM> due to an external force, thereby preventing the second corners <NUM> from being formed into sharp portions that could pierce or scratch the tab <NUM>. In some implementations, the shapes of the first notch <NUM> and the second notch <NUM> may be configured to be different from or the same as each other.

In some embodiments, the second bent connection portion <NUM> may be located at the side of the body <NUM> close to the second tab portion <NUM>. In a case where the welding protection sheet <NUM> is welded to the tab <NUM>, the welding protection sheet <NUM> may not distinguish mounting directions of the first bent connection portion <NUM> and the second bent connection portion <NUM>, thereby reducing welding steps for the welding protection sheet <NUM> and the tab <NUM>. Therefore, welding efficiency can be improved. In addition, welding errors are avoided, and a production yield of the energy storage device <NUM> is improved. In some embodiments, the first extending portion <NUM> and the second extending portion <NUM> may be symmetrically arranged relative to the body <NUM>, to reduce the manufacturing processes of the welding protection sheet <NUM>, thereby increasing the welding efficiency between the welding protection sheet <NUM> and the tab <NUM>.

A length L3 of the second extending portion <NUM> in the first direction X ranges from <NUM> to <NUM>, and the width W4 of the second extending portion <NUM> in the second direction Y ranges from <NUM> to <NUM>. In this way, it is possible to allow for sufficient welding area between the welding protection sheet <NUM> and the tab <NUM> at a position corresponding to the second extending portion <NUM>, thus ensuring that the welding protection sheet <NUM> and the tab <NUM> have sufficient connection strength, to improve the safety and reliability of the energy storage device <NUM>. For example, the length L3 of the second extending portion <NUM> may be <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or the like. The width W4 of the second extending portion <NUM> may be <NUM>, <NUM>, <NUM>, <NUM>, or the like. The second extending portion <NUM> has a length L3 less than <NUM> and a width W4 less than <NUM>, which easily results in the small welding area between the welding protection sheet <NUM> and the tab <NUM>, leading to the insufficient strength of the connection between the welding protection sheet <NUM> and the tab <NUM>, thereby impacting the reliability and service life of the energy storage device <NUM>. The second extending portion <NUM> has a length L3 greater than <NUM> and a width W4 greater than <NUM>, which is unfavorable for the compact design of the energy storage device <NUM>, resulting in the low energy density of the energy storage device <NUM>.

The first extending portion <NUM> has two first side walls <NUM> opposite to each other in the first direction X and a second side wall <NUM> located at a side away from the first bent connection portion <NUM>. The first notch <NUM> has a first notch wall <NUM> connected to the two first side walls <NUM> and a second notch wall <NUM> connected to the second side wall <NUM>. A rounded transition is achieved between the first sidewall <NUM> and the first notch wall <NUM>, a rounded transition is achieved between the second sidewall <NUM> and the second notch wall <NUM>, and a rounded transition is achieved between the first notch wall <NUM> and the second notch wall <NUM>. Therefore, it is possible to reduce sharp corners on the first extending portion <NUM>, to prevent the first extending portion <NUM> from damaging the tab <NUM>, which in turn improves the reliability of the energy storage device <NUM> and prolongs service life of the energy storage device <NUM>. The first corner <NUM> is formed at a connection between the second notch wall <NUM> and the second side wall <NUM>. The first corner <NUM> is constructed as a rounded corner. The distance D1 between the two first corners <NUM> in the first direction X may be a distance between the second notch walls <NUM> in the two first notches <NUM>.

The second extending portion <NUM> has two third side walls <NUM> opposite to each other in the first direction X and a fourth side wall <NUM> located at a side of the second extending portion <NUM> away from the second bent connection portion <NUM>. The second notch <NUM> has a third notch wall <NUM> connected to the two third side walls <NUM> and a fourth notch wall <NUM> connected to the fourth side wall <NUM>. A rounded transition is achieved between the third sidewall <NUM> and the third notch wall <NUM>, a rounded transition is achieved between the fourth sidewall <NUM> and the fourth notch wall <NUM>, and a rounded transition is achieved between the third notch wall <NUM> and the fourth notch wall <NUM>. In this way, it is possible to reduce sharp corners on the second extending portion <NUM>, to prevent the second extending portion <NUM> from damaging the tab <NUM>, which in turn improves the reliability of the energy storage device <NUM> and prolongs the service life of the energy storage device <NUM>. The second corner <NUM> is formed at a connection between the fourth notch wall <NUM> and the fourth side wall <NUM>. The second corner <NUM> is constructed as a rounded corner. The distance D2 between the two second corners <NUM> in the first direction X may be a distance between the fourth notch walls <NUM> in the two second notches <NUM>.

In some implementations, the second notch wall <NUM> and the first side wall <NUM> are arranged in parallel, and the fourth notch wall <NUM> and the third side wall <NUM> are arranged in parallel. In this way, it is possible to prevent the robotic arm from slipping in a case where the second notch wall <NUM> abuts against the fourth notch wall <NUM>, which allows the robotic arm to easily exert enough clamping force to the welding protection sheet <NUM>, thereby allowing the robotic arm to clamp the welding protection sheet <NUM> more reliably. In some implementations, the second notch wall <NUM> and the fourth notch wall <NUM> each are configured as a flat surface to avoid the slipping of the robotic arm in the case where the second notch wall <NUM> abuts against the fourth notch wall <NUM>.

In some embodiments, an obtuse angle is formed between the first notch wall <NUM> and the second notch wall <NUM>. In this way, a smoother transition between the first notch wall <NUM> and the second notch wall <NUM> is achieved, thereby reducing the internal stress of the first extending portion <NUM> near the corresponding first notch <NUM> after stamping the first notch <NUM>. Consequently, a problem such as the upwarp of the first corner <NUM> of the first extending portion <NUM> after stamping can be further avoided, thus preventing the first corner <NUM> from scratching the tab <NUM>. Therefore, it is possible to increase the reliability of the energy storage device <NUM> and prolong the service life of the energy storage device <NUM>. By forming the obtuse angle between the third notch wall <NUM> and the fourth notch wall <NUM>, a smoother transition between the third notch wall <NUM> and the fourth notch wall <NUM> is achieved, thereby reducing internal stress of the second extending portion <NUM> near the corresponding second notch <NUM> after stamping the second notch <NUM>. Consequently, a problem such as the upwarp of the second corner <NUM> of the second extending portion <NUM> after stamping can be further avoided, thus preventing the second corner <NUM> from scratching the tab <NUM>. In some embodiments, a right angle is formed between the first notch wall <NUM> and the second notch wall <NUM>, and a right angle is formed between the third notch wall <NUM> and the fourth notch wall <NUM>. In this way, it is possible to improve the sharpness of a stamping die head, thereby reducing the difficulty in stamping the first notch <NUM> and the second notch <NUM> into shape and reducing burrs on the notch wall of each of the first notch <NUM> and the second notch <NUM>.

The width W1 of the first notch <NUM> in the second direction Y ranges from <NUM> to <NUM>, and a length L4 of the first notch <NUM> in the first direction X ranges from <NUM> to <NUM>. In this way, the first corner <NUM> is sufficiently shrunk inwards relative to the body <NUM> in the first direction X, thereby reducing the contact between the first corner <NUM> and the tab <NUM>. Therefore, it is possible to prevent the tab <NUM> from being damaged by the first corner <NUM>. The width W1 of the first notch <NUM> in the second direction Y may be a distance between the first notch wall <NUM> and the second side wall <NUM> in the second direction Y. The length L4 of the first notch <NUM> in the first direction X may be a distance between the second notch wall <NUM> and the first side wall <NUM> in the first direction X. For example, the width W1 of the first notch <NUM> in the second direction Y may be <NUM>, <NUM>, <NUM>, or the like. The length L4 of the first notch <NUM> in the first direction X may be <NUM>, <NUM>, <NUM>, <NUM>, or the like. In a case where the first notch <NUM> has a width W1 less than <NUM> and a length L4 less than <NUM>, on the one hand, after the robotic arm reaches the first notch <NUM>, a clamped area of the welding protection sheet <NUM> by the robotic arm is insufficient, resulting in unstable clamping of the welding protection sheet <NUM> by the robotic arm for. As a consequence, the welding protection sheet <NUM> is prone to detachment, thereby lowering the production efficiency of the energy storage device <NUM>. On the other hand, an insufficient inward shrinking of the first corner <NUM> relative to the body <NUM> in the first direction X leads to increased contact with the tab <NUM>, easily causing damage to the tab <NUM>. Further, the insufficient inward shrinking may also easily cause the first corner <NUM> to be in contact with other objects, resulting in the upwarp of the first corner <NUM> away from the body <NUM> due to the external force, thereby piercing or scratching the tab. In a case where the first notch <NUM> has a width W1 greater than <NUM> and a length L4 greater than <NUM>, on the one hand, after placing the welding protection sheet <NUM> onto the tab <NUM>, the robotic arm would easily move the welding protection sheet <NUM> when releasing the welding protection sheet <NUM>, which affects the alignment precision between the welding protection sheet <NUM> and the tab <NUM>, thereby lowering the reliability of the energy storage device <NUM>. On the other hand, in a case where the first notch <NUM> has too large size, a connection area between the welding protection sheet <NUM> and the tab <NUM> would be reduced, leading to adverse effects on strength and stability of the connection between the welding protection sheet <NUM> and the tab <NUM> after welding the welding protection sheet to the tab.

The width W3 of the second notch <NUM> in the second direction Y ranges from <NUM> to <NUM>, and a length L5 of the second notch <NUM> in the first direction X ranges from <NUM> to <NUM>. In this way, the second corner <NUM> is sufficiently shrunk relative to the body <NUM> in the first direction X, thus reducing contact between the second corner <NUM> and the tab <NUM>, thereby preventing the second corners <NUM> from damaging the tab <NUM>. The width W3 of the second notch <NUM> in the second direction Y may be a distance between the third notch wall <NUM> and the fourth side wall <NUM> in the second direction Y. The length L5 of the second notch <NUM> in the first direction X may be a distance between the fourth notch wall <NUM> and the third side wall <NUM> in the first direction X. For example, the width W3 of the second notch <NUM> in the second direction Y may be <NUM>, <NUM>, <NUM>, or the like. The length L5 of the second notch <NUM> in the first direction X may be <NUM>, <NUM>, <NUM>, <NUM>, or the like. In a case where the second notch <NUM> has a width W3 less than <NUM> and a length L5 less than <NUM>, on the one hand, after the robotic arm reaches the second notch <NUM>, the clamped area of the welding protection sheet <NUM> by the robotic arm is insufficient, resulting in the unstable clamping of the welding protection sheet <NUM> by the robotic arm. As a consequence, the welding protection sheet <NUM> is prone to detachment, thereby lowering the production efficiency of the energy storage device <NUM>. On the other hand, an insufficient inward shrinking of the second corner <NUM> relative to the body <NUM> in the first direction X leads to increased contact with the tab <NUM>, easily causing damage to the tab <NUM>. Further, the insufficient inward shrinking may also easily cause the second corner <NUM> to be in contact with other objects, resulting in the upwarp of the second corner <NUM> away from the body <NUM> due to the external force, thereby piercing or scratching the tab. In a case where the second notch <NUM> has a width W3 greater than <NUM> and a length L5 greater than <NUM>, on the one hand, after placing the welding protection sheet <NUM> onto the tab <NUM>, the robotic arm may easily move the welding protection sheet <NUM> when releasing the welding protection sheet <NUM>, which affects the alignment precision between the welding protection sheet <NUM> and the tab <NUM>, thereby lowering the reliability of the energy storage device <NUM>. On the other hand, in a case where the second notch <NUM> has too large size, the connection area between the welding protection sheet <NUM> and the tab <NUM> would be reduced, leading to harmful effects on the strength and stability of the connection between the welding protection sheet <NUM> and the tab <NUM> after welding. The distance between the first notch wall <NUM> and the third notch wall <NUM> in the second direction Y may range from <NUM> to <NUM>. For example, the distance between the first notch wall <NUM> and the third notch wall <NUM> in the second direction Y may be <NUM>, <NUM>, <NUM>, <NUM>, or the like.

In some embodiments, the distance W5 between the second side wall <NUM> and the fourth side wall <NUM> in the first direction X ranges from <NUM> to <NUM>. On the one hand, a side of the first extending portion <NUM> away from the first bent connection portion <NUM> is allowed to be in contact with the tab <NUM>, and a side of the second extending portion <NUM> away from the second bent connection portion <NUM> is allowed to be in contact with the tab <NUM>. Therefore, it is possible to increase a friction surface and friction force between the welding protection sheet <NUM> and the tab <NUM>, which in turn avoids a slippage between the welding protection sheet <NUM> and the tab <NUM>. As a result, the problem such as solder false or incorrect welding during the welding between the welding protection sheet <NUM> and the tab <NUM> is avoided, which further improves the reliability of the energy storage device <NUM> and prolongs service life of the energy storage device <NUM>. On the other hand, such a design can provide a more compact structure for the welding protection sheet <NUM>, and the welding protection sheet <NUM> has a uniform thickness. Therefore, uniform welding between the welding protection sheet <NUM> and the tab <NUM> can be realized, thereby strengthening connection strength therebetween. In addition, the solder false or incorrect welding between the welding protection sheet <NUM> and the tab <NUM> can be avoided, which in turn improves the reliability of the energy storage device <NUM> and prolong service life of the energy storage device <NUM>. Further, the first extending portion <NUM> and the second extending portion <NUM> may be conveniently bent relative to the body <NUM>, to avoid generation of interference between the first extending portion <NUM> and the second extending portion <NUM>, thus reducing processing difficulty of the welding protection sheet <NUM>. Exemplarily, the distance W5 between the second side wall <NUM> and the fourth side wall <NUM> in the first direction X may be <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or the like. In a case where the distance between the second side wall <NUM> and the fourth side wall <NUM> in the first direction X is greater than <NUM>, and in a case where the welding connection piece <NUM> is welded to the tab <NUM>, a corresponding position of the body <NUM> between the first extending portion <NUM> and the second extending portion <NUM> is easy to be burned, causing damage to the tab <NUM>, thus affecting the production efficiency, the product reliability, and the service life of the energy storage device <NUM>. In some embodiments, an end of the first extending portion <NUM> away from the first bent connection portion <NUM> is disposed adjacent to an end of the second extending portion <NUM> away from the second bent connection portion <NUM>. A resistance increasing region <NUM> with a predetermined roughness may be formed at a corresponding position of the welding protection sheet <NUM> between the first extending portion <NUM> and the second extending portion <NUM>. In a case where the welding die head abuts the welding protection sheet <NUM> against the tab <NUM>, the resistance increasing region <NUM> can enlarge a friction coefficient between the welding protection sheet <NUM> and the welding die head or a friction coefficient between the welding protection sheet <NUM> and the tab <NUM>, thereby increasing the friction force between the welding protection sheet <NUM> and the tab <NUM>.

In some embodiments, in the third direction Z, the first extending portion <NUM> and the second extending portion <NUM> are attached to the body <NUM>, respectively. In this way, it is convenient to respectively weld the first extending portion <NUM> and the second extending portion <NUM> to the body <NUM>. Therefore, it is possible to improve the welding efficiency of the welding protection sheet <NUM> and the tab <NUM> and enhance the strength of the connection between the welding protection sheet <NUM> and the tab <NUM>. In addition, it is possible to prevent dust or forging matter from entering between the first extending portion <NUM> and the body <NUM> and between the second extending portion <NUM> and the body <NUM>, which would result in solder falser between the welding protection sheet <NUM> and the tab <NUM>. In some embodiments, in the third direction Z, each of the first extending portion <NUM> and the second extending portion <NUM> is spaced apart from the body <NUM> to reduce the molding difficulty of the welding protection sheet <NUM>.

<FIG> is a side view of a welding protection sheet <NUM> of <FIG>. Referring to <FIG>, <FIG>, <FIG>, the welding protection sheet <NUM> also includes a stop portion <NUM> connected to end portions of the body <NUM> in the first direction X. The body <NUM>, the first extending portion <NUM>, and the second extending portion <NUM> enclose an avoidance space <NUM> at a position corresponding to each of the first notch <NUM> and the second notch <NUM> to form the avoidance space <NUM>. The stop portion <NUM> is bent relative to the body <NUM>. The stop portion <NUM> is bent relative to the body <NUM> and extends into the avoidance space <NUM>. The stop portion <NUM> extends in the third direction Z. The third direction Z is perpendicular to both the first direction X and the second direction Y. The stop portion <NUM> is located at an outer side of each of the first corner <NUM> and the second corner <NUM> in the first direction X and can stop or shield the first corner <NUM> and the second corner <NUM> in the first direction X, which reduces the contact between the first corner <NUM> and the tab <NUM> and the contact between the second corner <NUM> and the tab <NUM>. Therefore, it is possible to avoid the upwarp of the first corner <NUM> and the second corner <NUM> away from the body <NUM> due to the external force, further avoiding damage to the tab <NUM> caused by the first corner <NUM> and the second corner <NUM>.

An orthographic projection of the end of the first extending portion <NUM> away from the first bent connection portion <NUM> in the first direction X overlaps with an orthographic projection of the stop portion <NUM> in the first direction X. The stop portion <NUM> may stop or shield the first corner <NUM> on the first extending portion <NUM> in the first direction X. In this way, the contact between the first corner <NUM> and the tab <NUM> is reduced, which in turn prevents the tab <NUM> from being damaged by the first corner <NUM>. An orthographic projection of the end of the second extending portion <NUM> away from the second bent connection portion <NUM> in the first direction X overlaps with the orthographic projection of the stop portion <NUM> in the first direction X. In addition, the stop portion <NUM> may stop or shield the second corner <NUM> on the second extending portion <NUM> in the first direction X, thereby reducing the contact between the second corner <NUM> and the tab <NUM>, which in turn prevents the tab <NUM> from being damaged by the second corner <NUM>. In this embodiment, two stop portions <NUM> are provided and located at the two opposite ends of the body <NUM> in the first direction X, to stop or shield the two first corners <NUM> of the first extending portion <NUM> and the two second corners <NUM> of the second extending portion <NUM>.

In the first direction X, the stop portion <NUM> is spaced apart from each of the first extending portion <NUM> and the second extending portion <NUM>. That is, the stop portion <NUM> is spaced apart from each of the second notch wall <NUM> and the fourth notch wall <NUM>, to form a stop space between the stop portion <NUM> and the first extending portion <NUM> and a stop space between the stop portion <NUM> and the second extending portion <NUM>. In this way, the stop portion <NUM> can further stop or shield the first corner <NUM> and the second corner <NUM>, to reduce the contact between the first corner <NUM> and the tab <NUM> and the contact between the second corner <NUM> and the tab <NUM>, thereby avoiding the upwarp of the first corner <NUM> and the second corner <NUM> away from the body <NUM> due to the external force. Therefore, it is possible to prevent the first extending portion <NUM> and the second extending portion <NUM> from interfering with the stop portion <NUM> during bending, or prevent the stop portion <NUM> from interfering with each of the first extending portion <NUM> and the second extending portion <NUM> during bending. In some embodiments, in the second direction Y, the stop portion <NUM> is spaced apart from each of the first extending portion <NUM> and the second extending portion <NUM>. That is, the stop portion <NUM> is spaced apart from each of the first notch wall <NUM> and the third notch wall <NUM>, to facilitate bending of each of the first extending portion <NUM> and the second extending portion <NUM> relative to the body <NUM>, thereby preventing the first extending portion <NUM> and the second extending portion <NUM> from interfering with the stop portion <NUM> during bending, or preventing the stop portion <NUM> from interfering with the first extending portion <NUM> and the second extending portion <NUM> during bending. Meanwhile, it is possible for the robotic arm to reach the first notch <NUM> and the second notch <NUM> to clamp the welding protection sheet <NUM>.

The first extending portion <NUM> has a first surface <NUM> located at a side of the first extending portion <NUM> away from the body <NUM>. The stop portion <NUM> has a second surface <NUM> located at a side of the stop portion <NUM> away from the body <NUM>. The second extending portion <NUM> has a third surface <NUM> located at a side of the second extending portion <NUM> away from the body <NUM>. The second surface <NUM> is coplanar with the first surface <NUM> and/or the third surface <NUM>. In some embodiments, the first surface <NUM>, the second surface <NUM>, and the third surface <NUM> are coplanar with each other. In this way, it is possible to avoid the upwarp of the first corner <NUM> and the second corner <NUM> away from the body <NUM> due to the external force, thereby avoiding any damage to the tab <NUM> caused by the first corner <NUM> and the second corner <NUM>. In some embodiments, the second surface <NUM> is coplanar with the first surface <NUM> or the third surface <NUM>, to reduce the manufacturing difficulty of the welding protection sheet <NUM>, thereby improving the production efficiency of the welding protection sheet.

A width W6 of the stop portion <NUM> in the second direction Y ranges from <NUM> to <NUM>, and a height H1 of the stop portion <NUM> in a third direction Z ranges from <NUM> to <NUM>. On the one hand, it is possible to prevent the stop portion <NUM> from affecting the clamping of the welding protection sheet <NUM> by the robotic arm. On the other hand, it is possible to allow the stop portion <NUM> to effectively stop or shield the first corner <NUM> and the second corner <NUM>, thereby reducing the contact of each of the first corner <NUM> and the second corner <NUM> with the tab <NUM>. In addition, it is possible to avoid the upwarp of the first corner <NUM> and the second corner <NUM> away from the body <NUM> due to the external force. Further, it is possible to prevent the stop portion <NUM> from protruding from the first extending portion <NUM> and the second extending portion <NUM>, and thereby avoiding the damage to the tab <NUM>. For example, the width W6 of the stop portion <NUM> in the second direction Y may be <NUM>, <NUM>, <NUM>, or the like. The height H1 of the stop portion <NUM> in the third direction Z may be <NUM>, <NUM>, <NUM>, or the like. In a case where the stop portion <NUM> has a width W6 less than <NUM> and a height H1 less than <NUM>, it is impossible to effectually stop or shield the first corner <NUM> and the second corner <NUM>, resulting in the tendency of the upwarp of the first corner <NUM> and the second corner <NUM> away from the body <NUM> due to the external force. In a case where the stop portion <NUM> has a width W6 greater than <NUM> and a height H1 greater than <NUM>, on the one hand, the stop portion <NUM> easily stops the robotic arm, causing the robotic arm to be difficult to reach the first notch <NUM> and the second notch <NUM>, thereby affecting the clamping of the welding protection sheet <NUM> by the robotic arm. On the other hand, in a case where the first extending portion <NUM> and the second extending portion <NUM> are bent relative to the body <NUM>, the stop portion <NUM> would easily interfere with the first extending portion <NUM> and the second extending portion <NUM>. Further, the stop portion <NUM> easily protrudes from the first extending portion <NUM> or the second extending portion <NUM> in the third direction Z, causing damage to the tab <NUM>.

In this embodiment, a width W7 of an end of the stop portion <NUM> close to the body <NUM> in the second direction Y is equal to a width W8 of an end of the stop portion <NUM> away from the body <NUM> in the second direction Y. In this way, it is possible to reduce the molding difficulty of the stop portion <NUM> and facilitate stamping of the stop portion <NUM>. The stop portion <NUM> and the body <NUM> can be integrally formed. The stop portion <NUM> is bent relative to the body <NUM>. In some embodiments, each of two sides of the stop portion <NUM> further has a bending notch <NUM> formed in the first direction X. The bending notch <NUM> also penetrates the body <NUM> in the third direction Z. The bending notch <NUM> is configured to prevent cracks from being formed at the connection between the stop portion <NUM> and the body <NUM> in a case where the stop portion <NUM> is bent relative to the body <NUM>, thereby improving the strength of the connection between the stop portion <NUM> and the body <NUM> and facilitating the bending of the stop portion <NUM> relative to the body <NUM>.

<FIG> is a side view of a welding protection sheet <NUM> according to some embodiments of the present disclosure. Referring to <FIG>, in some embodiments, the width W7 of the end of the stop portion <NUM> close to the body <NUM> in the second direction Y is greater than the width W8 of the end of the stop portion <NUM> away from the body <NUM> in the second direction Y. In this way, it is possible to reduce sharpness of the end of the body <NUM> away from the body <NUM>, thus preventing the tab <NUM> from being damaged by the body <NUM>. In addition, the transition between the stop portion <NUM> and the body <NUM> becomes smooth, thereby reducing internal stress at the connection between the stop portion <NUM> and the body <NUM> after the stop portion <NUM> is formed through stamping. Therefore, it is possible to avoid cracking between the stop portion <NUM> and the body <NUM>. In some embodiments, a rounded transition is achieved at the connection between the stop portion <NUM> and the body <NUM>, thereby further reducing the internal stress at the connection between the stop portion <NUM> and the body <NUM>. Two corners of a section of the stop portion <NUM> away from the body <NUM> are provided as rounded corners to avoid scratching the tab <NUM>.

Referring to <FIG>, in this embodiment, in a case where the welding protection sheet <NUM> is welded to the tab <NUM>, both the first extending portion <NUM> and the second extending portion <NUM> face towards the tab <NUM>. That is, the first extending portion <NUM> and the second extending portion <NUM> are located between the tab <NUM> and the body <NUM>. The first extending portion <NUM> and the second extending portion <NUM> are located between the first tab portion <NUM> of the tab <NUM> and the body <NUM> to allow the side of the first extending portion <NUM> away from the first bent connection portion <NUM> to be in contact with the tab <NUM> to increase the friction surface between the first extending portion <NUM> and the tab <NUM>, and to allow the side of the second extending portion <NUM> away from the second bent connection portion <NUM> to be in contact with the tab <NUM> to increase the friction surface between the second extending portion <NUM> and the tab <NUM>. Therefore, it is possible to increase the friction surface and friction force between the welding protection sheet <NUM> and the tab <NUM>, which in turn avoids the displacement of the welding protection sheet <NUM> relative to the tab <NUM>.

Referring to <FIG>, it can be understood that the resistance increasing region <NUM> with the predetermined roughness will be formed between the first extending portion <NUM> and the second extending portion <NUM>. In this embodiment, the first extending portion <NUM> and the second extending portion <NUM> are located between the tab <NUM> and the body <NUM>. The resistance increasing region <NUM> can improve the friction coefficient between the welding protection sheet <NUM> and the tab <NUM>, thereby improving the friction force between the first extending portion <NUM> and the tab <NUM> and the friction force between the second extending portion <NUM> and the tab <NUM>. Therefore, it is possible to avoid the problems such as slipping and displacement during the assembling between the welding protection sheet <NUM> and the tab <NUM>, thereby avoiding the problem such as solder false or incorrect welding between the welding protection sheet <NUM> and the tab <NUM>. Therefore, the connection stability between the welding protection sheet <NUM> and the tab <NUM> is further improved, and the reliability of the energy storage device <NUM> can be improved, and service life of the energy storage device <NUM> can be prolonged. In addition, the first extending portion <NUM> and the second extending portion <NUM> are located between the tab <NUM> and the body <NUM>. Therefore, it is also possible to prevent the first corner <NUM> and the second corner <NUM> from being exposed after the welding protection sheet <NUM> is welded to the tab <NUM>, thereby avoiding the problem such as the upwarp of the first corner <NUM> and the second corner <NUM>, which in turn avoids damage to the second tab portion <NUM> by the first corner <NUM> and the second corner <NUM>.

In some embodiments, in the case where the welding protection sheet <NUM> is welded to the tab <NUM>, the body <NUM> may face towards the tab <NUM>. That is, the first extending portion <NUM> and the second extending portion <NUM> are located at a side of the body <NUM> facing away from the tab <NUM>, to improve the attachment between the welding protection sheet <NUM> and the tab <NUM>, thereby improving the welding strength between the welding protection sheet <NUM> and the tab <NUM>. In this way, the problems such as solder false, incorrect welding, or leakage solder between the welding protection sheet <NUM> and the tab <NUM> can be avoided. The welding reliability between the welding protection sheet <NUM> and the tab <NUM> and the use safety of the energy storage device <NUM> are further enhanced.

<FIG> is a schematic structural view of a welding protection sheet <NUM> according to some other embodiments of the present disclosure. <FIG> is a schematic structural view of a welding protection sheet <NUM> and a tab <NUM> according to some other embodiments of the present disclosure. Referring to <FIG>, the welding protection sheet <NUM> has a welding region <NUM>. A plurality of welding spots <NUM> is formed in the welding region <NUM>. An orthographic projection of at least one of the plurality of welding spots <NUM> on the body <NUM> in a third direction Z overlaps with an orthographic projection of each of the first extending portion <NUM> and the second extending portion <NUM> on the body <NUM> in the third direction Z. In this case, the first extending portion <NUM> is welded to the second extending portion <NUM> after the welding protection sheet <NUM> is welded to the tab <NUM>. In this way, the welding protection sheet <NUM> is allowed to be uniformly welded to the tab <NUM>, which enhances the connection strength between the welding protection sheet <NUM> and the tab <NUM> and avoids the problem such as the solder false between the welding protection sheet <NUM> and the tab <NUM>. After the first extending portion <NUM> is welded to the second extending portion <NUM>, conductive uniformity of the welding protection sheet <NUM> can also be improved, allowing resistance at the connection between the first extending portion <NUM> and the second extending portion <NUM> to be similar to or the same as that of other positions, thereby improving charging or discharging performance, the safety, and the service life of the energy storage device <NUM>. Exemplarily, the plurality of welding spots <NUM> is arranged in the first direction X to form three columns. An orthographic projection of welding spots <NUM> in one column on the body <NUM> in the third direction Z overlaps with the orthographic projection of each of the first extending portion <NUM> and the second extending portion <NUM> on the body <NUM> in the third direction Z. It should be noted that, in <FIG>, for ease of description, the welding region <NUM> is formed at a side of each of the first extending portion <NUM> and the second extending portion <NUM> of the welding protection sheet <NUM>. In some embodiments, the welding region <NUM> may also be formed at a side of the body <NUM> of the welding protection sheet <NUM>.

Embodiments of the present disclosure further provide an electric device. The electric device includes the energy storage device as described above. The electric device may be for example a vehicle, a ship, an airplane, or the like that needs to be powered. The energy storage device is configured to supply electric energy to the electric device.

Claim 1:
An energy storage device (<NUM>), comprising:
a connector (<NUM>);
a tab (<NUM>) connected to the connector (<NUM>); and
a welding protection sheet (<NUM>) abutting against a surface of the tab (<NUM>) away from the connector (<NUM>), wherein the welding protection sheet (<NUM>) comprises a body (<NUM>), a first bent connection portion (<NUM>), and a first extending portion (<NUM>), wherein:
each of the body (<NUM>) and the first extending portion (<NUM>) extends in a first direction; the first bent connection portion (<NUM>) is connected between the first extending portion (<NUM>) and the body (<NUM>); and the first extending portion (<NUM>) is foldable relative to the body (<NUM>) to face towards the body (<NUM>);
each of two opposite ends of an end portion of the first extending portion (<NUM>) away from the first bent connection portion (<NUM>) in the first direction has a first notch (<NUM>), wherein the first notch (<NUM>) has a width in a second direction less than a width of the first extending portion (<NUM>) in the second direction, wherein the second direction is perpendicular to the first direction; and
two first corners (<NUM>) are formed at connections between two end portions of the first extending portion (<NUM>) in the first direction and the end portion of the first extending portion (<NUM>) away from the first bent connection portion (<NUM>), wherein a distance between the two first corners (<NUM>) in the first direction is less than a length of the body (<NUM>) in the first direction.