Battery, battery module and electric equipment

The present application relates to the field of batteries, in particular to a battery, a battery module and an electric equipment. The battery of the present application includes: a connection member, including a first connection portion configured to be electrically connected with an electrode assembly and a second connection portion configured to be electrically connected with an electrode terminal, and the first connection portion is in a folded state along a crease relative to the second connection portion; the crease is arranged between a first end face and a second end face of the first connection portion; and when the connection member is in an expanded state, the second end face and the first end face are arranged along a length direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is based on and claims the priority of the Chinese application No. 202010274181.2 and filed on Apr. 9, 2020, whose entire contents are incorporated herein by reference.

TECHNICAL FIELD

Embodiments of the present application relate to the field of batteries, in particular to a battery, a battery module and an electric equipment.

BACKGROUND

Owing to such advantages as high energy density, high power density, multiple cycles and long storage time, a cylindrical lithium-ion battery and other secondary batteries are widely used in electric vehicles (for example, electric cars, electric tricycles or electric bicycles), etc.

In secondary batteries such as cylindrical lithium-ion batteries, electrolyte enters between electrode plates of a cell via an end face of the cell, thus realizing an infiltration process.

In related technologies, the infiltration efficiency of the battery still needs to be improved.

SUMMARY OF THE INVENTION

Embodiments of the present application aim at providing a battery, a battery module, an electric equipment and a manufacturing method of the battery, to improve the infiltration efficiency of the battery.

The battery provided in the embodiments of the present application includes:

a connection member, including a first connection portion configured to be electrically connected with an electrode assembly and a second connection portion configured to be electrically connected with an electrode terminal, wherein the first connection portion is in a folded state along a crease relative to the second connection portion;

wherein the crease is arranged between a first end face and a second end face of the first connection portion; and

when the connection member is in the expanded state, the second end face and the first end face are arranged along a length direction.

In some embodiments, a first notch is arranged on a side of the first connection portion adjacent to the second connection portion, and the crease extends to the first notch.

In some embodiments, when the connection member is in the expanded state, the first notch extends along the length direction or along a direction intersected with the length direction.

In some embodiments, the second end face is far away from the second connection portion relative to the first end face, and along a direction from the first end face to the second end face, the first notch inclines towards a middle of a width direction of the connection member.

In some embodiments, the first notch includes an arc-shaped notch part, and an outline of the arc-shaped notch part is arc-shaped.

In some embodiments, the first connection portion includes a protruding part, and the protruding part protrudes out of the second connection portion along a width direction of the connection member.

In some embodiments, the connection member includes a connecting part, the connecting part is configured to be connected with the electrode assembly, and when the connection member is in the expanded state, the connecting part protrudes out of the crease along a direction from the first connection portion to the second connection portion.

In some embodiments, a projection of the connection member is not overlapped with a projection of an injection hole along an axial direction of the injection hole, wherein the injection hole is configured to allow electrolyte to be injected.

In some embodiments, the projection of the connection member is not overlapped with a projection of a hole plug along the axial direction of the injection hole, wherein the hole plug extends into the injection hole and penetrates out from a side of the injection hole adjacent to the electrode assembly.

In some embodiments, the battery further includes a protection member configured to prevent the hole plug from contacting with the connection member.

In some embodiments, the battery further includes a first insulating member, wherein the first insulating member is arranged at a side of an end cover of the battery adjacent to the electrode assembly, the first insulating member includes an insulating body and a limiting ring, and the limiting ring protrudes toward a direction close to the electrode assembly relative to the insulating body, and is arranged on a periphery of the connection member, so as to prevent the connection member from contacting with a case of the battery.

In some embodiments, the limiting ring is arranged on a periphery of an end, adjacent to the end cover, of a tab of the electrode assembly.

In some embodiments, the first insulating member includes a supporting part disposed on the insulating body, and the supporting part protrudes from the insulating body towards a direction where the electrode assembly is located, and is supported between the insulating body and the first connection portion.

In some embodiments, the supporting part and an inner surface of the limiting ring are arranged at intervals, or the supporting part is in contact with an inner surface of the limiting ring.

In some embodiments, the insulating body is provided with a weight reduction groove, and the weight reduction groove is concave towards a direction where the electrode assembly is located from an end face of the insulating body far away from the electrode assembly.

In some embodiments, the battery includes an end cover, wherein the end cover includes a body part, a first boss and a second boss, the first boss protrudes from the body part towards a side where the electrode assembly is located, the second boss protrudes from the first boss towards a side where the electrode assembly is located, and the injection hole penetrates through the first boss and the second boss.

The battery module provided in the embodiments of the present application includes the battery in the embodiments of the present application.

The electric equipment provided in the embodiments of the present application includes the battery module in the embodiments of the present application, wherein the battery module is configured to provide electric energy.

Other characteristics and advantages of the present application will become clear through a detailed description of the exemplary embodiments of the present application with reference to the accompanying drawings below.

DETAILED DESCRIPTION OF THE EMBODIMENTS

A clear and complete description will be given below on the technical solutions in the embodiments of the present application in combination with the accompanying drawings in the embodiments of the present application below, and apparently the embodiments described below are only a part but not all of the embodiments of the present application. The description of at least one exemplary embodiment below is merely illustration, rather than serving as any limitation to the embodiments of the present application and applications or uses thereof. Based upon the embodiments of the present application, all the other embodiments which can occur to those skilled in the art without any inventive effort shall fall into the protection scope of the embodiments of the present application.

The techniques, methods and devices known to those of ordinary skills in the art may not be discussed in detail, however, under appropriate conditions, the techniques, methods and devices should be deemed as a part of the authorized description.

In the description of the embodiments of the present application, it should be understood that, the defining of components and parts by such terms as “first” and “second” are merely for the convenience of distinguishing corresponding components and parts, unless otherwise stated, the above terms have no special meanings, therefore, such terms cannot be understood as a limitation to the protection scope of the embodiments of the present application.

In addition, the technical features involved in different embodiments of the present application described below can be combined mutually as long as they do not conflict with each other.

A battery generally includes a case, an electrode assembly, an electrode terminal and a connection member and the like. The electrode assembly is arranged in the case, and electrically connected with the electrode terminal through the connection member. The electrode terminal is exposed out of the case, and is configured to be electrically connected with an external circuit.

The electrolyte is injected into the case, enters between electrode plates of the electrode assembly, and performs an electrochemical reaction with active substances on the electrode plate, thereby generating a charge-discharge process.

The process in which electrolyte enters an electrode assembly is called an infiltration process, and the speed at which the electrolyte enters an electrode assembly is called infiltration efficiency.

In the process of practicing the embodiments of the present application, the inventor found that, in some batteries such as a cylindrical lithium-ion battery, the connection member is configured to be bendable, and in the related technology, the bent connection member shields more of the end face of the electrode assembly, thereby influencing the infiltration efficiency.

Based on the above findings, in the embodiments of the present application, the structure of the battery is improved, so as to improve the infiltration efficiency of the battery.

FIGS.1-26schematically show the structures of the electric equipment, the battery module and the battery in the embodiments of the present application and a manufacturing method of the battery.

To clearly describe each orientation below, firstly each direction is defined with a coordinate system inFIG.2, wherein a coordinate axis L represents a first direction, which is an arrangement direction of a first connection portion131and a second connection portion132when the connection member13is in an expanded state, and, in some embodiments, which is also a length direction of the connection member13in an expanded state; a coordinate axis H represents a second direction which is vertical to the first direction L and a third direction W, the second direction H is a stacking direction of the first connection portion131and the second connection portion132when the connection member13is in a folded state, and, in some embodiments, the second direction H is also a height direction of the battery module102, the thickness direction of the connection member13, and the axial direction of the battery10; and the coordinate axis W represents the third direction, which is vertical to the first direction L and the second direction H, and in some embodiments, which is also the width direction of the connection member13.

However, it should be understood that, the above-mentioned definitions of orientations are merely to facilitate description of embodiments of the present application and for simplified description, in the absence of a contrary illustration, these orientation terms do not indicate or imply that the device or element referred to must be located in a certain orientation or must be constructed or operated in a certain orientation, therefore, the terms cannot be understood as a limitation to the protection scope of the embodiments of the present application.

Referring toFIG.1, the embodiments of the present application provide an electric equipment100which takes a battery module102as a power source. The electric equipment100includes an equipment body101and a battery module102. The battery module102is arranged on the equipment body101to provide electric energy.

The electric equipment100is, for example, a mobile device such as a vehicle, a ship, a small aircraft, and includes a power source. The power source includes the battery module102, and the battery module102is configured to provide electric energy, thereby providing a driving force for the electric equipment100. In some embodiments, the driving force of the electric equipment100is totally electric energy, at this time, the power source only includes the battery module102. In some other embodiments, the driving force of the electric equipment100includes electric energy and other energies (for example, mechanical energy), at this time, the power source includes the battery module102and other power equipment such as an engine. Referring toFIG.1, taking a vehicle as an example, in some embodiments, the electric equipment10is a new energy vehicle, such as a battery electric vehicle, a hybrid electric vehicle, an extended-range vehicle, an electric tricycle or a two-wheeled electric vehicle.

In addition, the electric equipment100may be an energy storage device such as a battery cabinet, and include the battery module102. The number of the battery module102may be one, two or multiple, such that the battery cabinet can output electric energy.

Therefore, as long as including the battery module102, electric equipment100falls within the protection scope of the embodiments of the present application.

Referring toFIG.2, the battery module102includes a box102aand a battery10, and the battery10is accommodated in the box102a.

The box102aincludes a sleeve102b, a first box cover102cand a second box cover102d. The sleeve102b, which is an aluminum case for example, is hollow inside, and open at two ends opposite to each other along the second direction H. The first box cover102cand the second box cover102dare respectively covered on the two ends of the sleeve102bthat are opposite to each other along the second direction H, to close these two ends, which are opposite along the second direction H, of the sleeve102b, such that a closed space is formed inside the box102a, to accommodate the battery10, etc. The “closed” herein means cover or close, and may be sealed or unsealed.

When used on a two-wheeled electric car and other electric equipment10, generally, the first box cover102cis on the top, and the second box cover102dis on the bottom, that is, the first box cover102cis a top cover, while the second box cover102dis a bottom cover. During use, through opening and closing the first box cover102c, batteries10and other structural parts inside the box102aare maintained or replaced.

The shapes of the box102acan be varied, for example, referring toFIG.2, in some embodiments, the box102ais overally of a cubic shape. The sleeve102bis of a cubic shape which is hollow and open at two ends, and includes four side plates which are connected end to end in sequence, the four side plates are enclosed to form a cavity, and two adjacent side plates are vertical to each other. A height direction of the sleeve102bis along the second direction H. The shape of the first box cover102cis matched with the shape of the opening on the top of the sleeve102b. The shape of the second box cover102dis matched with the shape of the opening at the bottom end of the sleeve102b.

The battery10is accommodated in the box102a, is a core structural part of the battery module102and is configured to provide electric energy. The number of the battery10may be one, two or multiple. For example, referring toFIG.2, in some embodiments, multiple batteries10are disposed in the box102a, so as to provide more electric energies.

Referring toFIGS.2-4, in some embodiments, the battery10is a cylindrical battery with an axial direction along the second direction H, and the battery10includes a case3, an electrode assembly2and a top cover assembly1, etc.

The case3is internally provided with a cavity31configured to accommodate the electrode assembly2, etc. In the cylindrical battery, the case3is configured to be cylindrical.

The electrode assembly2is arranged in the cavity31of the case3, and for example is formed by stacking or winding of a first electrode plate, a second electrode plate and an insulating spacer arranged between the first electrode plate and the second electrode plate. One of the first electrode plate and the second electrode plate is served as a positive electrode plate, while the other one is served as a negative electrode plate, and the first electrode plate and the second electrode plate both have a first part coated with an active substance and a second part which extends outwards from the first part and is not coated with the active substance. Specifically, referring toFIG.4, the electrode assembly2includes a cell body22and a tab21. Wherein, the cell body22is coated with the active substance, corresponds to the first part of the first electrode plate and the second electrode plate, and is configured to generate electric energy. The tab21is arranged at the end part of the cell body22, and extends from the cell body22to the outside, and the tab21is not coated with the active substance, corresponds to the second part of the first electrode plate and the second electrode plate, and is configured to transmit outside the electric energy generated by the cell body22.

The tab21generally includes a first tab21aand a second tab21b, one of the first tab21aand the second tab21bserves as a positive tab, and the other one serves as a negative tab. Referring toFIG.4, in some embodiments, the first tab21aand the second tab21bare respectively arranged at two opposite ends, along the second direction H, of the battery body22. Moreover, referring toFIG.4, in some embodiments, in a direction far away from the cell body22, the cross sectional areas of the first tab21aand the second tab21bare both gradually decreased, and narrow towards the center of the electrode assembly2.

The end cover assembly1is disposed at the end part of the case3to close the cavity31, so as to protect the electrode assembly2and seal the case3. When the first tab21aand the second tab21bare respectively arranged at two opposite ends of the battery body22along the second direction H, the battery10includes two end cover assemblies1, the two end cover assemblies1, respectively corresponding to the first tab21aand the second tab21b, are respectively covered at two opposite ends of the case31along the second direction H, and the two end cover assemblies1may also be referred to as a first end cover assembly and a second end cover assembly for the convenience of distinguishing.

Referring toFIGS.3-6andFIGS.19-20, in some embodiments, the end cover assembly1includes an end cover11, an electrode terminal12and a connection member13, etc.

The end cover11closes the opening at the end part of the case3. Referring toFIG.4, in some embodiments, the structure of the end cover11of the first end cover assembly is not completely identical to the structure of the end cover11of the second end cover assembly. For example, in some embodiments, the end cover11of the first end cover assembly is provided with an injection hole11bfor the injection of electrolyte, and the end cover11of the second end cover assembly is not provided with an injection hole11b, but is provided with an vent18. Of course, in some other embodiments, the injection hole11bmay be arranged on the end cover11of the second end cover assembly, and the vent18is arranged on the end cover11of the first end cover assembly.

The electrode terminal12is arranged on the end cover11, and electrically connected with the electrode assembly2through the connection member13, so as to realize the electrical connection between the electrode assembly2and an external circuit. Referring toFIG.6andFIG.13, in some embodiments, the end cover11is provided with an electrode lead-out hole11a, and the electrode terminal12extends into the electrode lead-out hole11ato realize connection with the end cover11. Specifically, in some embodiments, the end cover11is provided with two electrode lead-out holes11a, the two electrode lead-out holes11aare respectively in one-to-one correspondence with two electrode terminals12, that is, the two electrode terminals12respectively extend into two electrode lead-out holes11a. Moreover, referring toFIG.6andFIG.18, in some embodiments, each electrode lead-out hole11ais provided with a sealing ring19, thereby realizing sealing between the electrode terminal12and the end cover11.

The connection member13is arranged on a side, adjacent to the electrode assembly2, of the end cover11, to electrically connect the electrode assembly2with the electrode terminal12. When the battery10is a cylindrical battery, the connection member13is configured to be foldable, in other words, the connection member13has an expanded state and a folded state, wherein when the connection member13is not assembled into a finished battery10, the connection member13is in an expanded state, and after the connection member13is assembled into a finished battery10, the connection member13is in a folded state.

For example, please refer toFIGS.5-11andFIGS.21-23, in some embodiments, the connection member13includes a first connection portion131and a second connection portion132. The first connection portion131is configured to be electrically connected with the electrode assembly2(specifically the tab21). The second connection portion132is configured to be electrically connected with the electrode terminal12. When the connection member13is in an expanded state, the first connection portion131and the second connection portion132are arranged along the first direction L. Moreover, the first connection portion131is bendable relative to the second connection portion132, and a crease131cis formed after the two are bent, that is, the first connection portion131and the second connection portion132are bent relatively at the crease131c. After the first connection portion131is bent relative to the second connection portion132along the crease131c, the first connection portion131and the second connection portion132are in the folded state. Referring toFIG.15, in the folded state, the first connection portion131is covered on an end face of the electrode assembly2, and the second connection portion132is stacked on a side, far away from the electrode assembly2, of the first connection portion131.

Please refer toFIG.10andFIG.22, in some embodiments, the connection member13is configured to be a switching piece, the first connection portion131is approximately disk-shaped, and the second connection portion132is approximately strip-shaped.

Referring further toFIG.10andFIG.22, in some embodiments, the first connection portion131protrudes relative to the second connection portion132in the third direction W, that is, a width of the first connection portion131is larger than a width of the second connection portion132.

Specifically, please continue to refer toFIG.10andFIG.23, the first connection portion131includes a protruding part131h, and the protruding part131hprotrudes relative to the second connection portion132along the third direction W. More specifically, two protruding parts131hare respectively arranged at two sides, along the third direction W, of the second connection portion132. The protruding part131hincludes a first end face131eand a second end face131fwhich are opposite along the first direction L, that is, the first end face131eand the second end face131fare arranged along the first direction (namely the length direction) L. Moreover, the second end face131fis far away from the second connection portion132relative to the first end face131e.

Of course, in other embodiments not shown in the figures, the first connection portion131may not protrude relative to the second connection portion132in the third direction W, that is, the width of the first connection portion131is smaller than or equal to that of the second connection portion132.

In the related technology, the crease131cis arranged on a side, far away from the second end face131f, of the first end face131e, or is arranged at the first end face131e. In this case, for the bent connection member13, the part of the first connection portion131between the first end face131eand the second end face131fcompletely covers on the end face of the electrode assembly2, and shields more of the electrode assembly2, thereby resulting in a slow speed at which the electrolyte enters inside the electrode assembly2from the end face of the electrode assembly2, which influences the infiltration efficiency of the battery10.

While different from the related technology, in the embodiment of the present application, as shown inFIG.10andFIG.22, when the connection member13is in the expanded state, the crease131cis arranged between the first end face131eand the second end face131f. In this way, when the connection member13is in the folded state, the part of the first connection portion131between the first end face131eand the second end face131fdoes not completely shield the end face of the electrode assembly2, instead, because of being bent, the part between the first end face131eand the crease131cno longer shields the end face of the electrode assembly2, such that the infiltration speed of the electrolyte is accelerated, and the infiltration efficiency of the battery10is improved.

In addition, disposing the crease131cbetween the first end face131eand the second end face131fis also beneficial for shortening the size along the first direction L (namely length) of the second connection portion132, thereby reducing the resistance of the battery10.

Meanwhile, disposing the crease131cbetween the first end face131eand the second end face131ffacilitates evading of the connection member13from the injection hole11b, which is beneficial for improving the injection efficiency.

In the related technology, the crease131cis arranged on a side, far away from the second end face131f, of the first end face131e, or is approximately flush with the first end face131e, such that after bending, a part of the connection member13is just arranged below the injection hole11b, then in the injection process, the connection member13blocks the electrolyte injected via the injection hole11b, thereby influencing the injection efficiency.

While in the embodiments of the present application, the crease131cis arranged between the first end face131eand the second end face131f, so that the connection member13is no longer exactly below the injection hole11bafter being folded, thereby reducing the blocking to the electrolyte by the connection member13in the injection process, and improving the injection efficiency.

For example, referring toFIG.5, in some embodiments, after the first connection portion131is bent relative to the second connection portion132along the crease131c, along the axial direction of the injection hole11b, the projection of the connection member13is not overlapped with the projection of the injection hole11b, in other words, after bending (that is, when the connection member13is in the folded state), the projection of the injection hole11bon the surface vertical to the second direction H is not overlapped with the connection member13. In this way, in the radial direction of the injection hole11b, the connection member13can evade from the injection hole11b, thereby reducing blocking to the electrolyte in the injection process, facilitating smooth injection of the electrolyte into the case3via the injection hole11b, so as to improve the injection efficiency.

As an implementing manner of enabling the crease131cto be arranged between the first end face131eand the second end face131f, referring toFIG.5,FIG.6,FIG.10andFIGS.19-23, in some embodiments, the first connection portion131is provided with at least one first notch131d, and the at least one first notch131dis arranged on at least one side, along the third direction W, of the crease131c. The first notch131dis arranged on the side, adjacent to the second connection portion132, of the first connection portion131. The crease131cextends to the first notch131d. In this way, under the effect of the first notch131d, the first connection portion131and the second connection portion132can be more conveniently and accurately bent relatively at the crease131cbetween the first end face131eand the second end face131f.

Specifically, please refer toFIG.10andFIG.22, in some embodiments, two first notches131dare arranged on the side, adjacent to the second connection portion132, of the first connection portion131, the two first notches131dare respectively arranged at two sides, along the third direction W, of the crease131c, that is, two ends of the crease131calong the third direction W are respectively provided one first notch131d, and moreover, two ends (specifically two ends along the third direction W) of the crease131crespectively extend to the two first notches131d. Wherein, the two first notches131dmay be symmetrically arranged at two sides, along the third direction W, of the crease131c. Based on this, in the relatively bending process, a deflection between the first connection portion131and the second connection portion132is less likely to occur.

Referring toFIGS.10-11, in some embodiments, when the connection member13is in the expanded state, the first notch131dextends along the first direction L, or, referring toFIGS.22-23, in some other embodiments, when the connection member13is in the expanded state, the first notch131dextends along a direction intersected with the first direction L.

Moreover, please continue to refer toFIGS.22-23, when the first notch131dextends along the direction intersected with the first direction L, in some embodiments, along a direction from the first end face131eto the second end face131f, the first notch131dinclines towards the middle part of the third direction W of the connection member13. In this way, a width of the crease131cis relatively small, thereby facilitating relative bending of the first connection portion131and the second connection portion132at the crease131c.

The specific shape of the first notch131dmay be varied.

For example, referring toFIG.11, in some embodiments, the contour lines of the first notch131dare all straight lines, and the width of each section of the first notch131dis basically the same.

For another example, referring toFIGS.22-23, in some other embodiments, the first notch131dincludes an arc-shaped notch part131i, and the contour of the arc-shaped notch part131iis arc-shaped. Wherein, the arc-shaped notch part131iis for example arranged at an end, adjacent to the second end face131f, of the first notch131d, that is, the part, adjacent to the send end face131f, of the first notch131dis configured to be the arc-shaped notch part131i. In this way, not only a processing of the first notch131dis facilitated, but also a stress concentration is reduced, thereby improving the stress state of the connection member13, and enhancing the bearing capacity of the connection member13. Specifically, please continue to refer toFIGS.22-23, in some embodiments, the first notch131dfurther includes a first notch section131j, the first notch section131jand the arc-shaped notch part131iare communicated in sequence along the direction from the first end face131eto the second end face131f, and the first notch section131jis configured to be a non-arc-shaped notch part. In this case, the arc-shaped notch part131imay also be referred as a second notch section. Wherein, along the direction from the first end face131eto the second end face131f, the size along the third direction W (namely the width) of the first notch section131jis gradually decreased. A rounded corner may be arranged at the connecting part between the first notch section131jand the arc-shaped notch part131i, so as to further improve stress concentration.

In addition, please refer toFIGS.5-11andFIGS.19-23, in some embodiments, the connection member13further includes a third connection member133, and the second connection portion132is electrically connected with the electrode terminal12through the third connection member133. Moreover, the second connection portion132is bendable relative to the third connection member133, and at this time, the second connection portion132is bendable both relative to the first connection portion131and the third connection member133. In this way, when the connection member13is in the expanded state, the third connection member133is connected to an end, far away from the first connection portion131, of the second connection portion132, in other words, the first connection portion131, the second connection portion132and the third connection member133are arranged along the first direction L, and are connected in sequence; and when the connection member13is in a folded state, the first connection portion131covers on the end face of the electrode assembly2, while the second connection portion132is stacked on a side, far away from the electrode assembly2, of the first connection portion131, and the third connection member133is stacked on a side, far away from the electrode assembly2, of the second connection portion132, that is, the second connection portion132and the third connection member133are stacked on a side, far away from the electrode assembly2, of the first connection portion131in sequence along the direction far away from the electrode assembly2.

Referring toFIGS.5-11andFIGS.19-23, in some embodiments, the first connection portion131is provided with a through hole131band a connecting part13d.

The through hole131bpenetrates through the first connection portion131along the second direction H, thereby facilitating location on the one hand, and facilitating flow of the electrolyte on the other hand. In an assembly process, the relative positional relationship between the connection member13and the electrode assembly2in the first direction L and the third direction W can be determined based on the through hole131b, for example, the through hole131bcan be aligned with the winding center of the electrode assembly2. Meanwhile, in the injection process of the electrolyte, the electrolyte can flow to the electrode assembly2through the through hole131b, thereby improving the infiltration efficiency and injection efficiency.

The connecting part13dis connected with the electrode assembly2, that is, the first connecting part131is connected with the electrode assembly2through the connecting part13d. The connecting part13dand the electrode assembly2are connected by welding or riveting.

In some embodiments, the connecting part13dis a boss which protrudes towards one side of the electrode assembly2, of the first connection portion131, so as to further facilitate the welding between the connecting part13dand the tab21. At this time, the connecting part13dmay be formed by stamping, and after stamping, the surface, far away from the electrode assembly2, of the first connecting part131is formed with a groove131a, and the connecting part13dand the groove131aare correspondingly arranged in a thickness direction of the connection member13. In some embodiments, the groove131ais V-shaped.

Continue to refer toFIGS.5-11andFIGS.19-23, in some embodiments, at least part of the connecting part13dis arranged on the protruding part131h, that is, in the third direction W, the connecting part13dprotrudes relative to the crease131c.

In addition, referring toFIG.10andFIG.22, in some embodiments, when the connection member13is in the expanded state, along the direction from the first connection portion131to the second connection portion132, that is, along the direction from the second end face131fto the first end face131e, the groove131aprotrudes relative to the crease131c, since the connecting part131dis corresponding to the groove131a, the connecting part13dalso protrudes relative to the crease131c, in other words, in the first direction L, the connecting part13dextends to the side, adjacent to the first end face131e, of the crease131c. In this way, the crease131cis arranged between the first end face131eand the second end face131f, thus the infiltration efficiency being improved, and the connecting part13dand the tab21have a bigger connecting area, thereby enhancing the connecting reliability between the connecting part13dand the tab21, and improving the overcurrent capacity of the battery10.

Specifically, please refer toFIG.5andFIG.21, in some embodiments, the first connection portion131is provided with two connecting parts13d, and the two connecting parts13dare symmetrically arranged on the first connection portion131. For example, in some embodiments, two connecting parts13dare arranged on the first connection portion131, and are arranged symmetrically relative to the through hole131b.

In addition, referring toFIG.10andFIG.22, in some embodiments, a third notch13eis arranged between the second end faces131fof the two protruding parts131hof the first connecting part131, and the third notch13eis concave along the direction from the second end face131fto the first end face131e. This setting has the following advantages: on the one hand, for the first end cover assembly, shielding to the end face of the electrode assembly2by the first connection portion131is reduced, thereby the infiltration efficiency being improved, on the other hand, for the second end cover assembly, the third notch13eis arranged on a side, adjacent to the electrode assembly2, of the vent18, thereby facilitating a high-pressure gas to act on the vent18, and enabling the vent18to be opened more reliably under a preset pressure.

Please refer toFIG.6,FIG.10,FIG.18andFIG.22, in some embodiments, the third connecting part133is provided with first connecting holes133a, the first connecting holes133aand the electrode terminals12are in one-to-one correspondence with each other, and the electrode terminal12penetrates through the first connecting hole133a, to realize the connection between the third connection member133and the electrode terminal12. In some embodiments, the third connection member133is also configured to be disk-shaped with a width greater than that of the second connection portion132.

To facilitate relative bending of the third connection member133and the second connection portion132, referring toFIG.10andFIG.22, in some embodiments, a second notch132ais arranged at the connecting part between the third connection member133and the second connection portion132. The second notch132aextends from the edge, along the third direction W, of the second connection portion132to the middle, along the third direction W, of the second connection portion132, that is, the second notch132ais concave from the edge, along the third direction W, of the second connection portion132to the middle, along the third direction W, of the second connection portion132. Moreover, please refer toFIG.10andFIG.22, in some embodiments, two sides of the second connection portion132along the third direction W are respectively provided with one second notch132a, that is, two second notches132aare arranged at two sides, along the third direction W, of the second connection portion132. In this way, the third connection member133and the second connection portion132can be bent relatively more conveniently at the second notch132a.

In addition, referring toFIG.6andFIG.20, in some embodiments, the end cover assembly1further includes a first insulating member15, a second insulating member16, a connecting block17and a hole plug141, etc.

The first insulating member15and the second insulating member16are respectively located at the sides, adjacent to and far away from the electrode assembly2, of the end cover11, to play an effect of insulation, and reduce the risk of short circuit.

The first insulating member15and the second insulating member16may be made of such insulating materials as plastics.

Referring toFIG.12, in some embodiments, the first insulating member15includes an insulating body151and a limiting ring152and a supporting part153which are arranged on the insulating body151.

Matching with the overall shape of the cylindrical battery, the insulating body151is approximately circular. Moreover, please refer toFIG.6,FIG.12and FIG.18, the insulating body151is provided with a second connecting hole151a, and the electrode terminal12penetrates through the second connecting hole151a. The second connecting hole151aand the electrode terminal12are in one-to-one correspondence.

The limiting ring152is configured to limit lateral displacement (that is, displacement in the plane vertical to the second direction H) of the connection member13, so as to reduce the risk of short circuit. Please refer toFIG.5,FIG.12,FIG.16andFIG.19, the limiting ring152protrudes towards a direction close to the electrode assembly2relative to the insulating body151, and is arranged on a periphery of the connection member13, so as to prevent the connection member13from contacting with the case3, thus avoiding a contact between the connection member13and the case3in cases such as the battery10is shaken and the connection member13is folded, which may cause short circuit problem.

Specifically, please refer toFIG.5,FIGS.15-16andFIG.19, the inner diameter of the limiting ring152is greater than the maximum size, along the first direction L and the third direction W, of the folded connection member13, and the limiting ring152extends to a side, adjacent to the electrode assembly2, of the first connection portion131from the insulating body151towards the side of the electrode assembly2, such that the limiting ring152is arranged around the periphery of the first connection portion131. In this way, the folded connection member13is overally arranged in the range defined by the limiting ring152, such that the limiting ring152can limit the lateral displacement of the connection member13to a certain extent, thereby preventing the connection member13from contacting with the case3due to an overlarge lateral displacement.

More specifically, with reference toFIG.16, in some embodiments, the limiting ring152not only extends to the side, adjacent to the electrode assembly2, of the first connection portion131, but also extends to the end, adjacent to the end cover11, of the tab21. At this time, the limiting ring152is not only arranged around the periphery of the connection member13, but also is arranged around the periphery of the end, adjacent to the end cover11, of the tab21, such that the limiting ring152can limit to a certain extent the lateral displacement of the electrode assembly2while limiting the lateral displacement of the connection member13, thereby preventing the problem of short circuit caused by the contact between the electrode assembly2and the case3due to an overlarge lateral displacement, and preventing the problem of short circuit caused by bending of the tab21atowards the case3.

Referring toFIG.12, in some embodiments, the limiting ring152is configured as a continuous circular ring, but at the same time, the limiting ring152is an unclosed circular ring, and an extending opening152ais arranged between two free ends of the limiting ring152, to allow the second connection portion132of the expanded connection member13to extend outside. Based on this, the limiting ring152not only can reliably limit lateral displacement of the connection member13, reducing the risk of short circuit, but also can facilitate the connection member13to be firstly assembled into the end cover assembly1in an expanded state and then to be folded.

The supporting part153is configured to limit a longitudinal displacement (that is, displacement along the second direction H) of the electrode assembly2, so as to prevent an overlarge longitudinal displacement of the electrode assembly2which may influence the performance and using safety of the battery10. With reference toFIG.12andFIG.18, the supporting part153protrudes towards the direction close to the electrode assembly2relative to the insulating body151, and is supported between the insulating body151and the first connection portion131. In this way, the supporting part153limits the longitudinal displacement of the electrode assembly2by butting against the first connection portion131, thereby being beneficial for reducing shaking of the electrode assembly2, and enabling the battery10to work more safely and reliably.

Specifically, please refer toFIG.12, in some embodiments, the supporting part153is constructed to be an arc-shaped section, at this time, the contact area between the supporting part153and the first connection portion131is relatively large, such that the longitudinal displacement of the electrode assembly2is limited more reliably.

In addition, referring toFIG.12andFIG.15, in some embodiments, the insulating body151is provided with two supporting parts153, and the two supporting parts153are opposite arranged at two sides of the second connection portion132, so as to abut against and limit the first connection portion131more stably. For example, with reference toFIG.12, in some embodiments, the supporting part153is located between the limiting ring152and the second connecting hole151a, and the two supporting parts153are arranged symmetrically relative to the center of the insulating body151. At this time, the two supporting parts153are both arranged at the inner side of the limiting ring152, and are opposite to each other, and can be more stably supported between the insulating body151and the first connection portion131, thereby abutting against and limiting the first connection portion131more stably and reliably.

Referring toFIG.12, in some embodiments, the supporting part153and an inner surface of the limiting ring152are arranged at intervals. To further increase a contact area of the supporting part153and the first connection portion131, with reference toFIG.24, in some other embodiments, the supporting part153is in contact with the inner surface of the limiting ring152. It can be known from comparison ofFIG.12andFIG.24that, under the premise that the radial distance between the supporting part153and the center of the insulating body151is unchanged, when the supporting part153is changed to be in contact with the inner surface of the limiting ring152from being arranged at intervals with the inner surface of the limiting ring152, a radial width of the supporting part153is increased, in this way, the surface area of the supporting part153contacting with the first connection portion131, is increased, so that the first connection portion131can be abutted against and limited more reliably.

In addition, referring toFIG.25, in some embodiments, the insulating body151is provided with a weight reduction groove154, and the weight reduction groove154is concave from the end face, far away from the electrode assembly2, of the insulating body151towards the direction where the electrode assembly2is located. On the one hand, the weight reduction groove154can reduce a weight of the first insulating member15, thereby reducing the weight of the battery10, and on the other hand, when the first insulating member15is molded through injection molding, the weight reduction groove154can further prevent the first insulating member15from producing shrinkage marks during injection molding.

With reference toFIG.25, in some embodiments, the weight reduction groove154includes at least two groove sections154a, and the at least two groove sections154aare arranged along a circumference of the insulating body151.

Please continue to refer toFIG.25, in some embodiments, the insulating body151is provided with two weight reduction grooves154, the two weight reduction grooves154are arranged on two sides of the center of the insulating body151, and are opposite to each other, that is, the two weight reduction grooves154are symmetrically arranged relative to the center of the insulating body151. In this way, weight can be more sufficiently reduced, and injection molding shrinkage marks can be more effectively prevented.

As can be seen in combination withFIG.24andFIG.25, in some embodiments, the insulating body151is simultaneously provided with the weight reduction groove154and the supporting part153. At this time, the weight reduction groove154and the supporting part153are arranged one by one in correspondence. The weight reduction groove154and the supporting part153are respectively arranged at two axial end faces of the insulating body151with the same circumferential and radial position and the same circumferential and radial size. In this way, even if the thickness of the supporting part153is relatively large, the weight reduction groove154still can effectively reduce weight and prevent shrinkage marks.

The second insulating member16and the connecting block17are disposed on the end cover11, and are arranged in sequence along the direction far away from the electrode assembly2, that is, the second insulating member16is arranged between the connecting block17and the end cover11, and is configured to realize insulation between the end cover11and the connecting block17. With reference to FIG.6, a third connecting hole161and the fourth connecting hole171are disposed on the second insulating member16and the connecting block17respectively. The third connecting hole161and the fourth connecting hole171are both arranged to be in one-to-one correspondence with the electrode terminal12. The electrode terminal12extends out from the electrode lead-out hole11a, and penetrates through the third connecting hole161and the fourth connecting hole171successively, thereby realizing the connection between the second insulating piece16and the connecting block17.

The hole plug141is configured to seal the injection hole11b. As shown inFIG.16, the hole plug141extends into the injection hole11b, and penetrates out from the side, adjacent to the electrode assembly2, of the injection hole11b. After injection, the hole plug141is inserted into the injection hole11bto prevent the injected electrolyte from flowing out from the injection hole11b, which results in leakage.

Meanwhile, referring toFIG.6andFIGS.15-17, in some embodiments, the end cover assembly1further includes a plugging member142, and the plugging member142is arranged on the end cover11, and plugs the axial end face, far away from the electrode assembly2, of the injection hole11b. For example, the plugging member142is arranged on an end, far away from the electrode assembly2, of the hole plug141, and is connected with the end cover11. Based on this, the plugging member142can improve the sealing effect on the injection hole11b, and meanwhile can also reduce the risk of falling off of the hole plug141. In addition to playing the sealing effect, the plugging member142can further prevent the hole plug141from escaping from the injection hole11bby limiting a displacement of the hole plug141towards the side far away from the electrode assembly2, which is beneficial for further improving the sealing effect, and reducing the leakage risk of the electrolyte.

For realizing the connection between the plugging member142and the end cover11, with reference toFIG.6, in some embodiments, the end cover11is provided with an accommodation groove11c, and the plugging member142is accommodated in the accommodation groove11c, and is welded on the end cover11. In this way, the plugging member142can be more stably fixed on the end cover11, so as to more reliably improve the sealing effect and prevent the hole plug141from falling off.

Further referring toFIG.5andFIG.16, in some embodiments, when the connection member13is in the folded state, along the axial direction of the injection hole11b, the projection of the connection member13is not overlapped with the projection of the hole plug141, that is, the projection of the hole plug141on the plane vertical to the axial direction of the injection hole11bis not overlapped with the connection member13, which is beneficial for reducing the risk of collision between the connection member13and the hole plug141when the connection member13moves toward the side far away from the electrode assembly2under such conditions as shaking, thereby avoiding the connection member13from influencing the installation of the plugging member142and the installation reliability of the plugging member142, and realizing a tighter sealing effect.

To improve the setting reliability of the hole plug141, with reference toFIG.13andFIG.16, in some embodiments, the end cover11includes a body part111, a first boss112and a second boss113, the first boss112protrudes from the body part111towards the side where the electrode assembly2is located, the second boss113protrudes from the first boss112towards the side where the electrode assembly2is located, and the injection hole11bpenetrates through the first boss112and the second boss113. Through additionally adding a second boss113on the basis of the body part111and the first boss112, and configuring the injection hole11bto penetrate through the first boss112and the second boss113, an axial length of the injection hole11bis increased, such that the contact area between the hole plug141and the injection hole11bis increased, and the risk of falling off of the hole plug141is reduced, thereby realizing more reliable setting of the hole plug141in the injection hole11b. In this case, referring toFIG.6andFIG.16, in some embodiments, a matching groove151bis disposed on the insulating body151, the matching groove151bwhich may be formed by stamping is configured to accommodate the first boss112, so as to realize a closer cooperation between the end cover11and the first insulating member15.

In addition, with reference toFIG.17, in some embodiments, the battery10further includes a protection member143, and the protection member143is configured to prevent the hole plug141from contacting with the connection member13. The protection member143protrudes towards the direction close to the electrode assembly2relative to the hole plug141, that is, an end of the protection member143adjacent to the electrode assembly2, is closer to the electrode assembly2than an end of the hole plug141adjacent to the electrode assembly2, or, in other words, in the second direction H, the distance between the protection member143and the electrode assembly2is smaller than that between the hole plug141and the electrode assembly2. In this way, the protection member143can protect the hole plug141to a certain extent, and prevent falling off of the hole plug141due to being collided by other structural parts in the case3such as the connection member13or the electrode assembly2, which moves upward in the shaking process of the battery10, that is, the protection member143can reduce the falling off risk of the hole plug141by preventing other structural parts in the case3from directly impacting the hole plug141, what's more, the hole plug141is prevented from moving towards a direction far away from the electrode assembly2due to the impact, such that influences on the installation of the plugging member142and the installation reliability of the plugging member142are avoided, thereby a tighter sealing effect being realized.

In some embodiments, the protection member143is arranged on the first insulating member15, and protrudes from the first insulating member15towards a side close to the electrode assembly2. Specifically, with reference toFIG.12andFIG.17, the protection member143is arranged on the insulating body151, and protrudes from the insulating body151towards the side where the electrode assembly2is located. More specifically, the protection member143is arranged on the boss which is formed through stamping the above-mentioned matching groove151b. The protection member143may be constructed as a convex column. At this time, referring toFIG.5,FIG.6andFIG.16, in some embodiments, the insulating body151is provided with a matching hole151c, and the hole plug141penetrates through the matching hole151c, and extends out through the side, adjacent to the electrode assembly2, of the matching hole151c, however, the bottom end of the hole plug141is still higher than the bottom end of the protection member143, such that when the electrode assembly2moves upwards, the protection member143can be in contact with the connection member13prior to the hole plug141, thus preventing the hole plug141from being impacted by the connection member13, etc, and playing a protective effect. The matching hole151cfor example penetrates through the boss formed by stamping the above-mentioned matching groove151b.

In addition, the number of the protection member143is not specifically defined, and may be one, two or more. For example, with reference toFIG.12andFIG.17, in some embodiments, the battery10includes two protection members143, and the two protection members143are arranged at two sides of the injection hole11brelatively, to protect the hole plug141more stably and reliably.

Referring toFIG.26, the manufacturing method of the battery10provided in embodiments of the present application includes the following steps:

S110, bending the first connection portion131relative to the second connection portion132at the position between the first end face131eand the second end face131fof the first connection portion131.

The above are merely exemplary embodiments of the present application, and are not used for limiting the present application. For any modifications, equivalent substitutions and improvements made within the spirit and principle of the present application, the parameters shall all fall within the protection scope of the present application.