Patent Description:
Batteries are widely used in electronic devices, such as mobile phones, laptops, battery cars, electric cars, electric planes, electric boats, electric toy cars, electric toy boats, electric toy planes and power tools, etc..

The battery cell generally comprises a housing and an electrode assembly. The housing is used to accommodate the electrode assembly and the electrolyte solution. The electrode assembly generally comprises a positive electrode sheet and a negative electrode sheet. Metal ions (such as, lithium ions) move between the positive electrode sheet and the negative electrode sheet to generate electrical energy.

For common battery cells, it is relatively difficult to inject electrolyte solution into the battery cell through the liquid injection hole, and the injection efficiency is low. <CIT> discloses a conventional battery cell having the features of the pre-characterising portion of claim <NUM>.

Embodiments of the present application provide a battery cell, a battery, an electrical device, and a method for manufacturing the battery cell, which can effectively improve the liquid injection efficiency.

In the first aspect, embodiments of the present application provide a battery cell, comprising: an electrode assembly, having a first tab; a housing, having an opening, with the housing configured for accommodating the electrode assembly; and an end cap, comprising a cap body and a first convex part, wherein the cap body is configured for connecting with the housing and covering the opening, the first convex part protrudes from an inner surface of the cap body towards the electrode assembly and abuts against the first tab; the end cap is provided with a liquid injection hole, and the liquid injection hole is configured for allowing electrolyte solution to enter an interior of the battery cell from outside of the battery cell, and the liquid injection hole is located inside of an outer peripheral surface of the first convex part, wherein the first convex part is provided with a flow guiding channel, the flow guiding channel communicates with the liquid injection hole and penetrates the outer peripheral surface, and the flow guiding channel is configured for allowing at least part of the electrolyte solution to flow to outside of the outer peripheral surface.

In the above technical solution, since the first convex part is provided with a flow guiding channel, the flow guiding channel is communicated with the liquid injection hole and penetrates the outer peripheral surface of the first convex part. During the process of injecting the electrolyte solution into the battery cell through the liquid injection hole, the electrolyte solution can flow laterally to outside of the outer peripheral surface of the first convex part through the flow guiding channel, so that the electrolyte solution can quickly flow to the outer circumference of the electrode assembly, improve the smoothness of flowing of the electrolyte solution, effectively improve the injection efficiency, and make the electrolyte solution sufficiently infiltrate the electrode assembly.

In some embodiments, one end of the first convex part away from the cap body is provided with an abutting surface, and the abutting surface is configured for abutting against the first tab; and the end cap is provided with a first concave part which is recessed from the abutting surface in a direction away from the electrode assembly, and the liquid injection hole communicates with the flow guiding channel through the first concave part.

In the above technical solution, the end cap is provided with a first concave part that is recessed from the abutting surface of the first convex part in the direction away from the electrode assembly, and the liquid injection hole is communicated with the flow guiding channel through the first concave part. With such structure, after the electrolyte solution enters the first concave part through the injection hole, a part of the electrolyte solution can directly enter the electrode assembly through the first concave part to infiltrate the electrode sheet, and a part of the electrolyte solution can enter the flow guiding channel through the first concave part and finally flow to outside of the outer peripheral surface of the first convex part, increasing the liquid injection efficiency, while improving the infiltration effect of the electrolyte solution.

In some embodiments, both ends of the flow guiding channel penetrate through the outer peripheral surface and an inner peripheral surface of the first concave part, respectively.

In the above technical solution, the two ends of the flow guiding channel penetrate through the outer peripheral surface and the inner peripheral surface of the first concave part respectively, which is conducive for the electrolyte solution to enter the flow guiding channel from the first concave part, and facilitates the electrolyte solution to laterally flow to outside of the outer peripheral surface of the first convex part.

In some embodiments, the end cap has a liquid outlet surface, one end of the liquid injection hole penetrates the liquid outlet surface, and the liquid outlet surface is located within the first concave part; and in a thickness direction of the end cap, the liquid outlet surface is further away from the electrode assembly than the abutting surface.

In the above technical solution, the liquid outlet surface is farther away from the electrode assembly than the abutting surface in the thickness direction of the end cap, so that there is a distance between the liquid outlet surface and the electrode assembly, which is convenient for the electrolyte solution to enter the first concave part from the liquid injection hole, facilitating the immersion of the electrolyte solution into the electrode assembly and facilitates the lateral flowing of the electrolyte solution.

In some embodiments, in the thickness direction of the end cap, the flow guiding channel, as a whole, is closer to the electrode assembly than the liquid outlet surface.

In the above technical solution, the flow guiding channel as a whole is closer to the electrode assembly than the liquid outlet surface in the thickness direction of the end cap, so that there is a larger distance between the liquid outlet surface and the electrode assembly, and the electrolyte solution is more likely to enter the flow guiding channel.

In some embodiments, the end cap further comprises: a second convex part located in the first concave part and protruding from the bottom surface of the first concave part towards the electrode assembly, and the liquid outlet surface is formed on one end of the second convex part facing the electrode assembly.

In the above technical solution, the second convex part located in the first concave part can strengthen the position of the end cap at which the liquid injection hole is provided, and improve the strength of the position of the end cap at which the liquid injection hole is provided.

In some embodiments, the flow guiding channel is a flow guiding groove disposed at one end of the first convex part away from the cap body.

In the above technical solution, the flow guiding channel is a flow guiding disposed at one end of the first convex part away from the cap body, so as to facilitate the formation of the flow guiding channel. In addition, since the side of the flow guiding groove facing the electrode assembly is open, a part of the electrolyte solution, when flowing in the flow guiding channel, can flow directly towards the inside of the electrode assembly, thereby improving the infiltration effect of the electrode assembly.

In some embodiments, the first convex part is provided with a plurality of the flow guiding channels circumferentially arranged at intervals with the liquid injection hole as a center.

In the above technical solution, the first convex part is provided with a plurality of flow guiding channels circumferentially arranged at intervals with the liquid injection hole as a center, and the electrolyte solution can flow in a plurality of different directions through the plurality of flow guiding channels, which further improves the liquid injection efficiency.

In some embodiments, the flow guiding channel extends along a radial direction of the liquid injection hole.

In the above technical solution, the flow guiding channel extends along the radial direction of the liquid injection hole, which facilitates the electrolyte solution to enter the flow guiding channel and improves the liquid injection efficiency.

In some embodiments, the liquid injection hole and the first convex part are coaxially arranged.

According to the invention, the electrode assembly has a central hole, and in the thickness direction of the end cap, the central hole and the liquid injection hole are disposed opposite to each other.

In the above technical solution, in the thickness direction of the end cap, the central hole and the liquid injection hole are arranged opposite to each other. During the process of injecting electrolyte solution into the battery cell through the liquid injection hole, the electrolyte solution having entered the liquid injection hole can quickly enter the central hole to infiltrate the electrode sheets in the electrode assembly.

In a second aspect, an embodiment of the present application provides a battery, comprising: the battery cell provided by any one of the embodiments of the first aspect; and a box for accommodating the battery cell.

In a third aspect, an embodiment of the present application provides an electrical device, comprising the battery provided by any one of the embodiments of the second aspect.

In a fourth aspect, an embodiment of the present application provides a method for manufacturing a battery cell, the method comprising: providing an electrode assembly having a first tab; providing a housing having an opening; providing an end cap; making the electrode assembly accommodated in the housing; and making the end cap cover the opening, wherein the end cap comprises a cap body and a first convex part, the cap body is configured for connecting with the housing and covering the opening, and the first convex part protrudes from an inner surface of the cap body towards the electrode assembly, and the first convex part is configured to abut against the first tab; the end cap is provided with a liquid injection hole, and the liquid injection hole is configured for allowing the electrolyte solution to enter an interior of the battery cell from outside of the battery cell, and the liquid injection hole is located inside of an outer peripheral surface of the first convex part; the first convex part is provided with a flow guiding channel, and the flow guiding channel is communicated with the liquid injection hole and passes through the outer peripheral surface, the flow guiding channel is configured for allowing the electrolyte solution having entered the liquid injection hole to flow to outside of the outer peripheral surface, wherein the electrode assembly has a central hole, and in a thickness direction of the end cap, the central hole and the liquid injection hole are disposed opposite to each other, the central hole is provided coaxially with the liquid injection hole, and the diameter of the liquid injection hole is smaller than that of the central hol.

In an illustrative example of the present application (not part of the invention), a device for manufacturing a battery cell is provided, the manufacturing device comprising: a first providing device, configured for providing an electrode assembly, the electrode assembly having a first tab; a second providing device, configured for providing a housing having an opening; a third providing device, configured for providing an end cap; and an assembling device, configured for making the electrode assembly accommodated in the housing, and for making the end cap cover the opening, wherein the end cap comprises a cap body and a first convex part, the cap body is configured for connecting with the housing and covering the opening, and the first convex part protrudes from an inner surface of the cap body towards the electrode assembly, and the first convex part is configured to abut against the first tab; the end cap is provided with a liquid injection hole, and the liquid injection hole is configured for allowing electrolyte solution to flow from outside of the battery cell to an interior of the battery cell, and the liquid injection hole is located inside of an outer peripheral surface of the first convex part; the first convex part is provided with a flow guiding channel, and the flow guiding channel is communicated with the liquid injection hole and passes through the outer peripheral surface, and the flow guiding channel is configured for allowing the electrolyte solution having entered the liquid injection hole to flow to outside of the outer peripheral surface.

In order to illustrate the technical solutions of the embodiments of the present application more clearly, the drawings needed to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore should be regarded as limitation on the scope. For those skilled in the art, other related drawings can also be obtained according to these drawings without any creative effort.

Reference Numbers: <NUM>-battery; <NUM>-box; <NUM>-first part; <NUM>-second part; <NUM>-accommodating space; <NUM>-battery cell; <NUM>-electrode assembly; <NUM>-first tab; <NUM>-main body part; <NUM>-second tab; <NUM>-central hole; <NUM>-housing; <NUM>-end wall; <NUM>-peripheral wall; <NUM>-roller groove; <NUM>-end cap; <NUM>-cap body; <NUM>-first convex part; <NUM>-abutting surface; <NUM>-liquid injection hole; <NUM>-flow guiding channel; <NUM>-first concave part; <NUM>-liquid outlet surface; <NUM>-second convex part; <NUM>-third convex part; <NUM>-second concave part; <NUM>-blocking member; <NUM>-insulation member, <NUM>-first connection part; <NUM>-second connection part; <NUM>-third connection part; <NUM>-fourth connection part; <NUM>-controller; <NUM>-motor; <NUM>-vehicle; <NUM>-manufacturing device; <NUM>-first providing device; <NUM>-second providing device; <NUM>-third providing device; <NUM>-assembling device; Z-thickness direction.

In order to make the purposes, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. Obviously, some, but not all, of embodiments are described. Based on the embodiments in the present application, all other embodiments, which are obtained by those skilled in the art without creative works, fall within the protection scope of the present application.

Unless defined otherwise, all technical and scientific terms used in the present application have the same meaning as commonly understood by those skilled in the technical field of the present application. The terms used in the present application in the specification of the present application are only for the purpose of describing specific embodiments, not intended to limit the present application. The terms "comprising" and "having" and any variations thereof in the description and claims of the present application and the above drawing description are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the description and claims of the present application or the above drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

The "embodiment" mentioned in the present application means that a particular feature, structure, or characteristic, which is described in connection with the embodiments, can be included in at least one embodiment of the present application. The appearances of the term in various places in the specification do not necessarily refer to a same embodiment, or a separate or alternative embodiment that is mutually exclusive of other embodiments.

In the description of the present application, it should be noted that, unless expressly specified and limited otherwise, the terms, "installed", "connected with", "connected to" and "attached" should be understood in a broad sense. For example, it may be a fixed connection, or a detachable connection, or an integral connection. It can be directly connected, or indirectly connected through an intermediate medium, and it can be internally communicated between two components. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

The term "and/or" in the present application is only an association relationship to describe associated objects, which means that there can be three kinds of relationships, for example, A and/or B can mean three cases, i.e., A exists alone, A and B exist at the same time, and B exists alone. In addition, the character "/" in the present application generally indicates that the related objects, which are before and after it, are in an "or" relationship.

In the embodiments of the present application, the same reference numeral denotes the same components. For the sake of brevity, detailed descriptions for the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application, as well as the overall thickness, length, width, and other dimensions of the integrated device are shown in the drawings, which are only exemplary descriptions, and should not constitute any limitation on the present application.

The appearance of "plurality" in the present application refers to two or more (including two).

In the present application, the battery cells may comprise lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., which are not limited in the embodiments of the present application. The battery cell may be in the form of a cylinder, a flat body, a cuboid, or other shapes, which are not limited in the embodiments of the present application. The battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells, and soft-pack battery cells, which are not limited in the embodiments of the present application.

The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may comprise a battery module or a battery pack, and the like. The battery typically comprises a box for enclosing one or more battery cells. The box can prevent liquids or other foreign objects from affecting the charging or discharging of the battery cells.

The battery cell comprises an electrode assembly and electrolyte solution. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell works mainly relying on the movement of metal ions between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet comprises a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer is coated on the surface of the positive electrode current collector, and the positive electrode current collector not coated with the positive electrode active material layer protrudes from the positive electrode current collector coated with the positive electrode active material layer. The positive electrode current collector not coated with the positive electrode active material layer is used as the positive electrode tab. With a lithium-ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganate, etc. The negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer is coated on the surface of the negative electrode current collector, and the negative electrode current collector not coated with the negative electrode active material layer is protruded from the negative electrode current collector that has been coated with the negative electrode active material layer. The negative electrode current collector not coated with the negative electrode active material layer is used as the negative electrode tab. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon, etc. In order to ensure that large current is passed without fusing, the number of positive electrode tabs is plural and stacked together, and the number of negative electrode tabs is plural and stacked together. The material of the separator can be PP (polypropylene) or PE (polyethylene), and the like. In addition, the electrode assembly may be of a wound structure or a laminated structure, which is not limited in the embodiment of the present application.

For a common battery cell, it is relatively difficult to inject electrolyte solution into the battery cell through the liquid injection hole, and the injection efficiency is low.

The inventor found that, in the battery cell, in the case that the end cap is electrically connected to the tab of the electrode assembly, the inner surface of the end cap abuts against the tab, and during the process of injecting electrolyte solution into the battery cell through the liquid injection hole on the end cap, it is difficult for the electrolyte solution to flow laterally between the inner surface of the end cap and the tab, resulting in a problem of low injection efficiency.

In view of this, an embodiment of the present application provides a technical solution. The end cap of the battery cell comprises a cap body and a first convex part. The first convex part protrudes from the inner surface of the cap body towards the electrode assembly and abuts against the first tab. The first convex part is provided with a flow guiding channel, and the flow guiding channel communicates with the liquid injection hole on the end cap and penetrates the outer peripheral surface of the first convex part, so that the electrolyte solution can flow laterally to the outside of the outer peripheral surface of the first convex part through the flow guiding channel, thereby improving the injection efficiency.

The technical solutions described in the embodiments of the present application are applicable to battery cells, batteries, and electrical device using batteries.

Electrical devices can be vehicles, mobile phones, portable devices, notebook computers, ships, spacecraft, electric toys and power tools, and so on. The vehicles can be fuel vehicles, gas vehicles or new energy vehicles, and the new energy vehicles can be pure electric vehicles, hybrid vehicles or extended-range vehicles, etc. The spacecraft includes airplanes, rockets, space shuttles, spacecraft, etc. The electric toys include the fixed or mobile electric toys, such as, game consoles, electric car toys, electric ship toys, electric airplane toys, etc. The electric tools include metal cutting power tools, grinding power tools, assembling power tools and railway power tools, such as, electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, electric impact drills, concrete vibrators and electric planers, etc. and the embodiments of the present application do not impose special limitation on the above-mentioned electrical devices.

In the following embodiments, for the convenience of description, the description is made with the example in which the electric device is a vehicle.

Referring to <FIG>, it is a schematic structural diagram of the vehicle <NUM> provided by some embodiments of the present application. A battery <NUM> is disposed inside the vehicle <NUM>, and the battery <NUM> may be disposed at the bottom, head or tail of the vehicle <NUM>. The battery <NUM> may be used for supplying power to the vehicle <NUM>, and for example, the battery <NUM> may be used as an operating power source of the vehicle <NUM>.

The vehicle <NUM> may also include a controller <NUM> and a motor <NUM>, with the controller <NUM> used for controlling the battery <NUM> to supply power to the motor <NUM>, e.g., for the work power requirements during starting, navigating, and driving the vehicle <NUM>.

In some embodiments of the present application, the battery <NUM> can be used as not only the operating power source of the vehicle <NUM>, but also the driving power source of the vehicle <NUM>, to replace or partially replace the fuel or natural gas to provide the driving power for the vehicle <NUM>.

In some embodiments, referring to <FIG>, it is a schematic structural diagram of a battery <NUM> provided by some embodiments of the present application. The battery <NUM> comprises a box <NUM> and a battery cell <NUM>, and the box <NUM> is used to accommodate the battery cell <NUM>.

The box <NUM> may include a first part <NUM> and a second part <NUM>, and the first part <NUM> and the second part <NUM> are covered with each other to define an accommodating space <NUM> for accommodating the battery cells <NUM>. The first part <NUM> and the second part <NUM> may be of various shapes, such as, a cuboid, a cylinder, and the like. The first part <NUM> can be a hollow structure with one side open, and the second part <NUM> can be a hollow structure with one side open as well. The open side of the second part <NUM> covers the open side of the first part <NUM> to form a box <NUM> with an accommodating cavity. As shown in <FIG>, it is also possible that the first part <NUM> is a hollow structure with one side open, the second part <NUM> is a plate-like structure, and the second part <NUM> covers the open side of the first part <NUM> to form a box <NUM> with an accommodating cavity. Exemplarily, in <FIG>, the first part <NUM> and the second part <NUM> are both of the cuboid structure.

Herein, the first part <NUM> and the second part <NUM> can be sealed by a sealing element, and the sealing element can be a sealing ring, a sealant or the like.

In the battery <NUM>, there may be one or plural battery cells <NUM>. If there are plural battery cells <NUM>, the plural battery cells <NUM> may be connected in series or in parallel or in a mixed connection. The mixed connection means that the plurality of battery cells <NUM> have some connected in series and the remaining in parallel. It is possible that the plurality of battery cells <NUM> are connected in series or in parallel or in mixed connection, to form a battery module, and then the plurality of battery modules may be connected in series or in parallel or in mixed connection to form a whole, which is accommodated in the box <NUM>. It is also possible that all the battery cells <NUM> are directly connected in series, in parallel or in a mixed connection, and then the whole formed by all the battery cells <NUM> is accommodated in the box <NUM>.

In some embodiments, the battery <NUM> may further include a bus component, and the plurality of battery cells <NUM> may be electrically connected through the bus component, so as to realize the series, parallel or mixed connection of the plurality of battery cells <NUM>.

The bus component may be a metal conductor, such as copper, iron, aluminum, stainless steel, aluminum alloys, and the like.

Referring to <FIG> and <FIG>, <FIG> is an exploded view of a battery cell <NUM> provided by some embodiments of the present application, and <FIG> is a sectional view of the battery cell <NUM> shown in <FIG>. The battery cell <NUM> comprises an electrode assembly <NUM>, a housing <NUM> and an end cap <NUM>. The electrode assembly <NUM> has a first tab <NUM>, the housing <NUM> has an opening, the housing <NUM> is used to accommodate the electrode assembly <NUM>, and the end cap <NUM> is used to be connected and cover the opening of the housing <NUM>.

Here, the end cap <NUM> comprises a cap body <NUM> and a first convex part <NUM>, the cap body <NUM> is used to connect with the housing <NUM> and cover the opening, and the first convex part <NUM> protrudes from the inner surface of the cap body <NUM> towards the electrode assembly <NUM> and abuts against the first tab <NUM>. The end cap <NUM> is provided with a liquid injection hole <NUM>. The liquid injection hole <NUM> is used for allowing the electrolyte solution to enter the battery cell <NUM> from the outside of the battery cell <NUM>. The liquid injection hole <NUM> is located inside of the outer peripheral surface of the first convex part <NUM>. The first convex part <NUM> is provided with a flow guiding channel <NUM>, the flow guiding channel <NUM> communicates with the liquid injection hole <NUM> and penetrates the outer peripheral surface of the first convex part <NUM>, and the flow guiding channel <NUM> is used for allowing at least part of the electrolyte solution to flow to outside of the outer peripheral surface of the first convex part <NUM>.

Since the first convex part <NUM> is provided with a flow guiding channel <NUM>, the flow guiding channel <NUM> communicates with the liquid injection hole <NUM> and penetrates the outer peripheral surface of the first convex part <NUM>. During the process of injecting the electrolyte solution into the battery cell <NUM> through the liquid injection hole <NUM>, the electrolyte solution can flow laterally to outside of the outer peripheral surface of the first convex part <NUM> through the flow guiding channel <NUM>, so that the electrolyte solution can quickly flow to the outer periphery of the electrode assembly <NUM>, improving the smoothness of flowing of the electrolyte solution, which can effectively increase the injection efficiency and enable the electrolyte solution to fully infiltrate the electrode assembly <NUM>. For the battery cell <NUM> with the above structure, the liquid injection can be realized without excessive liquid injection pressure, which can effectively reduce the damage of the separator in the electrode assembly <NUM> due to the excessive liquid injection pressure, which may cause the risk that the positive electrode sheet and the negative electrode sheet are directly contacted to result in the short circuit.

The first convex part <NUM> of the end cap <NUM> abuts against the first tab <NUM>, so that the electrical connection between the end cap <NUM> and the first tab <NUM> can be achieved. In order to ensure good contact between the first tab <NUM> and the end cap <NUM>, the first convex part <NUM> of the end cap <NUM> can be fixed to the first tab <NUM>, and for example, the first convex part <NUM> and the first tab <NUM> are welded together.

It should be noted that the liquid injection hole <NUM> is located inside of the outer peripheral surface of the first convex part <NUM>, that is, the outer peripheral surface of the first convex part <NUM> is located at the outer periphery of the liquid injection hole <NUM>. The liquid injection hole <NUM> may be located at the central position of the first convex part <NUM>, or the liquid injection hole <NUM> may be offset from the central position of the first convex part <NUM>. Exemplarily, the liquid injection hole <NUM> is disposed coaxially with the first convex part <NUM>, that is, the axis of the liquid injection hole <NUM> coincides with the axis of the outer peripheral surface of the first convex part <NUM>, so that the liquid injection hole <NUM> is located on the central position of the first convex part <NUM>.

In some embodiments, the electrode assembly <NUM> may further include a main body part <NUM> and a second tab <NUM>. Both the first tab <NUM> and the second tab <NUM> protrude from the main body part <NUM>, and the first tab <NUM> and the second tab <NUM> have polarities opposite to each other. If the first tab <NUM> is a positive electrode tab, the second tab <NUM> is a negative electrode tab; and if the first tab <NUM> is a negative electrode tab, the second tab <NUM> is a positive electrode tab. The first tab <NUM> is used for being electrically connected with the end cap <NUM>, and the second tab <NUM> is used for being electrically connected with the housing <NUM>.

Exemplarily, the first tab <NUM> and the second tab <NUM> respectively protrude from two ends of the main body part <NUM> which are opposite in the thickness direction Z of the end cap <NUM>.

The main body part <NUM> may include a positive electrode sheet, a negative electrode sheet and a separator. The main body part <NUM> may be a wound structure, which is formed by winding the positive electrode sheet, the separator and the negative electrode sheet. The main body part <NUM> may also be a stacked structure, which is formed by stacking the positive electrode tab, the separator and the negative electrode tab.

The positive electrode sheet comprises a positive electrode current collector and positive electrode active material layers coated on two opposite sides of the positive electrode current collector. The negative electrode sheet comprises a negative electrode current collector and negative electrode active material layers coated on two opposite sides of the negative electrode current collector. The main body part <NUM> may be the portion of the electrode assembly <NUM> corresponding to the region of the electrode sheet that is coated with the active material layer, and the tab may be the portion of the electrode assembly <NUM> corresponding to the region of the electrode sheet that is not coated with the active material layer. It is understandable that the positive electrode tab may be the area on the positive electrode sheet that is not coated with the positive active material layer, and the negative electrode tab may be the area on the negative electrode sheet that is not coated with the negative electrode active material layer.

In the embodiment of the present application, the housing <NUM> is used to accommodate the electrode assembly <NUM>, and the housing <NUM> may be in various shapes, such as, a cylinder, a cuboid, and the like. The shape of the housing <NUM> may be determined according to the specific shape of the electrode assembly <NUM>. For example, if the electrode assembly <NUM> is of a cylindrical structure, the housing <NUM> can be of a cylindrical structure; and if the electrode assembly <NUM> is of a cuboid structure, the housing <NUM> can be of a cuboid structure. Exemplarily, in <FIG> and <FIG>, the housing <NUM> is of a hollow cylindrical structure.

The housing <NUM> may be made of metal material, such as, copper, iron, aluminum, steel, aluminum alloy, and the like.

In some embodiments, the housing <NUM> may include an end wall <NUM> and a peripheral wall <NUM> surrounding the edge of the end wall <NUM>, the end wall <NUM> is located at one end of the peripheral wall <NUM>, the other end of the peripheral wall <NUM> forms an opening, and the end cap <NUM> is used for connecting with the peripheral wall <NUM> and covers the opening to form a sealed space for accommodating the electrode assembly <NUM> and the electrolyte solution.

Exemplarily, the second tab <NUM> is welded to the end wall <NUM> of the housing <NUM> to realize the electrical connection between the second tab <NUM> and the housing <NUM>.

It should be noted that, the end wall <NUM> and the peripheral wall <NUM> may be an integrally-formed structure or a separate structure. If the end wall <NUM> and the peripheral wall <NUM> are of a separate structure, the housing <NUM> is formed by assembling the two together.

In some embodiments, a first limit part <NUM> and a second limit part <NUM> are formed on the peripheral wall <NUM> of the housing <NUM>. The first limit part <NUM> is located on the side of the cap body <NUM> facing the electrode assembly <NUM>, and the second limit part <NUM> is located on the side of the cap body <NUM> away the electrode assembly <NUM>. In the thickness direction Z of the end cap <NUM>, the first limit part <NUM> is used to limit the cap body <NUM> from moving relative to the housing <NUM> towards the electrode assembly <NUM>, so as to reduce the risk that the end cap <NUM> is forced to press the electrode assembly <NUM> to cause the damage to the electrode assembly <NUM>. The second limit part <NUM> is used to limit the movement of the cap body <NUM> relative to the housing <NUM> in the direction away from the electrode assembly <NUM> so as to limit the end cap <NUM> from being detached from the housing <NUM>. That is to say, the first limit part <NUM> and the second limit part <NUM> function to cooperate with each other, for limiting the movement of the cap body <NUM> relative to the housing <NUM> along the thickness direction Z of the end cap <NUM>.

Both the first limit part <NUM> and the second limit part <NUM> may be of an annular structure.

Exemplarily, the peripheral wall <NUM> of the housing <NUM> is provided with a roller groove <NUM> which is recessed inward toward the outer peripheral surface of the peripheral wall <NUM>, and a first limit part <NUM> is formed on the inner peripheral surface of the peripheral wall <NUM> at a position corresponding to the roller groove <NUM>, so that the housing <NUM> is provided with a necking structure at the position where the first limit part <NUM> is formed.

Exemplarily, the second limit part <NUM> is a flanging structure which is formed at the opening position by partially inward folding the peripheral wall <NUM> of the housing <NUM>.

In the process of assembling the battery cell <NUM>, the electrode assembly <NUM> can be accommodated in the housing <NUM> first, and then the end cap <NUM> covers the end of the peripheral wall <NUM> away from the end wall <NUM>, and the end cap <NUM> cannot move to the inside of the housing <NUM> under the restriction of the first limit part <NUM>, and finally, the peripheral wall <NUM> of the housing <NUM> is partially folded inward to form a second limit part <NUM> to fix the end cap <NUM>.

In the embodiment of the present application, the flow guiding channel <NUM> is communicated with the liquid injection hole <NUM>. It is possible that the flow guiding channel <NUM> is directly connected with the liquid injection hole <NUM>. For example, one end of the flow guiding channel <NUM> directly penetrates the hole wall of the liquid injection hole <NUM>. Of course, it is also possible that the flow guiding channel <NUM> is in indirect communication with the liquid injection hole <NUM>.

In some embodiments, referring to <FIG> is a partial sectional view of the battery cell <NUM> shown in <FIG>. The flow guiding channel <NUM> is in indirect communication with the liquid injection hole <NUM>. Specifically, an abutting surface <NUM> is formed at one end of the first convex part <NUM> away from the cap body <NUM>, and the abutting surface <NUM> is used to abut against the first tab <NUM>. The end cap <NUM> is provided with a first concave part <NUM> which is recessed from the abutting surface <NUM> to the direction away from the electrode assembly <NUM>, and the liquid injection hole <NUM> communicates with the flow guiding channel <NUM> through the first concave part <NUM>. With such structure, it is enabled that after the electrolyte solution enters the first concave part <NUM> through the liquid injection hole <NUM>, a part of the electrolyte solution can directly enter the inside of the electrode assembly <NUM> through the first concave part <NUM> to infiltrate the electrode sheet, and a part of the electrolyte solution can enter the flow guiding channel <NUM> through the first concave part <NUM> and finally flows outside of the outer peripheral surface of the first convex part <NUM>, so as to improve the effect of the electrolyte solution infiltrating the electrode assembly <NUM> and increase the injection efficiency.

Exemplarily, the first concave part <NUM> is disposed coaxially with the liquid injection hole <NUM>.

It should be noted that, the first concave part <NUM> may be fully located in the first convex part <NUM>, or may be partially recessed into the cap body <NUM>. If the first concave part <NUM> is fully located in the first convex part <NUM>, in the thickness direction Z of the end cap <NUM>, the distance from the bottom surface of the first concave part <NUM> to the abutting surface <NUM> of the first convex part <NUM> is not greater than the distance from the inner surface of the cap body <NUM> to the abutting surface <NUM> of the first convex part <NUM>. As shown in <FIG>, if a part of the first concave part <NUM> is recessed into the cap body <NUM>, in the thickness direction Z of the end cap <NUM>, the distance from the bottom surface of the first concave part <NUM> to the abutting surface <NUM> of the first convex part <NUM> is greater than the distance from the inner surface of the cap body <NUM> to the abutting surface <NUM> of the first convex part <NUM>, which makes the first concave part <NUM> have deeper depth and capable of accommodating more electrolyte solution.

In some embodiments, the two ends of the flow guiding channel <NUM> penetrate through the outer peripheral surface of the first convex part <NUM> and the inner peripheral surface of the first concave part <NUM> respectively, which is beneficial for the electrolyte solution to enter the flow guiding channel <NUM> from the first concave part <NUM>, so that the electrolyte solution can flow laterally to the outside of the outer peripheral surface of the first convex part <NUM>.

The flow guiding channel <NUM> may extend along a straight line. The extending direction of the flow guiding channel <NUM> may be perpendicular to the axis of the liquid injection hole <NUM>, that is, the flow guiding channel <NUM> extends along the radial direction of the liquid injection hole <NUM>. The extending direction of the flow guiding channel <NUM> can also be arranged in the way that an acute angle is formed between it and the axis of the liquid injection hole <NUM>. For example, in the thickness direction Z of the end cap <NUM>, the end of the flow guiding channel <NUM> penetrating the outer peripheral surface of the first convex part <NUM> is closer to the electrode assembly <NUM> than the end of the channel <NUM> penetrating the inner peripheral surface of the first concave part <NUM>. That is, one end of the flow guiding channel <NUM> penetrating the outer peripheral surface of the first convex part <NUM> is lower than one end of the flow guiding channel <NUM> penetrating the inner peripheral surface of the first concave part <NUM>, so that the flow guiding channel <NUM> is in an inclined state, which is favorable for the electrolyte solution to flow within the flow guiding channel <NUM>. In <FIG>, the flow guiding channel <NUM> extends along the radial direction of the liquid injection hole <NUM>.

In other embodiments, both ends of the flow guiding channel <NUM> penetrate through the outer peripheral surface of the first convex part <NUM> and the bottom surface of the first concave part <NUM> respectively. In this embodiment, the flow guiding channel <NUM> may be a bent channel formed inside the end cap <NUM>.

In some embodiments, continuously referring to <FIG>, the end cap <NUM> has a liquid outlet surface <NUM>, one end of the liquid injection hole <NUM> penetrates the liquid outlet surface <NUM>, and the liquid outlet surface <NUM> is located in the first concave part <NUM>. In the thickness direction Z of the end cap <NUM>, the liquid outlet surface <NUM> is farther away from the electrode assembly <NUM> than the abutting surface <NUM>, so that there is a distance between the liquid outlet surface <NUM> and the electrode assembly <NUM>, which is convenient for the electrolyte solution to enter to the first concave part <NUM> from the liquid injection hole <NUM>, which is favorable for the electrolyte solution to infuse the electrode assembly <NUM> and facilitates the lateral flowing of the electrolyte solution.

Optionally, in the thickness direction Z of the end cap <NUM>, the flow guiding channel <NUM>, as a whole, is closer to the electrode assembly <NUM> than the liquid outlet surface <NUM>, so that there is a larger distance between the liquid outlet surface <NUM> and the electrode assembly <NUM>, and the electrolyte solution is easier to enter the flow guiding channel <NUM>.

Optionally, the end cap <NUM> may further include a second convex part <NUM>, the second convex part <NUM> is located in the first concave part <NUM> and protrudes from the bottom surface of the first concave part <NUM> towards the electrode assembly <NUM>, and the liquid outlet surface <NUM> is formed on one end of the second convex part <NUM> facing the electrode assembly <NUM>. The second convex part <NUM> can strengthen the position of the end cap <NUM> at which the liquid injection hole <NUM> is arranged, and improve the strength of the position of the end cap <NUM> at which the liquid injection hole <NUM> is arranged.

In some embodiments, the electrode assembly <NUM> has a central hole <NUM>. In the thickness direction Z of the end cap <NUM>, the central hole <NUM> is provided as opposite to the liquid injection hole <NUM>. During the process that the electrolyte solution is injected into the battery cell <NUM> through the liquid injection hole <NUM>, the electrolyte solution which has entered the liquid injection hole <NUM> can quickly flow into the central hole <NUM> to infiltrate the electrode sheets in the electrode assembly <NUM>.

It should be noted that, in the thickness direction Z of the end cap <NUM>, the central hole <NUM> is disposed opposite the liquid injection hole <NUM>, that is, in the thickness direction Z of the end cap <NUM>, the projection of the hole wall of the liquid injection hole <NUM> is at least partially located in the central hole <NUM>.

According to the invention, the central hole <NUM> is provided coaxially with the liquid injection hole <NUM>, and the diameter of the liquid injection hole <NUM> is smaller than that of the central hole <NUM>, so that the projection of the hole wall of the liquid injection hole <NUM> on the thickness direction Z of the end cap <NUM> is fully located in the central hole <NUM>, and thus the electrolyte solution can more easily enter the central hole <NUM> from the liquid injection hole <NUM> to infiltrate the electrode sheet.

In some embodiments, the end cap <NUM> may further include a third convex part <NUM>. The third convex part <NUM> protrudes from the outer surface of the cap body <NUM> in a direction away from the electrode assembly <NUM>. In the thickness direction Z of the end cap <NUM>, the projection of the third convex part <NUM> completely covers the first concave part <NUM>. The third convex part <NUM> can strengthen the position of the end cap <NUM> at which the first concave part <NUM> is provided, so as to improve the strength of the position of the end cap <NUM> at which the first concave part <NUM> is provided.

Exemplarily, the third convex part <NUM> is of a cylindrical structure.

In some embodiments, the second limit part <NUM> of the housing <NUM> is located on the outer periphery of the third convex part <NUM>, that is, the third convex part <NUM> is located inside of the inner peripheral surface of the second limit part <NUM>, and the second limit part <NUM> and the third convex part <NUM> serve as two output poles of the battery cell <NUM> respectively. The output pole is a portion of the battery cell <NUM> which is connected to other components and outputs the electrical energy. It is possible that the second limit part <NUM> is used as the positive output pole of the battery cell <NUM>, and the third convex part <NUM> is used as the negative output pole of the battery cell <NUM>. It is also possible that the second limit part <NUM> is used as the negative output pole of the battery cell <NUM> and the third convex part <NUM> serves as the positive output pole of the battery cell <NUM>. With an example in which the two battery cells <NUM> are electrically connected through the bus component to realize the series connection of the two battery cells <NUM>, the second limit part <NUM> of one battery cell <NUM> and the third convex part <NUM> of another battery cell <NUM> are both connected to the same bus component, e.g., by welding.

Optionally, the outer surface of the second limit part <NUM> (the surface of the second limit part <NUM>, which is away from the cap body <NUM> in the thickness direction Z of the end cap <NUM> ) is flush with the outer surface of the third convex part <NUM> (the surface of the third convex part <NUM>, which is away from the cap body <NUM> in the thickness direction Z of the end cap <NUM>), so that the second limit part <NUM> and the third convex part <NUM> are connected to the bus component.

In some embodiments, the battery cell <NUM> further comprises a blocking member <NUM>, and the blocking member <NUM> is used to block the liquid injection hole <NUM>. The end cap <NUM> is provided with a second concave part <NUM>. The second concave part <NUM> is recessed from the outer surface of the third convex part <NUM> towards the electrode assembly <NUM>. The second concave part <NUM> is used to accommodate the blocking member <NUM> to hide the blocking member <NUM>. The blocking member <NUM> is unlikely to affect the connection between the third convex part <NUM> and the bus component.

Exemplarily, both ends of the liquid injection hole <NUM> penetrate through the liquid outlet surface <NUM> and the bottom surface of the second concave part <NUM> respectively.

In some embodiments, referring to <FIG> is a schematic structural diagram of the end cap <NUM> shown in <FIG>. The flow guiding channel <NUM> is a flow guiding groove disposed at one end of the first convex part <NUM> away from the cap body <NUM> to facilitate the forming of the flow guiding channel <NUM>. In the actual production process, the flow guiding groove can be directly formed, by processing, on the abutting surface <NUM>.

In addition, since the side of the flow guiding groove facing the electrode assembly <NUM> is open, a part of the electrolyte solution, when flowing within the flow guiding channel <NUM>, can flow directly towards the inside of the electrode assembly <NUM>, which is convenient for the electrolyte solution to enter the electrode assembly <NUM> and infiltrate the electrode sheet, which can effectively improve the infiltration effect on the electrode assembly <NUM>.

Exemplarily, the flow guiding groove is disposed on the abutting surface <NUM> of the first convex part <NUM>.

In some embodiments, the flow guiding channel <NUM> extends along the radial direction of the liquid injection hole <NUM>, so that the electrolyte solution can easily enter the flow guiding channel <NUM>, which improves the injection efficiency.

As an example in which the first concave part <NUM> is formed on the end cap <NUM>, the two ends of the flow guiding channel <NUM> in the radial direction of the liquid injection hole <NUM> respectively penetrate the outer peripheral surface of the first convex part <NUM> and the inner peripheral surface of the first concave part <NUM>.

In the embodiment of the present application, there may be one or more flow guiding channels <NUM> on the first convex part <NUM>.

In some embodiments, continuously referring to <FIG>, the first convex part <NUM> is provided with a plurality of flow guiding channels <NUM>, which are circumferentially arranged at intervals with the liquid injection hole <NUM> as the center, so that the electrolyte solution can flow in plural different directions through the plurality of flow guiding channels <NUM>, so as to further increase the injection efficiency.

Exemplarily, in <FIG>, the first convex part <NUM> is provided with four flow guiding channels <NUM><NUM>, which are circumferentially arranged at intervals with the liquid injection hole <NUM> as the center, wherein the included angle between every two adjacent flow guiding channels <NUM> is <NUM> degrees.

In some embodiments, referring to <FIG>, which is a partial enlarged view of the battery cell <NUM> shown in <FIG>. The battery cell <NUM> may further include an insulating member <NUM> for isolating the end cap <NUM> from the housing <NUM>, for realizing the insulating connection between the end cap <NUM> and the housing <NUM>, so as to reduce the risk of short circuit caused by the contact between the end cap <NUM> and the housing <NUM>.

The insulating member <NUM> may be an insulating material, such as, plastic, rubber, or the like.

Exemplarily, the insulating member <NUM> is disposed between the peripheral wall <NUM> of the housing <NUM> and the cap body <NUM> of the end cap <NUM> to separate the cap body <NUM> from the peripheral wall <NUM> of the housing <NUM> to achieve the insulating connection between the end cap <NUM> and the housing <NUM>.

It should be noted that the insulating member <NUM> between the end cap <NUM> and the housing <NUM> can only play an insulating role, or can also play a sealing role while playing an insulating role, so as to realize the sealing of the end cap <NUM> and the housing <NUM>.

In some embodiments, the insulating member <NUM> comprises a first connection part <NUM>, a second connection part <NUM>, a third connection part <NUM> and a fourth connection part <NUM> which are connected in sequence. In the thickness direction Z of the end cap <NUM>, the first connection part <NUM> and the third connection part <NUM> are located on both sides of the cap body <NUM> respectively. The cap body <NUM> presses the third connection part <NUM> against the first limit part <NUM>, and the second limit part <NUM> presses the first connection part <NUM> against the cap body <NUM>. The second connection part <NUM> is located between the outer peripheral surface of the cap body <NUM> and the inner peripheral surface of the housing <NUM>. The fourth connection part <NUM> is located between the outer peripheral surface of the first convex part <NUM> and the inner peripheral surface of the first limit part <NUM>. The fourth connection part <NUM> is used to separate the first convex part <NUM> and the first limit part <NUM>, lowering the risk that the first convex part <NUM> is in contact with the first limit part <NUM> to cause a short circuit.

Herein, the first connection part <NUM>, the second connection part <NUM>, the third connection part <NUM> and the fourth connection part <NUM> may each be of an annular structure.

The embodiment of the present application provides a method for manufacturing a battery cell <NUM>. Referring to <FIG> is a flowchart of a method for manufacturing the battery cell <NUM> provided by some embodiments of the present application. The manufacturing method comprises:.

In the above method, the sequence of step S100, step S200 and step S300 is not limited. For example, it is possible that step S300 is performed first, then step S200 is performed, and then step S100 is performed.

It should be noted that, the related structure of the battery cell <NUM> manufactured by the manufacturing methods provided in the foregoing embodiments may be obtained by referring to the battery cell <NUM> provided in the foregoing embodiments, which is not described herein again.

In addition, an illustrative example of the present application further provides a manufacturing device <NUM> for a battery cell <NUM>. Referring to <FIG> is a schematic block diagram of a manufacturing device <NUM> for a battery cell <NUM> provided by an illustrative example of the present application. The manufacturing device <NUM> comprises a first providing device <NUM>, a second providing device <NUM>, a third providing device <NUM> and an assembling device <NUM>.

Here, the first providing device <NUM> is used for providing the electrode assembly <NUM>, and the electrode assembly <NUM> has a first tab <NUM>. The second providing device <NUM> is used to provide the housing <NUM>, which has an opening. The third providing device <NUM> is used for providing the end cap <NUM>. The assembling device <NUM> is used for making the electrode assembly <NUM> accommodated in the housing <NUM>. The assembly device <NUM> is also used to make the end cap <NUM> cover the opening.

Here, the end cap <NUM> comprises a cap body <NUM> and a first convex part <NUM>, the cap body <NUM> is used to connect with the housing <NUM> and cover the opening, and the first convex part <NUM> protrudes from the inner surface of the cap body <NUM> towards the electrode assembly <NUM>, and the first convex part <NUM> is used to abut against the first tab <NUM>. The end cap <NUM> is provided with a liquid injection hole <NUM>. The liquid injection hole <NUM> is used for allowing the electrolyte solution to enter the battery cell <NUM> from the outside of the battery cell <NUM>. The liquid injection hole <NUM> is located inside the outer peripheral surface of the first convex part <NUM>. The first convex part <NUM> is provided with a flow guiding channel <NUM>, which communicates with the liquid injection hole <NUM> and penetrates the outer peripheral surface. The flow guiding channel <NUM> is used for allowing the electrolyte solution having entered the liquid injection hole <NUM> to flow to outside of the outer peripheral surface.

It should be noted that, the related structure of the battery cell <NUM> manufactured by the manufacturing device <NUM> provided in the foregoing embodiment may be obtained by referring to the battery cell <NUM> provided in the foregoing embodiments, which is not described herein again.

It should be noted that the embodiments in the present application and the features of the embodiments may be combined with each other in the case of no conflict.

Claim 1:
A battery cell (<NUM>), comprising:
an electrode assembly (<NUM>), having a first tab (<NUM>);
a housing (<NUM>), having an opening, with the housing (<NUM>) configured for accommodating the electrode assembly (<NUM>); and
an end cap (<NUM>), comprising a cap body (<NUM>) and a first convex part (<NUM>), wherein the cap body (<NUM>) is configured for connecting with the housing (<NUM>) and covering the opening, the first convex part (<NUM>) protrudes from an inner surface of the cap body (<NUM>) towards the electrode assembly (<NUM>) and abuts against the first tab (<NUM>); the end cap (<NUM>) is provided with a liquid injection hole (<NUM>), and the liquid injection hole (<NUM>) is configured for allowing electrolyte solution to enter an interior of the battery cell (<NUM>) from outside of the battery cell (<NUM>), and the liquid injection hole (<NUM>) is located inside of an outer peripheral surface of the first convex part (<NUM>),
wherein the first convex part (<NUM>) is provided with a flow guiding channel (<NUM>), the flow guiding channel (<NUM>) communicates with the liquid injection hole (<NUM>) and penetrates the outer peripheral surface, and the flow guiding channel (<NUM>) is configured for allowing at least part of the electrolyte solution to flow to outside of the outer peripheral surface,
characterised in that
the electrode assembly (<NUM>) has a central hole (<NUM>), and in a thickness direction (Z) of the end cap (<NUM>), the central hole (<NUM>) and the liquid injection hole (<NUM>) are disposed opposite to each other, wherein
the central hole (<NUM>) is provided coaxially with the liquid injection hole (<NUM>), and
the diameter of the liquid injection hole (<NUM>) is smaller than that of the central hole (<NUM>).