Top cover assembly, and single cell

Abstract

The present application discloses a top cover assembly and a single battery, the top cover assembly including a top cover sheet and a lower plastic part, the lower plastic part including a first connecting member and a second connecting member spaced apart from each other on one side of the top cover sheet, and a buffer member connected between the first connecting member and the second connecting member, the buffer member being expandable and contractible in response to a change in the distance between the first connecting member and the second connecting member. By providing a buffer member expandable and contractible in response to a change in the distance between the first connecting member and the second connecting member, the force applied by the lower plastic part to the post terminal is reduced, the post terminal is prevented from being displaced due to the expansion of the lower plastic part due to heating and contraction due to cooling, and the post terminal maintains an excellent sealing ability together with the seal ring.

Description

Technical Field

[0001] This application claims the priority of a Chinese patent application filed with the China National Intellectual Property Administration on September 6, 2022, with the application number 202222372003.0 and the invention title "Top Cover Assembly and Single Cell", the entire content of which is incorporated herein by reference.

[0002] This application relates to the technical field of energy storage devices, and particularly to a top cover assembly and a single cell.

Background Art

[0003] With the development of technology, power batteries are widely applied to electric vehicles as an energy system. A typical power battery includes a top cover assembly for sealing the case. The top cover assembly includes a post, a top cover sheet, and a lower plastic part connected to the top cover sheet. Post mounting holes are provided in both the top cover sheet and the lower plastic part. The post is penetrated through the post mounting hole and is used for the electrical connection between the electrode group and an external electrical device. In order to achieve insulation between the post and the top cover sheet, a sealing ring is fitted on the outside of the post. However, when the lower plastic part undergoes expansion due to heating and contraction due to cooling, the lower plastic part moves the post, causing poor sealing.

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of this application is to solve at least one of the technical problems existing in the prior art. For this reason, this application proposes a top cover assembly that avoids the displacement of the post terminal due to the expansion of the lower plastic part caused by heating and the contraction caused by cooling, and ensures the sealing ability.

[0005] This application also proposes a single cell using the above top cover assembly.

Means for Solving the Problems

[0006] The top cover assembly in the first embodiment of this application is Top cover sheet and A lower plastic component connected to one side of the top cover sheet, the lower plastic component comprising a first connecting member and a second connecting member provided at a distance from each other, and a buffer member connected between the first connecting member and the second connecting member, wherein the buffer member comprises a lower plastic component that is expandable and contractible in response to changes in the distance between the first connecting member and the second connecting member.

[0007] The battery module according to the embodiment of the present invention has at least the following beneficial effects.

[0008] By providing a buffer member that can expand and contract in response to changes in the distance between the first connecting member and the second connecting member, the force applied by the lower plastic part to the post terminal is reduced, preventing the post terminal from shifting due to the expansion caused by heating and contraction caused by cooling of the lower plastic part, and allowing the post terminal to maintain excellent sealing performance together with the seal ring.

[0009] In other embodiments of the present application, the cushioning member includes a curved portion that is curved in the thickness direction of the lower plastic part.

[0010] In other embodiments of the present application, the first connecting member includes a first main body and a first protrusion, the first main body being connected to the top cover sheet and the first protrusion being provided on the side of the first main body away from the top cover sheet; the second connecting member includes a second main body and a second protrusion, the second main body being connected to the top cover sheet and the second protrusion being provided on the side of the second main body away from the top cover sheet; both ends of the curved portion are connected to the first and second protrusions, respectively; the curved portion is curved and provided on the top cover sheet; and the curved portion and the top cover sheet are spaced apart.

[0011] In other embodiments of the present application, the cushioning member includes a curved portion that is curved in the width direction of the lower plastic part.

[0012] In other embodiments of the present application, the buffer member includes a first buffer section and a second buffer section, one end of the first buffer section and one end of the second buffer section are connected to the first connecting member and the second connecting member, respectively, and the other end of the first buffer section and the other end of the second buffer section are connected to form the curved portion, or The curved portion is in the shape of a circular arc.

[0013] In other embodiments of the present application, the lower plastic component includes a plurality of buffer members spaced apart in its width direction, and / or the buffer members include a plurality of curved portions sequentially connected in the length direction of the lower plastic component.

[0014] In other embodiments of the present application, the cushioning member includes a deformable portion whose width is less than the width of the other part of the lower plastic component and / or whose thickness is less than the thickness of the other part of the lower plastic component.

[0015] In other embodiments of the present application, the buffer member includes a deformable portion, a first connecting portion, and a second connecting portion, wherein one end of the deformable portion is connected to the first connecting member via the first connecting portion, and the other end of the deformable portion is connected to the second connecting member via the second connecting portion, and the width of the deformable portion is less than the width of the first and second connecting portions, and / or the thickness of the deformable portion is less than the thickness of the first and second connecting portions.

[0016] In other embodiments of the present application, the lower plastic component includes a plurality of the cushioning members spaced apart in its width direction and / or a plurality of the deformable portions sequentially connected in its length direction.

[0017] The single cell according to the second embodiment of the present application is Battery case and The top cover assembly covered on the battery case, and an electrode group located within the battery case.

[0018] Additional aspects and advantages of the present application will be partially shown in the following description, will become apparent from the following description in part, or will be understood through the practice of the present application. Hereinafter, the present application will be further described with reference to the drawings and examples.

Brief Description of the Drawings

[0019] [Figure 1] It is a schematic diagram of the disassembly of the top cover assembly in the related art. [Figure 2] It is a cross-sectional view of the top cover assembly in FIG. 1. [Figure 3] It is an enlarged schematic view of part A in FIG. 2. [Figure 4] It is a schematic perspective view of the top cover assembly in an embodiment of the present application. [Figure 5] It is a schematic diagram of the disassembly of the top cover assembly in FIG. 4. [Figure 6] It is a cross-sectional view of the top cover assembly in FIG. 4. [Figure 7] It is an enlarged schematic view of part B in FIG. 6. [Figure 8] It is a schematic perspective view of the top cover assembly in another embodiment of the present application. [Figure 9] It is an enlarged schematic view of part C in FIG. 8. [Figure 10] 44>It is a schematic perspective view of the top cover assembly in a further embodiment of the present application. [Figure 11] It is a schematic perspective view of the top cover assembly in a further embodiment of the present application. [Figure 12] It is an enlarged schematic view of part D in FIG. 11. [Figure 13] It is an enlarged schematic view of the top cover assembly in a further embodiment of the present application. [Figure 14]This is an enlarged schematic diagram of a top cover assembly in a further embodiment of the present invention. [Figure 15] This is a cross-sectional view of a top cover assembly in a further embodiment of the present application. [Figure 16] This is an enlarged schematic diagram of section E in Figure 15. [Figure 17] This is a schematic diagram of the disassembled single cell in one embodiment of the present invention. [Modes for carrying out the invention]

[0020] The embodiments of the present application shown in the drawings will be described in detail below, where the same or similar reference numerals throughout the drawings indicate the same or similar elements, or elements having the same or similar function. The embodiments described below with reference to the drawings are illustrative and used solely to illustrate the present application, and should not be understood as limiting this specification.

[0021] Furthermore, in the description of this application, directions or positional relationships indicated by up, down, front, back, left, right, etc., are based on the directions or positional relationships shown in the drawings and are merely for the purpose of facilitating and simplifying the description of this application. It should be understood that these do not indicate or imply that the indicated device or element has a specific direction, or that it must be composed of and operate in a specific direction. Therefore, they should not be understood as limiting this application.

[0022] In the description of this application, "several" means one or more, and "multiple" means two or more. "Greater than," "smaller than," and "greater than" are understood to not include the number of items, while "greater than or equal to," "less than or equal to," and "within" are understood to include the number of items. "First" and "second" are merely for the purpose of distinguishing technical features and should not be understood to indicate or imply relative importance, the number of indicated technical features, or the order of the indicated technical features.

[0023] In the description of this application, unless otherwise explicitly limited, terms such as "to provide," "to install," and "to connect" should be understood in a broad sense, and a person skilled in the art can reasonably determine the specific meaning of these terms in this application by referring to the specific content of the technical proposal.

[0024] In this description, any reference to terms such as “one embodiment,” “several embodiments,” “exemplary embodiment,” “example,” “specific example,” or “several examples” means that the specific features, structures, materials, or properties described with reference to such embodiment or example are included in at least one embodiment or example of this application. In this specification, the general expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or properties described may be combined in an appropriate manner in any one or more embodiments or examples.

[0025] In the related technology, the post and the top cover sheet are insulated via a sealing ring. Specifically, as shown in Figures 1 to 3, the top cover sheet 110 is provided with a first through hole 111 and a second through hole 112, respectively. The lower plastic part 120 is connected to one side of the top cover sheet 110 (for example, the lower side in the figures), and a third through hole 1211 and a fourth through hole 1221 are provided corresponding to the first through hole 111 and the second through hole 112, respectively. In other words, the first through hole 111 and the third through hole 1211 are provided in correspondence and communicate with each other, and the second through hole 112 and the fourth through hole 1221 are provided in correspondence and communicate with each other. The single cell top cover assembly further includes a first post terminal 130 and a second post terminal 140, the first post terminal 130 being inserted through a first through hole 111 and a third through hole 1211 and fixedly connected to the top cover sheet 110 via an upper plastic component, the second post terminal 140 being inserted through a second through hole 112 and a fourth through hole 1221 and fixedly connected to the top cover sheet 110 via an upper plastic component, and a sealing ring 150 fitted to the outside of both the first post terminal 130 and the second post terminal 140. Under normal conditions, the post terminal is connected to the top cover sheet 110 in the normal orientation shown in the figure, and the seal ring 150 performs its sealing function normally. However, if the lower plastic part 120 is exposed to a high-temperature environment and expands due to heating, as shown in Figure 3, the lower plastic part 120 applies a leftward force to the first post terminal 130. Similarly, if it is exposed to a low-temperature environment and contracts due to cooling, it applies a leftward force to the first post terminal 130. In either of these two situations, the first post terminal 130 may shift, potentially causing a sealing failure of the seal ring 150.

[0026] Based on the above, the embodiment of the present application proposes a top cover assembly that solves the problem of sealing defects caused by the expansion of the lower plastic part due to heating and the contraction due to cooling, by dividing the lower plastic part into two parts and providing a cushioning member between the two parts to absorb deformation. The embodiment will be described in detail below with reference to the drawings.

[0027] As shown in Figures 4 to 7, the top cover assembly 100 of this embodiment includes a top cover sheet 110 and a lower plastic part 120, the top cover sheet 110 being provided with a first through hole 111 and a second through hole 112, respectively. The lower plastic part 120 is connected to one side of the top cover sheet 110 (for example, the lower side in the figure) and includes a spaced-apart first connecting member 121 and a second connecting member 122, the first connecting member 121 having a third through hole 1211 and the second connecting member 122 having a fourth through hole 1221, the first through hole 111 corresponding to the third through hole 1211 of the first connecting member 121 and the second through hole 112 corresponding to the fourth through hole 1221 of the second connecting member 122, the first post terminal 130 is inserted through the first through hole 111 and the third through hole 1211 and the second post terminal 140 is inserted through the second through hole 112 and the fourth through hole 1221.

[0028] The lower plastic part 120 further includes a buffer member 123 connected between a first connecting member 121 and a second connecting member 122, and the buffer member 123 may be connected to the first connecting member 121 and the second connecting member 122 to form an integral structure. The buffer member 123 is elastic, and when the lower plastic part 120 expands due to heating or contracts due to cooling, the distance between the first connecting member 121 and the second connecting member 122 changes, and the buffer member 123 can expand or contract in accordance with the change in distance. Specifically, when the lower plastic part 120 expands due to heating, the distance between the first connecting member 121 and the second connecting member 122 decreases, and the buffer member 123 enters a contracted state. When the lower plastic part 120 contracts due to cooling, the distance between the first connecting member 121 and the second connecting member 122 increases, and the buffer member 123 enters an extended state. In this way, the force applied by the lower plastic component 120 to the post terminal is reduced, preventing the post terminal from shifting due to the expansion of the lower plastic component due to heating and contraction due to cooling, and allowing the post terminal to maintain excellent sealing performance together with the seal ring 150.

[0029] As shown in Figures 6 and 7, in some embodiments, the cushioning member 123 includes a curved portion 1231 at both ends connected to a first connecting member 121 and a second connecting member 122, respectively. The curved portion 1231 is provided curved in the thickness direction of the lower plastic part 120. When the lower plastic part 120 expands due to heating, the curvature angle of the curved portion 1231 decreases, causing the cushioning member 123 to contract. When the lower plastic part 120 contracts due to cooling, the curvature angle of the curved portion 1231 increases, causing the cushioning member 123 to extend.

[0030] As one specific embodiment of the buffer member 123 in the above embodiment, as shown in Figure 7, the first connecting member 121 includes a first main body portion 1212 and a first protrusion portion 1213, the first main body portion 1212 is connected to a top cover sheet 110 having a first through hole 111, and the first protrusion portion 1213 is provided on the side of the first main body portion 1212 away from the top cover sheet 110 (for example, the lower side in the figure). Specifically, the first main body portion 1212 may be a plate-like structure, the first protrusion portion 1213 may be a boss or a plate-like structure perpendicular to the first main body portion 1212 in the figure, and the first main body portion 1212 and the first protrusion portion 1213 may be connected to form an integrated structure. Similarly, the second connecting member 122 includes a second main body portion 1222 and a second protrusion 1223. The second main body portion 1222 is connected to the top cover sheet 110, which has a second through hole 112. The second protrusion 1223 is located on the side of the second main body portion 1222 away from the top cover sheet 110 (for example, the lower side in the figure). In other words, the first protrusion 1213 and the second protrusion 1223 are located on the same side and are both located away from the top cover sheet 110.

[0031] To make the curved portion 1231 more flexible, it is required to have a certain degree of curvature, which means its height is usually greater than the thickness of the conventional lower plastic part. Also, when the curved portion 1231 expands and contracts, its height changes, and to prevent the curved portion 1231 from expanding and contracting and pushing against other structures, the highest point of the curved portion 1231 must be below the upper end of the lower plastic part 120, and its lowest point must be above the lower end of the lower plastic part 120. However, doing so increases the overall thickness of the lower plastic part 120, reduces the capacity of the electrode group, and lowers the energy density of the battery. Based on the above, both ends of the curved portion 1231 are connected to the first protrusion 1213 and the second protrusion 1223, respectively, specifically to the bottom ends of the first protrusion 1213 and the second protrusion 1223, the curved portion 1231 is provided curved on the top cover sheet 110, and the curved portion 1231 and the top cover sheet 110 are provided with a gap between them, so that when the lower plastic part 120 expands due to heating, the curved portion 1231 moves toward the top cover sheet 110, but even if it moves to its highest point However, the two parts do not come into contact with each other, thereby preventing the curved portion 1231 from expanding or contracting and pressing against the top cover sheet 110. Furthermore, because the curved portion 1231 is curved and positioned on the top cover sheet 110, the lowest point of the curved portion 1231 is never lower than the lowest points of the first protrusion 1213 and the second protrusion 1223. In other words, the change in height of the curved portion 1231 is limited to the space between the first protrusion 1213 and the second protrusion 1223, preventing the curved portion 1231 from pressing against the parts below it. In addition, the thickness of the first main body portion 1212 and the second main body portion 1222 can be reduced, thereby reducing the space occupied by the lower plastic part 120 inside the case.

[0032] As shown in Figures 8 to 10, in several other embodiments, the cushioning member 123 also includes a curved portion 1231, and both ends of the curved portion 1231 are connected to a first connecting member 121 and a second connecting member 122, respectively. Compared with the embodiments in Figures 6 and 7, this embodiment differs in that the curved portion 1231 is provided curved in the width direction of the lower plastic part 120. When the lower plastic part 120 expands due to heating, the curvature angle of the curved portion 1231 decreases, and the cushioning member 123 contracts. When the lower plastic part 120 contracts due to cooling, the curvature angle of the curved portion 1231 increases, and the cushioning member 123 extends, thus performing its cushioning function.

[0033] As shown in Figures 6 to 9, in some specific embodiments, the buffer member 123 includes a first buffer section 1232 and a second buffer section 1233, both of which are inclined, with one end of the first buffer section 1232 connected to a first connecting member 121 and one end of the second buffer section 1233 connected to a second connecting member 122, and the other end of the first buffer section 1232 and the other end of the second buffer section 1233 connected to each other to form the curved portion 1231.

[0034] As shown in Figure 10, in some other specific embodiments, the curved portion 1231 is arc-shaped.

[0035] As shown in Figures 5 to 9, in some embodiments, the lower plastic part 120 includes a plurality of buffer members 123 spaced apart in its width direction, thereby improving the connection strength between the first connecting member 121 and the second connecting member 122.

[0036] In some other embodiments, the cushioning member 123 includes a plurality of sequentially connected curved sections 1231 along the length of the lower plastic part 120, each curved section 1231 being able to expand and contract synchronously, thereby reducing the amount of expansion and contraction of a single curved section 1231 and avoiding excessive deformation of the curved sections 1231.

[0037] Furthermore, the above embodiments may be used in combination. Specifically, the lower plastic part 120 includes a plurality of cushioning members 123 provided at intervals in its width direction, and one cushioning member 123 includes a plurality of curved portions 1231 sequentially connected in the length direction of the lower plastic part 120. This serves to improve connection strength and reduce the amount of expansion and contraction of one curved portion 1231.

[0038] The present invention also proposes other methods for achieving expansion and contraction of the cushioning member 123, for example, as shown in Figures 11 to 14, the cushioning member 123 includes a deformable portion 1234, the width of which is less than the width of the other part of the lower plastic part 120, or, as shown in Figures 15 and 16, the thickness of which is less than the thickness of the other part of the lower plastic part 120, thereby making the deformable portion 1234 a weak point of the cushioning member 123 that deforms when subjected to a certain applied force. Compared to the above embodiment, in these embodiments, the cushioning member 123 of this embodiment bends only when the lower plastic part 120 expands due to heating and contracts due to cooling.

[0039] Furthermore, the above embodiments may be used in combination, meaning that the width and thickness of the deformed portion 1234 are both less than the width and thickness of other parts of the lower plastic part 120.

[0040] As shown in Figures 13 and 16, in one specific embodiment of the cushioning member 123, the cushioning member 123 as a whole is a flat plate structure flush with the first connecting member 121 and the second connecting member 122, and includes a deformable portion 1234, a first connecting portion 1235 and a second connecting portion 1236, wherein one end of the deformable portion 1234 is connected to the first connecting member 121 via the first connecting portion 1235, and the other end of the deformable portion 1234 is connected to the second connecting member 122 via the second connecting portion 1236, and the thicknesses of the first connecting portion 1235 and the first connecting member 121 may be equal, and the thicknesses of the second connecting portion 1236 and the second connecting member 122 may be equal. In Figure 13, the width of the deformable portion 1234 is less than the width of the first connecting portion 1235 and the second connecting portion 1236. When the lower plastic part 120 expands due to heating and contracts due to cooling, the deformable portion 1234 curves in the width direction, causing the cushioning member 123 to expand and contract. In Figure 16, the thickness of the deformable portion 1234 is less than the thickness of the first connecting portion 1235 and the second connecting portion 1236. When the lower plastic part 120 expands due to heating and contracts due to cooling, the deformable portion 1234 curves in the thickness direction, causing the cushioning member 123 to expand and contract.

[0041] As shown in Figures 11 to 16, in some embodiments, the lower plastic part 120 includes a plurality of buffer members 123 spaced apart in its width direction, thereby improving the connection strength between the first connecting member 121 and the second connecting member 122.

[0042] In some other embodiments, the lower plastic part 120 includes a plurality of sequentially connected deformable sections 1234 along its length, each deformable section 1234 being able to expand and contract synchronously, thereby reducing the amount of expansion or contraction of any one deformable section 1234 and avoiding excessive deformation of the deformable section 1234.

[0043] Furthermore, the above embodiments may be used in combination, that is, the lower plastic part 120 includes a plurality of cushioning members 123 provided at intervals in its width direction, and one cushioning member 123 includes a plurality of deformable parts 1234 sequentially connected in the length direction of the lower plastic part 120, thereby improving the connection strength and reducing the amount of expansion and contraction of one deformable part 1234.

[0044] The embodiments of the present application also include, as shown in Figure 17, a battery case 200, an electrode group 300, and a top cover assembly 100 of each of the above embodiments, wherein the electrode group 300 is located inside the battery case 200, and the top cover assembly 100 covers the battery case 200.

[0045] Although embodiments of the present application have been described in detail above with reference to the drawings, the present application is not limited to the embodiments described above, and various modifications can be made within the scope of the knowledge of those skilled in the art without departing from the spirit of the present application. Furthermore, the embodiments and features of the present application may be combined with each other, as long as they do not contradict each other. [Explanation of Symbols]

[0046] Top cover assembly 100, top cover sheet 110, first through hole 111, second through hole 112, lower plastic part 120, first connecting member 121, third through hole 1211, first main body part 1212, first protrusion 1213, second connecting member 122, fourth through hole 1221, second main body part 1222, second protrusion 1223, cushioning member 123, curved part 1231, first cushioning section 1232, second cushioning section 1233, deformable part 1234, first connecting part 1235, second connecting part 1236, first post terminal 130, second post terminal 140, seal ring 150, battery case 200, electrode group 300.

Claims

1. A top cover assembly that covers the battery case, A top cover sheet having a first through hole and a second through hole, A lower plastic component connected to one side of the top cover sheet, the lower plastic component includes a first connecting member and a second connecting member provided at a distance from each other, and a buffer member connected between the first connecting member and the second connecting member, Includes, The first connecting member is provided with a third through-hole corresponding to the first through-hole, The second connecting member is provided with a fourth through-hole corresponding to the second through-hole, The first post terminal is inserted through the first through hole and the third through hole, The second post terminal is inserted through the second through hole and the fourth through hole, The buffer member is expandable and contractible in response to changes in the distance between the first connecting member and the second connecting member. The lower plastic component includes a plurality of the cushioning members provided at intervals in its width direction, Multiple cushioning members are provided on one side of the lower plastic component in the longitudinal direction from the central position in the longitudinal direction of the lower plastic component. Multiple cushioning members are provided across the entire width of the lower plastic part. The cushioning member includes a curved portion that is curved in the width direction of the lower plastic part, A top cover assembly characterized in that each of the curved portions curves toward the same side in the width direction of the lower plastic component.

2. The buffer member includes a first buffer section and a second buffer section, one end of the first buffer section and one end of the second buffer section are connected to the first connecting member and the second connecting member, respectively, and the other end of the first buffer section and the other end of the second buffer section are connected to form the curved portion, or The top cover assembly according to claim 1, characterized in that the curved portion is arc-shaped.

3. The top cover assembly according to claim 1 or 2, characterized in that the cushioning member includes a plurality of curved portions sequentially connected in the longitudinal direction of the lower plastic component.

4. A top cover assembly that covers the battery case, A top cover sheet having a first through hole and a second through hole, A lower plastic component connected to one side of the top cover sheet, the lower plastic component includes a first connecting member and a second connecting member provided at a distance from each other, and a buffer member connected between the first connecting member and the second connecting member, Includes, The first connecting member is provided with a third through-hole corresponding to the first through-hole, The second connecting member is provided with a fourth through-hole corresponding to the second through-hole, A first post terminal is inserted through the first through hole and the third through hole. The second post terminal is inserted through the second through hole and the fourth through hole, The buffer member is expandable and contractible in response to changes in the distance between the first connecting member and the second connecting member. The lower plastic part includes a plurality of cushioning members provided at intervals in its width direction, Multiple cushioning members are provided on one side of the lower plastic component in the longitudinal direction from the central position in the longitudinal direction of the lower plastic component. Multiple cushioning members are provided across the entire width direction of the lower plastic part, The top cover assembly is characterized in that the cushioning member includes a deformable portion whose width is less than the width of the other part of the lower plastic component.

5. The top cover assembly according to claim 4, characterized in that the thickness of the deformed portion is less than the thickness of the other part of the lower plastic component.

6. The top cover assembly according to claim 4 or 5, wherein the buffer member further includes a first connecting portion and a second connecting portion, one end of the deformable portion is connected to the first connecting member via the first connecting portion, the other end of the deformable portion is connected to the second connecting member via the second connecting portion, and the width of the deformable portion is less than the width of the first connecting portion and the second connecting portion.

7. The top cover assembly according to claim 6, characterized in that the thickness of the deformed portion is less than the thickness of the first connecting portion and the second connecting portion.

8. The top cover assembly according to claim 4, characterized in that the lower plastic part includes a plurality of deformable parts that are sequentially connected in the longitudinal direction thereof.

9. Battery case and The top cover assembly according to claim 1 or 4, which is covered over the battery case, A single cell characterized by including a group of electrodes located within the battery case.

Images