Electrode assembly and battery cell having same

Abstract

The utility model discloses an electrode assembly and a battery monomer with the same. The projection of the electrode assembly in a projection plane perpendicular to the height direction of the electrode assembly is in a sector ring shape. According to the electrode assembly disclosed by the utility model, the projection of the electrode assembly in the projection plane in the height direction of the electrode assembly is set into the sector ring shape, so that the electrode assembly can be conveniently subjected to hot-pressing compaction, the electrode assembly can be more compact, and the single battery can have larger volume energy density.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to an electrode assembly and a battery monomer having the same. Background Art

[0002] Innovation and change are the manifestation of all walks of life and fields striving to break the shackles of old tools and concepts and achieve progress and improvement. The limitations of the original things are being recognized more and more deeply as society develops and science and culture continue to flourish.

[0003] At present, the most widely used battery is the cylindrical battery, which has good consistency, simple processing, high yield and a long history. However, in the processing of cylindrical batteries, the electrode assemblies in the cylindrical batteries are often wound into cylinders and assembled into cylindrical batteries after winding. The multiple pole pieces and diaphragms in the electrode assemblies are squeezed only by the tangential force during winding, so that the pole pieces and diaphragms are not firmly pressed together, resulting in a low energy density of the cylindrical battery. Utility Model Content

[0004] The present invention is based on the discovery of the following facts and problems by the inventor of the present application:

[0005] The electrode assembly in the cylindrical battery is a cylinder after winding, and the pole piece and the diaphragm cannot be hot-pressed, which makes the overall structure of the electrode assembly relatively loose, and thus makes the energy density of the cylindrical battery lower.

[0006] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model proposes an electrode assembly, which can well improve the energy density of a battery cell.

[0007] The utility model also provides a battery monomer having the electrode assembly.

[0008] According to the electrode assembly of the first aspect of the utility model, the projection of the electrode assembly in a projection plane perpendicular to the height direction of the electrode assembly is a fan-shaped shape.

[0009] According to the electrode assembly of the utility model, by setting the projection of the electrode assembly in the projection plane in its height direction as a fan ring, the electrode assembly can be conveniently hot-pressed, so that the electrode assembly can be more compact, and the battery cell can have a larger volume energy density.

[0010] In some embodiments of the present invention, the electrode assembly is wound.

[0011] In some embodiments of the present invention, the electrode assembly includes a plurality of pole pieces, the plurality of pole pieces are stacked along a thickness direction of the pole pieces, and the plurality of pole pieces extend along an arc line.

[0012] The battery cell according to the second aspect of the utility model comprises: a shell and a pole group assembly, wherein the pole group assembly is arranged in the shell, the pole group assembly comprises a plurality of electrode assemblies according to the first aspect of the utility model, and the pole group assembly is surrounded by the plurality of electrode assemblies into a cylindrical shape.

[0013] According to the battery cell of the utility model, by setting the electrode assembly of the first aspect mentioned above, the projection of the electrode assembly in the projection plane in its height direction is set to be a fan ring, so that the electrode assembly can be conveniently hot-pressed, so that the electrode assembly can be more compact, and thus the battery cell can have a larger volume energy density.

[0014] In some embodiments of the present invention, the number of the electrode assemblies is two, and both of the two electrode assemblies are semi-cylindrical.

[0015] In some embodiments of the present invention, in the circumferential direction of the pole group assembly, two adjacent electrode assemblies are arranged with an interval.

[0016] In one embodiment of the present invention, the battery cell further comprises: a separator, which extends in the radial direction of the electrode group assembly and is arranged between two adjacent electrode assemblies.

[0017] In some examples of the present invention, the partition is a plastic part.

[0018] In some examples of the present invention, a connecting hole is formed on the partition plate and passes through the partition plate along the thickness direction of the partition plate.

[0019] In some examples of the present invention, there is a gap between the separator and the electrode assembly in the circumferential direction of the electrode group assembly.

[0020] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of a battery cell according to an embodiment of the utility model;

[0022] Figure 2 It is a schematic diagram of an electrode assembly according to an embodiment of the utility model.

[0023] Reference numerals:

[0024] 10. Electrode assembly; 11. Pole piece;

[0025] 20. Shell; 30. Partition; 40. Pole;

[0026] 100. Battery cell. DETAILED DESCRIPTION

[0027] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0028] First, refer to Figure 1 The battery cell 100 according to the embodiment of the second aspect of the utility model is briefly described. The battery cell 100 is a cylindrical battery cell. The battery cell 100 includes a shell 20 and a pole group assembly. The pole group assembly is arranged in the shell 20 and includes a plurality of electrode assemblies 10.

[0029] Reference below Figure 1 and Figure 2 An electrode assembly 10 according to an embodiment of the first aspect of the present invention is described.

[0030] like Figure 1 and Figure 2 As shown, according to the electrode assembly 10 of the first embodiment of the utility model, the electrode assembly 10 is perpendicular to the height direction of the electrode assembly 10 (such as Figure 1 The projection in the projection plane (in the up and down direction shown) is a fan-shaped ring.

[0031] In this embodiment, the projection of the electrode assembly 10 in the projection plane in the height direction is a fan ring. Specifically, the electrode assembly 10 is formed with an arc surface on the radial outer side, and the electrode assembly 10 is also formed with an arc surface on the radial inner side, and the two arc surfaces are arranged coaxially. In this way, the electrode assembly 10 can be easily hot-pressed after being formed by winding or lamination. For example, when the electrode assembly 10 is hot-pressed, the hot-pressing device can clamp the electrode assembly 10 on the radial inner side and the radial outer side of the electrode assembly 10, so that the electrode assembly 10 can be hot-pressed and pressed in the radial direction, so that the pole piece 11 in the electrode assembly 10 is in close contact with the diaphragm, so that the electrode assembly 10 is more compact as a whole, and the electrode assembly 10 after hot pressing can have a smaller volume, so that the battery cell 100 can be wound or laminated with more pole pieces 11 and diaphragms in the electrode assembly 10 under the same electrical size, so that the volume energy density of the battery cell 100 can be well improved.

[0032] According to the electrode assembly 10 of the embodiment of the utility model, by setting the projection of the electrode assembly 10 in the projection plane in its height direction as a fan ring, the electrode assembly 10 can be conveniently hot-pressed, so that the electrode assembly 10 can be more compact, and the battery cell 100 can have a larger volume energy density.

[0033] In some embodiments of the present invention, reference Figure 1 and Figure 2 As shown, the electrode assembly 10 can be wound and formed. In this embodiment, the electrode assembly 10 is wound and formed, which has a simple structure, convenient processing and fast production.

[0034] In some embodiments of the present invention, Figure 2 As shown, the electrode assembly 10 may include a plurality of pole pieces 11 , and the plurality of pole pieces 11 are stacked along a thickness direction of the pole pieces 11 , and the plurality of pole pieces 11 extend along an arc line.

[0035] In the present embodiment, the plurality of pole pieces 11 in the electrode assembly 10 are arranged to be stacked in a thickness direction of the pole pieces 11 and to extend along an arc line, which can facilitate hot pressing of the electrode assembly 10 and enable the plurality of pole pieces 11 in the electrode assembly 10 to be stably and reliably pressed in a thickness direction during the hot pressing process, thereby making the overall structure of the electrode assembly 10 more stable during the hot pressing process.

[0036] Reference below Figure 1 and Figure 2 A battery cell 100 according to an embodiment of the second aspect of the present invention is described.

[0037] like Figure 1 and Figure 2 As shown, the battery cell 100 according to the embodiment of the utility model includes: a shell 20 and a pole group assembly, the pole group assembly is arranged in the shell 20, the pole group assembly includes a plurality of electrode assemblies 10 according to the embodiment of the first aspect of the utility model, and the pole group assembly is surrounded by a plurality of electrode assemblies 10 to form a cylindrical shape.

[0038] It can be understood that in a traditional cylindrical battery cell, the electrode assembly is formed into a cylindrical structure by winding, and the pole pieces and diaphragms in the electrode assembly are stacked along the radial direction of the electrode assembly, making it difficult or impossible to hot press the electrode assembly 10 along its radial direction. Specifically, there is insufficient space on the radial inner side of the electrode assembly to facilitate the hot pressing device to hot press the electrode assembly from the radial inner and radial outer sides of the electrode assembly.

[0039] In the present embodiment, the electrode group assembly is configured to include a plurality of electrode assemblies 10, and the plurality of electrode assemblies 10 are enclosed to form a cylindrical shape, which can make full use of the arrangement space in the battery cell so that the battery cell 100 can achieve a good energy density. The plurality of electrode assemblies 10 are processed and manufactured separately, so that the hot pressing device can conveniently hot press the electrode assembly 10 from the radial inner side and the radial outer side of the single electrode assembly 10, thereby making the overall structure of the electrode group assembly more compact and dense, thereby making the volume energy density of the electrode group assembly higher, and thereby greatly improving the energy density of the battery cell 100.

[0040] In this embodiment, the electrode assembly is composed of a plurality of electrode assemblies 10. The plurality of electrode assemblies 10 may be the same or different. Figure 1 and Figure 2 As shown, the central angles of the fan-shaped circles formed by the projections of the electrode assemblies 10 in the projection plane perpendicular to their height direction may be the same, or they may be different. For example, a portion of the multiple electrode assemblies 10 may be formed as an acute angle, and another portion of the multiple electrode assemblies 10 may be an obtuse angle. The central angles of the multiple electrode assemblies 10 may also be the same.

[0041] According to the battery cell 100 of the embodiment of the utility model, by setting the electrode assembly 10 of the above-mentioned first aspect embodiment, and by setting the projection of the electrode assembly 10 in the projection plane in its height direction as a fan-shaped ring, the electrode assembly 10 can be conveniently hot-pressed, so that the electrode assembly 10 can be more compact, and thus the battery cell 100 can have a larger volume energy density.

[0042] In some embodiments of the present invention, Figure 1 As shown, there may be two electrode assemblies 10 , and both electrode assemblies 10 are semi-cylindrical.

[0043] In the present embodiment, two electrode assemblies 10 are provided and both are semi-cylindrical, so that the two electrode assemblies 10 can be processed and manufactured by the same winding or lamination method, thereby simplifying the process of the electrode assembly 10 and making the production efficiency of the electrode group assembly higher. The electrode group assembly consists of two electrode assemblies 10, has a simple structure, and is easy to assemble.

[0044] In some embodiments of the present invention, Figure 1 As shown, in the circumferential direction of the electrode group assembly, two adjacent electrode assemblies 10 may be arranged with an interval therebetween.

[0045] In this embodiment, adjacent electrode assemblies 10 are arranged at intervals, which can better avoid interference, collision, damage, short circuit, etc. between adjacent electrode assemblies 10, so that the electrode group assembly can operate stably and reliably in the battery cell 100.

[0046] In one embodiment of the present invention, Figure 1 As shown, the battery cell 100 may further include: a separator 30 , which extends in the radial direction of the electrode group assembly and is disposed between two adjacent electrode assemblies 10 .

[0047] In this embodiment, a separator 30 is provided between adjacent electrode assemblies 10, and the separator 30 can reliably separate adjacent electrode assemblies 10, so that the electrode assembly is more convenient and easy to assemble, and the electrode assembly is stably arranged in the housing 20, so that the battery cell 100 operates more stably. The separator 30 extends along the radial direction of the electrode assembly, and can fix the electrode assembly 10 in the electrode assembly to a certain extent. Specifically, the separator 30 can limit and fix the movement of the electrode assembly 10 in the radial direction, so that the electrode assembly 10 can be arranged in the housing 20 more stably.

[0048] In some examples of the present invention, the partition 30 may be a plastic part. The partition 30 is set as a plastic part, which has a simple structure and can play a good role in insulation and separation, so that the battery cell 100 can operate more stably. Preferably, the partition 30 is a polypropylene part.

[0049] In some examples of the present invention, reference Figure 1 As shown, the separator 30 may be formed with a connecting hole that penetrates the separator 30 along the thickness direction of the separator 30. This can facilitate the electrolyte in the battery cell 100 to flow smoothly in the housing 20, avoid the separator 30 from hindering the flow of the electrolyte between the multiple electrode assemblies 10, and allow the electrolyte to better infiltrate the electrode assemblies 10.

[0050] In some examples of the present invention, reference Figure 1 As shown, in the circumferential direction of the electrode assembly, there may be a gap between the separator 30 and the electrode assembly 10. This makes it easier for the electrolyte to remain between the separator 30 and the electrode assembly 10, so that the electrode assembly 10 can operate well.

[0051] In some embodiments of the present invention, Figure 1 As shown, the battery cell 100 may also include a pole 40, and two poles 40 are provided. The two poles 40 are respectively provided at both ends of the housing 20 in the height direction, and the electrode assembly 10 is connected to the pole 40. In this embodiment, poles 40 are provided at both ends of the housing 20 in the height direction, and the two poles 40 can be respectively formed as the positive pole 40 and the negative pole 40 of the battery cell 100, so as to facilitate the connection between the battery cell 100 and the electrical connector. The multiple electrode assemblies 10 in the pole group assembly can be connected to the pole 40 through the adapter sheet, and the electrode assembly 10 can also be connected to the pole 40.

[0052] The following will refer to Figure 1 and Figure 2 A battery cell 100 according to a specific embodiment of the present invention is described.

[0053] like Figure 1 and Figure 2 As shown, the battery cell 100 of this embodiment can be but not limited to a lithium battery, a sodium battery, etc. The battery cell 100 includes a shell 20, a pole 40, a partition 30 and a pole group assembly. Two poles 40 are provided and are arranged at both ends of the shell 20 in the height direction, and the pole group assembly is arranged in the shell 20. The pole 40 assembly includes two electrode assemblies 10. The electrode assembly 10 is a semi-cylinder and the projection in the projection plane perpendicular to the height direction of the electrode assembly 10 is a fan ring. A partition 30 is arranged between the two electrode assemblies 10. The partition 30 is a polypropylene plate and has a plurality of connecting holes. The connecting holes penetrate the partition 30 along the thickness direction of the partition 30. The electrode assembly 10 has a plurality of pole pieces 11. The plurality of pole pieces 11 are stacked and arranged along the thickness direction of the pole pieces 11, and the pole pieces 11 all extend along arc lines.

[0054] When the battery cell 100 is processed and manufactured, the electrode assembly 10 is formed into a semi-cylinder through lamination and shaping, and the production personnel then heat-press the electrode assembly 10 through a hot pressing device to compress the stacked pole pieces 11 and the diaphragm. Specifically, the specific parameters of the hot pressing can be reasonably set according to the actual process and the need for the battery cell 100 to be wetted. After hot pressing, multiple electrode assemblies 10 are assembled into the housing 20 to form a unit assembly, and the separator 30 is arranged between two electrode assemblies 10.

[0055] According to the battery cell 100 of the embodiment of the utility model, by setting the projection of the electrode assembly 10 in the projection plane in its height direction as a fan ring, the electrode assembly 10 can be conveniently hot-pressed, so that the electrode assembly 10 can be more compact, and the battery cell 100 can have a larger volume energy density.

[0056] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0057] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0058] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0060] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An electrode assembly, characterized in that: The electrode assembly includes a plurality of pole pieces, and the plurality of pole pieces are stacked along the thickness direction of the pole pieces. The projection of the electrode assembly in a projection plane perpendicular to the height direction of the electrode assembly is a fan-shaped ring. The plurality of pole pieces extend along an arc line. An arc surface is formed on the radial outer side of the electrode assembly, and an arc surface is also formed on the inner side of the electrode assembly. The two arc surfaces are coaxially arranged.

2. The electrode assembly according to claim 1, characterized in that: The electrode assembly is wound into shape.

3. A battery cell, characterized in that: include: A shell and an electrode group assembly, wherein the electrode group assembly is arranged in the shell, the electrode group assembly comprises a plurality of electrode assemblies according to any one of claims 1 and 2, and the electrode group assembly is enclosed by the plurality of electrode assemblies into a cylindrical shape.

4. The battery cell according to claim 3, characterized in that: There are two electrode assemblies, and both electrode assemblies are semi-cylindrical.

5. The battery cell according to claim 3, characterized in that: In the circumferential direction of the pole group assembly, two adjacent electrode assemblies are arranged with an interval.

6. The battery cell according to claim 5, characterized in that: Also includes: A separator extends in the radial direction of the electrode group assembly and is arranged between two adjacent electrode assemblies.

7. The battery cell according to claim 6, characterized in that: The partition is a plastic part.

8. The battery cell according to claim 6, characterized in that: The partition plate has a communicating hole formed thereon, the communicating hole penetrating the partition plate in a thickness direction of the partition plate.

9. The battery cell according to claim 6, characterized in that: In the circumferential direction of the pole group assembly, there is a gap between the separator and the electrode assembly.

Images