Electrode assembly, battery cell and battery module
By designing a bare cell with a bottom surface width smaller than the top surface and a suitable casing, the problem of poor electrolyte wetting in high-performance cells was solved, improving the electrical and safety performance of the cells and ensuring complete electrolyte wetting and temperature control.
Patent Information
- Application Number
- CN202423030201.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-09
- Publication Date
- 2025-12-16
- Estimated Expiration
- 2034-12-09
AI Technical Summary
High-performance battery cells are prone to poor electrolyte wetting during long-term use, leading to lithium plating and affecting electrical and safety performance.
The bottom width of the bare cell is designed to be smaller than the top width. Combined with a suitable housing structure, this ensures that the electrolyte can more easily wet the middle area of the bare cell, and the temperature is regulated by the heat exchange medium to prevent thermal runaway.
This improves the electrical and safety performance of the battery cell, reduces the risk of poor electrolyte wetting, and ensures the stability and safety of the battery cell in high-performance battery cells.
Smart Images
Figure CN223680159U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of batteries, in particular to an electrode assembly, a battery cell and a battery module. BACKGROUND
[0002] The continuous progress and popularity of electric vehicles make them an important choice in the transportation field. Lithium-ion batteries have gradually become the mainstream battery technology for electric vehicles due to their high energy density, long service life, fast charging, lightweight design, and environmental sustainability.
[0003] Different vehicle models have different requirements for the model of lithium-ion batteries. Among them, the height requirement of truck, van and sport utility vehicle (SUV) projects for batteries exceeds 200 mm, so that the battery has greater capacity, and at the same time optimizes the use of vertical space of the vehicle body.
[0004] However, high-height battery cells (hereinafter referred to as high battery cells) have a higher risk of poor electrolyte infiltration, which makes high battery cells prone to lithium precipitation during long-term use, thereby adversely affecting the electrical performance and safety performance of high battery cells. UTILITY MODEL CONTENT
[0005] Therefore, the purpose of the present application is to provide an electrode assembly, a battery cell and a battery module to at least partially solve the problem of high risk of poor electrolyte infiltration of high battery cells.
[0006] To achieve the above purpose, the first aspect of the present application provides an electrode assembly, comprising: a cover plate having a first plate surface and a second plate surface arranged opposite to each other, the cover plate being connected with a positive electrode column and a negative electrode column protruding from the first plate surface, the positive electrode column and the negative electrode column being arranged in a first direction; the cover plate is provided with a through liquid injection hole; a bare battery cell is arranged on the side of the cover plate close to the second plate surface; the bare battery cell has a top surface close to the cover plate and a bottom surface away from the cover plate, the dimension of the bare battery cell in the first direction is defined as the width of the bare battery cell, and the width of the bottom surface is less than the width of the top surface.
[0007] Optionally, the width of the bare battery cell gradually decreases from the top surface to the bottom surface.
[0008] Optionally, the projection of the bare battery cell in a second direction is an isosceles trapezoid, and the second direction is perpendicular to the first direction.
[0009] Optionally, the width of the top surface is a, and the width of the bottom surface is b, a / 4≤b≤a / 3.
[0010] Based on the same inventive concept, the second aspect of the present application further provides an electric core, comprising a shell and an electrode assembly as described in the first aspect; the shell and the cover plate jointly form a containing cavity, and the bare electric core is located in the containing cavity; the shape of the containing cavity matches the shape of the bare electric core.
[0011] Optionally, the shell further comprises a heat exchange cavity for containing a heat exchange medium, and the heat exchange cavity is arranged on at least one side of the containing cavity along a first direction.
[0012] Optionally, the side wall of the shell is provided with a liquid inlet hole and a liquid outlet hole which communicate with the heat exchange cavity.
[0013] Optionally, the shell is provided with two heat exchange cavities, and the two heat exchange cavities are respectively located on two sides of the containing cavity along the first direction; the orthographic projection of the containing cavity and the two heat exchange cavities along a second direction is a rectangle.
[0014] Optionally, the bottom surface of the shell away from the cover plate is provided with a mounting through hole which communicates with the containing cavity, and an explosion-proof valve is connected to the shell through the mounting through hole.
[0015] Based on the same inventive concept, the third aspect of the present application further provides a battery module, comprising at least two electric cores as described in the second aspect, and the at least two electric cores are stacked along a second direction.
[0016] As can be seen from the above, the electrode assembly, the electric core and the battery module provided by the present application design the bottom surface width of the bare electric core to be less than the top surface width, and for the part of the bare electric core close to the bottom surface, the electrolyte located on both sides of the bare electric core along the first direction can be soaked into the middle area of the bare electric core after a short distance, which helps to achieve complete soaking of the part of the bare electric core close to the bottom surface, thereby reducing the risk of poor electrolyte soaking of the electric core and helping to improve the electrical performance and safety performance of the electric core. BRIEF DESCRIPTION OF DRAWINGS
[0017] In order to more clearly illustrate the technical solutions in the present application or related art, the following will briefly introduce the drawings needed to be used in the embodiments or related art descriptions. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.
[0018] Figure 1 It is a perspective view of the electrode assembly of the embodiment of the present application.
[0019] Figure 2 It is a front view of the electrode assembly of the embodiment of the present application.
[0020] Figure 3FIG. 1 is a perspective view of an electric cell according to an embodiment of the present application;
[0021] Figure 4 FIG. 2 is a perspective view of a battery module according to an embodiment of the present application. Figure 3 FIG. 3 is a sectional view of the A-A section of FIG. 2;
[0022] Figure 5 FIG. 4 is a sectional view of the B-B section of FIG. 2.
[0023] Legend of reference numerals:
[0024] 1000, electric cell; 100, cover plate; 110, first plate surface; 120, second plate surface; 130, liquid injection through hole;
[0025] 200, positive pole; 300, negative pole;
[0026] 400, bare electric cell; 410, top surface; 420, bottom surface; 430, side surface;
[0027] 500, shell; 510, accommodating cavity; 520, heat exchange cavity; 530, mounting through hole; 540, liquid inlet hole; 550, liquid outlet hole;
[0028] 610, liquid outlet pipeline; 620, liquid inlet pipeline;
[0029] 710, positive pole lug; 720, negative pole lug; 800, explosion-proof valve. DETAILED DESCRIPTION
[0030] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and specific embodiments.
[0031] It should be noted that the relative arrangement, numerical expressions and values of the components set forth in the embodiments are not intended to limit the scope of the present application unless otherwise specifically stated.
[0032] It should be understood that the sizes of the various parts shown in the drawings are not necessarily drawn to scale for the sake of convenience.
[0033] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the scope of the application or its application or uses.
[0034] It should be noted that, unless otherwise defined, technical terms or scientific terms used in the embodiments of the present application shall have the common meaning understood by one of ordinary skill in the art to which the present application pertains. The terms "first", "second", and similar terms used in the embodiments of the present application do not denote any order, quantity, or importance, but are used to distinguish different components. The terms "include", "contain", and similar terms mean that the elements or objects before the terms encompass the elements or objects listed after the terms and their equivalents, and do not exclude other elements or objects. The terms "connect" or "connected" and similar terms do not mean only physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right", and the like are used only to indicate relative positional relationships, and when the absolute positions of the described objects are changed, the relative positional relationships can also be changed accordingly.
[0035] Figure 1 A perspective view of the electrode assembly is shown in FIG. 1, wherein Figure 1 The cover plate 100 has a first plate face 110, and the cover plate 100 is connected with a positive electrode post 200 and a negative electrode post 300. The upper end of the positive electrode post 200 protrudes from the first plate face 110, and the upper end of the negative electrode post 300 also protrudes from the first plate face 110. The positive electrode post 200 and the negative electrode post 300 are arranged in a first direction (e.g., the X direction in FIG. 1). Figure 1 The cover plate 100 is also provided with a through liquid injection hole 130, which can be arranged between the positive electrode post 200 and the negative electrode post 300.
[0036] Figure 2 A front view of the electrode assembly is shown in FIG. 2, wherein Figure 2 The cover plate 100 has a second plate face 120 arranged opposite to the first plate face 110, and the bare cell 400 is arranged on one side of the cover plate 100 close to the second plate face 120.
[0037] For example, the bare cell 400 can include a plurality of positive electrode tabs and a plurality of negative electrode tabs that are isolated from each other. Each positive electrode tab has a portion protruding from the top face 410, and the protruding portions of the plurality of positive electrode tabs are stacked and connected to form a positive electrode tab 710. The bottom end of the positive electrode post 200 penetrates the cover plate 100, and the bare cell 400 is electrically connected to the bottom end of the positive electrode post 200 through the positive electrode tab 710. Similarly, each negative electrode tab has a portion protruding from the top face 410, and the protruding portions of the plurality of negative electrode tabs are stacked and connected to form a negative electrode tab 720. The bottom end of the negative electrode post 300 penetrates the cover plate 100, and the bare cell 400 is electrically connected to the bottom end of the negative electrode post 300 through the negative electrode tab 720.
[0038] The dimension of the bare cell 400 along the first direction defines the width of the bare cell 400. For example, along the axial direction of the liquid injection through hole 130 (for example, the Z direction in FIG. 13) Figure 1 and Figure 2 The liquid injection through hole 130 is located at the middle position of the width direction of the top surface 410 of the bare cell 400 in the orthographic projection of the bare cell 400.
[0039] The applicant found that when the cell 1000 is a high cell, during the process of filling the electrolyte through the liquid injection through hole 130, the electrolyte flows from the top surface 410 to the bottom surface 420 of the bare cell 400, and the wetting area gradually decreases during the flow of the electrolyte. Because the height (such as the Z direction size in FIG. 13) of the bare cell 400 in the cell 1000 is high, that is, the flow distance of the electrolyte from the top surface 410 to the bottom surface 420 of the bare cell 400 is long, when the electrolyte flows to the position close to the bottom surface 420, it can only wet a small area located in the middle of the width direction. Figure 2
[0040] At the same time, when the width of the bottom surface 420 and the width of the top surface 410 of the bare cell 400 are the same, because the width of the bottom surface 420 is large, the electrolyte located outside the bare cell 400 is also difficult to wet the middle area along the first direction, which leads to the problem that the lower part of the bare cell 400 close to the bottom surface 420 is prone to incomplete wetting of the electrolyte, that is, poor wetting.
[0041] In order to solve the above problems, as shown in Figure 2 , the embodiment of the present application provides a cell 1000, which comprises a bare cell 400, and the width b of the bottom surface 420 of the bare cell 400 is smaller than the width a of the top surface 410.
[0042] For example, the dimension of the bare cell 400 along the second direction (such as the Y direction in FIG. 13) defines the thickness of the bare cell 400, and the thickness of the bare cell 400 is uniform. The second direction is perpendicular to the first direction, and both the first direction and the second direction are parallel to the first plate surface 110. Figure 1 For example, as shown in the structure and direction in Figure 2 , in this embodiment, the width of the bottom surface 420 of the bare cell 400 is reduced, which can reduce the distance between the left and right side edges of the lower part of the bare cell 400 and the middle area. Correspondingly, the path of the electrolyte wetting from the left and right side edges of the bare cell 400 to the middle area is shorter, so that the electrolyte located on the left and right sides of the bare cell 400 can more easily wet the middle area of the bare cell 400 along the first direction, so that more areas of the lower part of the bare cell 400 can be wetted by the electrolyte.
[0043] Figure 2
[0044] The bare battery cell 400 has a width gradually decreasing from the top surface 410 to the bottom surface 420. In this way, the electrolyte can be fully soaked in the middle region of the bare battery cell 400 after flowing a short distance along the first direction, thereby reducing the risk of poor electrolyte soaking of the battery cell 1000 and improving the electrical performance and safety performance of the battery cell 1000.
[0045] For example, the width of the bare battery cell 400 gradually and continuously decreases or gradually and stepwise decreases from the top surface 410 to the bottom surface 420. Figure 2 In some embodiments, the width of the bare battery cell 400 gradually decreases from the top surface 410 to the bottom surface 420.
[0046] For example, the width of the bare battery cell 400 gradually and continuously decreases or gradually and stepwise decreases from the top surface 410 to the bottom surface 420.
[0047] For example, the bare battery cell 400 includes two side surfaces 430 oppositely arranged along the first direction. When the width of the bare battery cell 400 gradually and continuously decreases from the top surface 410 to the bottom surface 420, the side surfaces 430 are inclined surfaces. When the width of the bare battery cell 400 gradually and stepwise decreases from the top surface 410 to the bottom surface 420, the side surfaces 430 are stepped surfaces.
[0048] In combination with the foregoing, the area that can be soaked by the electrolyte gradually decreases as the electrolyte flows from the top surface 410 to the bottom surface 420 of the bare battery cell 400. In this embodiment, the width of the bare battery cell 400 is designed to gradually decrease from the top surface 410 to the bottom surface 420. On the one hand, the bare battery cell 400 can be fully soaked by the electrolyte from the top surface 410 to the bottom surface 420. On the other hand, the positive plate and the negative plate of the bare battery cell 400 have a large plate area, which helps to improve the electrical performance of the battery cell 1000.
[0049] For example, the width of the bare battery cell 400 gradually and continuously decreases or gradually and stepwise decreases from the top surface 410 to the bottom surface 420. Figure 2 In some embodiments, the projection of the bare battery cell 400 along the second direction is an isosceles inverted trapezoid.
[0050] The cross-sectional shape of the bare battery cell 400 perpendicular to the second direction is designed to be a regular isosceles inverted trapezoid. On the one hand, the width of the bottom surface 420 of the bare battery cell 400 is smaller than the width of the top surface 410. On the other hand, the cutting of the bare battery cell 400 is facilitated, which helps to reduce the difficulty of preparing the electrode assembly and is suitable for mass production.
[0051] For example, the width of the bare battery cell 400 gradually and continuously decreases or gradually and stepwise decreases from the top surface 410 to the bottom surface 420. Figure 2 In some embodiments, the width of the top surface 410 is a, the width of the bottom surface 420 is b, and a / 4≤b≤a / 3.
[0052] If the width b of the bottom surface 420 is too small, the positive and negative electrode plates of the bare battery cell 400 will have a small area, which will result in poor electrical performance of the battery cell 1000. If the width b of the bottom surface 420 is too large, the electrolyte cannot be infiltrated to the middle region of the bare battery cell 400 along the first direction, which cannot ensure that the bare battery cell 400 is completely infiltrated by the electrolyte.
[0053] Therefore, the width b of the bottom surface 420 is limited to a / 4≤b≤a / 3 in this embodiment, which can ensure that the bare battery cell 400 is completely infiltrated by the electrolyte and improve the electrical performance of the battery cell 1000.
[0054] Based on the same inventive concept and the description of the electrode assembly in the above embodiments, this embodiment provides a battery cell 1000, which has the technical effects of the electrode assembly in the above embodiments, which will not be described herein.
[0055] Figure 3 a perspective view of the battery cell 1000 is shown, Figure 4 a cross-sectional view of the battery cell 1000 is shown, Figure 3 a cross-sectional view of the battery cell 1000 is shown, Figure 3 and Figure 4 The battery cell 1000 provided in this embodiment includes a shell 500 and an electrode assembly as described in the above embodiments. The shell 500 and the cover plate 100 jointly form a containing cavity 510, and the bare battery cell 400 is located in the containing cavity 510. The shape of the containing cavity 510 matches the shape of the bare battery cell 400.
[0056] For example, the shell 500 has a top opening, and the cover plate 100 covers the opening of the shell 500.
[0057] For example, the thickness of the shell 500 is uniform.
[0058] For example, there is a gap between the inner wall of the containing cavity 510 and the bare battery cell 400.
[0059] In this embodiment, the shape of the containing cavity 510 matches the shape of the bare battery cell 400, i.e., the width of the lower part (i.e., the part away from the cover plate 100) of the containing cavity 510 is smaller than the width of the upper part (i.e., the part close to the cover plate 100). Compared with the containing cavity 510 with equal upper and lower widths, when the same amount of electrolyte is injected into the containing cavity 510 (e.g., the same amount of electrolyte is injected), the liquid level of the electrolyte in the containing cavity 510 of this embodiment is higher, and the electrolyte can more easily immerse the top surface 410 of the bare battery cell 400, i.e., the bare battery cell 400 can be completely immersed in the electrolyte, which can ensure that the bare battery cell 400 is completely infiltrated by the electrolyte, further reduce the risk of poor electrolyte infiltration of the battery cell 1000, and improve the electrical performance and safety performance of the battery cell 1000.
[0060] As Figure 4 In some embodiments, the shell 500 further comprises a heat exchange cavity 520 for accommodating a heat exchange medium, the heat exchange cavity 520 is arranged along the first direction at least on one side of the accommodating cavity 510.
[0061] For example, the heat exchange medium can be cooling liquid or air.
[0062] For example, a partition plate is arranged between the accommodating cavity 510 and the heat exchange cavity 520 to separate the two cavities, and heat exchange is performed between the accommodating cavity 510 and the heat exchange cavity 520 at least through the partition plate.
[0063] The temperature of the bare battery cell 400 in the accommodating cavity 510 can be adjusted by the heat exchange medium in the heat exchange cavity 520, which helps to control the temperature of the bare battery cell 400 within a preset temperature range, so that the battery cell 1000 can work more stably.
[0064] As Figure 4 In some embodiments, the side wall of the shell 500 is provided with a liquid inlet hole 540 and a liquid outlet hole 550 communicating with the heat exchange cavity 520.
[0065] For example, the liquid inlet hole 540 and the liquid outlet hole 550 communicating with the same heat exchange cavity 520 can be located on the same side of the heat exchange cavity 520, and the liquid inlet hole 540 is located on the side of the liquid outlet hole 550 away from the cover plate 100.
[0066] For example, a flow channel for the flow of the heat exchange medium can be arranged in the heat exchange cavity 520.
[0067] For example, the liquid inlet hole 540 can be connected with a heat exchange medium supply source through a pipeline, and the liquid outlet hole 550 can be connected with a heat exchange medium recovery source through a pipeline.
[0068] Taking the cooling liquid as an example, the cooling liquid can enter the heat exchange cavity 520 through the liquid inlet hole 540, and the cooling liquid completes heat exchange with the accommodating cavity 510 during the flow in the heat exchange cavity 520, and finally is discharged from the heat exchange cavity 520 through the liquid outlet hole 550.
[0069] The cooling medium in the heat exchange cavity 520 can flow through the liquid inlet hole 540 and the liquid outlet hole 550 to improve the heat exchange effect of the accommodating cavity 510, and the temperature of the bare battery cell 400 can be more reliably controlled within a preset temperature range.
[0070] As Figure 4 In some embodiments, the shell 500 is provided with two heat exchange cavities 520, and the two heat exchange cavities 520 are respectively located on both sides of the accommodating cavity 510 along the first direction; the orthographic projection of the accommodating cavity 510 and the two heat exchange cavities 520 along the second direction is a rectangle.
[0071] Exemplarily, the cross section shape of the containing cavity 510 perpendicular to the second direction is isosceles trapezoidal, and the cross section shape of the heat exchange cavity 520 perpendicular to the second direction is right triangle.
[0072] In combination with the foregoing, the upper portion of the containing cavity 510 has a larger width than the lower portion, and correspondingly, the upper portion of the containing cavity 510 has a larger inner wall surface area than the lower portion. It can be understood that the heat dissipation efficiency of the upper portion of the containing cavity 510 is higher than that of the lower portion. In this embodiment, since the heat exchange cavity 520 can be combined with the containing cavity 510 to form a rectangle, it indicates that the bottom end of the heat exchange cavity 520 has a larger width than the top end. In the bottom end of the heat exchange cavity 520, the flow of the cooling liquid is larger, and the heat exchange efficiency is higher, which can greatly improve the heat dissipation efficiency of the lower portion of the containing cavity 510, so that the temperature between the upper portion and the lower portion of the battery cell 1000 is more uniform.
[0073] Generally, the internal space of the battery pack is a regular cuboid space. If the containing cavity 510 and the two heat exchange cavities 520 can be combined to form a regular rectangle, the whole battery cell 1000 can be constructed as a cuboid that matches the internal space of the battery pack, which helps to improve the utilization rate of the internal space of the battery pack and improve the energy density of the battery pack.
[0074] As shown in FIG. 1, the battery cell 1000 comprises a shell 500, a plurality of battery cells 1000, a plurality of positive electrode posts 200, a plurality of negative electrode posts 300, and a plurality of explosion-proof valves 800. Figure 4 In some embodiments, the bottom surface of the shell 500 away from the cover plate 100 is provided with a mounting through hole 530 in communication with the containing cavity 510, and the explosion-proof valve 800 is connected to the shell 500 through the mounting through hole 530.
[0075] When the battery cell 1000 is in thermal runaway, the explosion-proof valve 800 can be opened and high-temperature substances can be ejected outward to avoid explosion of the battery cell 1000. The electrode posts (including the positive electrode posts 200 and the negative electrode posts 300) are used to electrically connect with the external circuit.
[0076] In this embodiment, the electrode posts are arranged on the cover plate 100 at the top of the shell 500, and the explosion-proof valve 800 is arranged at the bottom of the shell 500, so that the explosion-proof valve 800 and the electrode posts are completely physically isolated, i.e., thermoelectrically separated. In this way, when the battery cell 1000 is in thermal runaway, the high-temperature substances ejected by the explosion-proof valve 800 can be prevented from adversely affecting the external circuit, thereby preventing secondary hazards such as short circuit or insulation failure when the battery cell 1000 is in thermal runaway, which helps to improve the safety performance of the battery cell 1000.
[0077] Based on the same inventive concept and in combination with the description of the battery cell 1000 of each of the above embodiments, the present embodiment provides a battery module, which has the corresponding technical effects of the battery cell 1000 of each of the above embodiments, which will not be described here.
[0078] Figure 5 A perspective view of the battery module is shown as Figure 5 The battery module provided by the embodiment comprises at least two battery cells 1000 as described in the above embodiments, and the at least two battery cells 1000 are stacked along a second direction.
[0079] For example, for one battery cell 1000, one heat exchange cavity 520 is arranged on each side thereof along the first direction, and each heat exchange cavity 520 is correspondingly provided with a liquid inlet hole 540 and a liquid outlet hole 550, and the liquid inlet hole 540 and the liquid outlet hole 550 are located on the side wall of the shell 500 along the first direction.
[0080] The at least two battery cells 1000 are stacked into a battery cell stack along the second direction, and each side of the battery cell stack along the first direction can be provided with one pipe group, each pipe group comprising a liquid inlet pipe 620 and a liquid outlet pipe 610, the liquid inlet pipe 620 being connected to the liquid inlet hole 540 of each battery cell 1000 in the battery cell stack through a plurality of branches, and the liquid outlet pipe 610 being connected to the liquid outlet hole 550 of each battery cell 1000 in the battery cell stack through a plurality of branches. The heat exchange medium can be injected into the heat exchange cavity 520 of each battery cell 1000 through the liquid inlet pipe 620, and the heat exchange medium discharged from the heat exchange cavity 520 can be guided to a preset position through the liquid outlet pipe 610.
[0081] It should be noted that the above describes some embodiments of the present application. Other embodiments are within the scope of the appended claims.
[0082] Each embodiment in the present application is described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between the embodiments can be understood by mutual reference.
[0083] The description of the present application is given for example and description, and is not exhaustive or limits the present application to the disclosed form. Many modifications and changes are obvious to those skilled in the art. The embodiments are selected and described in order to better illustrate the principles and practical application of the present application, and to enable those skilled in the art to understand the present application so as to design various embodiments with various modifications suitable for specific purposes.
[0084] Those skilled in the art should understand that the discussion of any of the above embodiments is only exemplary, and is not intended to suggest that the scope of the present application is limited to these examples; under the idea of the present application, the above embodiments or technical features between different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the embodiments of the present application as described above. In order to be brief, they are not provided in details.
[0085] While the application has been described in connection with specific embodiments thereof, it will be understood that many modifications, substitutions, and changes will be apparent to those of ordinary skill in the art from the foregoing description.
[0086] It is intended to cover all alternatives, modifications, and variations of this application falling within the scope of the application. Accordingly, any and all such alternatives, modifications and variations should be included within the scope of the present application.
Claims
1. An electrode assembly, characterized in that, include: A cover plate has a first plate surface and a second plate surface arranged opposite to each other. The cover plate is connected to a positive electrode post and a negative electrode post protruding from the first plate surface. The positive electrode post and the negative electrode post are spaced apart along a first direction. The cover plate is provided with a through-hole for liquid injection. A bare battery cell is disposed on the side of the cover plate near the second plate surface; the bare battery cell has a top surface near the cover plate and a bottom surface away from the cover plate, the dimension of the bare battery cell along the first direction is defined as the width of the bare battery cell, and the width of the bottom surface is smaller than the width of the top surface.
2. The electrode assembly according to claim 1, characterized in that, The width of the bare battery cell gradually decreases from the top surface to the bottom surface.
3. The electrode assembly according to claim 2, characterized in that, The orthographic projection of the bare cell along the second direction is an isosceles inverted trapezoid, and the second direction is perpendicular to the first direction.
4. The electrode assembly according to claim 1, characterized in that, The width of the top surface is a, and the width of the bottom surface is b, where a / 4 ≤ b ≤ a / 3.
5. A battery cell, characterized in that, The device includes a housing and an electrode assembly as described in any one of claims 1 to 4; the housing and the cover plate together form a receiving cavity, and the bare battery cell is located within the receiving cavity; The shape of the receiving cavity matches the shape of the bare battery cell.
6. The battery cell according to claim 5, characterized in that, The housing further includes a heat exchange cavity for containing a heat exchange medium, the heat exchange cavity being disposed on at least one side of the containing cavity along a first direction.
7. The battery cell according to claim 6, characterized in that, The side wall of the shell is provided with an inlet hole and an outlet hole that connect to the heat exchange chamber.
8. The battery cell according to claim 6, characterized in that, The housing is provided with two heat exchange cavities, which are located on both sides of the receiving cavity along the first direction; the orthographic projection of the receiving cavity and the two heat exchange cavities along the second direction is combined to form a rectangle.
9. The battery cell according to claim 5, characterized in that, The bottom surface of the housing away from the cover plate is provided with a mounting through hole that communicates with the receiving cavity, and the explosion-proof valve is connected to the housing through the mounting through hole.
10. A battery module, characterized in that, It includes at least two battery cells as described in any one of claims 5 to 9, wherein the at least two battery cells are stacked along a second direction.