Battery cell, battery module and power device
By setting up liquid return capillaries on the large surface of the electrode group of the lithium-ion cell, the problem of the electrode group not being wet when the battery is inverted is solved, and the electrolyte reflux to the electrode group is realized, and the cycle life of the battery is improved.
Patent Information
- Application Number
- CN202420480978.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-12
- Publication Date
- 2025-02-18
- Estimated Expiration
- 2034-03-12
AI Technical Summary
When the lithium-ion battery is inverted, the electrolyte accumulates near the top cover under gravity, resulting in the pole set at the bottom of the battery not being soaked, affecting the cycle life of the battery.
The liquid return capillary is provided on the large surface of the electrode group of the battery cell. The edge of the liquid return capillary protrudes from the edge of the electrode group and is in contact with the cover plate, so that the electrolyte can be absorbed and reflowed to the electrode group.
Through the design of the liquid return capillary, the electrolyte can return upward to the electrode group when the battery cell is inverted, achieving full impregnation of the electrode group and improving the cycle life of the battery cell.
Smart Images
Figure CN222507679U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of batteries, and in particular to a battery cell, a battery module and a power device. Background Art
[0002] As lithium-ion battery technology becomes increasingly mature, lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage fields, and people have increasing requirements for the performance and safety of lithium-ion batteries.
[0003] At present, in order to improve the energy density of the battery pack, the requirement of inverted battery installation is proposed when optimizing the battery layout.
[0004] When the battery is inverted, the electrolyte inside the battery will gather near the top cover of the battery under the action of gravity. Therefore, the pole group far away from the top cover, that is, near the bottom of the shell, cannot be wetted, which affects the cycle life of the battery. Utility Model Content
[0005] In view of this, the utility model provides a battery cell, a battery module and a power device to solve the problem that when the battery cell is inverted, the electrode group at the bottom of the battery cell cannot be wetted along the direction of gravity, thereby affecting the battery cycle life.
[0006] In the first aspect, the utility model provides a battery cell, comprising a shell, a pole group and a cover plate. The shell comprises an inner cavity with an open end; the cover plate is arranged at the open end of the shell; the pole group is encapsulated in the inner cavity of the shell by the cover plate; the pole group comprises two large faces arranged opposite to each other, at least one large face of the pole group is provided with a liquid return capillary, on the pole ear side of the pole group, the edge of the liquid return capillary protrudes from the edge of the pole group, the pole group and the liquid return capillary are in contact with the cover plate, and the liquid return capillary is suitable for absorbing electrolyte and returning the electrolyte toward the pole group.
[0007] Beneficial effects: The battery cell provided by the utility model has a liquid return capillary on the large surface of the electrode group, which can absorb the electrolyte and make the electrolyte flow back toward the electrode group. Therefore, when the battery cell is inverted, the electrolyte will flow to and accumulate at the cover plate under the action of gravity. The electrolyte can flow back upward to the electrode group through the liquid return capillary, so that the electrode group is fully infiltrated, thereby improving the cycle life of the battery cell.
[0008] In an optional embodiment, the liquid return capillary element is a sheet-like structure, and the liquid return capillary element is in contact with a large surface of the electrode group.
[0009] Beneficial effects: With this arrangement, the liquid return capillary has a simple structure and a light weight. The sheet structure is conducive to the infiltration and reflux of the electrolyte, and when the liquid return capillary is a sheet structure, it occupies a small space and has a large contact area with the electrode group, which can improve the electrode group wetting effect.
[0010] In an optional embodiment, the thickness of the liquid return capillary element is not greater than 0.3 mm.
[0011] Beneficial effect: This arrangement can control the space occupied by the liquid return capillary component and ensure that the liquid return capillary component does not affect the energy density of the battery.
[0012] In an optional embodiment, the length of the liquid return capillary element is not less than 20 mm, and the width of the liquid return capillary element is not less than 20 mm.
[0013] Beneficial effect: This arrangement can ensure the contact area between the liquid return capillary and the electrode group, ensure the return amount of the electrolyte, and then ensure that the electrode group is fully infiltrated with the electrolyte, thereby improving the cycle life of the battery cell.
[0014] In an optional embodiment, the electrode group is coated with an insulating film, and the liquid return capillary is arranged between the electrode group and the insulating film.
[0015] Beneficial effects: The insulating film coated on the outside of the electrode group can play an insulating role, and the liquid return capillary component is arranged between the electrode group and the insulating film, which can play a fixing role for the liquid return capillary component.
[0016] In an alternative embodiment, the liquid return capillary element comprises a flannel patch.
[0017] Beneficial effect: the liquid return capillary piece adopts a flannel patch, which has good electrolyte absorption and reflux effects, and the flannel patch has a low cost, which can effectively control the production cost of the battery cell.
[0018] In an optional embodiment, the flannel patch is adhered to the inner side of the insulating film facing the pole group.
[0019] Beneficial effect: With such arrangement, the liquid return capillary can be fixed on the surface of the electrode group, and the liquid return capillary can fully contact and absorb the electrolyte accumulated on the cover plate.
[0020] In an optional embodiment, the liquid return capillary avoids the pole, and / or the explosion-proof valve, and / or the liquid injection hole on the cover plate.
[0021] Beneficial effect: This arrangement ensures that the normal operation of the components on the cover plate is not hindered.
[0022] In a second aspect, the utility model also provides a battery module, comprising a battery cell according to any one of the above technical solutions.
[0023] Beneficial effect: The battery module provided by the utility model includes the above-mentioned battery cell. Therefore, since the large surface of the electrode group of the battery cell is provided with a liquid return capillary, the liquid return capillary can absorb the electrolyte and make the electrolyte flow back toward the electrode group. Therefore, when the battery cell is inverted, the electrolyte will flow to and accumulate at the cover plate under the action of gravity. The electrolyte can flow back upward to the electrode group through the liquid return capillary, so that the electrode group is fully infiltrated, thereby improving the cycle life of the battery cell.
[0024] In a third aspect, the utility model also provides a power device, comprising the battery cell in the above technical solution.
[0025] Beneficial effects: Since the power device provided in this embodiment includes the above-mentioned battery module, it has the same beneficial effects as the battery module, which will not be described again here. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0027] Figure 1 This is a front view of an inverted battery cell according to an embodiment of the utility model;
[0028] Figure 2 It is a plan view of the insulating film when it is unfolded;
[0029] Figure 3 for Figure 2 A perspective view of the insulating film and the pole group when wrapped from the main viewing angle;
[0030] Figure 4 for Figure 2 The side view of the insulating film and the electrode group is shown.
[0031] Description of reference numerals:
[0032] 10. Battery cell; 1. Shell; 2. Cover plate; 3. Pole group; 31. Large surface; 4. Liquid return capillary; 5. Insulating film; 51. Hot melt zone; 6. Pole; 7. Explosion-proof valve; 8. Tape. DETAILED DESCRIPTION
[0033] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.
[0034] Combine the following Figures 1 to 4 , describing an embodiment of the utility model.
[0035] According to an embodiment of the utility model, on the one hand, a battery cell 10 is provided, comprising a housing 1, a pole group 3 and a cover plate 2. The housing 1 comprises an inner cavity with an open end; the cover plate 2 is arranged at the open end of the housing 1; the pole group 3 is encapsulated in the inner cavity of the housing 1 by the cover plate 2; the pole group 3 comprises two large surfaces 31 arranged opposite to each other, at least one large surface 31 of the pole group 3 is provided with a liquid return capillary 4, on the pole ear side of the pole group 3, the edge of the liquid return capillary 4 protrudes from the edge of the pole group 3, the pole group 3 and the liquid return capillary 4 are in contact with the cover plate 2, and the liquid return capillary 4 is suitable for absorbing electrolyte and making the electrolyte flow back toward the pole group 3.
[0036] In the battery cell 10 provided in this embodiment, since the large surface 31 of the electrode group 3 is provided with a liquid return capillary 4, the liquid return capillary 4 can absorb the electrolyte and make the electrolyte flow back toward the electrode group 3. Therefore, when the battery cell 10 is inverted, Figure 1 The cover plate 2 is placed downwardly as shown, and the electrolyte will flow to and accumulate on the cover plate 2 under the action of gravity. The electrolyte can flow back upward to the electrode group 3 through the liquid return capillary 4, so that the electrode group 3 is fully infiltrated, thereby improving the cycle life of the battery cell 10.
[0037] In one embodiment, the liquid return capillary member 4 is a sheet-like structure, and the liquid return capillary member 4 is in contact with the large surface 31 of the electrode group 3 .
[0038] By setting the liquid return capillary member 4 as a sheet structure, such a liquid return capillary member 4 has a simple structure and a light weight. The sheet structure is conducive to the infiltration and reflux of the electrolyte, and when the liquid return capillary member 4 is a sheet structure, it occupies a small space and has a large contact area with the electrode group 3, which can improve the wetting effect of the electrode group 3.
[0039] In one embodiment, the thickness of the liquid-return capillary member 4 is no greater than 0.3 mm.
[0040] By controlling the thickness of the liquid return capillary member 4 to be no greater than 0.3 mm, the space occupied by the liquid return capillary member 4 can be controlled, thereby ensuring that the liquid return capillary member 4 does not affect the energy density of the battery.
[0041] In one embodiment, the length of the liquid-return capillary member 4 is not less than 20 mm, and the width of the liquid-return capillary member 4 is not less than 20 mm.
[0042] Specifically, the size of the liquid return capillary 4 is not less than 20 mm×20 mm, so that the contact area between the liquid return capillary 4 and the electrode group 3 can be ensured, the return amount of the electrolyte can be ensured, and then the electrode group 3 can be fully infiltrated with the electrolyte, thereby improving the cycle life of the battery cell 10.
[0043] In one embodiment, the electrode group 3 is coated with an insulating film 5 , and the liquid return capillary 4 is disposed between the electrode group 3 and the insulating film 5 .
[0044] The insulating film 5 coated on the outside of the electrode group 3 can play an insulating role. Specifically, the insulating film 5 is a Mylar film. The Mylar film includes PP material, and the thickness of Mylar is between 0.1mm and 0.3mm. The liquid return capillary 4 is arranged between the electrode group 3 and the insulating film 5, which can play a role in fixing the liquid return capillary 4.
[0045] Specifically, Figure 2 As shown, the insulating film 5 includes three surfaces, which correspond to the two large surfaces 31 of the electrode group 3 and the bottom surface connecting the two large surfaces 31. Each surface of the insulating film 5 is provided with connecting ears on both sides. When the insulating film 5 and the electrode group 3 are coated, the connecting ears are folded to the adjacent sides and fixedly connected by the tape 8. The portion of the top of the insulating film 5 protruding from the edge of the electrode group 3 is fixedly connected with the plastic on the cover plate 2 by hot melting. The liquid return capillary 4 avoids the hot melting area 51 and is pasted. The electrode group 3 coated with the insulating film 5 is integrally loaded into the shell 1, and then the seam between the cover plate 2 and the shell 1 is laser welded and sealed. When the battery cell 10 is used upside down in the whole package, the flannel patch on the Mylar absorbs the accumulated liquid on the bottom cover plate 2 of the inverted battery cell 10 and flows back to the attached electrode group 3 for absorption, thereby increasing the infiltration of the electrode group 3 and providing the cycle life of the battery cell 10.
[0046] In one embodiment, the liquid return capillary member 4 comprises a flannel patch.
[0047] The liquid return capillary member 4 is a flannel patch, which has good electrolyte absorption and reflux effects, and the flannel patch has a low cost, which can effectively control the production cost of the battery cell 10.
[0048] In one embodiment, the flannel patch is adhered to the inner side of the insulating film 5 facing the electrode group 3 .
[0049] During production, the flannel patch is pasted on the inner side of the insulating film 5, and then the insulating film 5 is covered on the outer surface of the electrode group 3, so that the liquid return capillary 4 can be fixed on the surface of the electrode group 3. Specifically, the flannel patch is pasted on the inner surface of the insulating film 5 by acrylic glue. When pasting, the upper edge of the flannel patch is flush with the upper edge of the insulating film 5. When the insulating film 5 is connected to the electrode group 3, on the side of the pole ear close to the electrode group 3, the edge of the insulating film 5 protrudes from the edge of the electrode group 3. Therefore, the edge of the liquid return capillary 4 protrudes from the edge of the electrode group 3. In this way, the liquid return capillary 4 can fully contact and absorb the electrolyte accumulated on the cover plate 2.
[0050] In one embodiment, the liquid return capillary 4 avoids the pole 6 , and / or the explosion-proof valve 7 , and / or the liquid injection hole on the cover plate 2 .
[0051] This arrangement ensures that the normal operation of the components on the cover plate 2 is not hindered. Since the larger the area of the liquid return capillary 4 is, the more electrolyte is absorbed and the greater the electrolyte return amount is, the width of the liquid return capillary 4 is not limited in case of avoiding the components on the cover plate 2. Similarly, in case of not hindering the components on the cover plate 2, the number of liquid return capillary 4 is not limited, for example, two liquid return capillary 4 are set between a large surface 31 of the electrode group 3 along the length direction of the cover plate 2.
[0052] According to an embodiment of the present utility model, in a second aspect, a battery module is further provided, comprising a battery cell 10 according to any one of the above technical solutions.
[0053] The battery module provided in this embodiment includes the above-mentioned battery cell 10. Therefore, since the large surface 31 of the electrode group 3 of the battery cell 10 is provided with a liquid return capillary member 4, the liquid return capillary member 4 can absorb the electrolyte and make the electrolyte flow back toward the electrode group 3. Therefore, when the battery cell 10 is inverted, Figure 1 The cover plate 2 is placed downwardly as shown, and the electrolyte will flow to and accumulate on the cover plate 2 under the action of gravity. The electrolyte can flow back upward to the electrode group 3 through the liquid return capillary 4, so that the electrode group 3 is fully infiltrated, thereby improving the cycle life of the battery cell 10.
[0054] According to an embodiment of the present utility model, in a third aspect, a power device is also provided, comprising the battery cell 10 in the above technical solution.
[0055] The power device provided in this embodiment includes the above-mentioned battery module and therefore has the same beneficial effects as the battery module, which will not be described in detail here.
[0056] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.
Claims
1. A battery cell, characterized in that: include: a housing including an interior cavity having an open end; A cover plate, the cover plate being arranged at the open end of the shell; The electrode group is encapsulated in the inner cavity of the shell by the cover plate; the electrode group includes two large surfaces arranged opposite to each other, at least one large surface of the electrode group is provided with a liquid return capillary, on the ear side of the electrode group, the edge of the liquid return capillary protrudes from the edge of the electrode group, the electrode group and the liquid return capillary are in contact with the cover plate, and the liquid return capillary is suitable for absorbing electrolyte and making the electrolyte flow back toward the electrode group.
2. The battery cell according to claim 1, characterized in that: The liquid return capillary piece is a sheet-like structure, and the liquid return capillary piece is in contact with a large surface of the electrode group.
3. The battery cell according to claim 2, characterized in that: The thickness of the liquid return capillary member is not greater than 0.3 mm.
4. The battery cell according to claim 2 or 3, characterized in that: The length of the liquid return capillary member is not less than 20 mm, and the width of the liquid return capillary member is not less than 20 mm.
5. The battery cell according to any one of claims 1 to 3, characterized in that: The electrode group is coated with an insulating film, and the liquid return capillary is arranged between the electrode group and the insulating film.
6. The battery cell according to claim 5, characterized in that: The liquid return capillary member comprises a flannel patch.
7. The battery cell according to claim 6, characterized in that: The flannel patch is adhered to the inner side of the insulating film facing the pole group.
8. The battery cell according to claim 4, characterized in that: The liquid return capillary element avoids the pole, and / or the explosion-proof valve, and / or the liquid injection hole on the cover plate.
9. A battery module, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 8.
10. A power device, characterized in that: Comprising the battery cell as claimed in claim 9.