Battery cell, battery module and power device
By setting back liquid capillaries near the end surface of the pole group of the battery cell, the problem of the pole group not being wet when the battery cell is inverted is solved, the effective reflow of the electrolyte is achieved, and the cycle life of the battery cell is improved.
Patent Information
- Application Number
- CN202420487481.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-12
- Publication Date
- 2025-03-14
- Estimated Expiration
- 2034-03-12
AI Technical Summary
When the battery cell is inverted, the electrolyte accumulates near the top cover of the battery under gravity, resulting in the pole group at the bottom of the battery cell not being soaked, affecting the cycle life of the battery.
The liquid return capillary is arranged on the end surface of the electrode group of the battery cell. The liquid return capillary can absorb the electrolyte and reflow the electrolyte towards the electrode group, so that the electrolyte is flowed to the cover plate by gravity when the battery cell is inverted, and the electrolyte is returned upward to the electrode group through the liquid return capillary.
Through the design of the return capillary parts, the electrolyte can effectively return to the electrode group when the battery cell is inverted, solving the problem of the electrode group not being infiltrated and improving the cycle life of the battery cell.
Smart Images
Figure CN222619812U_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 a first aspect, the utility model provides a battery cell, comprising a shell, a cover plate and an electrode group. The shell comprises an inner cavity with an open end; the cover plate is arranged at the open end of the shell; the electrode group is encapsulated in the inner cavity of the shell by the cover plate; a liquid return capillary is arranged on the end surface of the electrode group close to the cover plate, and the liquid return capillary is suitable for absorbing electrolyte and returning the electrolyte to the electrode group.
[0007] Beneficial effects: The battery cell provided by the utility model has a liquid return capillary provided on the end surface of the electrode group close to the cover plate. 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.
[0008] In an optional embodiment, the electrode group includes a stacked positive electrode sheet, a negative electrode sheet, and a diaphragm disposed between the positive electrode sheet and the negative electrode sheet, the liquid return capillary piece is a sheet structure, and the liquid return capillary piece is connected to the diaphragm.
[0009] Beneficial effects: With this arrangement, the liquid return capillary component has a simple structure and a light weight. The sheet structure is conducive to the infiltration and reflux of the electrolyte. The liquid return capillary component is connected to the diaphragm of the electrode group, and the liquid return capillary component and the electrode group can be fixedly connected to achieve the absorption and reflux of the electrolyte to the electrode group.
[0010] In an optional embodiment, the liquid return capillary element is provided with multiple layers, and the multiple layers of liquid return capillary elements are respectively connected to the diaphragms stacked to form the multiple layers.
[0011] Beneficial effect: This arrangement can increase the reflux rate of the electrolyte.
[0012] In an optional embodiment, the liquid return capillary and the diaphragm are an integrated structure, and the diaphragm is provided with an extension portion facing the cover plate, the extension portion constitutes the liquid return capillary, and the extension portion is in contact with the cover plate.
[0013] Beneficial effect: This arrangement reduces the connection process between the liquid return capillary and the diaphragm, and can reduce the processing steps of the battery cell.
[0014] In an optional embodiment, the diaphragms are stacked to form multiple layers along the thickness direction of the electrode group, and the multiple layers of diaphragms are all provided with extension portions.
[0015] Beneficial effect: This arrangement can increase the number of extension parts, that is, increase the number of liquid return capillaries, thereby increasing the reflux amount of absorbed electrolyte, ensuring that the electrode group fully absorbs the electrolyte, and improving the cycle life of the battery cell.
[0016] In an optional embodiment, the extension portion has a length margin of 3 mm after contacting the cover plate in a straightened state.
[0017] Beneficial effect: This arrangement ensures that when the battery cell is inverted, the extended portion of the diaphragm can fully contact the cover plate as a liquid return capillary, thereby absorbing the electrolyte located at the cover plate and returning the electrolyte to the electrode group, and can also ensure that the length of the extended portion is appropriate, and the amount of diaphragm will not increase due to excessive length, thereby controlling the battery cell cost.
[0018] In an optional embodiment, along the width direction of the pole group, the width of the extension portion is not less than 0.5 mm.
[0019] Beneficial effect: This arrangement can ensure that the extension part absorbs the return amount of electrolyte when serving as a liquid return capillary, ensuring that the electrode group can be fully infiltrated by the electrolyte.
[0020] In an optional embodiment, the extension portion avoids the pole, and / or the explosion-proof valve, and / or the 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: Since the battery module includes the above-mentioned battery cell, a liquid return capillary is provided on the end surface of the electrode group of the battery cell close to the cover plate, and 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 toward the cover plate under the action of gravity, and 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 includes the above-mentioned battery module, it has the same beneficial effects as the battery module, which will not be repeated 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 schematic diagram of the exploded structure of a battery cell according to an embodiment of the utility model;
[0028] Figure 2 for Figure 1 A top view of the battery cell shown;
[0029] Figure 3 For along Figure 2 Sectional view at AA in the middle;
[0030] Figure 4 for Figure 3 A partial enlarged view of the middle liquid return capillary;
[0031] Figure 5 For along Figure 3 Sectional view at the middle BB;
[0032] Figure 6 for Figure 5 A partial enlarged view of the middle cover;
[0033] Figure 7 Schematic diagram of the internal structure of the electrode group.
[0034] Description of reference numerals:
[0035] 10. Battery cell; 1. Shell; 2. Cover plate; 3. Electrode group; 31. Positive electrode sheet; 32. Negative electrode sheet; 33. Diaphragm; 331. Extension part; 34. Ear; 4. Liquid return capillary; 5. Pole; 6. Explosion-proof valve; 7. Liquid injection hole. DETAILED DESCRIPTION
[0036] 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.
[0037] Combine the following Figures 1 to 7 , describing an embodiment of the utility model.
[0038] According to an embodiment of the utility model, in a first aspect, a battery cell 10 is provided, comprising a housing 1, a cover plate 2 and an electrode group 3. 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 electrode group 3 is encapsulated in the inner cavity of the housing 1 by the cover plate 2; a liquid return capillary 4 is arranged on the end surface of the electrode group 3 close to the cover plate 2, and the liquid return capillary 4 is suitable for absorbing electrolyte and making the electrolyte flow back toward the electrode group 3.
[0039] In the battery cell 10 provided in this embodiment, since the end surface of the electrode group 3 close to the cover plate 2 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, that is, Figure 2 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.
[0040] In one embodiment, the electrode group 3 includes a stacked positive electrode sheet 31 , a negative electrode sheet 32 , and a diaphragm 33 disposed between the positive electrode sheet 31 and the negative electrode sheet 32 . The liquid return capillary 4 is a sheet-like structure, and the liquid return capillary 4 is connected to the diaphragm 33 .
[0041] By setting the liquid return capillary 4 as a sheet structure, such a liquid return capillary 4 has a simple structure and a light weight. The sheet structure is conducive to the permeation and reflux of the electrolyte. The liquid return capillary 4 is connected to the diaphragm 33 of the electrode group 3, and the liquid return capillary 4 and the electrode group 3 are fixedly connected, so that the electrolyte is sucked and refluxed to the electrode group 3.
[0042] In one embodiment, the liquid return capillary 4 comprises flannel, and the flannel can be connected to the diaphragm 33 by gluing.
[0043] In one embodiment, the liquid return capillary member 4 is provided with multiple layers, and the multiple layers of liquid return capillary members 4 are respectively connected to the diaphragms 33 stacked to form multiple layers.
[0044] Since the diaphragms 33 of the electrode group 3 are stacked to form multiple layers, the liquid return capillary members 4 are arranged in multiple layers. The multiple layers of liquid return capillary members 4 can be connected to the diaphragms 33 one by one, which can increase the reflux amount of the electrolyte.
[0045] In one embodiment, the liquid return capillary element 4 and the diaphragm 33 are an integral structure. The diaphragm 33 is provided with an extension portion 331 on the side facing the cover plate 2 . The extension portion 331 constitutes the liquid return capillary element 4 , and the extension portion 331 is in contact with the cover plate 2 .
[0046] The liquid return capillary 4 and the diaphragm 33 are an integrated structure, which reduces the connection process of the liquid return capillary 4 and the diaphragm 33, and can reduce the processing steps of the battery cell 10. By setting an extension portion 331 on the side of the diaphragm 33 facing the cover plate 2, that is, setting an extension portion 331 on the side of the pole ear 34, the length of the extension portion 331 can be in contact with the cover plate 2. The extension portion 331 can be used as a liquid return capillary 4 to absorb the electrolyte at the end of the cover plate 2 and make the electrolyte flow back toward the electrode group 3. Since the liquid return capillary 4 is an extension portion 331 integrated with the diaphragm 33, the extension portion 331 can be reserved by cutting the diaphragm 33 to form the liquid return capillary 4.
[0047] In one embodiment, along the thickness direction of the electrode group 3 , the diaphragms 33 are stacked to form multiple layers, and the multiple layers of diaphragms 33 are all provided with an extension portion 331 .
[0048] The diaphragms 33 in the electrode group 3 are stacked to form multiple layers, and each layer of the diaphragms 33 is provided with an extension portion 331, which can increase the number of extension portions 331, that is, increase the number of liquid return capillaries 4, thereby increasing the reflux amount of absorbed electrolyte, ensuring that the electrode group 3 fully absorbs the electrolyte, and improving the cycle life of the battery cell 10.
[0049] exist Figure 1 In the embodiment, the multi-layered extension portions 331 are stacked to form a block-like structure.
[0050] In one embodiment, the extension portion 331 has a length margin of 3 mm after contacting the cover plate 2 in the straightened state.
[0051] The length of the extension portion 331 is controlled to have a 3 mm margin after contacting the cover plate 2. This ensures that when the battery cell 10 is inverted, the extension portion 331 of the diaphragm 33 can fully contact the cover plate 2 as the liquid return capillary 4, thereby absorbing the electrolyte located at the cover plate 2 and returning the electrolyte to the electrode group 3. It also ensures that the length of the extension portion 331 is appropriate, and the amount of the diaphragm 33 will not be increased due to excessive length, thereby controlling the cost of the battery cell 10.
[0052] In one embodiment, along the width direction of the electrode group 3 , the width of the extension portion 331 is not less than 0.5 mm.
[0053] The width of the extension portion 331 is controlled within a range of not less than 0.5 mm. By controlling the lower limit of the width of the extension portion 331, it is possible to ensure that the extension portion 331 absorbs the reflux amount of electrolyte when used as a liquid return capillary 4, thereby ensuring that the electrode group 3 can be fully infiltrated by the electrolyte.
[0054] In one embodiment, the extension portion 331 avoids the pole 5 , and / or the explosion-proof valve 6 , and / or the injection hole 7 on the cover plate 2 .
[0055] 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 extension 331, the more electrolyte is absorbed and the greater the electrolyte return amount, the width of the extension 331 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 extensions 331 is not limited. For example, along the length direction of the cover plate 2, two liquid return capillaries 4 can be arranged between the cover plate 2 and the electrode group 3.
[0056] 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.
[0057] The battery module provided in this embodiment includes the above-mentioned battery cell 10. Therefore, since a liquid return capillary 4 is provided on the end surface of the electrode group 3 of the battery cell 10 close to the cover plate 2, 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, the electrolyte will flow toward the cover plate 2 under the action of gravity, and 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.
[0058] 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.
[0059] 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.
[0060] 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; a liquid return capillary is provided on the end surface of the electrode group close to the cover plate, and the liquid return capillary is suitable for absorbing electrolyte and returning the electrolyte to the electrode group; the electrode group includes a stacked positive electrode sheet, a negative electrode sheet and a diaphragm arranged between the positive electrode sheet and the negative electrode sheet, and the liquid return capillary is a sheet structure, and the liquid return capillary is connected to the diaphragm.
2. The battery cell according to claim 1, characterized in that: The liquid return capillary element is provided with multiple layers, and the multiple layers of the liquid return capillary element are respectively connected to the diaphragms stacked to form multiple layers.
3. The battery cell according to claim 1 or 2, characterized in that: The liquid return capillary element and the diaphragm are an integrated structure. The diaphragm is provided with an extension portion on the side facing the cover plate. The extension portion constitutes the liquid return capillary element and is in contact with the cover plate.
4. The battery cell according to claim 3, characterized in that: The diaphragms are stacked to form multiple layers along the thickness direction of the pole group, and the multiple layers of diaphragms are all provided with the extension portion.
5. The battery cell according to claim 3, characterized in that: When the extension portion is in a straightened state, a length margin of 3 mm is left after contacting the cover plate.
6. The battery cell according to claim 3, characterized in that: Along the width direction of the pole group, the width of the extension portion is not less than 0.5 mm.
7. The battery cell according to claim 3, characterized in that: The extension portion avoids the pole, and / or explosion-proof valve, and / or injection hole on the cover plate.
8. A battery module, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 7.
9. A power device, characterized in that: Comprising the battery cell as claimed in claim 8.