Battery cell, battery module and power device

Abstract

The utility model relates to the technical field of batteries, and discloses a battery cell, a battery module and a power device. The battery cell comprises a shell, a pole group and a top cover assembly, the shell comprises an inner cavity with an open end; the pole group is arranged in the inner cavity of the shell; the top cover assembly is connected to the open end of the shell, and the pole group is packaged in the shell; the top cover assembly comprises a liquid return capillary piece, at least part of the liquid return capillary piece abuts against the pole group, and the liquid return capillary piece is suitable for sucking the electrolyte and enabling the electrolyte to flow back towards the direction of the pole group. According to the battery cell provided by the utility model, the top cover assembly is provided with the liquid return capillary piece, the liquid return capillary piece can absorb the electrolyte and enable the electrolyte to flow back towards the pole group, and at least part of the liquid return capillary piece is propped against the pole group, so that when the battery cell is inverted, the electrolyte flows to and is accumulated at the top cover assembly under the action of gravity; and the electrolyte can flow back to the pole group upwards through the liquid return capillary piece, so that the pole group is fully infiltrated, and the cycle life of the battery cell is prolonged.

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, including a shell, a pole group and a top cover assembly. The shell includes an inner cavity with an open end; the pole group is arranged in the inner cavity of the shell; the top cover assembly is connected to the open end of the shell to encapsulate the pole group in the shell; the top cover assembly includes a liquid return capillary member, the liquid return capillary member at least partially abuts against the pole group, and the liquid return capillary member 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 top cover assembly provided with a liquid return capillary component, which can absorb electrolyte and make the electrolyte flow back toward the electrode group, and the liquid return capillary structure is at least partially in contact with the electrode group. Therefore, when the battery cell is inverted, the electrolyte will flow to and accumulate at the top cover assembly under the action of gravity, and the electrolyte can flow back upward to the electrode group through the liquid return capillary component, so that the electrode group is fully infiltrated, thereby improving the cycle life of the battery cell.

[0008] In an optional embodiment, the top cover assembly is provided with a mounting groove, and along the thickness direction of the top cover assembly, a first opening is provided on the end face of the mounting groove close to the pole group, the liquid return capillary is arranged in the mounting groove, and at least a portion of the liquid return capillary is in contact with the pole group through the first opening.

[0009] Beneficial effect: By setting the installation groove, the liquid return capillary can be fixed and limited, thus ensuring the assembly stability of the liquid return capillary. Since the first opening is set on the end surface of the installation groove close to the electrode group, the liquid return capillary can abut against the electrode group through the first opening, so that the electrolyte can flow back and infiltrate the electrode group.

[0010] In an optional embodiment, the size of the first opening of the mounting groove is smaller than the size of the inner cavity of the mounting groove, the liquid return capillary is a block structure matching the mounting groove, the liquid return capillary has a protrusion matching the first opening, the liquid return capillary is arranged in the mounting groove, and the protrusion of the liquid return capillary passes through the first opening and abuts against the electrode group.

[0011] Beneficial effect: This arrangement forms a rib between the inner wall of the first opening and the side wall of the mounting groove, which can limit the liquid return capillary component. After the protrusion passes through the first opening, it abuts against the electrode group, ensuring that the liquid return capillary component can absorb the electrolyte and return it to the electrode group, so that the electrode group is fully infiltrated with the electrolyte.

[0012] In an optional embodiment, the height of the protrusion protruding toward the pole group side after passing through the first opening does not exceed 2 mm.

[0013] Beneficial effect: This arrangement ensures that the protrusion is not too large to cause pressure on the electrode group, so that the electrode group is not affected.

[0014] In an optional embodiment, at least two liquid return capillaries are arranged at intervals along the length direction of the top cover assembly.

[0015] Beneficial effect: With such arrangement, along the length direction of the electrode group, it can be ensured that all parts of the electrode group can be fully infiltrated by the electrolyte, so as to improve the cycle life of the battery cell.

[0016] In an optional embodiment, the top cover assembly includes a cover plate and an insulating member connected to each other, the cover plate is connected to the shell, the insulating member abuts against the pole group, the mounting groove is provided on the insulating member, and the bottom of the liquid return capillary member abuts against the cover plate.

[0017] Beneficial effect: This arrangement can ensure that the liquid return capillary member is fixed between the cover plate and the electrode group. Specifically, the insulating member includes a lower plastic.

[0018] In an optional embodiment, the lower plastic includes a raised support portion, the support portion is suitable for abutting and limiting the electrode group, and the mounting groove is provided on the support portion.

[0019] Beneficial effect: The support part of the lower plastic is in contact with the electrode group, which limits the electrode group and prevents the electrode group from moving in the shell, thus ensuring the stability of the battery performance. Since the support part protrudes from the main body of the lower plastic, the installation groove is arranged on the support part of the lower plastic, which can effectively utilize the support part of the lower plastic, so that the liquid return capillary will not increase the space occupied in the height direction of the battery cell.

[0020] In an optional embodiment, a second opening is provided on the end surface of the mounting groove away from the electrode group, the second opening is connected to the first opening, and the size of the second opening is not less than the size of the liquid return capillary.

[0021] Beneficial effect: With this arrangement, the liquid return capillary member can be installed into the mounting groove through the second opening, which facilitates the assembly of the liquid return capillary member.

[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 battery cell described in any one of the above technical solutions, and the top cover assembly 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 pole group, and the liquid return capillary structure is at least partially in contact with the pole group. Therefore, when the battery cell is inverted, the electrolyte will flow to and accumulate at the top cover assembly under the action of gravity, and the electrolyte can be returned upward to the pole group through the liquid return capillary, so that the pole 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: The power device adopted by the utility model has all the beneficial effects of the battery module because it includes the battery module of the above technical solution. 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] Description of reference numerals:

[0034] 10. Battery cell; 1. Shell; 2. Pole group; 3. Top cover assembly; 31. Liquid return capillary; 311. Raised portion; 32. Mounting groove; 33. Cover plate; 34. Insulating member; 341. Support portion; 4. Pole; 5. Explosion-proof valve; 6. Liquid injection hole. DETAILED DESCRIPTION

[0035] 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.

[0036] Combine the following Figures 1 to 6 , describing an embodiment of the utility model.

[0037] According to an embodiment of the utility model, on the one hand, a battery cell 10 is provided, comprising a housing 1, an electrode group 2 and a top cover assembly 3. The housing 1 comprises an inner cavity with an open end; the electrode group 2 is arranged in the inner cavity of the housing 1; the top cover assembly 3 is connected to the open end of the housing 1, and the electrode group 2 is encapsulated in the housing 1; the top cover assembly 3 comprises a liquid return capillary 31, the liquid return capillary 31 at least partially abuts against the electrode group 2, and the liquid return capillary 31 is suitable for absorbing electrolyte and making the electrolyte flow back toward the electrode group 2.

[0038] In the battery cell 10 provided in this embodiment, the top cover assembly 3 is provided with a liquid return capillary member 31, which can absorb electrolyte and make the electrolyte flow back toward the electrode group 2, and the liquid return capillary structure is at least partially in contact with the electrode group 2. Therefore, when the battery cell 10 is inverted, that is, Figure 3The cover plate 33 is placed downwardly as shown, and the electrolyte will flow to and accumulate at the top cover assembly 3 under the action of gravity. The electrolyte can flow back upward to the electrode group 2 through the liquid return capillary 31, so that the electrode group 2 is fully infiltrated, thereby improving the cycle life of the battery cell 10.

[0039] In one embodiment, the top cover assembly 3 is provided with a mounting groove 32, and along the thickness direction of the top cover assembly 3, the end surface of the mounting groove 32 close to the pole group 2 is provided with a first opening, and the liquid return capillary 31 is arranged in the mounting groove 32, and at least a part of the liquid return capillary 31 abuts against the pole group 2 through the first opening.

[0040] By providing the mounting groove 32, the liquid return capillary 31 can be fixed and limited, thus ensuring the assembly stability of the liquid return capillary 31. Since the first opening is provided on the end surface of the mounting groove 32 close to the electrode group 2, the liquid return capillary 31 can abut against the electrode group 2 through the first opening, so that the electrolyte can flow back and infiltrate the electrode group 2.

[0041] In one embodiment, the size of the first opening of the mounting groove 32 is smaller than the size of the inner cavity of the mounting groove 32, the liquid return capillary 31 is a block structure matching the mounting groove 32, the liquid return capillary 31 has a protrusion 311 matching the first opening, the liquid return capillary 31 is arranged in the mounting groove 32, and the protrusion 311 of the liquid return capillary 31 passes through the first opening and abuts against the electrode group 2.

[0042] Since the size of the first opening of the mounting groove 32 is smaller than the size of the inner cavity of the mounting groove 32, a rib is formed between the inner wall of the first opening and the side wall of the mounting groove 32. Accordingly, the structure of the liquid return capillary 31 matches the structure of the mounting groove 32, the main body of the liquid return capillary 31 matches the inner cavity of the mounting groove 32, the raised portion 311 of the liquid return capillary 31 matches the first opening of the mounting groove 32, and the rib at the first opening can limit the liquid return capillary 31. After passing through the first opening, the raised portion 311 abuts against the electrode group 2, ensuring that the liquid return capillary 31 can absorb the electrolyte and return it to the electrode group 2, so that the electrode group 2 is fully infiltrated with the electrolyte.

[0043] In one embodiment, the height of the protrusion 311 protruding toward the pole group 2 after passing through the first opening does not exceed 2 mm.

[0044] Specifically, in Figure 4 or Figure 5 In the figure, the height of the upper surface of the protrusion 311 is no more than 2 mm above the upper surface of the mounting groove 32. The protrusion 311 can contact the electrode group 2 to drive the electrolyte to flow back toward the electrode group 2. The height of the protrusion 311 protruding from the first opening is no more than 2 mm, ensuring that the protrusion 311 is not too large to cause pressure on the electrode group 2, so that the electrode group 2 is not affected.

[0045] In one embodiment, at least two liquid return capillaries 31 are arranged at intervals along the length direction of the top cover assembly 3 .

[0046] Since the assembly space of the top cover assembly 3 in the length direction is large, at least two liquid return capillaries 31 can be arranged at intervals along the length direction of the top cover assembly 3. In this way, along the length direction of the electrode group 2, it can be ensured that all parts of the electrode group 2 can be fully infiltrated with the electrolyte to improve the cycle life of the battery cell 10.

[0047] Specifically, since the top cover assembly 3 is also provided with a pole 4, an explosion-proof valve 5 and a liquid injection hole 6, in order not to affect the normal operation of the above components, the position of the liquid return capillary 31 can avoid the pole 4, the explosion-proof valve 5 and the liquid injection hole 6, and the other positions are not restricted.

[0048] In one embodiment, the top cover assembly 3 includes a cover plate 33 and an insulating member 34 connected to each other, the cover plate 33 is connected to the shell 1, the insulating member 34 abuts against the electrode group 2, the mounting groove 32 is provided on the insulating member 34, and the bottom of the liquid return capillary member 31 abuts against the cover plate 33.

[0049] The mounting groove 32 is arranged on the insulating member 34, so as to ensure that the liquid return capillary member 31 is fixed between the cover plate 33 and the electrode group 2. Specifically, the insulating member 34 includes a lower plastic.

[0050] In one embodiment, the lower plastic includes a protruding support portion 341 . The support portion 341 is suitable for abutting and limiting the electrode group 2 . The mounting groove 32 is disposed on the support portion 341 .

[0051] Since the lower plastic is provided with a support portion 341, the support portion 341 abuts against the electrode group 2, which limits the electrode group 2, prevents the electrode group 2 from moving in the housing 1, and ensures the stability of the battery performance. Since the support portion 341 protrudes from the main body of the lower plastic, the installation groove 32 is provided on the support portion 341 of the lower plastic, which can effectively utilize the lower plastic support portion 341, so that the liquid return capillary 31 does not increase the space occupied by the battery cell 10 in the height direction.

[0052] In one embodiment, the mounting groove 32 is disposed in the middle along the width direction of the lower plastic.

[0053] This arrangement enables the electrode group 2 to be evenly infiltrated with the electrolyte.

[0054] In one embodiment, a second opening is provided on the end surface of the mounting groove 32 away from the electrode group 2 , the second opening is connected to the first opening, and the size of the second opening is not less than the size of the liquid return capillary 31 .

[0055] By providing a second opening at the end surface of the mounting groove 32 away from the pole group 2, Figure 4 or Figure 5The lower surface of the mounting groove 32 is shown in Figure 1 In the battery cell 10 shown, the second opening is located on the upper surface of the mounting groove 32. Since the size of the second opening of the mounting groove 32 is not less than the size of the liquid return capillary 31, the liquid return capillary 31 can be installed in the mounting groove 32 through the second opening, which facilitates the assembly of the liquid return capillary 31. After the liquid return capillary 31 is installed in the mounting groove 32, the cover plate 33 and the housing 1 are laser welded to encapsulate the liquid return capillary 31 in the cavity of the mounting groove 32.

[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 battery cell 10 according to any one of the above embodiments, and the top cover assembly 3 of the battery cell 10 is provided with a liquid return capillary member 31, which can absorb electrolyte and make the electrolyte flow back toward the electrode group 2, and the liquid return capillary structure at least partially abuts against the electrode group 2. Therefore, when the battery cell 10 is inverted, that is, Figure 3 The cover plate 33 is placed downwardly as shown, and the electrolyte will flow to and accumulate at the top cover assembly 3 under the action of gravity. The electrolyte can flow back upward to the electrode group 2 through the liquid return capillary 31, so that the electrode group 2 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 adopted in this embodiment includes the battery module of the above-mentioned embodiment and therefore has all the beneficial effects of the battery module.

[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 pole group, the pole group is arranged in the inner cavity of the shell; A top cover assembly, the top cover assembly is connected to the open end of the shell, and the electrode group is encapsulated in the shell; the top cover assembly includes a liquid return capillary member, the liquid return capillary member at least partially abuts against the electrode group, and the liquid return capillary member is suitable for absorbing electrolyte and causing the electrolyte to flow back toward the electrode group; The top cover assembly is provided with a mounting groove, and along the thickness direction of the top cover assembly, the end surface of the mounting groove close to the electrode group is provided with a first opening, the liquid return capillary member is arranged in the mounting groove, and at least a part of the liquid return capillary member abuts against the electrode group through the first opening; The size of the first opening of the mounting groove is smaller than the size of the inner cavity of the mounting groove. The liquid return capillary is a block structure matching the mounting groove. The liquid return capillary has a protrusion matching the first opening. The liquid return capillary is arranged in the mounting groove. The protrusion of the liquid return capillary passes through the first opening and abuts against the electrode group.

2. The battery cell according to claim 1, characterized in that: The height of the protrusion protruding toward the pole group side after passing through the first opening does not exceed 2 mm.

3. The battery cell according to claim 1 or 2, characterized in that: At least two liquid return capillaries are arranged at intervals along the length direction of the top cover assembly.

4. The battery cell according to claim 1 or 2, characterized in that: The top cover assembly includes a cover plate and an insulating member connected to each other, the cover plate is connected to the shell, the insulating member abuts against the pole group, the mounting groove is provided on the insulating member, and the bottom of the liquid return capillary member abuts against the cover plate.

5. The battery cell according to claim 4, characterized in that: The insulating member includes a lower plastic, the lower plastic includes a raised support portion, the support portion is suitable for abutting and limiting the pole group, and the mounting groove is provided on the support portion.

6. The battery cell according to claim 1 or 2, characterized in that: A second opening is provided on the end surface of the mounting groove away from the electrode group. The second opening is connected to the first opening, and the size of the second opening is not less than the size of the liquid return capillary.

7. A battery module, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 6.

8. A power device, characterized in that: Comprising the battery cell as claimed in claim 7.

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