Battery cell and battery pack

Abstract

The utility model relates to the technical field of power batteries, and discloses a battery cell and a battery pack, the battery cell comprises a shell, one side of which is provided with an opening; the peripheral contour of the cover plate is matched with the shape of the opening of the shell, a pair of pole columns are installed on the cover plate, the pole columns penetrate through the cover plate, and a through groove is formed in the position, between the pole columns, of the cover plate; one end of each connecting sheet is connected with the corresponding pole, and the other end of each connecting sheet extends to the position of the through groove; the pole group is arranged in the shell, one end of the pole group is provided with a pole lug, and the pole lug extends towards the direction of the cover plate and is bent towards the direction of the connecting sheet; the periphery outline of the sealing plate is matched with the through groove, a liquid injection hole is formed in the sealing plate, a plurality of shielding parts are arranged at the position, located at the liquid injection hole, of the lower surface of the sealing plate, and the shielding parts are distributed at intervals in the circumferential direction of the liquid injection hole. And the liquid injection is difficult, so that the production efficiency is influenced.

Description

Technical Field

[0001] The utility model relates to the technical field of power batteries, and in particular to a battery core and a battery pack. Background Art

[0002] Power batteries are the primary source of power for new energy vehicles, providing continuous and stable electrical energy. Power batteries are composed of multiple interconnected battery cells, each consisting of an internal electrode group and a housing. The electrode group is equipped with positive and negative tabs for conducting current, while the housing is equipped with pole posts, which connect to the corresponding tabs via connectors, thus connecting the battery cell to the circuit. After the power battery cell is assembled, the cell is vacuumed through the injection port and then liquid electrolyte is injected into the cell to improve battery performance and battery life.

[0003] In the related art, in order to facilitate the connection between the battery cell and the power supply circuit, the pole and injection hole of some battery cells are arranged on the top of the shell, the pole ear led out from the pole group is arranged on the lower side of the pole, and a connecting plate is provided on the lower side of the pole. Since the pole ear needs to be directly or indirectly connected to the pole, the pole ear needs to be arranged near the pole, the pole ear led out from the pole group is arranged on the lower side of the pole, and a connecting plate is provided on the lower side of the pole. The connecting plate is arranged in a U shape with two parallel connecting parts, and the two connecting parts of the connecting plate are arranged opposite to each other up and down, one of the connecting parts is connected to the bottom end of the pole, and the other is connected to the pole ear, thereby realizing the connection between the pole and the pole group.

[0004] However, in the above-mentioned related technologies, since the position of the pole ear is close to the position of the injection hole, during the process of vacuuming the inside of the battery cell and injecting liquid electrolyte into the battery cell, the pole ear is disturbed by the airflow or liquid electrolyte, and the high-temperature tape used to fix the pole ear easily blocks the injection hole, resulting in difficulty in injection and affecting production efficiency. Utility Model Content

[0005] In view of this, the present invention provides a battery cell and a battery pack to solve the problem that during the liquid injection process, the tabs or high-temperature tapes easily block the liquid injection holes, causing liquid injection difficulties and thus affecting production efficiency.

[0006] In the first aspect, the utility model provides a battery cell, comprising: a shell, one side of which is provided with an opening; a cover plate, the circumferential side contour of which is adapted to the opening shape of the shell, a pair of poles being installed on the cover plate, the poles being arranged to pass through the cover plate, and a through slot being provided on the cover plate between the pair of poles; a pair of connecting plates, one end of each connecting plate being connected to the corresponding pole, and the other end extending to the position of the through slot; a pole group, which is arranged in the shell, one end of the pole group is provided with a pole ear, the pole ear extending toward the cover plate and bending toward the connecting plate, the bent portion of the pole ear abutting against the upper surface of the connecting plate; a sealing plate, the circumferential side contour of which is adapted to the through slot, a liquid injection hole being provided on the sealing plate, and a plurality of shielding portions are provided on the lower surface of the sealing plate at the liquid injection hole, and the plurality of shielding portions are distributed at intervals along the circumference of the liquid injection hole.

[0007] Beneficial effects: The cover plate and the shell are set separately, which makes it easier for accessories such as the pole group to be installed in the shell. A through groove is set on the cover plate, and the pole group is located in the shell, and the pole ear is led out of the pole group from a position opposite to the through groove, which makes it easier for workers to weld the connecting piece and the pole ear. Since one end of the connecting piece is connected to the pole post and the other end extends to a position opposite to the through groove and is connected to the pole ear, the pole post, the connecting piece and the pole ear are staggered in a direction parallel to the cover plate surface, saving space in the height direction of the shell, providing more space for the arrangement of the pole group, thereby improving the performance of the battery cell. In addition, although the pole ear is set near the injection hole, since multiple shielding parts are set on the sealing plate, the shielding parts are located on the lower side of the sealing plate and surround the circumference of the injection hole. During the injection or vacuum operation, even if the high-temperature tape fixing the pole ear is disturbed and displaced from its original position, it is not easy to block the injection hole under the limit of the shielding part, so that it is not easy to affect the assembly and processing process of the battery cell, thereby improving the processing efficiency of the battery cell.

[0008] In an optional embodiment, at least one sinking groove is provided on the lower surface of the sealing plate, and the sinking groove is located in the gap between adjacent shielding parts, and the sinking groove extends to a side of the shielding part away from the liquid injection hole.

[0009] Beneficial effect: The sink is set in the gap between adjacent shielding parts, so that a channel is formed between the shielding parts on the side of the injection hole to ensure the passage of airflow or liquid electrolyte. During the injection process and vacuum process, the efficiency of air extraction or liquid electrolyte injection can be improved, thereby improving the processing efficiency of the battery cell.

[0010] In an optional embodiment, a plurality of the sinks are provided, and the plurality of sinks are evenly spaced and distributed around the circumference of the liquid injection hole, and are respectively located in the gaps between different adjacent shielding portions.

[0011] Beneficial effect: Since there are multiple sinks and the multiple sinks are evenly distributed around the injection hole, when the staff performs the injection or air extraction process, the flow of air or liquid electrolyte passing through the sink is prevented from being excessively concentrated and causing strong disturbance to the structure around the injection hole, especially the disturbance of the tabs and high-temperature glue by air or liquid electrolyte, which causes the high-temperature glue and other structures to be out of place and block the injection hole, affecting the processing of the battery cell.

[0012] In an optional embodiment, a distance L is between an end of the sink away from the liquid injection hole and an edge of the shielding portion away from the liquid injection hole, and L>0.2 mm.

[0013] Beneficial effect: Since the sinking groove is set between each group of adjacent shielding parts, by ensuring the length of the sinking groove, there is sufficient space between the adjacent shielding parts, so that the shielding parts can have sufficient elasticity, and during the assembly process of the battery cell, hard contact between the shielding parts and structures such as the tabs is avoided, which may cause scratches or tears on the tabs and affect the performance of the battery cell.

[0014] In an optional embodiment, the width of the shielding portion along the radial direction of the liquid injection hole is d, and satisfies d≥0.25 mm.

[0015] Beneficial effect: By controlling the value of d, the shielding part has sufficient thickness to cope with the load pressure caused by vacuuming or injecting electrolyte, so that the structural strength of the shielding part is guaranteed and the structural reliability is improved.

[0016] In an optional embodiment, the height of the shielding portion along the axis of the liquid injection hole is h, and satisfies h≥0.25 mm.

[0017] Beneficial effect: By controlling h and ensuring that h ≥ 0.25 mm, the ability of the shielding part to prevent the injection hole from being blocked is further improved, and when the high-temperature tape is attached to the end of the shielding part away from the cover plate, since the shielding part has a sufficient height, the gap between the shielding parts still has enough space for airflow or electrolyte to flow through, ensuring smooth processing and sufficient liquid electrolyte is injected into the battery cell to ensure the infiltration effect of the liquid electrolyte in the battery cell.

[0018] In an optional embodiment, the groove wall of the through groove is inclined from top to bottom toward the axial direction of the through groove, and the inclination angle between the groove wall of the through groove and the cover plate surface ranges from 2° to 88°, the edge of the lower surface of the sealing plate is provided with a chamfer, and the groove wall of the through groove is provided with a guide fillet at the upper opening of the through groove.

[0019] Beneficial effects: By tilting the groove wall of the through groove, it is convenient for the staff to press the sealing plate into the through groove more smoothly, and at the same time, it can also make the edge of the sealing plate more closely abut against the groove wall of the through groove, thereby improving the welding quality of the sealing plate and the cover plate. By controlling the inclination angle of the groove wall of the through groove, it is avoided that the inclination angle is too large to affect the welding of the sealing plate and the cover plate, and at the same time, it is avoided that the inclination angle is too small to affect the pre-positioning of the sealing plate before welding. In addition, by setting a chamfer at the edge of the lower surface of the sealing plate, it is further convenient for the staff to press the sealing plate into the through groove, thereby reducing the possibility of the sealing plate getting stuck during assembly, thereby further improving the assembly efficiency.

[0020] In an optional embodiment, the thickness of the sealing plate is t, the thickness of the cover plate is T, and the thickness of the sealing plate and the thickness of the cover plate satisfy 0.25T≤t≤0.8T.

[0021] Beneficial effect: By controlling the ratio of the thickness of the sealing plate to the thickness of the cover plate, it is possible to avoid the situation where the thickness of the sealing plate is too low compared to the cover plate, resulting in the sealing plate being weak and easy to be damaged, or the sealing plate being unable to be stably positioned on the cover plate, affecting the welding quality. At the same time, it is also possible to avoid the situation where the thickness of the sealing plate is too large compared to the cover plate, resulting in the upper side of the sealing plate or the convex part formed during welding protruding from the upper side of the cover plate after the sealing plate and the cover plate are welded, thereby avoiding the situation where it affects the assembly of the top patch of the battery cell.

[0022] In an optional embodiment, the distance between the upper surface of the sealing plate and the upper surface of the cover plate is a, and satisfies 0.15t≤a≤0.5t.

[0023] Beneficial effect: By controlling the ratio of the distance between the upper side of the sealing plate and the upper side of the cover plate to the thickness of the sealing plate, workers can avoid the situation where the convex part formed at the weld protrudes from the upper side of the cover plate during the welding operation between the cover plate and the sealing plate when the distance is too small, affecting the assembly of the battery cell top patch. At the same time, it can also avoid the situation where the distance is too large, due to the large depth of the sealing plate in the through groove, affecting the laser welding operation and thus affecting the welding quality.

[0024] In a second aspect, the present invention further provides a battery pack comprising: a plurality of the above-mentioned battery cells.

[0025] Beneficial effect: The battery cell group in the battery pack is composed of the above-mentioned battery cells, thereby improving the reliability of the battery pack. By setting a shielding structure, the situation where the tabs and high-temperature glue seal the filling holes is avoided, the processing efficiency is stabilized, and the battery pack production efficiency is indirectly improved. 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 any creative work.

[0027] Figure 1 This is a schematic diagram of the overall structure of a battery cell according to an embodiment of the present utility model;

[0028] Figure 2 This is a schematic diagram of a battery cell according to an embodiment of the present utility model, used to illustrate the structure of the shielding portion on the sealing plate;

[0029] Figure 3 for Figure 2 A partial enlarged schematic diagram;

[0030] Figure 4 This is a cross-sectional schematic diagram of the internal structure of a battery cell according to an embodiment of the present utility model;

[0031] Figure 5 for Figure 4 A partial enlarged schematic diagram of B in the middle;

[0032] Figure 6 for Figure 4 A partial enlarged schematic diagram of center C;

[0033] Figure 7 This is a schematic diagram of an electrode group of a battery cell according to an embodiment of the present invention, showing the structure before welding of the electrode tab and the connecting plate;

[0034] Figure 8 This is a schematic diagram of the electrode group of a battery cell according to an embodiment of the present invention, which is used to reflect the structure after the electrode tab and the connecting plate are welded.

[0035] Description of reference numerals:

[0036] 100, shell; 200, cover plate; 201, pole; 202, through groove; 2021, guide fillet; 300, connecting piece; 400, pole group; 401, pole ear; 500; sealing plate; 501, liquid injection hole; 5011, shielding part; 502, sink groove; 503, chamfer. DETAILED DESCRIPTION

[0037] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0038] The following combination Figures 1 to 8 , describing the embodiments of the present utility model.

[0039] According to an embodiment of the present invention, on the one hand, a battery cell is provided, comprising: a shell 100, having an opening on one side; a cover plate 200, the peripheral profile of which is adapted to the shape of the opening of the shell 100; a pair of poles 201 mounted on the cover plate 200, the poles 201 passing through the cover plate 200, a through slot 202 being provided on the cover plate 200 between the pair of poles 201; a pair of connecting pieces 300, one end of each connecting piece 300 being connected to the corresponding pole 201, and the other end extending to the position of the through slot 202; a pole group 400, arranged in the shell 100, one end of the pole group 400 is provided with a pole ear 401, the pole ear 401 extends toward the cover plate 200 and bends toward the connecting piece 300, and the bent part of the pole ear 401 abuts against the upper surface of the connecting piece 300; the sealing plate 500, the circumferential side contour is adapted to the through groove 202, and a liquid injection hole 501 is provided on the sealing plate 500, and a plurality of shielding portions 5011 are provided on the lower surface of the sealing plate 500 at the liquid injection hole 501, and the plurality of shielding portions 5011 are distributed at intervals along the circumference of the liquid injection hole 501.

[0040] In this embodiment, the cover plate 200 is separately provided with the shell 100, so as to facilitate the installation of accessories such as the pole group 400 into the shell 100. A through groove 202 is provided on the cover plate 200, the pole group 400 is located in the shell 100, and the pole ear 401 is led out of the pole group 400 from a position opposite to the through groove 202, so that the staff can weld the connecting piece 300 and the pole ear 401. Since one end of the connecting piece 300 is connected to the pole post 201 and the other end extends to a position opposite to the through groove 202 and is connected to the pole ear 401, the pole post 201, the connecting piece 300 and the pole ear 401 are staggered in a direction parallel to the plate surface of the cover plate 200, saving space in the height direction of the shell 100, providing more space for the arrangement of the pole group 400, and thus improving the performance of the battery cell. In addition, although the pole tab 401 is arranged near the liquid injection hole 501, since multiple shielding parts 5011 are arranged on the sealing plate 500, the shielding parts 5011 are located on the lower side of the sealing plate 500 and surround the circumference of the liquid injection hole 501. During the liquid injection or vacuum operation, even if the high-temperature tape fixing the pole tab 401 is disturbed and out of place, it is not easy to block the liquid injection hole 501 due to the limitation of the shielding part 501, so it is not easy to affect the assembly and processing process of the battery cell, thereby improving the processing efficiency of the battery cell.

[0041] In the above embodiment, specifically, a pair of poles 201 are provided at both ends of the cover plate 200 in the longitudinal direction, and are respectively connected to the positive and negative electrodes of the electrode group 400, and the through-slot 202 is located between the two poles 201. The connecting piece 300 is provided in a substantially flat sheet shape, and includes a connecting portion for the pole 201 and a connecting portion for the tab 401 that are interconnected. The connecting portion for the pole 201 and the connecting portion for the tab 401 can be integrally provided or separately provided and connected to form a whole by welding or other means. Note that the connecting portion is located at the lower end of the pole 201 and is welded to the pole 201, and the connecting portion for the tab 401 extends to the through-slot 202 adjacent to the pole 201.

[0042] The electrode group 400 includes at least one electrode core, and the electrode tab 401 of the electrode core is led out of the electrode core at a position near the through slot 202 and attached to the connection portion of the electrode tab 401 of the connecting piece 300 by bending and welding, thereby achieving electrical connection with the connecting piece 300. Since the connection portion of the pole post 201 is electrically connected to the pole post 201, the electrical connection between the electrode tab 401 and the pole post 201 is achieved. Exemplarily, the electrode group 400 includes two electrode cores arranged side by side, and the electrode tabs 401 of the two electrode cores are led out from the corresponding electrode cores along opposite sides of the width direction of the electrode group 400 and extend toward the connecting piece 300. After the electrode tab 401 contacts the side wall of the connecting piece 300, it bends upward and then bends horizontally, thereby contacting and welding with the upper side of the electrode sheet.

[0043] In addition, the above embodiment does not limit the specific form and number of the shielding portion 5011. For example, there are four shielding portions 5011, which are evenly distributed around the circumference of the liquid injection hole 501. The shielding portions 5011 can be integrally provided with the sealing plate 500, and can be flanges protruding downward from the sealing plate 500. In some embodiments not shown, the shielding portions 5011 can be protrusions connected to the sealing plate 500 by welding, bonding, or fasteners such as screws.

[0044] In one embodiment, at least one sinking groove 502 is provided on the lower surface of the sealing plate 500 . The sinking groove 502 is located in the gap between adjacent shielding portions 5011 . The sinking groove 502 extends to a side of the shielding portion 5011 away from the liquid injection hole 501 .

[0045] In this embodiment, the sink 502 is arranged in the gap between adjacent shielding parts 5011, thereby forming a channel between the shielding parts 5011 around the injection hole 501 to ensure the passage of airflow or liquid electrolyte. During the injection process and the vacuum process, the efficiency of air extraction or liquid electrolyte injection can be improved, thereby improving the processing efficiency of the battery cell.

[0046] In one embodiment, a plurality of sinks 502 are provided, and the plurality of sinks 502 are evenly spaced and distributed around the circumference of the liquid injection hole 501 , and are respectively located in the gaps between different adjacent shielding portions 5011 .

[0047] In this embodiment, since there are multiple sinking grooves 502 and the multiple sinking grooves 502 are evenly distributed around the injection hole 501, when the staff performs the injection or air extraction process, the flow of air or liquid electrolyte passing through the sinking groove 502 is prevented from being excessively concentrated to cause strong disturbance to the structure around the injection hole 501, especially to prevent the air or liquid electrolyte from disturbing the tab 401 and the high-temperature glue, causing the high-temperature glue and other structures to be out of place and block the injection hole 501, thereby affecting the processing of the battery cell.

[0048] In one embodiment, the distance between the end of the sink 502 away from the liquid injection hole 501 and the edge of the shielding portion 5011 away from the liquid injection hole 501 is L, and L>0.2 mm.

[0049] In this embodiment, since the sinking groove 502 is arranged between each group of adjacent shielding parts 5011, by ensuring the length of the sinking groove 502, there is sufficient space between adjacent shielding parts 5011, so that the shielding parts 5011 can have sufficient elasticity, and during the assembly process of the battery cell, hard contact between the shielding parts 5011 and structures such as the pole ear 401 is avoided, which may cause scratches or tears of the pole ear 401 and affect the performance of the battery cell.

[0050] In one embodiment, the width of the shielding portion 5011 along the radial direction of the liquid injection hole 501 is d, and satisfies d≥0.25 mm.

[0051] In this embodiment, by controlling the value of d, the shielding portion 5011 has a sufficient thickness to cope with the load pressure on the shielding portion 5011 during vacuuming or electrolyte injection operations, thereby ensuring the structural strength of the shielding portion 5011 and improving structural reliability.

[0052] In one embodiment, the height of the shielding portion 5011 along the axis of the liquid injection hole 501 is h, and satisfies h≥0.25 mm.

[0053] In this embodiment, by controlling h and ensuring that h ≥ 0.25 mm, the ability of the shielding portion 5011 to prevent the liquid injection hole 501 from being blocked is further enhanced. Furthermore, when the high-temperature tape is attached to the end of the shielding portion 5011 away from the cover plate 200, the shielding portion 5011 has sufficient height, leaving ample space for airflow or electrolyte to flow through the gap between the shielding portions 5011. This ensures smooth processing and sufficient liquid electrolyte is injected into the battery cell, ensuring effective infiltration of the liquid electrolyte within the cell.

[0054] In one embodiment, the groove wall of the through groove 202 is inclined from top to bottom toward the axial direction of the through groove 202, and the inclination angle between the groove wall of the through groove 202 and the plate surface of the cover plate 200 ranges from 2° to 88°, a chamfer 503 is provided at the edge of the lower surface of the sealing plate 500, and a guide fillet 2021 is provided on the groove wall of the through groove 202 at the upper opening of the through groove 202.

[0055] In this embodiment, by setting the groove wall of the through groove 202 to be inclined, it is convenient for the staff to press the sealing plate 500 into the through groove 202 more smoothly. At the same time, it can also make the edge of the sealing plate 500 more closely abut against the groove wall of the through groove 202, thereby improving the welding quality of the sealing plate 500 and the cover plate 200. By controlling the inclination angle of the groove wall of the through groove 202, it is avoided that the inclination angle is too large to affect the welding of the sealing plate 500 and the cover plate 200, while it is avoided that the inclination angle is too small to affect the pre-positioning of the sealing plate 500 before welding. In addition, by setting a chamfer 503 at the edge of the lower surface of the sealing plate 500, it is further convenient for the staff to press the sealing plate 500 into the through groove 202, thereby reducing the possibility of the sealing plate 500 being stuck during assembly, thereby further improving the assembly efficiency.

[0056] In one embodiment, the thickness of the sealing plate 500 is t, the thickness of the cover plate 200 is T, and the thickness of the sealing plate 500 and the thickness of the cover plate 200 satisfy 0.25T≤t≤0.8T.

[0057] In this embodiment, by controlling the ratio of the thickness of the sealing plate 500 to the thickness of the cover plate 200, it is avoided that the sealing plate 500 is too thin compared with the cover plate 200, resulting in the sealing plate 500 being weak in strength and easy to be damaged, or the sealing plate 500 cannot be stably positioned on the cover plate 200, affecting the welding quality. At the same time, it is also avoided that the sealing plate 500 is too thick compared with the cover plate 200, resulting in the upper side of the sealing plate 500 or the convex part formed during welding protruding from the upper side of the cover plate 200 after the sealing plate 500 and the cover plate 200 are welded, thereby avoiding the situation that affects the assembly of the top chip of the battery cell.

[0058] In one embodiment, the distance between the upper surface of the sealing plate 500 and the upper surface of the cover plate 200 is a, and satisfies 0.15t≤a≤0.5t.

[0059] In this embodiment, by controlling the ratio between the distance between the upper side of the sealing plate 500 and the upper side of the cover plate 200 and the thickness of the sealing plate 500, the staff can avoid the situation where the raised portion formed at the weld protrudes from the upper side of the cover plate 200 during the welding operation of the cover plate 200 and the sealing plate 500 when the distance is too small, thereby affecting the assembly of the top patch of the battery cell. At the same time, it can also avoid the situation where the distance is too large, due to the large depth of the sealing plate 500 in the through groove 202, affecting the laser welding operation and thus affecting the welding quality.

[0060] According to an embodiment of the present invention, on the other hand, a battery pack is provided, comprising: a plurality of the above-mentioned battery cells.

[0061] In this embodiment, the battery cell group in the battery pack is composed of the above-mentioned battery cells, thereby improving the reliability of the battery pack, and by providing the shielding portion 5011 structure, the situation where the tab 401 and the high-temperature glue seal the injection hole 501 is avoided, thereby stabilizing the processing efficiency and indirectly improving the battery pack production efficiency.

[0062] Although the embodiments of the present invention have been described with reference to 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 shall fall within the scope defined by the appended claims.

Claims

1. A battery cell, characterized in that: include: a housing having an opening on one side; A cover plate, the circumferential profile of which is adapted to the opening shape of the housing, a pair of poles being mounted on the cover plate, the poles being arranged to pass through the cover plate, and a through slot being provided on the cover plate between the pair of poles; a pair of connecting pieces, one end of each connecting piece being connected to the corresponding pole and the other end extending to the position of the through slot; An electrode group is disposed in the housing, and a pole ear is provided at one end of the electrode group. The pole ear extends toward the cover plate and bends toward the connecting piece, and the bent portion of the pole ear abuts against the upper surface of the connecting piece. A sealing plate, the circumferential side profile of which is adapted to the through groove, the sealing plate being provided with a liquid injection hole, and a plurality of shielding portions being provided on the lower surface of the sealing plate at the liquid injection hole, the plurality of shielding portions being distributed at intervals along the circumference of the liquid injection hole; At least one sinking groove is provided on the lower surface of the sealing plate, the sinking groove is located in the gap between adjacent shielding parts, and the sinking groove extends to a side of the shielding part away from the liquid injection hole; The groove wall of the through groove is inclined from top to bottom toward the axial direction of the through groove, and the inclination angle between the groove wall of the through groove and the cover plate surface ranges from 2° to 88°. The edge of the lower surface of the sealing plate is chamfered, and the groove wall of the through groove is provided with a guide fillet at the upper opening of the through groove.

2. The battery cell according to claim 1, characterized in that There are a plurality of sinks, and the sinks are evenly spaced and distributed around the circumference of the liquid injection hole, and are respectively located in the gaps between different adjacent shielding parts.

3. The battery cell according to claim 2, characterized in that A distance L is between an end of the sink away from the liquid injection hole and an edge of the shielding portion away from the liquid injection hole, and L>0.2 mm.

4. The battery cell according to any one of claims 1 to 3, characterized in that The width of the shielding portion along the radial direction of the liquid injection hole is d, and satisfies d≥0.25mm.

5. The battery cell according to claim 4, characterized in that: The height of the shielding portion along the axis of the liquid injection hole is h, and satisfies h≥0.25mm.

6. The battery cell according to claim 1, characterized in that The thickness of the sealing plate is t, the thickness of the cover plate is T, and the thickness of the sealing plate and the thickness of the cover plate satisfy 0.25T≤t≤0.8T.

7. The battery cell according to claim 6, characterized in that The distance between the upper surface of the sealing plate and the upper surface of the cover plate is a, and satisfies 0.15t≤a≤0.5t.

8. A battery pack, characterized in that: include: A plurality of battery cells according to any one of claims 1 to 7.

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