Battery cell and battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a battery cell and a battery pack. The battery cell comprises a shell, the shell comprises an end plate and a side plate surrounding the end plate, a cavity with an opening is defined by the end plate and the side plate, and a welding through hole and a mounting hole are formed in the end plate; the electrode group is arranged in the cavity, one side of the electrode group is provided with a plurality of tab groups corresponding to one welding through hole, and each tab group comprises two tabs; the polar columns are mounted at the mounting holes; the connecting piece is provided with a pole connecting segment and a tab connecting segment, the pole connecting segment is connected with the pole, the tab connecting segment is provided with penetrating holes for the corresponding tab group to penetrate through, each tab penetrates through the corresponding penetrating hole and then is bent to form a bent part, and the bent part is welded with the tab connecting segment through a welding through hole. And only the tabs need to be bent, the connecting sheets do not need to be bent, and the thickness of the connecting sheets and the tabs is reduced after connection, so that the occupied space in the battery cell is reduced, the energy density of the battery cell is improved, and the utilization rate of the space in the battery cell is improved.

Description

Technical Field

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

[0002] With the continuous development of the new energy industry, batteries have been rapidly developed and applied in the fields of power, energy storage, etc. A battery cell is the basic unit of a battery and can be understood as the "heart" of the battery. It is an energy conversion and storage system composed of a positive electrode material, a negative electrode material, an electrolyte, a separator, etc. that can carry out electrochemical reactions. The battery cell itself has the ability to generate and store electrical energy, but usually other components such as a protection circuit and a housing are also needed to form a complete battery product.

[0003] Currently, battery cells can be divided into cylindrical battery cells, square battery cells, and soft-pack battery cells according to their shapes. In square battery cells, the tabs of the battery cell are connected to a transfer piece, and the transfer piece is connected to a terminal. The tabs are located below the transfer piece. When the connecting piece and the electrode plate are connected, bending is required, which results in a relatively thick thickness after the connecting piece and the tab are connected, occupying more internal space of the battery cell, and the utilization rate of the internal space of the battery cell is relatively low. Summary of the Utility Model

[0004] In view of this, the utility model provides a battery cell and a battery pack to solve the problem that when the connecting piece and the electrode plate are connected, bending is required, resulting in a relatively thick thickness after the connecting piece and the tab are connected, occupying more internal space of the battery cell.

[0005] In a first aspect, the utility model provides a battery cell, comprising: a housing, including an end plate and a side plate surrounding the end plate, the end plate and the side plate enclosing a cavity with an opening, and a welding through-hole and a mounting hole are formed on the end plate; a pole group, arranged in the cavity, one side of the pole group has a plurality of tab groups corresponding to a welding through-hole, and each tab group includes two tabs; a terminal, the terminal is installed at the mounting hole; a connecting piece, having a terminal connecting segment and a tab connecting segment, the terminal connecting segment is connected to the terminal, a through-hole for the corresponding tab group to pass through is formed on the tab connecting segment, and each tab forms a bent portion after passing through the corresponding through-hole, and the bent portion is welded to the tab connecting segment through a welding through-hole.

[0006] Beneficial effects: When welding the connecting piece and the tab, first insert the electrode into the cavity of the housing and sequentially pass the tab group through the corresponding through holes and welding through holes. Then, after bending the tab, the bent portion is welded to the tab connecting segment of the connecting piece by welding processes such as laser welding or ultrasonic welding. Only the tab needs to be bent, and there is no need to bend the connecting piece. Compared with the connection method in the prior art where both the connecting piece and the tab need to be bent during connection, the thickness after connection of the connecting piece and the tab becomes thinner, which can reduce the space occupied inside the battery cell, contribute to improving the energy density of the battery cell, and enhance the space utilization rate inside the battery cell. Moreover, the bending process of the connecting piece is reduced, the manufacturing process is simplified, the production efficiency is improved, the production cost is reduced, and the potential damage or deformation risk caused by bending the connecting piece is also reduced. Without bending the connecting piece, material waste can be reduced and costs can be saved. The arrangement of the welding through holes avoids the bending equipment and welding equipment, which not only facilitates bending the tab but also facilitates welding the tab and the connecting piece, improving the welding efficiency and reducing the cost.

[0007] In an optional embodiment, the battery cell further includes a sealing plate, and the sealing plate covers the welding through hole and is used for sealing the welding through hole.

[0008] Beneficial effects: After the connecting piece and the tab are welded, the welding through hole can be effectively sealed by the sealing plate to prevent external moisture and contaminants from entering the battery interior, ensuring the long-term performance and reliability of the battery, and also helping to prevent the leakage of the electrolyte inside the battery and reducing potential safety hazards.

[0009] In an optional embodiment, the battery cell further includes an insulating member, the insulating member is disposed at the welding through hole, and the sealing plate is disposed above the insulating member.

[0010] Beneficial effects: The insulating member is used to isolate the sealing plate from charged components such as the tab to prevent short circuits, and can also support internal components of the battery, such as the tab, to keep its position stable and avoid displacement during transportation or use.

[0011] In an optional embodiment, the sealing plate is provided with a liquid injection hole.

[0012] Beneficial effects: The liquid injection hole is used to inject electrolyte into the battery cell. During the process of injecting the electrolyte, gas may be generated inside the battery cell. The liquid injection hole can serve as an exhaust hole to release the gas and prevent the internal pressure of the battery cell from being too high. After the electrolyte injection is completed, the liquid injection hole is sealed by a sealing plug or the like to ensure the sealing of the internal environment of the battery cell, prevent electrolyte leakage or invasion of external moisture. By directly providing the liquid injection hole on the sealing plate, there is no need to provide a liquid injection hole on the cover plate, which is convenient for welding the connecting piece and the tab and injecting the electrolyte on the same side of the battery cell. Operating on the same side of the housing can reduce the operation complexity.

[0013] In an alternative embodiment, an explosion-proof valve is provided on the sealing plate.

[0014] Beneficial effects: The explosion-proof valve can automatically open when the internal pressure of the battery cell exceeds the safety threshold, release the internal pressure, and prevent the battery cell from exploding; the explosion-proof valve is in a closed state during the normal operation of the battery cell, which can effectively prevent the leakage of the electrolyte, help maintain the sealing of the battery cell, and extend the service life of the battery cell. Setting both the explosion-proof valve and the liquid injection hole on the sealing plate and operating on the same side of the housing can reduce the complexity on the production line and help improve production efficiency; it is convenient for maintenance personnel to maintain and detect when problems occur in the battery cell; setting the liquid injection hole and the explosion-proof valve centrally can reduce the number of openings on the outer shell formed by the housing and the cover plate, thereby reducing potential leakage points and helping to improve the overall sealing of the battery and prevent the leakage of the electrolyte; designing a heat dissipation channel or adding heat dissipation materials on the side where the liquid injection hole and the explosion-proof valve are located can control the battery temperature and further optimize the thermal management inside the battery.

[0015] In an alternative embodiment, the thickness T1 of the pole connection segment is 0.8 mm - 1.5 mm.

[0016] Beneficial effects: Setting the thickness T1 of the pole connection segment within the range of 0.8 mm - 1.5 mm, that is, setting the thickness T1 of the pole connection segment within a reasonable range, can not only ensure the welding reliability between the connection piece and the pole, but also reduce the space occupied inside the battery cell, help improve the energy density of the battery cell, and enhance the space utilization rate inside the battery cell.

[0017] In an alternative embodiment, the thickness T2 of the tab connection segment is greater than or equal to 1.5 mm.

[0018] Beneficial effects: Setting the thickness T2 of the tab connection segment to be greater than or equal to 1.5 mm can ensure the strength of the connection piece itself, which is not easily bent during welding, and ensure that the laser does not penetrate the connection piece when welding the tab, thereby improving the welding reliability.

[0019] In an alternative embodiment, in each tab group, the bending directions of the two tabs are opposite.

[0020] Beneficial effects: When bending the tabs, the bending head of the bending device can occupy the bending space before the tabs are bent, and there is no need to open too large welding through-holes on the end plate for avoidance, which can maximize the utilization rate of the battery width direction and minimize the width of the welding through-holes on the end plate.

[0021] In an alternative embodiment, the number of through-holes is two, and the two through-holes are arranged in one-to-one correspondence with the two tab groups.

[0022] In a second aspect, the present invention also provides a battery pack, including: the above-mentioned battery cell. Brief Description of the Drawings

[0023] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 A perspective view of a battery cell according to an embodiment of the present invention;

[0025] Figure 2 is Figure 1 A top view of the battery cell shown;

[0026] Figure 3 is Figure 2 A sectional view taken along the A-A direction of the battery cell shown;

[0027] Figure 4 is Figure 3 A partially enlarged view of the battery cell shown;

[0028] Figure 5 is Figure 2 A partial sectional view taken along the B-B direction of the battery cell shown;

[0029] Figure 6 is Figure 1 A perspective view of two connecting tabs of the battery cell shown;

[0030] Figure 7 is Figure 6 A sectional view of one of the connecting tabs shown;

[0031] Figure 8 is Figure 1 A perspective view of the electrode tab of the battery cell passing through the connecting tab shown;

[0032] Figure 9 is Figure 8 A perspective view of the electrode group and the connecting tab shown;

[0033] Figure 10 is Figure 8 A perspective view of the electrode tab bent 90° shown;

[0034] Figure 11 is Figure 10 A perspective view of the electrode group and the connecting tab shown.

[0035] Description of the Reference Numerals:

[0036] 1. Housing; 101. End plate; 1011. Welding through-hole; 1012. Liquid injection hole; 1013. Explosion-proof valve; 102. Side plate;

[0037] 2. Cover plate;

[0038] 3. Terminal;

[0039] 4. Electrode group; 401. Tab; 4011. Bent portion;

[0040] 5. Connecting piece; 501. Terminal connection segment; 502. Tab connection segment; 5021. Through-hole;

[0041] 6. Sealing plate;

[0042] 7. Insulating part;

[0043] 8. First plastic part;

[0044] 9. Second plastic part;

[0045] 10. Sealing ring. Detailed implementation manners

[0046] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some but not all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0047] The following Figures 1 to 11 , describes the embodiments of the present utility model.

[0048] According to an embodiment of the present utility model, on the one hand, a battery cell is provided, including: a housing 1, an electrode group 4, a terminal 3 and a connecting piece 5. The housing 1 includes an end plate 101 and a side plate 102 surrounding the end plate 101. The end plate 101 and the side plate 102 enclose a cavity with an opening. A welding through-hole 1011 and a mounting hole are formed in the end plate 101. The electrode group 4 is disposed in the cavity. One side of the electrode group 4 has a plurality of tab groups corresponding to a welding through-hole 1011. Each tab group includes two tabs 401. The terminal 3 is mounted at the mounting hole. The connecting piece 5 has a terminal connection segment 501 and a tab connection segment 502. The terminal connection segment 501 is connected to the terminal 3. A through-hole 5021 for the corresponding tab group to pass through is provided on the tab connection segment 502. After each tab 401 passes through the corresponding through-hole 5021, it is bent to form a bent portion 4011. The bent portion 4011 and the tab connection segment 502 are welded through a welding through-hole 1011.

[0049] When applying the battery cell of this embodiment to weld the connecting piece 5 and the tab 401, first place the electrode assembly 4 into the cavity of the housing 1 and pass the tab group through the corresponding through holes 5021 and welding through holes 1011 in sequence. Then, after bending the tab 401, weld the bent portion 4011 to the tab connecting segment 502 of the connecting piece 5 by welding processes such as laser welding or ultrasonic welding. Only the tab 401 needs to be bent, without bending the connecting piece 5. Compared with the connection method in the prior art where both the connecting piece and the tab need to be bent during connection, the thickness after the connection of the connecting piece 5 and the tab 401 becomes thinner, which can reduce the space occupied inside the battery cell, contribute to improving the energy density of the battery cell, and enhance the space utilization rate inside the battery cell. Moreover, the bending process of the connecting piece 5 is reduced, simplifying the manufacturing process, improving production efficiency, reducing production costs, and also reducing the potential damage or deformation risk caused by the bending of the connecting piece 5. Without bending the connecting piece 5, material waste can be reduced and costs can be saved. The setting of the welding through hole 1011 avoids the bending equipment and welding equipment, which not only facilitates bending the tab 401 but also facilitates welding the tab 401 and the connecting piece 5, improving welding efficiency and reducing costs.

[0050] Furthermore, the end plate 101 and the side plate 102 are integrally formed without the need for welding connection, so that the structure strength of the housing 1 is high, which can better resist external impacts and pressures, reduce the risk of the battery cell malfunctioning when suffering an accidental impact, and thus ensure the safety and reliability of the battery cell.

[0051] In one embodiment, as Figures 1 to 4 shown, the battery cell further includes a sealing plate 6, which covers the welding through hole 1011 and is used to seal the welding through hole 1011. After the connecting piece 5 and the tab 401 are welded, the welding through hole 1011 can be effectively sealed by the sealing plate 6, preventing external moisture and contaminants from entering the battery interior, ensuring the long-term performance and reliability of the battery, and also helping to prevent the leakage of the electrolyte inside the battery and reducing potential safety hazards.

[0052] Furthermore, the sealing plate 6 generally uses materials with high heat resistance, good chemical stability, and excellent sealing performance. These materials need to be able to withstand the high-temperature and high-pressure environment during battery operation and be compatible with the material of the housing 1 to ensure long-term sealing effectiveness. The material of the sealing plate 6 can be metal materials such as stainless steel, aluminum, or aluminum alloy. It can be understood that the material of the sealing plate 6 can also be composite materials that combine metal and plastic, etc.

[0053] In one embodiment, as Figure 4As shown, the battery cell further includes an insulating member 7, which is disposed at the welding through-hole 1011, and the sealing plate 6 is disposed above the insulating member 7. The insulating member 7 is used to isolate the sealing plate 6 from the charged components such as the ear 401 to prevent short circuits, and can also support the internal components of the battery, such as the ear 401, to keep its position stable and avoid displacement during transportation or use.

[0054] Furthermore, the material of the insulating member 7 is plastic. Plastic has the advantages of electrical insulation, light weight, corrosion resistance, high structural strength, easy processing, strong plasticity, good thermal stability, etc.

[0055] In one embodiment, as Figure 1 and Figure 2 shown, the sealing plate 6 is provided with a liquid injection hole 1012. The liquid injection hole 1012 is used to inject electrolyte into the battery cell. During the process of injecting the electrolyte, gas may be generated inside the battery cell. The liquid injection hole 1012 can be used as a vent hole to release the gas and prevent the internal pressure of the battery cell from being too high; after the electrolyte injection is completed, the liquid injection hole 1012 is sealed by a sealing plug or the like to ensure the tightness of the internal environment of the battery cell and prevent electrolyte leakage or external moisture intrusion. Setting the liquid injection hole 1012 directly on the sealing plate 6 eliminates the need to provide the liquid injection hole 1012 on the cover plate 2, which facilitates the welding of the connection piece 5 and the ear 401 and the electrolyte injection on the same side of the battery cell. Operating on the same side of the housing 1 can reduce the operation complexity.

[0056] In one embodiment, as Figure 1 and Figure 2 shown, the sealing plate 6 is provided with an explosion-proof valve 1013. The explosion-proof valve 1013 can automatically open when the internal pressure of the battery cell exceeds the safety threshold to release the internal pressure and prevent the battery cell from exploding; the explosion-proof valve 1013 is in a closed state during the normal operation of the battery cell, which can effectively prevent electrolyte leakage, help maintain the tightness of the battery cell, and extend the service life of the battery cell. Setting both the explosion-proof valve 1013 and the liquid injection hole 1012 on the sealing plate 6 and operating on the same side of the housing 1 can reduce the complexity on the production line and help improve production efficiency; it is convenient for maintenance personnel to maintain and detect when problems occur in the battery cell; concentrating the liquid injection hole 1012 and the explosion-proof valve 1013 can reduce the number of openings on the outer shell formed by the housing and the cover plate, thereby reducing potential leakage points and helping to improve the overall tightness of the battery and prevent electrolyte leakage; designing a heat dissipation channel or adding heat dissipation materials on the side where the liquid injection hole 1012 and the explosion-proof valve 1013 are located can control the battery temperature and further optimize the thermal management inside the battery.

[0057] In one embodiment, as Figure 7 shown, the thickness T1 of the pole connection segment 501 is 0.8 mm - 1.5 mm. The thickness of the pole connection segment 501 is also Figure 7The vertical dimension of the middle pole connection segment 501. The thickness of the pole connection segment 501 should neither be too large nor too small. If the thickness of the pole connection segment 501 is too small, it indicates that the welding strength between the connection piece 5 and the pole 3 is weak, and thus the welding reliability between the connection piece 5 and the pole 3 cannot be ensured. If the thickness of the pole connection segment 501 is too large, it means that the thickness of the connection piece 5 is relatively thick, occupying a relatively large space inside the battery cell, and the utilization rate of the space inside the battery cell is low. Therefore, setting the thickness T1 of the pole connection segment 501 within the range of 0.8 mm - 1.5 mm, that is, setting the thickness T1 of the pole connection segment 501 within a reasonable range, can not only ensure the welding reliability between the connection piece 5 and the pole 3, but also reduce the space occupied inside the battery cell, which helps to improve the energy density of the battery cell and enhance the utilization rate of the space inside the battery cell.

[0058] In one embodiment, as Figure 7 shown, the thickness T2 of the tab connection segment 502 is greater than or equal to 1.5 mm. The thickness T2 of the tab connection segment 502 is also Figure 7 the vertical dimension of the middle tab connection segment 502. Setting the thickness T2 of the tab connection segment 502 to be greater than or equal to 1.5 mm can ensure the strength of the connection piece 5 itself, making it not easy to bend during welding, and ensuring that the laser does not penetrate the connection piece 5 when welding the tab 401, thereby improving the welding reliability.

[0059] In one embodiment, in each tab group, the bending directions of the two tabs 401 are opposite. When bending the tab 401, the bending head of the bending device can occupy the bending space before the tab 401 is bent, and there is no need to open a too large welding through-hole 1011 on the end plate 101 for avoidance, which can maximize the utilization rate in the width direction of the battery, and minimize the width of the welding through-hole 1011 of the end plate 101.

[0060] In one embodiment, the number of through-holes 5021 is two, and the two through-holes 5021 are arranged in one-to-one correspondence with the two tab groups. At this time, the pole group 4 has four tab groups, and four tabs 401 are welded on one connection piece 5.

[0061] It can be understood that in another embodiment, the number of through-holes 5021 is one, and one through-hole is arranged in one-to-one correspondence with one tab group. At this time, the pole group has 2 tab groups, and two tabs 401 are welded on one connection piece 5.

[0062] In one embodiment, the battery cell further includes a cover plate 2, two first plastic parts 8, a second plastic part 9, and two sealing rings 10. The cover plate 2 covers the opening. The number of the pole columns 3 and the connecting pieces 5 is two. Each pole column 3 is installed at the installation hole through a first plastic part 8 and a sealing ring 10. The second plastic part 9 is arranged on the inner surface of the end plate 101. The first plastic part 8 is sleeved outside the corresponding pole column 3 and assembled at the corresponding installation hole. The first plastic part 8 can completely isolate the pole column 3 and the housing 1, prevent a short circuit between the pole column 3 and the housing 1, and ensure the electrical isolation between the pole column 3 and the housing 1. The second plastic part 9 is located inside the end plate 101 and is used to isolate the end plate 101 from the charged components such as the electrode group 4 inside the battery, preventing a short circuit; it can also support the internal components of the battery, such as the tab 401, keep its position stable, and avoid displacement during transportation or use. The sealing ring 10 is sleeved outside the pole column 3 and is in sealing cooperation with the end plate 101 and the pole column connecting segment 501, and is used to ensure the sealing performance of the battery, prevent the leakage of the electrolyte, and at the same time prevent external moisture and impurities from entering the inside of the battery cell.

[0063] Further, the two pole columns 3 are respectively a positive pole column and a negative pole column, the two connecting pieces 5 are respectively a positive pole connecting piece and a negative pole connecting piece. The positive pole connecting piece is welded to the positive pole column, and the negative pole connecting piece is welded to the negative pole column. The materials of the positive pole column and the negative pole column are metals. Generally, the material of the negative pole column is copper, aluminum, etc., and the material of the positive pole column is aluminum, etc.

[0064] It should be noted that before welding the connecting piece 5 and the tab 401, the pole column 3, the first plastic part 8, the second plastic part 9, and the sealing ring 10 have been assembled on the end plate 101, and the pole column connecting segment 501 of the connecting piece 5 has been fixed on the pole column 3.

[0065] According to an embodiment of the present invention, on the other hand, a battery pack is further provided, including: the above-mentioned battery cell.

[0066] In the related art, two downward bending parts are formed by bending the two sides of the connecting piece. A pair of tabs pass through between the two downward bending parts and are bent on the corresponding downward bending parts. When the connecting piece and the tab are welded, bending is required, which results in a relatively thick thickness after the connecting piece and the tab are connected, occupying more internal space of the battery, and the process is also complex.

[0067] In this embodiment, the first plastic part 8, the second plastic part 9, the positive electrode post, the negative electrode post, the sealing ring 10, the connecting piece 5, etc. are arranged on the end plate 101 of the housing 1. A welding through hole 1011 for welding the connecting piece 5 and the tab 401 is arranged on the end plate 101. The vertical tabs 401 of the electrode group 4 are first assembled above the connecting piece 5, and then bent by 90°. Then, welding processes such as laser welding or ultrasonic welding are used to weld the connecting piece 5 and the tab 401 through the welding through hole 1011, reducing the bending process of the connecting piece 5, improving the space utilization rate inside the battery, and enhancing the production efficiency.

[0068] Specifically, the connecting piece 5 is divided into a pole post connecting segment 501 and a tab connecting segment 502. The pole post connecting segment 501 is welded to the pole post 3. Two through holes 5021 are formed in the tab connecting segment 502. The two through holes 5021 respectively allow the two tab groups to pass through and be bent by 90°. The bent tabs 401 are welded to the tab connecting segment 502. The bending directions of the two tabs 401 of each tab group are opposite, that is, the two tabs 401 of each tab group are bent towards each other, which can maximize the utilization rate in the width direction of the battery, minimize the width of the welding through hole on the end plate, and ensure the strength of the housing 1.

[0069] Furthermore, the welding through hole 1011 is a stepped hole. The stepped surface of the welding through hole 1011 facilitates the fixing of the insulating part 7 and the sealing plate 6. The upper surface of the tab connecting segment 502 is higher than the upper surface of the pole post connecting segment 501, that is, the connecting piece 5 has a stepped structure. Since the surface of the tab 401 on the side close to the electrode plate of the electrode group 4 is convex, the stepped structure can adapt to the structure of the tab 401 on the side close to the electrode plate.

[0070] It should be noted that the upper surface of the pole post connecting segment 501 forms a welding area (such as Figure 6 the grid-like area shown), and the upper surface of the bent portion 4011 forms a welding area (such as Figure 10 the grid-like area shown).

[0071] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery cell, characterized in that, Comprising: A housing, including an end plate and a side plate surrounding the end plate, the end plate and the side plate enclosing a cavity with an opening, and a welding through-hole and a mounting hole being provided on the end plate; An electrode group, disposed in the cavity, one side of the electrode group having a plurality of tab groups corresponding to one of the welding through-holes, each tab group including two tabs; A terminal post, the terminal post being installed at the mounting hole; A connecting piece, having a terminal post connecting segment and a tab connecting segment, the terminal post connecting segment being connected to the terminal post, the tab connecting segment being provided with a through-hole for the corresponding tab group to pass through, each tab being bent to form a bent portion after passing through the corresponding through-hole, and the bent portion being welded to the tab connecting segment through one of the welding through-holes.

2. The battery cell according to claim 1, characterized in that, The battery cell further includes a sealing plate, the sealing plate covering the welding through-hole and being used for sealing the welding through-hole.

3. The battery cell according to claim 2, characterized in that, The battery cell further includes an insulating member, the insulating member being disposed at the welding through-hole, and the sealing plate being disposed above the insulating member.

4. The battery cell according to claim 2, characterized in that, A liquid injection hole is provided on the sealing plate.

5. The cell according to claim 2, characterized in that, An explosion-proof valve is provided on the sealing plate.

6. The battery cell according to any one of claims 1 to 5, characterized in that, The thickness T1 of the terminal post connecting segment is 0.8 mm - 1.5 mm.

7. The battery cell according to any one of claims 1 to 5, characterized in that The thickness T2 of the tab connecting segment is greater than or equal to 1.5 mm.

8. The battery cell according to any one of claims 1 to 5, characterized in that, In each tab group, the bending directions of the two tabs are opposite.

9. The battery cell according to any one of claims 1 to 5, characterized in that, The number of the through-holes is two, and the two through-holes are arranged in one-to-one correspondence with the two tab groups.

10. A battery pack, characterized in that, Comprising: The battery cell according to any one of claims 1 to 9.

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