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. Wherein the battery cell comprises a shell, a pole group, a cover plate and a sealing plate, the shell is provided with a containing cavity and an opening communicated with the containing cavity, the pole group is arranged in the containing cavity, one end of the pole group is provided with a negative pole lug and a positive pole lug, two through holes are formed in the cover plate at intervals in the length direction, and a liquid injection hole is formed in the position, between the two through holes, of the cover plate; the two through holes are used for allowing the negative electrode lug and the positive electrode lug to penetrate through respectively, the plastic plate is arranged on the lower surface of the sealing plate body in a hot melting mode, the lower surface of the sealing plate body abuts against the step face, and the side wall of the sealing plate body is welded to the inner walls of the through holes. According to the utility model, the two through holes are formed in the cover plate, and the welding bottom plate and the tab can be welded and connected through the two through holes, so that the space occupied by bending of the tab after welding is avoided, the length of the tab is shortened, the use space of the accommodating cavity in the shell in the length direction is increased, and the utilization rate of the internal space of the battery cell is increased.

Description

Technical Field

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

[0002] With the increasing maturity of battery technology, batteries are widely used in electric vehicles and energy storage fields, and the requirements for the use performance and safety of batteries are increasing day by day. An electric core is the basic component unit of a battery and can independently generate and store electric energy.

[0003] In the prior art, both the connecting piece and the tab need to be bent, and the connecting piece, the terminal post and the tab are usually located on the same vertical plane, so a large space inside the electric core needs to be occupied, resulting in low space utilization rate of the electric core. Summary of the Utility Model

[0004] In view of this, the utility model provides an electric core and a battery pack to solve the problem of low space utilization rate of the electric core.

[0005] In the first aspect, the utility model provides an electric core, comprising:

[0006] A housing, which is provided with a receiving cavity and an opening communicating with the receiving cavity;

[0007] A pole group, which is arranged in the receiving cavity, and a negative tab and a positive tab are arranged at one end of the pole group;

[0008] A cover plate, which is covered at the opening, two through holes are arranged at intervals along the length direction on the cover plate, a liquid injection hole is arranged between the two through holes on the cover plate, the negative tab and the positive tab respectively pass through the two through holes, and a step surface is arranged on the inner wall of each through hole;

[0009] A sealing plate, which is correspondingly covered at the through hole, the sealing plate comprises a sealing plate body and a plastic plate, the plastic plate is hot-melted on the lower surface of the sealing plate body, the lower surface of the sealing plate body abuts against the step surface, and the side wall of the sealing plate body is welded to the inner wall of the through hole.

[0010] Beneficial effects: When assembling this battery cell, first place the electrode group into the accommodating cavity of the housing, and cover the cover plate on the opening of the housing. Since there are two through holes opened on the cover plate, and the positions of the two through holes correspond to the positions of the negative electrode tab and the positive electrode tab on the electrode group respectively, therefore, the negative electrode tab and the positive electrode tab on the electrode group can respectively pass through the through holes on the cover plate. The installer can bend the negative electrode tab and the positive electrode tab through the two through holes, so that the negative electrode tab and the positive electrode tab respectively abut against the negative welding base plate and the positive welding base plate correspondingly. The installer can also weld and fix the negative welding base plate and the negative electrode tab, and the positive welding base plate and the positive electrode tab through the through holes. Finally, cover the sealing plate correspondingly at the through holes and seal the accommodating cavity to complete the assembly of the battery cell.

[0011] By opening two through holes on the cover plate, the welding connection between the welding base plate and the electrode tab can be carried out through the two through holes, thereby avoiding the space occupied by the bending of the electrode tab after welding, shortening the length of the electrode tab, improving the utilization space of the accommodating cavity in the housing in the length direction, and thus improving the internal space utilization rate of the battery cell. Since the inner wall of the through hole is provided with a stepped surface, by abutting the stepped surface against the bottom surface of the sealing plate body and welding the side wall of the sealing plate body and the inner wall of the through hole, the close contact between the sealing plate and the through hole can be ensured, improving the sealing performance and reducing the risk of electrolyte leakage. The welding of the side wall of the sealing plate body and the inner wall of the through hole enhances the connection strength and further improves the sealing effect.

[0012] A liquid injection hole is arranged between the two through holes on the cover plate, so that the liquid injection hole is located in the middle area of the cover plate. Inject electrolyte into the housing through the liquid injection hole in the middle area to facilitate the uniform distribution of the electrolyte in the housing. Since a plastic plate is heat-melted on the bottom surface of the sealing plate body, the plastic plate is used to prevent the negative electrode tab and the positive electrode tab from directly contacting the cover body, avoiding short circuit of the battery cell. At the same time, the plastic plate can improve the sealing performance between the sealing plate and the top wall, ensure the sealing inside the battery cell, and prevent electrolyte leakage.

[0013] In an alternative embodiment, the lower surface of each said plastic plate is set to be a plane, and the area of each said plastic plate is smaller than the area of the sealing plate body.

[0014] Beneficial effects: Since the lower surface of the plastic plate is set to be a plane, there is no need to set structures such as exhaust holes or liquid inlet holes on the plastic plate, which is convenient for the production and manufacture of the plastic plate and reduces the manufacturing cost of the plastic plate. Since the area of the plastic plate is smaller than the area of the sealing plate body, it can ensure that there is a gap between the edge of the plastic plate and the edge of the sealing plate body, so that the lower surface of the sealing plate body abuts against the stepped surface, improving the sealing performance at the connection between the sealing plate and the through hole.

[0015] In an alternative embodiment, it further includes an explosion-proof valve, and the explosion-proof valve is arranged in the middle area of the bottom wall of the housing.

[0016] Beneficial effects: By providing an explosion-proof valve on the bottom wall of the housing, when the pressure inside the housing is too high, the excess gas inside the housing is released by opening the explosion-proof valve, preventing the battery cell from exploding. Additionally, since the explosion-proof valve is provided at the bottom of the housing and the liquid injection hole is provided at the top of the housing, the positions of the explosion-proof valve and the liquid injection hole are oppositely arranged, preventing the residual electrolyte during liquid injection from contaminating the explosion-proof valve.

[0017] In an alternative embodiment, a plurality of mounting grooves are formed on the lower surface of each sealing plate body, and the plurality of mounting grooves are spaced along the length direction of the sealing plate body in the middle region of the sealing plate body. A heat-melting column corresponding to each mounting groove is provided on the upper surface of each plastic plate.

[0018] Beneficial effects: By forming a plurality of mounting grooves on the lower surface of the sealing plate body and providing a plurality of heat-melting columns on the upper surface of the plastic plate, when installing the sealing plate body and the plastic plate, the heat-melting columns are inserted into the mounting grooves to complete the preliminary combination of the plastic plate and the sealing plate body. Subsequently, by heating the upper surface of the sealing plate body, the heat-melting columns are melted in the mounting grooves, and the melted heat-melting columns are fixed in the mounting grooves, ensuring a more secure connection between the sealing plate body and the plastic plate.

[0019] Since there are two through holes on the cover plate and also two sealing plates, the size of the sealing plate is relatively small. Therefore, by linearly arranging a plurality of mounting grooves in the middle region of the sealing plate body, the sealing plate body and the plastic plate can be firmly fixed, reducing the processing quantity of the mounting grooves on the sealing plate body and the heat-melting columns on the plastic plate, and lowering the production cost of the sealing plate body and the plastic plate.

[0020] In an alternative embodiment, the inner wall of each mounting groove is provided with an inclined surface that slopes downward from top to bottom towards the axis of the mounting groove, and the diameter of the heat-melting column is less than or equal to the minimum inner diameter of the mounting groove.

[0021] Beneficial effects: Since the diameter of the heat-melting column is less than the minimum inner diameter of the mounting groove, it is convenient for the heat-melting column to be inserted into the mounting groove. Since the inner wall of the mounting groove is inclined, the mounting groove gradually contracts from top to bottom. During the melting process of the heat-melting column, the heat-melting column in the mounting groove deforms and then fills the mounting groove, making the melted heat-melting column fixed in the mounting groove and ensuring a more secure connection between the sealing plate body and the plastic plate.

[0022] In an alternative embodiment, the minimum inner diameter of the mounting groove is d, the maximum inner diameter of the mounting groove is D, and D - d ≥ 0.3 mm.

[0023] Beneficial effects: By ensuring that the difference between the maximum inner diameter and the minimum inner diameter of the installation groove is at least 0.3 mm, it can ensure that there is enough space for the hot melt column to deform during the melting process, so as to fill the installation groove. At the same time, the larger inner diameter difference helps to ensure that the melted hot melt column is firmly fixed in the installation groove, preventing the hot melt column from detaching from the installation groove, and further ensuring that the sealing plate body and the plastic plate are firmly fixed.

[0024] In an alternative embodiment, the minimum inner diameter of the installation groove is d, and 0.5 mm ≤ d ≤ 6 mm.

[0025] Beneficial effects: By setting the minimum inner diameter of the installation groove within 0.5 mm - 6 mm, thereby limiting the diameter of the hot melt column, and limiting the diameter of the hot melt column to 0.5 mm - 6 mm, it ensures that the hot melt column has a certain strength. At the same time, when heating the upper surface of the sealing plate body, it is convenient for the hot melt column to quickly melt and fill the installation groove, shortening the installation time of the plastic plate and the sealing plate body.

[0026] In an alternative embodiment, the distance from the bottom surface of the installation groove to the upper surface of the sealing plate body is t, and 0.2 mm ≤ t ≤ 1.5 mm.

[0027] Beneficial effects: By setting the distance t from the bottom surface of the installation groove to the upper surface of the sealing plate body within the range of 0.2 mm to 1.5 mm, the relatively thin thickness t helps to improve the heat conduction efficiency. It can ensure that when heating the upper surface of the sealing plate body, heat can be quickly transferred to the installation groove, accelerating the melting speed of the hot melt column, helping to shorten the heating time, and improving the assembly efficiency.

[0028] In an alternative embodiment, the depth of the installation groove is H, and the height of the hot melt column is h, and h - H ≥ 0.25 mm.

[0029] Beneficial effects: The difference between the height h of the hot melt column and the depth H of the installation groove is at least 0.25 mm, that is, the height of the hot melt column is greater than the depth of the installation groove. Since the maximum inner diameter of the installation groove is greater than the diameter of the hot melt column, when the hot melt column is melted by heat, the melted part of the hot melt column can fully fill the internal space of the installation groove, making the hot melt column firmly fixed in the installation groove, and ensuring that the plastic plate and the sealing plate body are firmly fixed.

[0030] In a second aspect, the present utility model further provides a battery pack, including: a plurality of battery cells.

[0031] Beneficial effects: This battery pack includes the battery cells as described above, and has all the beneficial technical effects of the battery cells, which will not be elaborated here. Description of the Drawings

[0032] To more clearly illustrate the specific embodiments of the present utility model 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 utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0033] Figure 1 Structural schematic diagram of a battery cell according to an embodiment of the present utility model;

[0034] Figure 2 is Figure 1 cross-sectional view of;

[0035] Figure 3 Structural schematic diagram of a cover plate in a battery cell according to an embodiment of the present utility model;

[0036] Figure 4 is Figure 3 cross-sectional view of;

[0037] Figure 5 Structural schematic diagram of a sealing plate in a battery cell according to an embodiment of the present utility model;

[0038] Figure 6 is Figure 5 cross-sectional view of;

[0039] Figure 7 is Figure 6 partial enlarged schematic diagram of;

[0040] Figure 8 Structural schematic diagram of a plastic plate in a battery cell according to an embodiment of the present utility model;

[0041] Figure 9 is Figure 8 cross-sectional view of;

[0042] Figure 10 Structural schematic diagram of a battery cell after hiding the sealing plate according to an embodiment of the present utility model;

[0043] Figure 11 Structural schematic diagram of a pole group in a battery cell according to an embodiment of the present utility model.

[0044] Explanation of reference numerals:

[0045] 1. Housing; 2. Pole group; 3. Negative pole tab; 4. Positive pole tab; 5. Cover plate; 501. Through hole; 502. Liquid injection hole; 6. Sealing plate; 601. Sealing plate body; 6011. Installation groove; 602. Plastic plate; 6021. Heat melting column; 7. Explosion-proof valve; 8. Negative pole welding bottom plate; 9. Positive pole welding bottom plate; 10. Lower plastic box. 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] In the related art, both the connecting piece and the tab need to be bent, and the connecting piece, the pole column, and the tab are usually located on the same vertical plane. Therefore, a relatively large space inside the battery cell needs to be occupied, resulting in a low space utilization rate of the battery cell.

[0048] To solve the above technical problems, the embodiments of the present utility model will be described below in conjunction with Figures 1 to 11 , describing the embodiments of the present utility model.

[0049] According to an embodiment of the present utility model, on the one hand, as Figures 1 to 11 shown, a battery cell is provided, including a housing 1, a pole group 2, a cover plate 5, and a sealing plate 6.

[0050] Specifically, as Figure 1 and Figure 2 shown, the housing 1 is provided with a receiving cavity (not shown in the figure), and an opening (not shown in the figure) is provided at the top of the housing 1. The opening communicates with the receiving cavity.

[0051] Specifically, in combination with Figure 2 and Figure 11 shown, the pole group 2 is disposed in the receiving cavity, and a negative tab 3 and a positive tab 4 are provided at one end of the pole group 2.

[0052] Specifically, as Figures 1 to 4 shown, the cover plate 5 is covered at the opening, and two through holes 501 are provided on the cover plate 5. The two through holes 501 are spaced along the length direction of the cover plate 5. A liquid injection hole 502 is further provided on the cover plate 5, and the liquid injection hole 502 is provided between the two through holes 501. Among them, the two through holes 501 respectively allow the negative tab 3 and the positive tab 4 to pass through, and a stepped surface is provided on the inner wall of each through hole 501.

[0053] Specifically, as Figures 1 to 10 shown, the sealing plate 6 is correspondingly covered on the through hole 501. Among them, the sealing plate 6 includes a sealing plate body 601 and a plastic plate 602. The plastic plate 602 is heat-melted and disposed on the lower surface of the sealing plate body 601. The lower surface of the sealing plate body 601 abuts against the stepped surface, and the side wall of the sealing plate body 601 is welded to the inner wall of the through hole 501.

[0054] For this battery cell, when assembling the battery cell, first place the electrode assembly 2 into the accommodating cavity of the housing 1, and cover the cover plate 5 on the opening of the housing 1. Since there are two through holes 501 opened on the cover plate 5, and the positions of the two through holes 501 correspond to the positions of the negative electrode tab 3 and the positive electrode tab 4 on the electrode assembly 2 respectively, thus, the negative electrode tab 3 and the positive electrode tab 4 on the electrode assembly 2 can respectively pass through the through holes 501 on the cover plate 5. The installer can bend the negative electrode tab 3 and the positive electrode tab 4 through the two through holes 501, so that the negative electrode tab 3 and the positive electrode tab 4 respectively abut against the negative electrode welding base plate 8 and the positive electrode welding base plate 9 correspondingly. The installer can also weld and fix the negative electrode welding base plate 8 and the negative electrode tab 3, and the positive electrode welding base plate 9 and the positive electrode tab 4 through the through holes 501. Finally, cover the sealing plate 6 correspondingly on the through holes 501 and seal the accommodating cavity to complete the assembly of the battery cell.

[0055] By opening two through holes 501 on the cover plate 5, the welding connection between the welding base plate and the tab can be carried out through the two through holes 501, thereby avoiding the space occupied by the bending of the tab after welding, shortening the length of the tab, improving the utilization space of the accommodating cavity in the housing 1 in the length direction, and thus improving the internal space utilization rate of the battery cell. Since the inner wall of the through hole 501 is provided with a stepped surface, by abutting the stepped surface against the bottom surface of the sealing plate body 601 and welding the side wall of the sealing plate body 601 and the inner wall of the through hole 501, the close contact between the sealing plate 6 and the through hole 501 can be ensured, improving the sealing performance and reducing the risk of electrolyte leakage. The welding of the side wall of the sealing plate body 601 and the inner wall of the through hole 501 enhances the connection strength and further improves the sealing effect.

[0056] A liquid injection hole 502 is arranged between the two through holes 501 on the cover plate 5, so that the liquid injection hole 502 is in the middle area of the cover plate 5. Inject electrolyte into the housing 1 through the liquid injection hole 502 in the middle area to facilitate the uniform distribution of the electrolyte in the housing 1. Since the bottom surface of the sealing plate body 601 is hot-melted with a plastic plate 602, the plastic plate 602 is used to prevent the negative electrode tab 3 and the positive electrode tab 4 from directly contacting the cover body, avoiding short circuit of the battery cell. At the same time, the plastic plate 602 can improve the sealing performance between the sealing plate 6 and the top wall, ensure the tightness inside the battery cell, and prevent electrolyte leakage.

[0057] Specifically, the through hole 501 can be set in any existing shape such as a rounded rectangular hole, a square hole, a circular hole, etc. In the embodiment of the present application, the shape of the through hole 101 is not specifically limited.

[0058] Specifically, the shape and size of the sealing plate 6 are adapted to the shape and size of the through hole 501. In the embodiment of the present application, the shape and size of the sealing plate 6 are not specifically limited.

[0059] Specifically, the step surface can be an inclined surface or a horizontal surface. In the embodiments of the present application, the type of the step surface is not specifically limited.

[0060] In one embodiment, as shown in Figures 5 to 8 each lower surface of the plastic plates 602 is set as a flat surface, and the area of each plastic plate 602 is smaller than the area of the sealing plate body 601.

[0061] Since the lower surface of the plastic plate 602 is smoothly arranged, there is no need to provide structures such as exhaust holes or liquid inlet holes on the plastic plate 602, which is convenient for the production and manufacturing of the plastic plate 602 and reduces the manufacturing cost of the plastic plate 602. Since the area of the plastic plate 602 is smaller than the area of the sealing plate body 601, a gap can be ensured between the edge of the plastic plate 602 and the edge of the sealing plate body 601, so that the lower surface of the sealing plate body 601 abuts against the step surface, improving the sealing performance at the connection between the sealing plate 6 and the through hole 501.

[0062] In one embodiment, as shown in Figure 2 it further includes an explosion-proof valve 7, and the explosion-proof valve 7 is arranged in the middle area of the bottom wall of the housing 1.

[0063] By arranging the explosion-proof valve 7 on the bottom wall of the housing 1, when the internal pressure of the housing 1 is too high, the excess gas in the housing 1 can be released by opening the explosion-proof valve 7 to prevent the battery cell from exploding. In addition, since the explosion-proof valve 7 is arranged at the bottom of the housing 1 and the liquid injection hole 502 is arranged at the top of the housing 1, the positions of the explosion-proof valve 7 and the liquid injection hole 502 are oppositely arranged to prevent the residual electrolyte during liquid injection from polluting the explosion-proof valve 7.

[0064] Specifically, the explosion-proof valve 7 can be arranged in the middle area of the bottom wall of the housing 1 or near both ends of the bottom wall of the housing 1. In the embodiments of the present application, the position of the explosion-proof valve 7 on the bottom wall of the housing 1 is not specifically limited.

[0065] In one embodiment, as shown in Figures 5 to 9 a plurality of installation grooves 6011 are formed on the lower surface of each sealing plate body 601. The plurality of installation grooves 6011 are arranged at intervals along the length direction of the sealing plate body 601, and the plurality of installation grooves 6011 are arranged in the middle area of the sealing plate body 601. A hot melt column 6021 corresponding to each installation groove 6011 is provided on the upper surface of each plastic plate 602.

[0066] A plurality of mounting grooves 6011 are formed on the lower surface of the sealing plate body 601, and a plurality of hot melt columns 6021 are provided on the upper surface of the plastic plate 602. When installing the sealing plate body 601 and the plastic plate 602, the hot melt columns 6021 are inserted into the mounting grooves 6011 so that the plastic plate 602 and the sealing plate body 601 are preliminarily combined. Subsequently, by heating the upper surface of the sealing plate body 601, the hot melt columns 6021 are melted in the mounting grooves 6011, and the melted hot melt columns 6021 are fixed in the mounting grooves 6011 to ensure a more secure connection between the sealing plate body 601 and the plastic plate 602.

[0067] Since two through holes 501 are formed in the cover plate 5 and two are also provided on the sealing plate 6, the size of the sealing plate 6 is relatively small. Therefore, a plurality of mounting grooves 6011 are linearly arranged in the middle area of the sealing plate body 601, which can ensure that the sealing plate body 601 and the plastic plate 602 are firmly fixed, reduce the processing quantity of the mounting grooves 6011 on the sealing plate body 601 and the hot melt columns 6021 on the plastic plate 602, and reduce the production cost of the sealing plate body 601 and the plastic plate 602.

[0068] In one embodiment, as Figure 6 and Figure 7 shown, the inner wall of each mounting groove 6011 is provided with an inclined surface that slopes downward from top to bottom toward the axis of the mounting groove 6011, and the diameter of the hot melt column 6021 is less than or equal to the minimum inner diameter of the mounting groove 6011.

[0069] Since the diameter of the hot melt column 6021 is less than the minimum inner diameter of the mounting groove 6011, it is convenient for the hot melt column 6021 to be inserted into the mounting groove 6011. Since the inner wall of the mounting groove 6011 is inclined, the mounting groove 6011 gradually contracts in the direction from top to bottom. During the melting process of the hot melt column 6021, the hot melt column 6021 in the mounting groove 6011 deforms and then fills the mounting groove 6011, so that the melted hot melt column 6021 is fixed in the mounting groove 6011 to ensure a more secure connection between the sealing plate body 601 and the plastic plate 602.

[0070] Specifically, the mounting groove 6011 can be set as a circular groove or a square groove, etc. In the embodiment of the present application, the shape of the mounting groove 6011 is not specifically limited.

[0071] Specifically, the hot melt column 6021 can be set as a cylindrical shape, a square column shape, etc., as long as the hot melt column 6021 can be inserted into the mounting groove 6011. In the embodiment of the present application, the shape of the hot melt column 6021 is not specifically limited.

[0072] In one embodiment, as Figure 7 shown, the minimum inner diameter of the mounting groove 6011 is d, the maximum inner diameter of the mounting groove 6011 is D, and D - d ≥ 0.3 mm.

[0073] By ensuring that the difference between the maximum inner diameter and the minimum inner diameter of the installation groove 6011 is at least 0.3 mm, it can be ensured that there is enough space for the hot melt column 6021 to deform during the melting process, so as to fill the installation groove 6011. At the same time, the larger inner diameter difference helps to ensure that the melted hot melt column 6021 is firmly fixed in the installation groove 6011, preventing the hot melt column 6021 from detaching from the installation groove 6011, and further ensuring that the sealing plate body 601 and the plastic plate 602 are firmly fixed.

[0074] In one embodiment, as Figure 7 shown, the minimum inner diameter of the installation groove 6011 is d, and 0.5 mm ≤ d ≤ 6 mm.

[0075] By setting the minimum inner diameter of the installation groove 6011 within 0.5 mm - 6 mm, the diameter of the hot melt column 6021 is further limited. The diameter of the hot melt column 6021 is limited to 0.5 mm - 6 mm, ensuring that the hot melt column 6021 has a certain strength. At the same time, when heating the upper surface of the sealing plate body 601, it is convenient for the hot melt column 6021 to quickly melt and fill the installation groove 6011, shortening the installation time of the plastic plate 602 and the sealing plate body 601.

[0076] If the minimum inner diameter of the installation groove 6011 is less than 0.5 mm, the diameter of the hot melt column 6021 is also less than 0.5 mm. At this time, the diameter of the hot melt column 6021 is relatively thin, and under the action of external force or vibration, it is easy to cause the hot melt column 6021 to break, resulting in the separation of the sealing plate body 601 and the plastic plate 602.

[0077] If the minimum inner diameter of the installation groove 6011 is greater than 6 mm, the diameter of the hot melt column 6021 is also greater than 6 mm. At this time, the diameter of the hot melt column 6021 is relatively thick, and when melting the hot melt column 6021, it takes a long time to melt the hot melt column 6021, resulting in a long installation time for the sealing plate body 601 and the plastic plate 602.

[0078] In one embodiment, as Figure 7 shown, the distance from the bottom surface of the installation groove 6011 to the upper surface of the sealing plate body 601 is t, and 0.2 mm ≤ t ≤ 1.5 mm.

[0079] By setting the distance t from the bottom surface of the installation groove 6011 to the upper surface of the sealing plate body 601 within the range of 0.2 mm to 1.5 mm, the relatively thin thickness t helps to improve the heat conduction efficiency. It can be ensured that when heating the upper surface of the sealing plate body 601, the heat can be quickly transferred into the installation groove 6011, accelerating the melting speed of the hot melt column 6021, helping to shorten the heating time, and improving the assembly efficiency.

[0080] In one embodiment, as Figures 7 to 9 shown, the depth of the installation groove 6011 is H, the height of the hot melt column 6021 is h, and h - H ≥ 0.25 mm.

[0081] The difference between the height h of the hot melt column 6021 and the depth H of the installation groove 6011 is at least 0.25 mm, that is, the height of the hot melt column 6021 is greater than the depth of the installation groove 6011. Since the maximum inner diameter of the installation groove 6011 is greater than the diameter of the hot melt column 6021, when the hot melt column 6021 is melted by heat, the melted part of the hot melt column 6021 can fully fill the internal space of the installation groove 6011, so that the hot melt column 6021 is firmly fixed in the installation groove 6011, ensuring that the plastic plate 602 and the sealing plate body 601 are firmly fixed.

[0082] Specifically, as Figure 11 shown, it further includes a negative welding bottom plate 8 and a positive welding bottom plate 9. The negative welding bottom plate 8 and the positive welding bottom plate 9 are both arranged below the cover plate 5, and the negative welding bottom plate 8 and the positive welding bottom plate 9 respectively extend to the corresponding through holes 501.

[0083] The positive welding bottom plate 9 and the negative welding bottom plate 8 are arranged below the cover plate 5, and the positive welding bottom plate 9 and the negative welding bottom plate 8 extend to the through holes 501. By bending the negative pole ear 3 and the positive pole ear 4, the negative welding bottom plate 8 and the positive welding bottom plate 9 are correspondingly abutted against the negative pole ear 3 and the positive pole ear 4. The installer can weld and fix the negative welding bottom plate 8 and the negative pole ear 3, and the positive welding bottom plate 9 and the positive pole ear 4 through the through holes 501.

[0084] Specifically, the negative welding bottom plate 8 and the negative pole column can be fixed on the cover plate 5 by riveting, and the positive welding bottom plate 9 and the positive pole column can be fixed on the cover plate 5 by riveting.

[0085] Specifically, as Figure 4 shown, it further includes a lower plastic box 10. The lower plastic box 10 is arranged between the negative welding bottom plate 8, the positive welding bottom plate 9 and the cover plate 5, and through holes corresponding to the through holes 501 are formed on the lower plastic box 10.

[0086] The lower plastic box 10 is arranged between the positive welding bottom plate 9, the negative welding bottom plate 8 and the cover plate 5 to ensure insulation between the positive welding bottom plate 9, the negative welding bottom plate 8 and the cover plate 5 through the lower plastic box 10. Since through holes corresponding to the through holes 501 are formed on the lower plastic box 10, the negative pole ear 3 and the positive pole ear 4 can pass through the through holes of the lower plastic box 10 and pass out through the through holes 501.

[0087] The installation process of the battery cell in this embodiment is described as follows:

[0088] First, wrap the insulating film around the outer surface of the electrode group 2, and then insert the electrode group 2 into the accommodation cavity of the housing 1 from the opening of the housing 1.

[0089] Cover the cover plate 5 at the opening of the housing 1. Since there are two through holes 501 formed in the cover plate 5, and the two through holes 501 respectively correspond to the positions of the negative electrode tab 3 and the positive electrode tab 4, therefore, the negative electrode tab 3 and the positive electrode tab 4 on the electrode group 2 pass through the through holes 501 on the cover plate 5. The installer can bend the negative electrode tab 3 and the positive electrode tab 4 through the through holes 501, so that the negative electrode tab 3 and the positive electrode tab respectively abut against the negative electrode welding bottom plate 8 and the positive electrode welding bottom plate 9. The installer can also weld and fix the negative electrode welding bottom plate 8 and the negative electrode tab 3, and the positive electrode welding bottom plate 9 and the positive electrode tab 4 through the through holes 501.

[0090] Finally, cover two sealing plates 6 at the two through holes 501 respectively, abut against the bottom surface of the sealing plate body 601 through the stepped surface, and weld the side wall of the sealing plate 6 and the inner wall of the first groove section to ensure close contact between the sealing plate 6 and the through hole 501, thus completing the assembly of the battery cell.

[0091] According to an embodiment of the present invention, on the other hand, a battery pack including a battery cell is also provided.

[0092] This battery pack includes the battery cell as described above and has all the beneficial technical effects of the battery cell, which will not be elaborated here.

[0093] 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: include: A shell body having a receiving cavity and an opening communicating with the receiving cavity; An electrode group is arranged in the accommodating cavity, and a negative electrode tab and a positive electrode tab are arranged at one end of the electrode group; A cover plate, covering the opening, the cover plate having two through holes spaced apart in the length direction, a liquid injection hole being arranged between the two through holes, the two through holes being respectively used for the negative electrode tab and the positive electrode tab to pass through, and an inner wall of each through hole being provided with a step surface; The sealing plates are respectively covered at the through holes, and the sealing plates include a sealing plate body and a plastic plate. The plastic plate is hot-melted on the lower surface of the sealing plate body. The lower surface of the sealing plate body abuts against the step surface, and the side wall of the sealing plate body is welded to the inner wall of the through hole.

2. The battery cell according to claim 1, characterized in that: The lower surface of each of the plastic plates is configured as a plane, and the area of ​​each of the plastic plates is smaller than the area of ​​the sealing plate body.

3. The battery cell according to claim 1, characterized in that: It also includes an explosion-proof valve, which is arranged in the middle area of ​​the bottom wall of the shell.

4. The battery cell according to claim 1, characterized in that: A plurality of mounting grooves are provided on the lower surface of each sealing plate body, and the plurality of mounting grooves are arranged at intervals in the middle area of ​​the sealing plate body along the length direction of the sealing plate body. A hot melt column is provided on the upper surface of each plastic plate in one-to-one correspondence with the mounting grooves.

5. The battery cell according to claim 4, characterized in that: The inner wall of each installation groove is provided with an inclined surface which is inclined from top to bottom toward the axis of the installation groove, and the diameter of the hot melt column is less than or equal to the minimum inner diameter of the installation groove.

6. The battery cell according to claim 5, characterized in that: The minimum inner diameter of the installation groove is d, the maximum inner diameter of the installation groove is D, and Dd≥0.3 mm.

7. The battery cell according to claim 5, characterized in that: The minimum inner diameter of the installation groove is d, 0.5mm≤d≤6mm.

8. The battery cell according to claim 5, characterized in that: The distance from the bottom surface of the installation groove to the upper surface of the sealing plate body is t, 0.2mm≤t≤1.5mm.

9. The battery cell according to claim 5, characterized in that: The depth of the installation groove is H, the height of the hot melt column is h, and hH≥0.25mm.

10. A battery pack, characterized in that: include: A plurality of battery cells according to any one of claims 1 to 9.

Images