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 cover plate and a sealing plate, the cover plate is provided with a through hole, the through hole is provided with a stepped groove arranged around the inner wall of the through hole, the stepped groove comprises a first groove section and a second groove section which are arranged up and down, the size of the first groove section is larger than that of the second groove section, and a stepped surface is formed at the joint of the first groove section and the second groove section; the sealing plate comprises a sealing plate body and a plastic plate, the plastic plate is arranged on the lower surface of the sealing plate body in a hot melting mode, the sealing plate body covers the through hole, the lower surface of the sealing plate body abuts against the step face, and the side wall of the sealing plate is welded to the inner wall of the first groove section. According to the utility model, the cover plate is provided with the through hole, and the welding bottom plate and the tab can be welded and connected through the through hole, so that the tab is prevented from being bent after being welded to occupy a space, 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 a battery cell 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. A battery cell is the basic component unit of a battery and can independently generate and store electrical 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. Therefore, a large space inside the battery cell needs to be occupied, resulting in low space utilization rate of the battery cell. 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 of low space utilization rate of the battery cell.

[0005] In a first aspect, the utility model provides a battery cell, comprising:

[0006] A cover plate, provided with a through hole, and a stepped groove is arranged on the inner wall surrounding the through hole. The stepped groove comprises a first groove section and a second groove section arranged up and down. The size of the first groove section is larger than that of the second groove section, and a step surface is formed at the connection between the first groove section and the second groove section;

[0007] A sealing plate, comprising a sealing plate body and a plastic plate. The plastic plate is hot-melted on the lower surface of the sealing plate body. The sealing plate body is covered at the through hole. The lower surface of the sealing plate body abuts against the step surface, and the side wall of the sealing plate is welded to the inner wall of the first groove section.

[0008] Advantageous effects: For this battery cell, when assembling the battery cell, first place the electrode assembly into the accommodation cavity of the housing, and cover the cover plate on the opening of the housing. Since a through hole is provided on the cover plate and the position of the through hole corresponds to the positions of the negative tab and the positive tab on the electrode assembly, the negative tab and the positive tab on the electrode assembly can pass through the through hole on the cover plate. The installer can bend the negative tab and the positive tab through the through hole so that the negative tab and the positive tab respectively abut against the negative welding bottom plate and the positive welding bottom plate. The installer can also weld and fix the negative welding bottom plate and the negative tab, and the positive welding bottom plate and the positive tab through the through hole. Finally, cover the sealing plate at the through hole and seal the accommodation cavity to complete the assembly of the battery cell.

[0009] By providing through holes in the cover plate, the welding bottom plate and the tab can be welded through the through holes, thereby avoiding the space occupied by the tab after welding and bending, shortening the length of the tab, increasing the usable space of the accommodation 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 groove, and a step surface is formed at the connection between the first groove section and the second groove section of the stepped groove, the step surface abuts against the bottom surface of the sealing plate body, and the side wall of the sealing plate body and the inner wall of the first groove section are welded, which can ensure close contact between the sealing plate and the through hole, improve the sealing performance, reduce the risk of electrolyte leakage, and 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.

[0010] Since a plastic plate is provided on the bottom surface of the sealing plate body, the plastic plate prevents the negative tab and the positive 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.

[0011] In an alternative embodiment, a plurality of mounting grooves are formed on the lower surface of the sealing plate body, heat melting posts corresponding to the mounting grooves one by one are provided on the upper surface of the plastic plate, and the inner wall of each mounting groove is provided with an inclined surface inclined downward from top to bottom towards the axis of the mounting groove, and the diameter of the heat melting post is less than or equal to the minimum inner diameter of the mounting groove.

[0012] Beneficial effects: By providing a plurality of mounting grooves on the lower surface of the sealing plate body and a plurality of heat melting posts on the upper surface of the plastic plate, when installing the sealing plate body and the plastic plate, since the diameter of the heat melting post is less than the minimum inner diameter of the mounting groove, it is convenient for the heat melting post to be inserted into the mounting groove. Inserting the heat melting post into the mounting groove completes 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 post melts in 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 post, the heat melting post in the mounting groove deforms, and then fills the mounting groove, so that the melted heat melting post is fixed in the mounting groove, ensuring a more firm connection between the sealing plate body and the plastic plate.

[0013] 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.

[0014] Beneficial effects: By ensuring that the difference between the maximum inner diameter and the minimum inner diameter of the mounting groove is at least 0.3 mm, it can ensure that the heat melting post has enough space to deform during the melting process, so as to fill the mounting groove. At the same time, the larger inner diameter difference helps to ensure that the melted heat melting post is firmly fixed in the mounting groove, preventing the heat melting post from detaching from the mounting groove, and thus ensuring a firm fixation between the sealing plate body and the plastic plate.

[0015] In an alternative embodiment, the minimum inner diameter of the installation groove is d, where 0.5 mm ≤ d ≤ 6 mm.

[0016] Beneficial effects: By setting the minimum inner diameter of the installation groove within 0.5 mm - 6 mm, the diameter of the hot melt column is thus limited to 0.5 mm - 6 mm, ensuring 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.

[0017] 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, where 0.2 mm ≤ t ≤ 1.5 mm.

[0018] 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 into the installation groove, accelerating the melting speed of the hot melt column, helping to shorten the heating time, and improving the assembly efficiency.

[0019] In an alternative embodiment, the depth of the installation groove is H, and the height of the hot melt column is h, where h - H ≥ 0.25 mm.

[0020] 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.

[0021] In an alternative embodiment, it further includes an explosion-proof valve, which is provided on the sealing plate body, and a plurality of air outlet holes are provided at the position corresponding to the explosion-proof valve on the plastic plate.

[0022] Beneficial effects: By providing air outlet holes on the plastic plate, the gas flow path around the explosion-proof valve can be optimized, improving the gas discharge efficiency. By providing an explosion-proof valve on the sealing plate body, the combined use of the explosion-proof valve and the air outlet holes can ensure that the battery can release pressure in a timely manner under abnormal conditions, prevent the battery from exploding, and improve the reliability of the system.

[0023] In an alternative embodiment, a negative electrode welding bottom plate and a positive electrode welding bottom plate are further included. The negative electrode welding bottom plate and the positive electrode welding bottom plate are disposed below the cover plate, and the negative electrode welding bottom plate and the positive electrode welding bottom plate respectively extend to the through holes.

[0024] Advantageous effects: The positive electrode welding bottom plate and the negative electrode welding bottom plate are arranged below the cover plate, and the positive electrode welding bottom plate and the negative electrode welding bottom plate extend to the through holes. By bending the negative electrode tab and the positive electrode tab, the negative electrode welding bottom plate and the positive electrode welding bottom plate are correspondingly abutted against the negative electrode tab and the positive electrode tab, and the installer can weld and fix the negative electrode welding bottom plate and the negative electrode tab, and the positive electrode welding bottom plate and the positive electrode tab through the through holes.

[0025] In an alternative embodiment, a lower plastic box is further included. The lower plastic box is disposed between the negative electrode welding bottom plate, the positive electrode welding bottom plate and the cover plate, and a through hole corresponding to the through hole is formed on the lower plastic box.

[0026] Advantageous effects: The lower plastic box is arranged between the positive electrode welding bottom plate, the negative electrode welding bottom plate and the cover plate to ensure insulation between the positive electrode welding bottom plate, the negative electrode welding bottom plate and the cover plate through the lower plastic box. Since a through hole corresponding to the through hole is formed on the lower plastic box, the negative electrode tab and the positive electrode tab can pass through the through hole of the lower plastic box and pass out through the through hole.

[0027] In a second aspect, the present invention further provides a battery pack, including: a plurality of battery cells.

[0028] Advantageous 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

[0029] 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 use in 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, other drawings can be obtained based on these drawings without creative efforts.

[0030] Figure 1 It is a schematic structural diagram of a battery cell according to an embodiment of the present invention;

[0031] Figure 2 It is a cross-sectional view of a battery cell according to an embodiment of the present invention;

[0032] Figure 3 It is for Figure 2 a partial enlarged schematic diagram of

[0033] Figure 4Schematic diagram of the structure of the middle cover plate of a battery cell according to an embodiment of the present invention;

[0034] Figure 5 Cross-sectional view of the middle cover plate of a battery cell according to an embodiment of the present invention;

[0035] Figure 6 Schematic diagram of the structure of the middle cover plate and the electrode group of a battery cell according to an embodiment of the present invention;

[0036] Figure 7 Schematic diagram of the structure of the middle electrode group of a battery cell according to an embodiment of the present invention;

[0037] Figure 8 Schematic diagram of the structure of the middle sealing plate of a battery cell according to an embodiment of the present invention;

[0038] Figure 9 Cross-sectional view of the middle sealing plate of a battery cell according to an embodiment of the present invention;

[0039] Figure 10 is Figure 9 partial enlarged schematic diagram;

[0040] Figure 11 Schematic diagram of the structure of the middle plastic plate of a battery cell according to an embodiment of the present invention;

[0041] Figure 12 Cross-sectional view of the middle plastic plate of a battery cell according to an embodiment of the present invention.

[0042] Explanation of reference numerals:

[0043] 1. Cover plate; 101. Through hole; 1011. Step groove; 10111. First groove section; 10112. Second groove section; 2. Sealing plate; 201. Sealing plate body; 2011. Installation groove; 202. Plastic plate; 2021. Heat melting column; 2022. Air outlet hole; 3. Explosion-proof valve; 4. Negative electrode welding bottom plate; 5. Positive electrode welding bottom plate; 6. Lower plastic box; 7. Shell; 8. Electrode group; 801. Positive electrode tab; 802. Negative electrode tab. Detailed implementation manners

[0044] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0045] 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.

[0046] To solve the above technical problems, the embodiments of the present invention will be described below in conjunction with Figures 1 to 12 as shown.

[0047] According to an embodiment of the present invention, on the one hand, as Figures 1 to 12 shown, a battery cell is provided, which includes a cover plate 1 and a sealing plate 2.

[0048] Specifically, as Figures 1 to 6 shown, a through hole 101 is formed in the cover plate 1, and a stepped groove 1011 is provided around the inner wall of the through hole 101. Among them, the stepped groove 1011 includes a first groove section 10111 and a second groove section 10112. The first groove section 10111 is provided above the second groove section 10112, and the size of the first groove section 10111 is larger than that of the second groove section 10112. A step surface is formed at the connection between the first groove section 10111 and the second groove section 10112.

[0049] Specifically, the sealing plate 2 includes a sealing plate body 201 and a plastic plate 202. The plastic plate 202 is thermally melted and provided on the lower surface of the sealing plate body 201. The sealing plate body 201 is covered at the through hole 101, and the lower surface of the sealing plate body 201 abuts against the step surface. The side wall of the sealing plate 2 is welded to the inner wall of the first groove section 10111.

[0050] For this battery cell, when assembling the battery cell, first place the electrode assembly 8 into the accommodating cavity of the housing 7, and cover the cover plate 1 at the opening of the housing 7. Since a through hole 101 is formed in the cover plate 1, and the position of the through hole 101 corresponds to the positions of the negative tab 802 and the positive tab 801 on the electrode assembly 8, therefore, the negative tab 802 and the positive tab 801 on the electrode assembly 8 can pass through the through hole 101 on the cover plate 1. The installer can bend the negative tab 802 and the positive tab 801 through the through hole 101, so that the negative tab 802 and the positive tab respectively abut against the negative welding bottom plate 4 and the positive welding bottom plate 5. The installer can also weld and fix the negative welding bottom plate 4 and the negative tab 802, and the positive welding bottom plate 5 and the positive tab 801 through the through hole 101. Finally, cover the sealing plate 2 at the through hole 101 and seal the accommodating cavity to complete the assembly of the battery cell.

[0051] By opening a through-hole 101 in the cover plate 1, the welding bottom plate and the tab can be welded and connected through the through-hole 101, thereby avoiding the space occupied by the tab after welding and bending, shortening the length of the tab, increasing the usable space of the accommodation cavity in the housing 7 in the length direction, and thus improving the internal space utilization rate of the battery cell. Since the inner wall of the through-hole 101 is provided with a stepped groove 1011, and a step surface is formed at the connection between the first groove section 10111 and the second groove section 10112 of the stepped groove 1011, by abutting the step surface against the bottom surface of the sealing plate body 201 and welding the side wall of the sealing plate body 201 and the inner wall of the first groove section 10111, the tight contact between the sealing plate 2 and the through-hole 101 can be ensured, the sealing performance can be improved, the risk of electrolyte leakage can be reduced, and the welding between the side wall of the sealing plate body 201 and the inner wall of the through-hole 101 enhances the connection strength and further improves the sealing effect.

[0052] Since a plastic plate 202 is provided on the bottom surface of the sealing plate body 201, the plastic plate 202 is used to prevent the negative tab 802 and the positive tab 801 from directly contacting the cover body, avoiding short circuit of the battery cell. At the same time, the plastic plate 202 can improve the sealing performance between the sealing plate 2 and the top wall, ensure the sealing inside the battery cell, and prevent electrolyte leakage.

[0053] Specifically, the through-hole 101 can be opened in the middle area of the cover plate 1 to ensure that the positions of the positive tab 801 and the negative tab 802 correspond to the position of the through-hole 101. The through-hole 101 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 and its position on the cover plate 1 are not specifically limited.

[0054] Specifically, the sizes of the first groove section 10111 and the second groove section 10112 can be adjusted according to design requirements, and then the size of the step surface can be adjusted. In the embodiment of the present application, the sizes of the first groove section 10111 and the second groove section 10112 are not specifically limited.

[0055] Specifically, the shape and size of the sealing plate 2 are adapted to the shape and size of the through-hole 101. In the embodiment of the present application, the shape and size of the sealing plate 2 are not specifically limited.

[0056] Specifically, the step surface formed at the first groove section 10111 and the second groove section 10112 can be an inclined surface or a horizontal surface. In the embodiment of the present application, the type of the step surface is not specifically limited.

[0057] In one embodiment, as Figure 8 and Figure 9As shown in the figure, a plurality of mounting grooves 2011 are formed on the lower surface of the sealing plate body 201, and a plurality of hot melt columns 2021 are provided on the upper surface of the plastic plate 202. The hot melt columns 2021 and the mounting grooves 2011 are arranged in one-to-one correspondence. Among them, the inner wall of each mounting groove 2011 is provided with an inclined surface that slopes from top to bottom toward the axis direction of the mounting groove 2011, and the diameter of the hot melt column 2021 is smaller than the minimum inner diameter of the mounting groove 2011.

[0058] A plurality of mounting grooves 2011 are formed on the lower surface of the sealing plate body 201, and a plurality of hot melt columns 2021 are provided on the upper surface of the plastic plate 202. When installing the sealing plate body 201 and the plastic plate 202, since the diameter of the hot melt column 2021 is smaller than the minimum inner diameter of the mounting groove 2011, it is convenient for the hot melt column 2021 to be inserted into the mounting groove 2011. Inserting the hot melt column 2021 into the mounting groove 2011 completes the preliminary combination of the plastic plate 202 and the sealing plate body 201. Subsequently, by heating the upper surface of the sealing plate body 201, the hot melt column 2021 melts in the mounting groove 2011. Since the inner wall of the mounting groove 2011 is inclined, the mounting groove 2011 gradually contracts from top to bottom. During the melting process of the hot melt column 2021, the hot melt column 2021 in the mounting groove 2011 deforms, and then fills the mounting groove 2011, so that the melted hot melt column 2021 is fixed in the mounting groove 2011, ensuring a more firm connection between the sealing plate body 201 and the plastic plate 202.

[0059] Specifically, the plurality of mounting grooves 2011 can be respectively arranged on both sides of the sealing plate body 201, and are arranged at intervals along the length direction of the sealing plate body 201. The mounting grooves 2011 can also be distributed around the periphery of the sealing plate body 201. In the embodiment of the present application, the distribution manner of the plurality of mounting grooves 2011 is not specifically limited.

[0060] Specifically, the mounting groove 2011 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 2011 is not specifically limited.

[0061] Specifically, the hot melt column 2021 can be set as a cylindrical shape, a square column shape, etc., as long as the hot melt column 2021 can be inserted into the mounting groove 2011. In the embodiment of the present application, the shape of the hot melt column 2021 is not specifically limited.

[0062] In one embodiment, as Figure 9 and Figure 10 shown, the minimum inner diameter of the mounting groove 2011 is d, the maximum inner diameter of the mounting groove 2011 is D, and D - d ≥ 0.3 mm.

[0063] By ensuring that the difference between the maximum inner diameter and the minimum inner diameter of the installation groove 2011 is at least 0.3 mm, it can ensure that there is enough space for the hot melt column 2021 to deform during the melting process, so as to fill the installation groove 2011. At the same time, the larger inner diameter difference helps to ensure that the melted hot melt column 2021 is firmly fixed in the installation groove 2011, preventing the hot melt column 2021 from detaching from the installation groove 2011, and further ensuring that the sealing plate body 201 and the plastic plate 202 are firmly fixed.

[0064] In one embodiment, as Figure 9 and Figure 10 shown, the minimum inner diameter of the installation groove 2011 is d, and 0.5 mm ≤ d ≤ 6 mm.

[0065] By setting the minimum inner diameter of the installation groove 2011 within 0.5 mm - 6 mm, and further limiting the diameter of the hot melt column 2021 to be within 0.5 mm - 6 mm, it ensures that the hot melt column 2021 has a certain strength. At the same time, when heating the upper surface of the sealing plate body 201, it is convenient for the hot melt column 2021 to quickly melt and fill the installation groove 2011, shortening the installation time of the plastic plate 202 and the sealing plate body 201.

[0066] If the minimum inner diameter of the installation groove 2011 is less than 0.5 mm, then the diameter of the hot melt column 2021 is also less than 0.5 mm. At this time, the diameter of the hot melt column 2021 is relatively thin, and under the action of external force or vibration, it is easy to cause the hot melt column 2021 to break, resulting in the separation of the sealing plate body 201 and the plastic plate 202.

[0067] If the minimum inner diameter of the installation groove 2011 is greater than 6 mm, then the diameter of the hot melt column 2021 is also greater than 6 mm. At this time, the diameter of the hot melt column 2021 is relatively thick, and when melting the hot melt column 2021, it takes a long time to melt the hot melt column 2021, resulting in a long installation time for the sealing plate body 201 and the plastic plate 202.

[0068] In one embodiment, as Figure 9 and Figure 10 shown, the distance from the bottom surface of the installation groove 2011 to the upper surface of the sealing plate body 201 is t, and 0.2 mm ≤ t ≤ 1.5 mm.

[0069] By setting the distance t from the bottom surface of the installation groove 2011 to the upper surface of the sealing plate body 201 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 201, the heat can be quickly transferred into the installation groove 2011, accelerating the melting speed of the hot melt column 2021, helping to shorten the heating time, and improving the assembly efficiency.

[0070] In one embodiment, as Figure 10 and Figure 12 shown, the depth of the installation groove 2011 is H, the height of the hot melt column 2021 is h, and h - H ≥ 0.25 mm.

[0071] The difference between the height h of the hot melt column 2021 and the depth H of the installation groove 2011 is at least 0.25 mm, that is, the height of the hot melt column 2021 is greater than the depth of the installation groove 2011. Since the maximum inner diameter of the installation groove 2011 is greater than the diameter of the hot melt column 2021, when the hot melt column 2021 is melted by heat, the melted part of the hot melt column 2021 can fully fill the internal space of the installation groove 2011, so that the hot melt column 2021 is firmly fixed in the installation groove 2011, ensuring that the plastic plate 202 and the sealing plate body 201 are firmly fixed.

[0072] In one embodiment, as Figure 8 and Figure 11 shown, it further includes an explosion-proof valve 3, and the explosion-proof valve 3 is arranged on the sealing plate body 201. Among them, a plurality of air outlet holes 2022 are provided at the position corresponding to the explosion-proof valve 3 on the plastic plate 202.

[0073] By providing the air outlet holes 2022 on the plastic plate 202, the gas flow path around the explosion-proof valve 3 can be optimized, and the gas discharge efficiency can be improved. By providing the explosion-proof valve 3 on the sealing plate body 201, the combined use of the explosion-proof valve 3 and the air outlet holes 2022 can ensure that the battery can release pressure in time under abnormal conditions, prevent the battery from exploding, and improve the reliability of the system.

[0074] In one embodiment, as Figures 5 to 7 shown, it further includes a negative electrode welding bottom plate 4 and a positive electrode welding bottom plate 5. The negative electrode welding bottom plate 4 and the positive electrode welding bottom plate 5 are both arranged below the cover plate 1, and the negative electrode welding bottom plate 4 and the positive electrode welding bottom plate 5 respectively extend to the through hole 101.

[0075] By arranging the positive electrode welding bottom plate 5 and the negative electrode welding bottom plate 4 below the cover plate 1 and extending the positive electrode welding bottom plate 5 and the negative electrode welding bottom plate 4 to the through hole 101, by bending the negative electrode tab 802 and the positive electrode tab 801, the negative electrode welding bottom plate 4 and the positive electrode welding bottom plate 5 are correspondingly abutted against the negative electrode tab 802 and the positive electrode tab 801, and the installer can weld and fix the negative electrode welding bottom plate 4 and the negative electrode tab 802, the positive electrode welding bottom plate 5 and the positive electrode tab 801 through the through hole 101.

[0076] Specifically, the negative electrode welding bottom plate 4 and the negative electrode pole can be fixed on the cover plate 1 by riveting, and the positive electrode welding bottom plate 5 and the positive electrode pole can be fixed on the cover plate 1 by riveting.

[0077] In one embodiment, as Figure 5As shown, it further includes a lower plastic box 6, and the lower plastic box 6 is arranged between the negative electrode welding bottom plate 4, the positive electrode welding bottom plate 5 and the cover plate 1. A through hole corresponding to the through hole 101 is formed on the lower plastic box 6.

[0078] The lower plastic box 6 is arranged between the positive electrode welding bottom plate 5, the negative electrode welding bottom plate 4 and the cover plate 1, and the insulation between the positive electrode welding bottom plate 5, the negative electrode welding bottom plate 4 and the cover plate 1 is ensured through the lower plastic box 6. Since a through hole corresponding to the through hole 101 is formed on the lower plastic box 6, the negative electrode tab 802 and the positive electrode tab 801 can pass through the through hole of the lower plastic box 6 and pass out from the through hole 101.

[0079] Specifically, the size and position of the through hole can be adapted to the size and position of the through hole 101. In the embodiments of the present application, the shape of the through hole is not specifically limited.

[0080] The installation process of the battery cell in this embodiment is described as follows:

[0081] First, the insulating film is wrapped on the outer surface of the electrode group 8, and then the electrode group 8 is inserted into the accommodating cavity of the housing 7 from the opening of the housing 7.

[0082] The cover plate 1 is covered on the opening of the housing 7. Since the through hole 101 is formed on the cover plate 1 and the through hole 101 corresponds to the positions of the negative electrode tab 802 and the positive electrode tab 801, the negative electrode tab 802 and the positive electrode tab 801 on the electrode group 8 pass out from the through hole 101 on the cover plate 1. The installer can bend the negative electrode tab 802 and the positive electrode tab through the through hole 101 so that the negative electrode tab 802 and the positive electrode tab respectively abut against the negative electrode welding bottom plate 4 and the positive electrode welding bottom plate 5. The installer can also perform welding fixation on the negative electrode welding bottom plate 4 and the negative electrode tab 802, and the positive electrode welding bottom plate 5 and the positive electrode tab 801 through the through hole 101.

[0083] Finally, the sealing plate 2 is covered on the through hole 101, abuts against the bottom surface of the sealing plate body 201 through the step surface, and welds the side wall of the sealing plate 2 and the inner wall of the first groove section 10111 to ensure the close contact between the sealing plate 2 and the through hole 101, thus completing the assembly of the battery cell.

[0084] According to an embodiment of the present invention, on the other hand, a battery pack including a battery cell is also provided.

[0085] 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.

[0086] Although embodiments of the present utility model 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 utility model, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A battery cell, characterized in that: include: A cover plate, having a through hole, wherein the through hole is provided with a stepped groove arranged around the inner wall of the through hole, wherein the stepped groove comprises a first groove section and a second groove section arranged up and down, wherein the size of the first groove section is larger than the size of the second groove section and a step surface is formed at the connection between the first groove section and the second groove section; The sealing plate comprises a sealing plate body and a plastic plate, wherein the plastic plate is hot-melted on the lower surface of the sealing plate body, the sealing plate body cover is arranged at the through hole, the lower surface of the sealing plate body abuts against the step surface, and the side wall of the sealing plate is welded to the inner wall of the first groove section.

2. The battery cell according to claim 1, characterized in that: A plurality of mounting grooves are provided on the lower surface of the sealing plate body, and a heat-melt column is provided on the upper surface of the plastic plate corresponding to the mounting grooves one by one. The inner wall of each mounting groove is arranged as an inclined surface inclined from top to bottom toward the axis of the mounting groove, and the diameter of the heat-melt column is less than or equal to the minimum inner diameter of the mounting groove.

3. The battery cell according to claim 2, 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.

4. The battery cell according to claim 2, characterized in that: The minimum inner diameter of the installation groove is d, 0.5mm≤d≤6mm.

5. The battery cell according to claim 2, 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.

6. The battery cell according to claim 2, characterized in that: The depth of the installation groove is H, the height of the hot melt column is h, and hH≥0.25mm.

7. The battery cell according to any one of claims 1 to 6, characterized in that: It also includes an explosion-proof valve, which is arranged on the sealing plate body, and a plurality of air outlet holes are opened on the plastic plate at positions corresponding to the explosion-proof valve.

8. The battery cell according to any one of claims 1 to 6, characterized in that: It also includes a negative electrode welding bottom plate and a positive electrode welding bottom plate, wherein the negative electrode welding bottom plate and the positive electrode welding bottom plate are arranged below the cover plate, and the negative electrode welding bottom plate and the positive electrode welding bottom plate extend to the through hole respectively.

9. The battery cell according to claim 8, characterized in that: It also includes a lower plastic box, which is arranged between the negative electrode welding bottom plate, the positive electrode welding bottom plate and the cover plate, and the lower plastic box is provided with a through hole corresponding to the through hole.

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

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