Battery cell and battery pack

Abstract

The utility model provides a battery cell and a battery pack, and relates to the technical field of power batteries. The battery cell comprises a shell, a cover plate assembly and sealant, an opening is formed in at least one end of the shell, at least part of a cover plate body is inserted into the shell through the opening, and the cover plate body and the inner wall of the shell are bonded through the sealant. The cover plate body and the shell are connected and fixed through the sealant, sealing between the cover plate body and the shell is achieved, the cover plate body can be made of low-price resin plastic materials, and the material cost is lower than that of traditional aluminum materials; moreover, the shape of the cover plate body can be manufactured through an injection molding process before assembly, and precise mechanical milling is not needed, so that the processing cost and difficulty of the cover plate body and the shell are reduced, the production efficiency is improved, and the rejection rate is reduced.

Description

Technical Field

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

[0002] In new energy vehicles, battery cell production is crucial and is also one of the main directions of current new energy vehicle development. In the battery cell manufacturing process, for any type of battery cell, the assembly of the cover assembly itself and the assembly of the cover body and the shell in the cover assembly are particularly important, and both sealing and insulation properties need to be considered.

[0003] For example, in existing battery cells, in order to improve the energy density and heat dissipation performance of the battery cells, the outer shell is usually made of aluminum alloy material. In order to achieve a sealed environment inside the outer shell, the cover body is also basically made of aluminum alloy material. The outer shell and the cover body are connected and sealed through aluminum and aluminum laser welding. At the same time, in order to ensure the laser welding yield, the connection between the outer shell and the cover body usually requires precise mechanical milling. Because the thickness of the outer shell is usually very thin (only 0.4mm-0.6mm), the processing accuracy of the outer shell and the cover body made of aluminum alloy is very high, the production efficiency is low, and the processing cost and scrap rate are high.

[0004] In addition, in existing battery cells, the outer surface of the shell is usually covered with an insulating film to ensure that it is insulated from surrounding metal or conductive parts. Since the cover body is welded and fixed to the top of the shell, usually by laser welding, the laser welding process will inevitably produce welding slag or weld protrusions. Sharp protrusions may damage the insulating film and cause insulation failure. Utility Model Content

[0005] The utility model aims to solve at least one of the above technical problems.

[0006] In order to solve the above problems, the utility model provides a battery cell, including a shell, a cover assembly and a sealant. At least one end of the shell is provided with an opening. The cover assembly includes a cover body. At least a part of the cover body is inserted into the shell through the opening. The cover body is bonded to the inner wall of the shell by the sealant.

[0007] Compared with the prior art, the battery cell provided by the utility model has but is not limited to the following technical effects:

[0008] The battery cell can be, for example, a rectangular battery cell, that is, the shell and the cover body are rectangular as a whole. At least one end of the shell is provided with an opening, and the cover body can be at least partially inserted into the shell through the opening, and a gap is realized between the cover body and the inner wall of the shell, so that the sealant can be placed in the gap between the cover body and the inner wall of the shell, and then the cover body and the shell are connected and fixed by the sealant, and the seal between the cover body and the shell is realized. Since the cover body and the shell do not need to be fixed by welding, but are bonded and sealed by sealant, the connection between the shell and the cover body does not need to be precisely milled, which reduces the processing cost and time, improves the production efficiency, and reduces the scrap rate; and since laser welding is not required, the generation of laser welding slag and the subsequent grinding and slag removal process can be avoided from the root, which solves the problem that the insulation failure between the battery cell and the external environment is caused by the welding slag or the raised weld piercing the insulating film.

[0009] Furthermore, the cover plate body is a plastic part.

[0010] Further, the cover plate body comprises a plate body portion and a cylinder body portion, and the plate body portion is arranged at one end of the cylinder body portion;

[0011] At least a portion of the barrel is inserted into the shell, and at least a portion of the sealant is disposed between the outer wall of the barrel and the inner wall of the shell.

[0012] Furthermore, a first protrusion is arranged around the outer wall of the cylinder portion, and the first protrusion abuts against the inner wall of the outer shell. The outer wall of the cylinder portion, the first protrusion and the outer shell can form a first annular space, and at least a part of the sealant is arranged in the first annular space.

[0013] Furthermore, the battery cell also includes a first sealing ring, a second protrusion is arranged around the outer wall of the cylindrical portion, the second protrusion is arranged on the side of the first protrusion away from the opening, the first sealing ring is arranged between the second protrusion and the first protrusion, and the first sealing ring is respectively abutted against the inner wall of the outer shell and the outer wall of the cylindrical portion.

[0014] Furthermore, a positioning block is protruding from the outer wall of the cylinder, and one end of the positioning block is bent toward the opening to form a positioning boss, and the other end of the positioning block is inserted into the shell, and the positioning boss abuts against the end surface of the shell at the opening.

[0015] Furthermore, a first raised platform is provided at the center of the plate body portion protruding toward the outside of the shell, the cylindrical body portion and the portion of the plate body portion not provided with the first raised platform are provided inside the shell, part of the sealant is provided between the outer wall of the cylindrical body portion and the inner wall of the shell, and other parts of the sealant are provided between the peripheral side wall of the first raised platform and the inner wall of the shell.

[0016] Furthermore, the cover plate assembly also includes an explosion-proof valve plate, a first mounting groove is arranged on the outer side of the plate body, an air leakage hole is arranged at the bottom of the first mounting groove, and the explosion-proof valve plate is attached to the first mounting groove.

[0017] Furthermore, a second sealing ring is embedded in the bottom of the first installation groove, the air leakage hole is arranged in the second sealing ring, and the second sealing ring abuts against the explosion-proof valve plate;

[0018] And / or, the cover plate assembly further comprises a fixing ring plate, at least a portion of which is disposed in the first mounting groove and abuts against the explosion-proof valve plate, and a periphery of the fixing ring plate is fixedly welded to the plate body.

[0019] Furthermore, the cover plate assembly further comprises a fixing plate, and a liquid injection channel is provided on the plate body;

[0020] At least a portion of the fixing sheet is attached to the liquid injection channel, or the fixing sheet abuts against the outer side of the plate body and covers the liquid injection channel;

[0021] The periphery of the fixing plate is fixed to the plate body by welding.

[0022] The utility model also provides a battery pack, comprising the battery core as described above.

[0023] Since the connection between the shell and the cover body in the aforementioned battery cell does not need to be processed by precise mechanical milling, the processing cost and time are reduced, the production efficiency is improved, and the scrap rate is reduced; and since laser welding is not required, the generation of laser welding slag and the subsequent grinding and slag removal process can be avoided from the root, and the problem of insulation failure between the battery cell and the external environment caused by welding slag or raised welds piercing the insulation film is solved. Therefore, the battery pack with this battery cell also has higher production efficiency, lower production cost and scrap rate, and higher safety and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure of a battery cell according to an embodiment of the utility model;

[0025] Figure 2 This is a schematic diagram of the explosion structure of a battery cell according to an embodiment of the utility model;

[0026] Figure 3 for Figure 2 Side view of

[0027] Figure 4 This is a schematic diagram of the structure of the cover body of an embodiment of the utility model;

[0028] Figure 5 It is a schematic diagram of a partial cross-sectional structure of a battery cell according to an embodiment of the utility model;

[0029] Figure 6 for Figure 5 The enlarged view of point A in the middle;

[0030] Figure 7 for Figure 5 The enlarged view of point B in the middle;

[0031] Figure 8 This is a schematic structural diagram of an explosion-proof valve sheet according to an embodiment of the utility model;

[0032] Fig. 9 This is a schematic diagram of the cross-sectional structure of a sealing ring according to an embodiment of the utility model;

[0033] Fig.10 A schematic diagram of a half-section structure of a battery cell according to an embodiment of the utility model in a side view;

[0034] Fig.11 It is a schematic diagram of the cross-sectional structure of the battery cell of an embodiment of the utility model in the main viewing angle.

[0035] Description of reference numerals:

[0036] 1. Shell; 2. Cover plate assembly; 21. Cover plate body; 211. Plate body; 212. Cylinder body; 213. First protrusion; 214. Second protrusion; 2141. First inclined guide wall; 215. Positioning block; 2151. Second inclined guide wall; 216. Positioning boss; 217. First protruding platform; 2171. Pole hole; 2172. First mounting groove; 2173. Air vent; 2174. Second mounting groove; 2175. Liquid injection hole; 22. Pole assembly; 221. Electrode terminal; 222. Pole body; 223. Current collector; 231. First sealing ring; 232. Second sealing ring; 233. Sealing plug; 241. Fixed ring plate; 242. Fixed plate; 25. Explosion-proof valve plate; 251. Weak groove; 3. Sealant; 4. First sealing ring. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0038] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "back", etc., indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0039] Moreover, the Z axis in the drawings represents the vertical direction, that is, the up-down direction, and the positive direction of the Z axis represents the top, and the negative direction of the Z axis represents the bottom; the Y axis in the drawings represents the horizontal direction, that is, the left-right direction, and the positive direction of the Y axis represents the left, and the negative direction of the Y axis represents the right; the X axis in the drawings represents the longitudinal direction, that is, the front-back direction, and the positive direction of the X axis represents the front, and the negative direction of the X axis represents the back. It should also be noted that the aforementioned Z axis, Y axis, and X axis are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0040] See also Figure 1 , Figure 4-6 A battery cell according to an embodiment of the utility model comprises a shell 1, a cover assembly 2 and a sealant 3, wherein at least one end of the shell 1 is provided with an opening, the cover assembly 2 comprises a cover body 21, at least a portion of the cover body 21 is inserted into the shell 1 through the opening, and the cover body 21 is bonded to the inner wall of the shell 1 by the sealant 3.

[0041] In this embodiment, the battery cell may be a rectangular battery cell, that is, the housing 1 and the cover body 21 are rectangular as a whole. At least one end of the housing 1 is provided with an opening, such as Figure 2 The top end (the end in the positive direction of the X-axis) of the shell 1 shown is provided with an opening, and the cover body 21 can be at least partially inserted into the shell 1 through the opening, and a gap is formed between the cover body 21 and the inner wall of the shell 1, so that at least a portion of the sealant 3 can be placed in the gap between the cover body 21 and the inner wall of the shell 1, and then the cover body 21 and the shell 1 are connected and fixed by the sealant 3, and the seal between the cover body 21 and the shell 1 is achieved. Since the cover body 21 and the shell 1 do not need to be fixed by welding, but are bonded and sealed by the sealant 3, the connection between the shell 1 and the cover body 21 does not need to be precisely milled, reducing processing costs and time, improving production efficiency, and reducing scrap rate; and since laser welding is not required, the generation of laser welding slag and the subsequent grinding and slag removal process can be avoided from the root, solving the problem of welding slag or raised welds piercing the insulating film and causing insulation failure between the battery cell and the external environment.

[0042] Optionally, the cover body 21 is made of plastic, that is, the cover body 21 is a plastic part.

[0043] In this embodiment, the material of the cover body 21 can be a low-cost resin plastic material, which not only has lower material cost than traditional aluminum material; but also the shape of the cover body 21 can be made by injection molding before assembly, and the entire cover body 21 does not need to be subjected to precise mechanical milling processing, thereby reducing the processing cost and difficulty of the cover body 21 and the outer shell 1, improving production efficiency, and reducing scrap rate.

[0044] See also Figure 1 , Figure 4-6 Optionally, the cover body 21 includes a plate body portion 211 and a cylinder body portion 212, and the plate body portion 211 is disposed at one end of the cylinder body portion 212;

[0045] At least a portion of the barrel portion 212 is inserted into the housing 1 , and at least a portion of the sealant 3 is disposed between the outer wall of the barrel portion 212 and the inner wall of the housing 1 .

[0046] In this embodiment, the cover body 21 includes a plate body portion 211 and a barrel portion 212 connected to each other, and at least a portion of the barrel portion 212 may be inserted into the housing 1 through an opening, and at least a portion of the sealant 3 is disposed between the barrel portion 212 and the inner wall of the housing 1 to achieve sealing and fixing between the cover body 21 and the housing 1. Among them, at least a portion of the sealant 3 is disposed between the barrel portion 212 and the inner wall of the housing 1, firstly, it can be ensured that the overall height (Z-direction dimension) of the battery cell does not need to be increased, and secondly, it can be ensured that at least a portion of the sealant 3 is located inside the housing 1, and the housing 1 has a certain protective effect on the sealant 3 inside.

[0047] Among them, the plate body 211 and the cylinder body 212 can be an integrally molded structure. Especially when the material of the cover body 21 is plastic, the plate body 211 and the cylinder body 212 can be integrally molded using an injection molding process to achieve the finished product production of the plastic part of the cover body 21, which can further reduce processing costs and difficulty and improve production efficiency.

[0048] It should be noted that "plastic part" refers to the finished product of plastic material after processing and forming, and the cover body 21 is a plastic part, which means that the cover body 21 is processed and formed by plastic material, and the finished product after processing and forming is a kind of "plastic part".

[0049] It should be noted that the cylindrical portion 212 refers to a hollow structure with open ends. After the plate portion 211 is set at one end of the cylindrical portion 212, the opening at this end of the cylindrical portion 212 will be closed. The cross-sectional shape of the cylindrical portion 212 is not limited, for example, it can be a round cylinder or a square cylinder.

[0050] See also Figure 2-6 Optionally, a first protrusion 213 is arranged around the outer wall of the barrel portion 212, and the first protrusion 213 abuts against the inner wall of the outer shell 1. The barrel portion 212, the first protrusion 213 and the outer shell 1 can form a first annular space, and at least part of the sealant 3 is arranged in the first annular space.

[0051] In this embodiment, a first protrusion 213 is arranged around the outer wall of the barrel portion 212. When one end of the barrel portion 212 away from the plate portion 211 (the lower end shown in the figure) is inserted into the shell 1 through the opening of the shell 1, the outer circle of the first protrusion 213 can abut against the inner wall of the shell 1. In this way, a first annular space with an open top can be enclosed between the barrel portion 212, the upper side wall of the first protrusion 213 and the inner wall of the shell 1, and then glue can be injected into at least the first annular space. After the glue is cured, a sealant 3 is formed, thereby realizing the sealing and connection fixation between the cover body 21 and the shell 1.

[0052] It is understandable that the first protrusion 213 is also a part of the cover body 21 and can be integrally formed by an injection molding process.

[0053] See also Figure 2-6 Optionally, the battery cell further includes a first sealing ring 4, and a second protrusion 214 is arranged around the outer wall of the barrel portion 212, and the second protrusion 214 is arranged on the side of the first protrusion 213 away from the opening, and the first sealing ring 4 is arranged between the second protrusion 214 and the first protrusion 213, and the first sealing ring 4 is respectively in contact with the inner wall of the shell 1 and the outer wall of the barrel portion 212.

[0054] In this embodiment, the second protrusion 214 is located below the first protrusion 213. Before the cover body 21 is inserted into the housing 1, the first sealing ring 4 is first sleeved between the first protrusion 213 and the second protrusion 214. The material of the first sealing ring 4 is rubber and has a rebound function. After the first sealing ring 4 is sleeved between the first protrusion 213 and the second protrusion 214, the lower end of the barrel 212 is inserted into the housing 1, and then the outer ring of the first sealing ring 4 can be squeezed and deformed in the radial direction by the inner wall of the housing 1 to achieve sealing. After that, glue is injected into the first annular space to form a solid sealant 3. Due to the sealing effect of the first sealing ring 4, it can prevent the glue from leaking downward when the glue is injected.

[0055] It is understandable that the first protrusion 213 is also a part of the cover body 21 and can be integrally formed by an injection molding process.

[0056] See also Fig. 9Optionally, a dimension of the first sealing ring 4 in the insertion direction of the cylindrical portion 212 is L1, and a distance from an inner ring to an outer ring of the first sealing ring 4 is L2, wherein L1≥L2.

[0057] In this embodiment, the vertical dimension of the first sealing ring 4 is larger, that is, the distance between the first protrusion 213 and the second protrusion 214 is greater than or equal to the distance from the outer wall of the barrel 212 to the inner wall of the shell 1. In this way, after the first sealing ring 4 is sleeved between the first protrusion 213 and the second protrusion 214, it can be ensured that the shape and relative position of the first sealing ring 4 are maintained and do not fall off during the process of inserting the lower end of the barrel 212 into the shell 1, meeting the sealing requirements. Secondly, the first sealing ring 4 can work together with the sealant 3 to seal the cover body 21 and the inner wall of the shell 1.

[0058] See also Figure 3 Optionally, a first inclined guide wall 2141 is provided between the outer ring wall surface of the second protrusion 214 and a side wall of the second protrusion 214 away from the opening.

[0059] In this embodiment, a first inclined guide wall 2141 is provided between the outer ring wall surface of the second protrusion 214 and the lower side wall, so that the barrel portion 212 can be smoothly inserted into the shell 1 to avoid the problem of jamming due to deformation of the top edge of the shell 1.

[0060] See also Figure 3-5 Optionally, a positioning block 215 is protruding from the outer wall of the barrel portion 212, and the positioning block 215 is bent toward one end of the opening to form a positioning boss 216. The other end of the positioning block 215 is inserted into the shell 1, and the positioning boss 216 abuts against the end face of the shell 1 at the opening.

[0061] In this embodiment, the outer wall of the barrel 212 is also protruding with a positioning block 215, and the lower end of the positioning block 215 is inserted into the interior of the shell 1 together with the barrel 212 until the positioning boss 216 abuts against the top surface of the shell 1, thereby realizing the insertion position of the cover body 21 in place, so that the cover body 21 and the shell 1 have a specific relative position relationship along the insertion direction; and the lower end of the positioning block 215 is inserted into the interior of the shell 1 together with the barrel 212, so that a gap can be formed between the outer wall of the barrel 212 and the inner wall of the shell 1, so as to facilitate filling of sealant. Figure 4-5 As shown, there are multiple positioning blocks 215, and the multiple positioning blocks 215 are sequentially spaced along the circumferential direction of the cylinder portion 212. Figure 3 , the width C of the positioning boss 216 can be the same as the wall thickness of the housing 1.

[0062] See also Figure 3Optionally, a second inclined guide wall 2151 is provided between a side wall of the positioning block 215 away from the center of the barrel portion 212 and a side wall of the positioning block 215 away from the opening.

[0063] In this embodiment, a second inclined guide wall 2151 is provided between a side wall of the positioning block 215 away from the center of the plate body 211 and a lower side wall thereof to ensure that the lower end of the positioning block 215 can be smoothly inserted into the housing 1 to prevent jamming.

[0064] See also Figure 4-5 Optionally, a first raised platform 217 is provided at the center of the plate body 211 protruding toward the outside of the shell 1, the barrel portion 212 and the portion of the plate body 211 not provided with the first raised platform 217 are provided inside the shell 1, part of the sealant 3 is provided between the outer wall of the barrel portion 212 and the inner wall of the shell 1, and other parts of the sealant 3 are provided between the peripheral side wall of the first raised platform 217 and the inner wall of the shell 1.

[0065] In this embodiment, the portion of the plate body 211 not protruding with the first raised platform 217 is inserted into the housing 1, that is, the portion of the plate body 211 not protruding with the first raised platform 217 and the cylinder body 212 are located at the lower side of the top surface of the housing 1, so that a relatively wide annular space is formed between the peripheral side wall of the first raised platform 217 and the inner wall of the housing 1, which is recorded as the second annular space. That is, if Fig.10 As shown, the width L3 of the second annular space is greater than the gap L4 formed between the outer wall of the barrel 212 and the inner wall of the shell 1. In this way, the minimum operating space of the glue injection equipment in the production process can be met, that is, the glue injection head of the glue injection equipment can be inserted into the wider second annular space and perform glue injection. During the glue injection process, the glue in the second annular space can flow into and supplement the glue in the narrow first annular space in time to ensure that the glue in the first annular space is fully filled. After the glue injection is completed and the glue is cured, part of the sealant 3 is located in the first annular space, and the other part is located in the second annular space.

[0066] See also Figure 4-5 and Figure 7 Optionally, a pole hole 2171 is provided on the plate body 211 , the pole assembly 22 is inserted into the pole hole 2171 , and a first sealing ring 231 is provided between the pole assembly 22 and the pole hole 2171 .

[0067] It should be noted that in the existing battery cells, since the cover body 21 is made of aluminum, the metal parts in the cover assembly, such as the pole assembly 22, need to be insulated with additional upper plastic and lower plastic when installed on the cover body 21. In particular, the lower plastic is large in volume and usually needs to cover the opening of the outer shell 1. The upper plastic and the lower plastic require a large amount of material, which not only makes assembly more troublesome but also increases the material cost.

[0068] In this embodiment, since the material of the barrel portion 212 can be a low-cost resin plastic material, which has insulation properties, no additional insulating parts are required on the barrel portion 212, such as upper plastic and lower plastic to insulate the pole assembly 22, which can further reduce costs and improve the assembly efficiency of the cover assembly. Since there is no need to consider the insulation of the pole assembly 22, it is only necessary to set a first sealing ring 231 between the pole assembly 22 and the inner wall of the pole hole 2171.

[0069] Specifically, Figure 7 and Fig.11 As shown, the pole assembly 22 includes an electrode terminal 221, a pole body 222 and a current collector 223 from top to bottom, the current collector 223 is located on the side of the plate body 211 facing the inside of the housing 1, the electrode terminal 221 is located on the side of the plate body 211 facing the outside of the housing 1, the pole body 222 is inserted into the pole hole 2171, and the first sealing ring 231 is located between the pole body 222 and the hole wall of the pole hole 2171, and the axial ends of the first sealing ring 231 abut against the electrode terminal 221 and the current collector 223 respectively. Among them, the current collector 223 is used to be welded with the pole ear of the winding core inside the housing 1, the bottom end of the pole body 222 is welded with the current collector 223, and the top end of the pole body 222 and the electrode terminal 221 can be fixed by riveting.

[0070] See also Figure 4-6 and Fig.11 Optionally, the cover plate assembly 2 also includes an explosion-proof valve plate 25, a first mounting groove 2172 is provided on the outer side of the plate body 211, a vent hole 2173 is provided at the bottom of the first mounting groove 2172, and the explosion-proof valve plate 25 is arranged in the first mounting groove 2172.

[0071] It should be noted that in the existing battery cells, the explosion-proof valve sheet, as a metal component of the cover assembly, also needs to be insulated from the aluminum cover body by an insulating member. In the present embodiment, since the cover body 21 is made of plastic material, which has insulating properties, the installation of the explosion-proof valve sheet 25 does not require additional insulating members, which can further reduce the cost of the cover assembly and improve the assembly efficiency of the cover assembly. Specifically, a first mounting groove 2172 is provided on the upper side of the plate body 211 of the cover body 21, and a vent hole 2173 for pressure relief is provided at the bottom of the first mounting groove 2172. The explosion-proof valve sheet 25 is arranged in the middle of the first mounting groove 2172, and the explosion-proof valve sheet 25 located in the first mounting groove will not increase the height dimension (Z-direction dimension) of the battery cell.

[0072] In addition, the explosion-proof valve plate 25 and the pole assembly can be specifically arranged on the first raised platform 217 of the plate body 211, that is, the first mounting groove 2172 and the pole hole 2171 can be respectively arranged on the first raised platform 217 of the plate body 211. In this way, it can be prevented that the glue spreads to the above structure during the process of pouring the glue to form the sealant 3, thereby affecting the product yield.

[0073] See also Figure 6 and Figure 8 Specifically, a weak groove 251 is provided in the center of the explosion-proof valve sheet 25, and the weak groove 251 is connected to the air relief hole 2173. The weak groove 251 can be machined at the central position of the explosion-proof valve, which is equivalent to thinning the central position of the explosion-proof valve sheet 25. The thin part of the explosion-proof valve sheet 25 corresponds to the pressure relief hole. In this way, when the electrochemical reaction inside the battery cell is abnormal or damaged by external force, in order to avoid explosion, the pressure inside the battery cell will break through the thin part of the explosion-proof valve sheet 25 to release high-pressure gas and ensure the safety of the battery cell.

[0074] See also Figure 4-6 and Fig.11 Optionally, a second sealing ring 232 is embedded in the bottom of the first installation groove 2172, the air leakage hole 2173 is arranged in the second sealing ring 232, and the second sealing ring 232 abuts against the explosion-proof valve plate 25;

[0075] And / or, the cover plate assembly 2 further includes a fixed ring piece 241 , at least a portion of which is disposed in the first mounting groove 2172 and abuts against the explosion-proof valve piece 25 , and a periphery of the fixed ring piece 241 is welded and fixed to the plate body 211 .

[0076] In this embodiment, after the explosion-proof valve disc 25 is arranged in the first installation groove 2172, the first sealing can be achieved through the second sealing ring 232 abutting against it. In addition, at least a portion of the fixed ring disc 241 can be arranged in the first installation groove 2172 and the periphery of the fixed ring disc 241 is welded to the plate body 211, so that the fixed ring disc 241 is pressed against the second sealing ring 232, and the second sealing is achieved by welding the periphery of the fixed ring disc 241 to the plate body 211, and the sealing effect is better.

[0077] The material of the fixing ring piece 241 can be the same as that of the cover body 21 (i.e., the fixing ring piece 241 can also be a plastic part made of plastic material), so that the two can be welded and fixed. Optionally, the side of the fixing ring piece 241 away from the explosion-proof valve piece 25 is flush with the surface of the plate body 211 around the first installation groove 2172. Specifically, the edge of the fixing ring piece 241 is welded and fixed to the plate body 211, which makes welding more convenient and reduces the difficulty of welding.

[0078] See also Figure 4 , Figure 6 and Fig.11 , Optionally, the cover plate assembly 2 further includes a fixing sheet 242, and a liquid injection channel is provided on the plate body 211;

[0079] At least a portion of the fixing sheet 242 is disposed in the injection channel, or the fixing sheet 242 abuts against the outer side of the plate body 211 and covers the injection channel;

[0080] The periphery of the fixing plate 242 is fixed to the plate body 211 by welding.

[0081] In this embodiment, a liquid injection channel is provided on the plate body 211, and electrolyte can be injected into the housing 1 through the liquid injection channel. After the electrolyte is injected, at least part of the fixing sheet 242 can be set in the liquid injection channel, or the fixing sheet 242 can be abutted against the outer side of the plate body 211 and cover the liquid injection channel, and then the periphery of the fixing sheet 242 can be welded and fixed to the plate body 211, so that the fixing sheet 242 is fixed and sealed by welding. The material of the fixing sheet 242 can be the same as that of the cover body 21 (that is, the fixing sheet 242 can also be a plastic part made of plastic material), so that the two can be welded and fixed.

[0082] Optionally, the cover plate assembly 2 also includes a sealing plug 233, a second mounting groove 2174 is provided on the outer side of the plate body 211, a liquid injection hole 2175 is provided at the bottom of the second mounting groove 2174 (the second mounting groove 2174 and the liquid injection hole 2175 together constitute the aforementioned liquid injection channel), and a sealing plug 233 is provided in the liquid injection hole 2175, the fixing plate 242 is attached to the bottom of the second mounting groove 2174 and abuts against the sealing plug 233, a side of the fixing plate 242 away from the sealing plug 233 is flush with a partial surface of the plate body 211 surrounding the second mounting groove 2174, and the edge of the fixing plate 242 is welded and fixed to the plate body 211.

[0083] In this embodiment, the bottom of the second mounting groove 2174 is provided with a liquid injection hole 2175, through which electrolyte can be injected into the housing 1. After the electrolyte is injected, the sealing plug 233 is sealed at the liquid injection hole 2175, and then the fixing sheet 242 is attached to the bottom of the second mounting groove 2174, and the fixing sheet 242 is welded to the plate body 211, so as to press and fix the plugging head through the fixing sheet 242. Among them, the liquid injection hole 2175 can be a stepped hole with a "T"-shaped cross section, and the plugging head can be a sealing nail made of rubber material. After the fixing sheet 242 is attached to the bottom of the second mounting groove 2174, at least the edge position of the top thereof is flush with the surface of the surrounding plate body 211, so that the two are easy to be welded by plastic laser, reducing the difficulty of welding. At the same time, the sealing plug 233 pressed and fixed by the fixing plate 242 constitutes the first seal of the injection channel, and the fixing plate 242 welded and fixed to the plate body 211 constitutes the second seal of the injection channel, and the sealing effect is better.

[0084] The injection channel may be arranged at the first raised platform 217 of the plate body 211 , so as to prevent the glue from spreading to the injection channel during the process of forming the sealant 3 by pouring glue, thereby affecting the product yield.

[0085] Another embodiment of the present invention provides a battery pack, comprising the battery cell as described above.

[0086] Since the connection between the shell and the cover body in the aforementioned battery cell does not need to be processed by precise mechanical milling, the processing cost and time are reduced, the production efficiency is improved, and the scrap rate is reduced; and since laser welding is not required, the generation of laser welding slag and the subsequent grinding and slag removal process can be avoided from the root, and the problem of insulation failure between the battery cell and the external environment caused by welding slag or raised welds piercing the insulation film is solved. Therefore, the battery pack with this battery cell also has higher production efficiency, lower production cost and scrap rate, and higher safety and reliability.

[0087] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include at least one of the features.

[0088] Although the utility model is disclosed as above, the protection scope of the utility model is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the utility model, and these changes and modifications will fall within the protection scope of the utility model.

Claims

1. A battery cell, It is characterized in that The invention comprises an outer shell (1), a cover plate assembly (2) and a sealant (3); at least one end of the outer shell (1) is provided with an opening; the cover plate assembly (2) comprises a cover plate body (21); at least a portion of the cover plate body (21) is inserted into the outer shell (1) through the opening; and the cover plate body (21) is bonded to the inner wall of the outer shell (1) by the sealant (3).

2. The battery cell according to claim 1, It is characterized in that The cover plate body (21) is a plastic part.

3. The battery cell according to claim 1 or 2, It is characterized in that The cover plate body (21) comprises a plate body portion (211) and a cylinder body portion (212), wherein the plate body portion (211) is arranged at one end of the cylinder body portion (212); At least a portion of the cylindrical portion (212) is inserted into the outer shell (1), and at least a portion of the sealant (3) is disposed between the outer wall of the cylindrical portion (212) and the inner wall of the outer shell (1).

4. The battery cell according to claim 3, It is characterized in that The outer wall of the cylindrical portion (212) is surrounded by a first protrusion (213), and the first protrusion (213) abuts against the inner wall of the outer shell (1). The cylindrical portion (212), the first protrusion (213) and the outer shell (1) can form a first annular space, and at least part of the sealant (3) is arranged in the first annular space.

5. The battery cell according to claim 4, It is characterized in that The invention also comprises a first sealing ring (4); a second protrusion (214) is arranged around the outer wall of the cylindrical body (212); the second protrusion (214) is arranged on a side of the first protrusion (213) away from the opening; the first sealing ring (4) is arranged between the second protrusion (214) and the first protrusion (213); the first sealing ring (4) is respectively in contact with the inner wall of the outer shell (1) and the outer wall of the cylindrical body (212).

6. The battery cell according to claim 3, It is characterized in that A positioning block (215) is protruding from the outer wall of the barrel portion (212); the positioning block (215) is bent toward one end of the opening to form a positioning boss (216); the other end of the positioning block (215) is inserted into the outer shell (1); and the positioning boss (216) abuts against the end surface of the outer shell (1) at the opening.

7. The battery cell according to claim 3, It is characterized in that A first raised platform (217) is provided at the center of the plate body (211) protruding toward the outside of the shell (1); the portion of the cylinder body (212) and the plate body (211) not provided with the first raised platform (217) are provided inside the shell (1); a portion of the sealant (3) is provided between the outer wall of the cylinder body (212) and the inner wall of the shell (1); and the other portion of the sealant (3) is provided between the peripheral side wall of the first raised platform (217) and the inner wall of the shell (1).

8. The battery cell according to claim 3, It is characterized in that The cover plate assembly (2) further comprises an explosion-proof valve plate (25); a first mounting groove (2172) is arranged on the outer side of the plate body (211); a vent hole (2173) is arranged at the bottom of the first mounting groove (2172); and the explosion-proof valve plate (25) is arranged in the first mounting groove (2172).

9. The battery cell according to claim 8, It is characterized in that A second sealing ring (232) is embedded in the bottom of the first installation groove (2172), the air leakage hole (2173) is arranged in the second sealing ring (232), and the second sealing ring (232) abuts against the explosion-proof valve plate (25); And / or, the cover plate assembly (2) further comprises a fixed ring plate (241), at least a portion of which is disposed in the first mounting groove (2172) and abuts against the explosion-proof valve plate (25), and a periphery of the fixed ring plate (241) is welded and fixed to the plate body (211).

10. The battery cell according to claim 3, It is characterized in that The cover plate assembly (2) further comprises a fixing plate (242), and a liquid injection channel is provided on the plate body (211); At least a portion of the fixing sheet (242) is disposed in the liquid injection channel, or the fixing sheet (242) abuts against the outer side of the plate body (211) and covers the liquid injection channel; The periphery of the fixing plate (242) is fixed to the plate body (211) by welding.

11. A battery pack, It is characterized in that Comprising the battery cell as described in any one of claims 1 to 10.

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