Battery

Abstract

The invention belongs to the technical field of batteries, and discloses a battery which comprises a pole group, a cover plate assembly and a shell, the pole group is connected with a protruding part and tabs, the protruding part is arranged on the end face of the pole group, and the tabs are arranged on the two sides of the protruding part in the first direction; the cover plate assembly comprises a cover plate body, a protective side plate and a pole, the cover plate body comprises a first part and a second part, the first part corresponds to the protruding part, the protective side plate and the first part define a space for containing the protruding part, the second part is connected with the first part, and the pole penetrates through the second part and is connected with the first part in the third direction. The surface, deviating from the pole group, of the first part protrudes out of the surface, deviating from the pole group, of the pole; the pole group is arranged in the shell, and the cover plate body and the protective side plates are connected with the shell. Thus, the protruding part can increase the capacity of the battery, assembling spaces can be reserved on the two sides of the protruding part so that the adjacent pole sets can be connected, the pole sets and the protruding part can be protected through the protection side plates and the cover plate body, and the structural strength of the cover plate assembly is improved.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to a battery. Background Technology

[0002] Lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage. A lithium-ion battery includes an electrode assembly, a cover plate, and a housing. The cover plate and housing enclose the space for housing the electrode assembly. The electrode assembly is connected to tabs at its ends. The cover plate is provided with terminals that are electrically connected to the tabs. The terminals are connected to rivet blocks, and both the terminals and the rivet blocks protrude from the cover plate.

[0003] However, the rivet blocks and poles on the protruding cover plate have poor protection, and are prone to bumps and scratches during transportation and assembly, which affects the safety performance and appearance of the battery. The space utilization of the cover plate is low, and it is difficult to adapt it to the shape of the cell, which affects the cell capacity and assembly ratio. In addition, the cover plate is usually made of thin aluminum sheet with low structural strength. After being connected to the electrode assembly, it is not easy to push the electrode assembly into the shell, which can easily cause defects such as electrode damage, reduce battery yield, and increase the risk of deformation. Summary of the Invention

[0004] The purpose of this invention is to provide a battery that solves the problems of low cover space utilization and low structural strength in lithium-ion batteries.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A battery includes: an electrode assembly, the electrode assembly being connected to a protrusion and a tab, the protrusion being disposed on an end face of the electrode assembly, and the tabs being disposed on both sides of the protrusion in a first direction; a cover plate assembly, the cover plate assembly including a cover plate body, a protective side plate, and a terminal post, the cover plate body including a first part and a second part, the first part being disposed corresponding to the protrusion, the protective side plate and the first part enclosing a space for accommodating the protrusion, the second part being connected to the first part, and the terminal post passing through the second part. In a third direction, the surface of the first part opposite to the electrode assembly protrudes from the surface of the terminal post opposite to the electrode assembly; a housing, the electrode assembly being disposed inside the housing, and the cover plate body and the protective side plate being connected to the housing; the first direction is the length direction of the cover plate body, and the third direction is the height direction of the cover plate body.

[0007] Preferably, the cover plate assembly further includes a riveting block, which is connected to one end of the pole post opposite to the pole group. Along the third direction, the first part of the surface opposite to the pole group protrudes from the surface of the riveting block opposite to the pole group.

[0008] Preferably, the area of ​​the protrusion away from the end of the electrode group is smaller than the area of ​​the protrusion facing the end of the electrode group.

[0009] Preferably, the cover plate assembly further includes an explosion-proof valve, and the protective side plate has a mounting hole for installing the explosion-proof valve.

[0010] Preferably, the cover plate assembly further includes a first plastic and a second plastic, the first plastic being disposed between the first portion and the protrusion, and the second plastic being disposed between the end of the pole facing the pole group and the cover plate body.

[0011] Preferably, the first plastic part has an exhaust hole on its sidewall facing the mounting hole.

[0012] Preferably, a limiting step is fixedly connected to the side of the protective side plate facing the first part, and a limiting groove is formed in the first part corresponding to the position of the limiting step, so that the first part can be engaged with the protective side plate.

[0013] Preferably, a limiting boss is provided at the position where the limiting groove is formed in the first part. The limiting boss is located at the end of the first part facing the second part, and the protective side plate abuts against the limiting boss.

[0014] Preferably, the width of the limiting boss in the second direction is A, and the length of the limiting boss in the first direction is B, satisfying 0.63mm. 2 ≤A*B≤3mm 2 The second direction is the width direction of the cover plate body; and / or, along the second direction, the width of the cover plate body where the limiting groove is opened is L1, and the width of the cover plate body where the pole post is set is L2, and satisfies 1.4mm≤L2-L1≤3mm, where the second direction is the width direction of the cover plate body.

[0015] Preferably, the thickness of the protective side plate is T1, and satisfies 1mm≤T1≤2mm.

[0016] The beneficial effects of this invention are:

[0017] A battery includes an electrode assembly, a cover plate assembly, and a housing. The electrode assembly has a protrusion and tabs connected to it. The protrusion is disposed on the end face of the electrode assembly, and the tabs are disposed on both sides of the protrusion in a first direction. The cover plate assembly includes a cover plate body, a protective side plate, and a terminal post. The cover plate body includes a first part and a second part. The first part is disposed corresponding to the protrusion. The protective side plate and the first part enclose a space for accommodating the protrusion. The second part is connected to the first part, and the terminal post passes through the second part. In a third direction, the surface of the first part opposite to the electrode assembly protrudes from the surface of the terminal post opposite to the electrode assembly. The electrode assembly is disposed inside the housing, and the cover plate body and the protective side plate are both connected to the housing. The first direction is the length direction of the cover plate body, and the third direction is the height direction of the cover plate body.

[0018] In this way, by setting the protrusion, the space in the thickness direction of the cover plate body can be effectively utilized, so that the protrusion can increase the battery capacity while protecting the terminal post, reducing the risk of the terminal post being bumped by the outside world, improving the safety and stability of the battery, and there is enough assembly space on both sides of the protrusion so that the terminal posts of adjacent terminal groups can be stably connected; after the protective side plate is connected to the first part, it can protect the protrusion, improve the structural strength of the cover plate assembly, and prevent deformation when the cover plate body is welded to the shell. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the battery structure in one embodiment of the present invention;

[0020] Figure 2 This is a partial cross-sectional view of a battery in one embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the first structure of the cover plate assembly in one embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the second structure of the cover plate assembly in one embodiment of the present invention;

[0023] Figure 5 This is a front sectional view of a cover plate assembly according to an embodiment of the present invention;

[0024] Figure 6 This is a side sectional view of the first part and the protective side plate in one embodiment of the present invention;

[0025] Figure 7 This is a front view of the protective side panel in one embodiment of the present invention;

[0026] Figure 8 This is a side view of the protective side plate in one embodiment of the present invention;

[0027] Figure 9 This is a schematic diagram of the cover plate body in one embodiment of the present invention;

[0028] Figure 10 This is a front view of the cover plate body in one embodiment of the present invention;

[0029] Figure 11 This is a top view of the cover plate body in one embodiment of the present invention;

[0030] Figure 12 This is a schematic diagram of the structure of the first plastic in one embodiment of the present invention;

[0031] Figure 13 This is a front view of the first plastic in one embodiment of the present invention;

[0032] Figure 14 This is a first exploded view of the cover plate assembly in one embodiment of the present invention;

[0033] Figure 15 This is a second exploded view of the cover plate assembly in one embodiment of the present invention.

[0034] In the picture:

[0035] 1. Electrode assembly; 11. Protrusion; 12. Electrode lug; 2. Cover plate assembly; 21. Cover plate body; 211. First part; 212. Second part; 213. Limiting groove; 214. Limiting boss; 22. Protective side plate; 221. Mounting hole; 222. Limiting step; 223. Protrusion; 23. Electrode post; 231. Conductive block; 24. Riveting block; 25. First plastic; 251. Vent hole; 252. Overlap; 26. Second plastic; 27. Third plastic; 28. Sealing ring; 3. Housing. Detailed Implementation

[0036] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0037] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0039] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0040] See Figure 1 and Figure 2 The present invention provides a battery comprising an electrode assembly 1, a cover plate assembly 2, and a housing 3. The electrode assembly 1 is connected to a protrusion 11 and a tab 12. The protrusion 11 is disposed on the end face of the electrode assembly 1, and the tab 12 is disposed on both sides of the protrusion 11 in a first direction X. The cover plate assembly 2 comprises a cover plate body 21, a protective side plate 22, and a terminal post 23. The cover plate body 21 comprises a first part 211 and a second part 212. The first part 211 is disposed corresponding to the protrusion 11, and the protective side plate 22 surrounds the first part 211 to form a shape. The space is used to accommodate the protrusion 11. The second part 212 is connected to the first part 211. The pole post 23 passes through the second part 212. Along the third direction Z, the surface of the first part 211 away from the pole group 1 protrudes from the surface of the pole post 23 away from the pole group 1. That is, the distance between the surface of the first part 211 away from the pole group 1 and the pole group 1 is greater than the distance between the surface of the pole post 23 away from the pole group 1 and the pole group 1. The pole group 1 is disposed inside the housing 3. The cover plate body 21 and the protective side plate 22 are both connected to the housing 3.

[0041] The first direction X is the length direction of the cover plate body 21, and the third direction Z is the height direction of the cover plate body 21.

[0042] In this embodiment, the protrusion 11 is integrally formed with the electrode assembly 1. Two tabs 12 are provided at the end of the electrode assembly 1, respectively located on both sides of the protrusion 11. The cover plate body 21 is made of aluminum. The shape of the first part 211 matches the shape of the protrusion 11. Two protective side plates 22 are provided, respectively located on both sides of the first part 211 and fixedly connected to it. The shape of the protective side plates 22 matches the sidewall shape in the thickness direction of the protrusion 11, so that the space formed by the protective side plates 22 and the first part 211 matches the shape of the protrusion 11. Two second parts 212 are provided, each integrally formed with both ends of the first part 211, and the second parts 212 extend along the width direction of the electrode assembly 1. The electrode post 23 is fixedly disposed on the second part 212.

[0043] Thus, by setting the protrusion 11, the battery capacity can be increased, and the space in the thickness direction of the cover body 21 can be effectively utilized, so that assembly space can be reserved on both sides of the protrusion 11 to facilitate the connection of adjacent electrode groups 1; after the protective side plate 22 is connected to the first part 211, it can provide protection for the protrusion 11, improve the structural strength of the cover assembly 2, and prevent deformation when the cover body 21 is welded to the shell 3; and since the protrusion 11 protrudes from the electrode post 23, it can protect the electrode post 23, reduce the risk of the electrode post 23 being bumped to the outside, and improve the safety and stability of the battery.

[0044] It is understandable that the protrusion 11 can be provided only at one end of the electrode group 1, or it can be provided at both ends of the electrode group 1. The position of the protrusion 11 can be adjusted according to actual needs, and will not be listed in detail here.

[0045] See Figure 1 and Figure 2 In some embodiments, the cover plate assembly 2 further includes a riveting block 24, which is fixedly connected to one end of the pole post 23 away from the pole group 1. Along the third direction Z, the surface of the first part 211 away from the pole group 1 protrudes from the surface of the riveting block 24 away from the pole group 1.

[0046] In this way, the first part 211 can protect the pole post 23 and the rivet block 24, prevent them from colliding with the external structure, and improve the overall structural strength of the cover plate assembly.

[0047] See Figure 3 In some embodiments, the protective side plate 22 is welded to the first part 211.

[0048] In this embodiment, the protective side plate 22 and the first part 211 are fixedly connected by laser welding. The surface of the protective side plate 22 facing the shell 3 and the surface of the second part 212 facing the shell 3 are both fixedly connected to the edge of the shell 3 by welding.

[0049] Thus, by setting the protective side plate 22 and the first part 211 between the two riveting blocks 24, the space on the side of the cover plate body 21 away from the electrode group 1 can be effectively utilized. After the protective side plate 22 is assembled to the first part 211, the cover plate assembly 2 is then assembled to the housing 3. This can restrict the relative position of the protrusion 11 and the cover plate assembly 2, improve the safety of the cover plate assembly 2, reduce the risk of displacement, and facilitate the stable connection of the electrode group 1 to the electrode post 23 through the electrode tab 12. Furthermore, the protective side plate 22 and the first part 211 can protect the protrusion 11, improve the structural strength of the connection between the cover plate assembly 2 and the electrode group 1, reduce the risk of damage to the electrode group 1 and movement during housing insertion, and improve the safety performance of the battery.

[0050] It is understandable that the protective side plate 22 can also be fixedly connected to the first part 211 by bolts, clips and other fasteners. In this embodiment, welding is used to connect them in order to improve the structural strength and sealing performance of the connection between the protective side plate 22 and the first part 211. The connection method between the protective side plate 22 and the first part 211 can be adjusted according to actual needs, and will not be listed in detail here.

[0051] See Figure 2 In some embodiments, the area of ​​the protrusion 11 away from the electrode group 1 is smaller than the area of ​​the protrusion 11 facing the electrode group 1. In this embodiment, the protrusion 11 is a trapezoidal boss structure, and correspondingly, the protective side plate 22 is a trapezoidal plate structure.

[0052] Thus, along the direction away from the pole group 1, the cross-sectional area of ​​the protrusion 11 gradually decreases, so that there is enough space on both sides of the protrusion 11 to connect the adjacent pole group 1, thereby improving the space utilization of the cover plate assembly 2, saving assembly space, and thus improving the module assembly rate.

[0053] It is understandable that the protrusion 11 can also be a cuboid structure. The shape of the protrusion 11 and the shape of the protective side plate 22 can be adjusted according to actual needs, which will not be listed in detail here.

[0054] See Figure 3 and Figure 4 In some embodiments, the cover plate assembly 2 also includes an explosion-proof valve (not shown in the figure), and the protective side plate 22 has a mounting hole 221 for installing the explosion-proof valve.

[0055] In this embodiment, the length direction of the explosion-proof valve is parallel to the length direction of the protective side plate 22, and the explosion-proof valve is symmetrically arranged on one of the protective side plates 22 and fixedly connected to it by welding.

[0056] Thus, placing the explosion-proof valve on the protective side plate 22 not only makes the position of the explosion-proof valve more flexible, allowing it to adapt to more application scenarios, but also reduces the risk of scratches during battery assembly, improves the safety and stability of the cover plate assembly 2, and effectively utilizes the space on the protective side plate 22, improving the space utilization rate of the cover plate assembly 2. During assembly, the explosion-proof valve can be welded to the protective side plate 22 first, and then the protective side plate 22 with the explosion-proof valve can be welded to the first part 211, reducing the assembly difficulty.

[0057] It is understandable that the shape and location of the explosion-proof valve can be adjusted according to actual needs, which will not be elaborated here.

[0058] See Figure 5 and Figure 6 In some embodiments, the cover plate assembly 2 further includes a first plastic 25 and a second plastic 26, the first plastic 25 being disposed between the first portion 211 and the protrusion 11, and the second plastic 26 being disposed between the end of the pole post 23 facing the pole group 1 and the cover plate body 21.

[0059] In this embodiment, see Figure 12 and Figure 13 The shape of the first plastic 25 is adapted to the shape of the protrusion 11.

[0060] Further, see Figure 14 and Figure 15 The second plastic piece 26 is provided in a one-to-one correspondence with the electrode post 23, that is, there are two second plastic pieces 26. The end of the electrode post 23 facing the electrode group 1 is provided with a conductive block 231. The cover plate assembly 2 also includes a sealing ring 28 (see Figure 5 The sealing ring 28 is sleeved on the pole post 23 and connected to the second plastic 26. The second plastic 26 has a groove (not shown in the figure) for accommodating the conductive block 231 to limit the position of the first plastic 25 and the pole post 23 on the cover plate body 21. The first plastic 25 has overlapping portions 252 fixedly connected to both ends, so that the first plastic 25 can be snapped with the first part 211 and achieve an insulating connection between the first part 211 and the protrusion 11. When the first plastic 25 and the second plastic 26 are both assembled to the cover plate body 21, the side wall of the overlapping portion 252 abuts against the side wall of the second plastic 26.

[0061] Thus, the separate arrangement of the first plastic 25 and the second plastic 26 reduces assembly difficulty, prevents the second plastic 26 from deflecting during assembly and affecting the assembly effect, improves the insulation effect of the first plastic 25 and the second plastic 26, and thus improves the safety of the cover assembly 2; the first plastic 25 is snapped into the first part 211 through the overlapping part 252, reducing the risk of the first plastic 25 shifting during assembly and improving the structural performance of the cover assembly 2, preventing the cover assembly 2 from deforming when the pole group 1 is inserted into the shell.

[0062] Furthermore, the cover plate assembly 2 also includes a third plastic 27, which has a groove (not shown) for accommodating the rivet block 24, so that the rivet block 24 and the second part 212 are insulatedly connected.

[0063] See Figure 6 In some embodiments, the first plastic 25 has an exhaust hole 251 on its sidewall facing the mounting hole 221.

[0064] In this embodiment, multiple vent holes 251 are provided, and the multiple vent holes 251 are spaced apart on the side wall of the first plastic 25, so that the mounting hole 221 communicates with the interior of the first plastic 25.

[0065] In this way, when the battery experiences thermal runaway, the large amount of high-temperature gas generated can be discharged to the explosion-proof valve through the exhaust port 251, enabling the explosion-proof valve to open quickly and release pressure, thereby improving the battery's safety performance.

[0066] It is understandable that the shape of the vent hole 251 can also be the same as the shape of the mounting hole 221. The shape of the vent hole 251 can be adjusted according to actual needs, and will not be listed in detail here.

[0067] See Figures 7 to 9 In some embodiments, a limiting step 222 is fixedly connected to the side of the protective side plate 22 facing the first part 211, and a limiting groove 213 is formed in the first part 211 at the position corresponding to the limiting step 222 so that the first part 211 can be engaged with the protective side plate 22.

[0068] In this embodiment, the limiting step 222 and the protective side plate 22 are integrally formed. The bottom surface of the limiting step 222 is flush with the bottom surface of the protective side plate 22. The side surface of the limiting step 222 is spaced apart from the side surface of the protective side plate 22. The depth of the limiting groove 213 is equal to the thickness of the limiting step 222, so that when the limiting step 222 is engaged in the limiting groove 213, the protective side plate 22 abuts against the side wall of the first part 211.

[0069] Thus, by setting the limiting step 222, the assembly difficulty can be reduced, the protective side plate 22 and the first part 211 can be initially positioned, and the protective side plate 22 can be prevented from shifting during the assembly process and causing poor welding. This improves the connection stability between the protective side plate 22 and the first part 211 and the structural strength of the connection, so that the cover plate assembly 2 can protect the protrusion 11 and reduce the risk of the rivet block 24 colliding with the external structure, thereby improving the safety of the battery.

[0070] See Figure 9 and Figure 10In some embodiments, a limiting boss 214 is provided at the position where the limiting groove 213 is opened in the first part 211. The limiting boss 214 is provided at the end of the first part 211 facing the second part 212, and the protective side plate 22 abuts against the limiting boss 214.

[0071] In this embodiment, the limiting bosses 214 are respectively disposed at the four corners of the end of the first part 211 facing the pole group 1, and the bottom of both ends of the protective side plate 22 are integrally formed with protrusions 223, which overlap and are disposed above the limiting bosses 214.

[0072] Thus, the limiting boss 214 can provide stable support for the protective side plate 22, preventing deformation when the protective side plate 22 is welded to the first part 211, improving the structural strength at the connection between the protective side plate 22 and the first part 211, and thus improving the overall structural strength of the cover assembly 2. This allows the cover assembly 2 to protect the protrusion 11, increasing battery capacity while saving space on both sides of the protrusion 11, and reducing the risk of the rivet block 24 colliding with the outside. When multiple adjacent pole groups 1 are connected, the adjacent first parts 211 are abutted together, and the cover assembly 2 has sufficient structural strength to prevent deformation of the first part 211 and the protective side plate 22 during assembly, thereby improving battery safety and yield.

[0073] See Figure 11 In some embodiments, the width of the limiting boss 214 in the second direction Y is A, and the length of the limiting boss 214 in the first direction X is B, satisfying 0.63mm. 2 ≤A*B≤3mm 2 Along the second direction Y, the width of the limiting groove 213 on the cover body 21 is L1, and the width of the pole post 23 on the cover body 21 is L2, and the condition 1.4mm≤L2-L1≤3mm is met. The second direction Y is the width direction of the cover body 21.

[0074] In this embodiment, the product of the width A and the length B of the limiting boss 214 is also the surface area of ​​the limiting boss 214. The product of the width A and the length B of the limiting boss 214 can be 0.63mm. 2 -3mm 2 Any value between or between any two values, for example, 0.63mm. 2 0.7mm 2 0.8mm 2 1mm 2 1.5mm 2 2mm 2 2.5mm 2 3mm 2The width L1 of the cover body 21 where the limiting groove 213 is opened is also the width of the first part 211, and the maximum width L2 is also the width of the part of the second part 212 where the limiting groove 213 is not opened. The difference between the maximum width L2 of the cover body 21 and the width L1 of the cover body 21 where the limiting groove 213 is opened can be any value between 1.4mm and 3mm or any two values, such as 1.4mm, 1.5mm, 2mm, 2.5mm, 3mm, etc.

[0075] In this way, the limiting boss 214 can stably support the protective side plate 22 without occupying too much space, so that the first plastic 25 and the protrusion 11 can be covered by the first part 211 and the protective side plate 22, and ensure that the cover body 21 has sufficient structural strength. Since the surface of the cover body 21 facing the electrode group 1 is flat, the welding effect of the cover body 21 and the protective side plate 22 to the shell 3 can be improved, thereby improving the safety and stability of the battery.

[0076] Understandably, the product of the width A and length B of the limiting boss 214 cannot be too small. If it is too small, the area of ​​the limiting boss 214 will be insufficient, making it difficult to provide support for the protective side plate 22, increasing the risk of displacement of the protective side plate 22 during assembly, and affecting the welding yield. The product of the width A and length B of the limiting boss 214 cannot be too large either, as this will increase the difficulty of the stamping process. The difference between the maximum width L2 of the cover plate body 21 and the width L1 at the location where the limiting groove 213 is opened on the cover plate body 21 is... The value cannot be too small. If it is too small, the edge size of the protective side plate 22 will be insufficient, which will easily lead to defects such as insufficient molten pool during welding and affect the welding effect, thus reducing the welding yield. The difference between the maximum width L2 of the cover plate body 21 and the width L1 at the opening of the limiting groove 213 of the cover plate body 21 should not be too large. If it is too large, it will reduce the structural strength of the cover plate body 21, increase the risk of deformation of the cover plate body 21 during welding, and if the width L1 at the opening of the limiting groove 213 of the cover plate body 21 is too small, the space to accommodate the protrusion 11 will be smaller, which will affect the battery capacity.

[0077] See Figure 8 In some embodiments, the thickness of the protective side plate 22 is T1, and satisfies 1mm≤T1≤2mm.

[0078] It should be noted that the thickness T1 of the protective side plate 22 includes the thickness of the limiting step 222.

[0079] In this embodiment, the thickness T1 of the protective side plate 22 can be any value between 1mm and 2mm or any range between two values, such as 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2mm, etc.

[0080] In this way, the protective side plate 22 can maintain sufficient structural strength while avoiding occupying too much space inside the first part 211, improving the space utilization of the cover plate assembly 2, so that the protrusion 11 has sufficient volume to increase the battery capacity, and the protective side plate 22 can protect the side wall of the protrusion 11, preventing the protrusion 11 from being damaged by external impacts, reducing the risk of deformation of the cover plate assembly 2 and the protrusion 11, and improving the safety of the battery.

[0081] Understandably, the thickness T1 of the protective side plate 22 cannot be too small. If it is too small, the protective side plate 22 will be insufficient in thickness, and the structural strength of the protective side plate 22 after the explosion-proof valve is installed will be insufficient. It will be easy to deform when welding with the first part 211, which will affect the performance of the cover plate assembly 2. The thickness T1 of the protective side plate 22 cannot be too large either. If it is too large, it will increase the overall weight of the cover plate assembly 2 and squeeze the internal space of the first part 211, reducing the space volume used to accommodate the protrusion 11, which will affect the battery capacity.

[0082] To verify the rationality of the ranges of thickness T1 of protective side plate 22, thickness T2 of side wall of first plastic 25, height H of first part 211, width L1 of limit groove 213 of cover body 21, maximum width L2 of cover body 21, thickness W1 of second part 212, and thickness W2 of first part 211, as shown in Table 1, this embodiment provides six sets of embodiments and six sets of comparative examples for illustration.

[0083]

[0084] As shown in Examples 1 to 6 in the table, after meeting the range limitations, the yield rate of the battery cells meets the requirements, and no abnormalities such as the assembly or strength of the cover plate assembly 2 are found. The cover plate body 21, the protective side plate 22, the electrode group 1, and the electrode tab 12 are all undamaged and undeformed.

[0085] As shown in Comparative Example 1 in the table, when the thickness T1 of the protective side plate 22 is too small, the yield of the battery cell does not meet the requirements. When the thickness of the protective side plate 22 is insufficient, the structural strength of the protective side plate 22 is not strong after the explosion-proof valve is installed, and it will deform when it is welded to the cover plate body 21, affecting the performance.

[0086] As shown in Comparative Example 2 in the table, when the thickness T1 of the protective side plate 22 is too large, the yield of the battery cell does not meet the requirements. The thickness of the protective side plate 22 is too large, which increases the cost and weight.

[0087] As can be seen from Comparative Example 3 in the table, when the difference between the maximum width L2 of the cover plate body 21 and the width L1 at the opening of the limiting groove 213 of the cover plate body 21 is too small, the width difference of the cover plate body 21 is too small, and the corresponding edge size of the protective side plate 22 is insufficient. That is, the connection area between the protective side plate 22 and the first part 211 is too small. During welding, there is insufficient molten pool and low welding yield.

[0088] As shown in Comparative Example 4 in the table, when the difference between the maximum width L2 of the cover body 21 and the width L1 at the opening of the limiting groove 213 of the cover body 21 is too large, the cell yield does not meet the requirements. The large difference in the width of the cover body 21 reduces the structural strength of the cover body 21, occupies the width of the protective side plate 22, and reduces the battery capacity.

[0089] As shown in Comparative Example 5 in the table, when the product of the width A and the length B of the limiting boss 214 is too small, the yield of the battery cell does not meet the requirements. The area of ​​the limiting boss 214 is insufficient, causing displacement during assembly and insufficient positioning accuracy, which leads to a decrease in the welding yield.

[0090] As shown in Comparative Example 6 in the table, when the product of the width A and the length B of the limiting boss 214 is too large, the yield of the battery cell does not meet the requirements. The area of ​​the limiting boss 214 is too large, which increases the difficulty of the stamping process and leads to an increase in the cost and weight of the cover plate body 21.

[0091] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A battery, characterized in that, include: A pole assembly (1) is connected with a protrusion (11) and a tab (12). The protrusion (11) is disposed on the end face of the pole assembly (1), and the tab (12) is disposed on both sides of the protrusion (11) in the first direction (X). The cover plate assembly (2) includes a cover plate body (21), a protective side plate (22), and a pole post (23). The cover plate body (21) includes a first part (211) and a second part (212). The first part (211) is disposed corresponding to the protrusion (11). The protective side plate (22) and the first part (211) enclose a space for accommodating the protrusion (11). The second part (212) is connected to the first part (211). The pole post (23) passes through the second part (212) along a third direction (Z). The surface of the first part (211) facing away from the pole group (1) protrudes from the surface of the pole post (23) facing away from the pole group (1). The housing (3) has the pole group (1) disposed inside the housing (3), and the cover plate body (21) and the protective side plate (22) are both connected to the housing (3); The first direction (X) is the length direction of the cover body (21), and the third direction (Z) is the height direction of the cover body (21).

2. The battery according to claim 1, characterized in that, The cover plate assembly (2) further includes a riveting block (24), which is connected to the end of the pole post (23) away from the pole group (1). Along the third direction (Z), the surface of the first part (211) away from the pole group (1) protrudes from the surface of the riveting block (24) away from the pole group (1).

3. The battery according to claim 1, characterized in that, The area of ​​the protrusion (11) away from the pole group (1) is smaller than the area of ​​the protrusion (11) facing the pole group (1).

4. The battery according to claim 1, characterized in that, The cover plate assembly (2) also includes an explosion-proof valve, and the protective side plate (22) has an installation hole (221) for installing the explosion-proof valve.

5. The battery according to claim 4, characterized in that, The cover plate assembly (2) further includes a first plastic (25) and a second plastic (26), the first plastic (25) being disposed between the first part (211) and the protrusion (11), and the second plastic (26) being disposed between the end of the pole post (23) facing the pole group (1) and the cover plate body (21).

6. The battery according to claim 5, characterized in that, The first plastic (25) has an exhaust hole (251) on its side wall facing the mounting hole (221).

7. The battery according to any one of claims 1-6, characterized in that, The protective side plate (22) is fixedly connected to a limiting step (222) on the side facing the first part (211). The first part (211) has a limiting groove (213) at the position corresponding to the limiting step (222) so that the first part (211) can be engaged with the protective side plate (22).

8. The battery according to claim 7, characterized in that, A limiting boss (214) is provided at the position where the limiting groove (213) is opened in the first part (211). The limiting boss (214) is located at the end of the first part (211) facing the second part (212). The protective side plate (22) abuts against the limiting boss (214).

9. The battery according to claim 8, characterized in that, The width of the limiting boss (214) in the second direction (Y) is A, and the length of the limiting boss (214) in the first direction (X) is B, satisfying 0.63mm. 2 ≤A*B≤3mm 2 The second direction (Y) is the width direction of the cover body (21); and / or, along the second direction (Y), the width of the cover body (21) where the limiting groove (213) is opened is L1, and the width of the cover body (21) where the pole post (23) is set is L2, and satisfies 1.4mm≤L2-L1≤3mm, where the second direction (Y) is the width direction of the cover body (21).

10. The battery according to any one of claims 1-6, characterized in that, The thickness of the protective side plate (22) is T1, and it satisfies 1mm≤T1≤2mm.

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