Battery cell cover plate and battery cell

Abstract

This invention relates to the field of battery technology, providing a cell cover and a cell. The cell cover includes: a cover body comprising a substrate and a boss, the boss protruding from the substrate along its thickness direction, and a through hole penetrating the boss; a terminal post passing through the through hole and protruding from the boss; and a protective component comprising a patch and a plastic part. The patch is attached to the substrate and has a through hole for the boss to pass through. The plastic part includes a retaining portion and a covering portion. The retaining portion is in contact with the side of the patch away from the substrate and surrounds the through hole. The covering portion is connected to the end of the retaining portion away from the patch and forms a window. The terminal post is opposite the window, and the covering portion is attached to the top surface of the boss and / or the end face of the terminal post. This cell cover can protect the terminal post position through the boss and the protective component, preventing electrolyte from reaching the terminal post position and affecting the safety performance of the cell.

Description

Technical Field

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

[0002] The battery pack includes a housing and battery modules assembled inside the housing. Each battery module consists of multiple cells, and the terminals of the multiple cells are electrically connected through busbars. The housing provides physical support and protection for the battery modules. Each battery cell includes a cell housing, a cell cover, and an electrode assembly, which is located within a cavity formed by the cell housing and the cell cover.

[0003] The cell cover includes a cover body, terminals, insulating components, and protective patches. The terminals are located on the cover body, while the insulating components and protective patches are located on opposite sides of the cover body. The insulating components are positioned between the cover body and the terminal assembly for insulation between the terminal assembly and the cover body. The protective patches are used for insulation between the cover body and the external structure. After the cell is assembled, electrolyte is injected into the cell through the injection holes on the cell cover. However, during the injection process, electrolyte can easily flow to the terminals, affecting the cell's safety performance. Summary of the Invention

[0004] This invention provides a cell cover plate and a cell to solve the problem in the prior art where electrolyte easily flows to the terminal position during cell filling, affecting the cell's safety performance.

[0005] This invention provides a battery cell cover plate, comprising: The cover plate body includes a base plate and a boss, the boss protruding from the base plate along the thickness direction of the base plate, and the cover plate body having a through hole penetrating the boss; The pole post passes through the through hole and protrudes from the boss; A protective component includes a patch and a plastic part. The patch is attached to the substrate and has a through hole for the boss to pass through. The plastic part includes a retaining portion and a covering portion. The retaining portion is in contact with the side of the patch away from the substrate and surrounds the through hole. The covering portion is connected to the end of the retaining portion away from the patch and forms a window. The pole is opposite to the window. The covering portion is attached to the top surface of the boss and / or the end face of the pole.

[0006] According to a battery cell cover provided by the present invention, the cover portion is provided with a first notch, through which a busbar connected to the electrode post can pass; the enclosure portion is provided with a second notch corresponding to the position of the first notch, and the first notch and the second notch are connected to form an avoidance notch.

[0007] According to a battery cell cover plate provided by the present invention, the boss has a support portion and a mounting portion connected in the length direction of the substrate, and the electrode post passes through the mounting portion; in the thickness direction, the height of the support portion relative to the substrate is greater than the height of the end of the electrode post protruding from the mounting portion relative to the substrate.

[0008] According to the present invention, a battery cell cover plate includes a first frame portion and a second frame portion connected in the length direction. The first frame portion is provided with a first window and covers the top periphery of the support portion, and the second frame portion is provided with a second window and covers the top periphery of the mounting portion.

[0009] According to a battery cell cover plate provided by the present invention, a first adhesive layer is provided on the side of the first frame portion facing the through hole, the first adhesive layer is annularly surrounding the first opening and is bonded to the top surface of the support portion; And / or, a second adhesive layer is provided on the side of the second frame portion facing the through hole, the second adhesive layer is disposed circumferentially along the second frame portion and is bonded to the end face of the pole post.

[0010] According to a battery cell cover provided by the present invention, the plastic part further includes a partition plate, the partition plate being protruding from the cover portion on the side facing the through hole and located between the electrode post and the support portion.

[0011] According to the present invention, in the thickness direction of the substrate, the distance between the partition and the mounting portion is b, where 0.2mm≤b≤0.5mm.

[0012] A cell cover plate provided by the present invention further includes: An explosion-proof valve is disposed on the substrate. The patch includes an adhesive portion and a release portion. The release portion is opposite to the explosion-proof valve in the thickness direction of the substrate. A serration line is provided between the release portion and the adhesive portion. When the explosion-proof valve is opened, the patch can be torn along the serration line to form an exhaust port.

[0013] According to a battery cell cover plate provided by the present invention, the distance between the enclosure portion and the peripheral side surface of the boss in the direction parallel to the substrate is c, where 0.2mm≤c≤0.5mm; And / or, in the thickness direction of the substrate, the distance between the second frame portion and the top surface of the support portion is d, 0.2mm≤d≤0.5mm; And / or, the thickness of the patch is T1, and the wall thickness of the enclosure and the cover is T2, 0.2mm≤T1≤0.3mm, 0.9mm≤T2≤1.2mm.

[0014] The present invention also provides a battery cell, comprising: The battery cell casing has an opening; In any of the above-mentioned cell cover plates, the cell cover plate is disposed in the opening and surrounds the cell housing to form a receiving cavity; An electrode assembly is disposed within the receiving cavity, and the electrode tabs of the electrode assembly are connected to the electrode post.

[0015] The battery cell cover and battery cell provided by this invention, by providing a boss on the cover body and having the electrode post protruding from the boss, prevents electrolyte from flowing into the mating gap between the electrode post and the cover body during electrolyte injection through the injection hole on the substrate, thus preventing sealing failure and voltage abnormalities. Furthermore, a patch can be used to protect the substrate, and the enclosing portion of the plastic component prevents electrolyte from entering between the patch and the cover body through the through-hole of the patch, thereby avoiding corrosion of the cover body by the electrolyte. The boss and protective components provide reliable protection for the substrate and electrode post positions. Simultaneously, by using the covering portion of the plastic component to adhere to the top surface of the boss and / or the end face of the electrode post, a separate design of the plastic component and the patch can be achieved, improving the bonding yield of the protective component and the cover body. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of the battery cell cover plate provided by the present invention.

[0018] Figure 2 yes Figure 1 A top view of the battery cell cover plate.

[0019] Figure 3 yes Figure 1 Side view of the cell cover plate.

[0020] Figure 4 yes Figure 1 Exploded view of the battery cell cover plate.

[0021] Figure 5 This is a schematic diagram of the plastic component structure in the battery cell cover provided by the present invention.

[0022] Figure 6 This is an exploded view of a portion of the structure of the battery cell cover plate provided by the present invention.

[0023] Figure 7 yes Figure 1 A schematic diagram of the battery cell cover from another perspective.

[0024] Figure 8 yes Figure 2 A partial cross-sectional view of the cell cover plate at BB.

[0025] Figure 9 yes Figure 8 A partial structural diagram.

[0026] Figure 10 This is a schematic diagram of the battery cell provided by the present invention.

[0027] Figure label: 1. Cover plate body; 11. Base plate; 12. Boss; 121. Support part; 1211. Liquid injection hole; 122. Mounting part; 2. Pole post; 21. Connecting post; 22. Riveting block; 3. Explosion-proof valve; 4. Insulating component; 41. Protrusion; 42. Stepped groove; 43. Exhaust structure; 5. Connecting piece; 51. Welding part; 52. Base part; 53. Connecting part; 6. Top plastic; 7. Protective component; 71. Patch; 710. Through hole; 71 1. Adhesive part; 712. Separation part; 713. Scoring line; 714. Reserved hole; 72. Plastic part; 721. Enclosure part; 722. Covering part; 7221. First frame part; 7222. Second frame part; 7231. First window; 7232. Second window; 724. Avoidance notch; 7241. First notch; 7242. Second notch; 731. First adhesive layer; 732. Second adhesive layer; 74. Separator; 8. Battery cell casing. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0029] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "first" and "second" are numbered for the purpose of clearly identifying product components and do not represent any substantial difference. The terms "installed," "connected," and "linked" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances. Furthermore, "multiple" means two or more. In the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0030] The following is combined Figures 1-10 The present invention describes the cell cover plate and the cell.

[0031] like Figures 1-3 As shown, the battery cell cover provided in this embodiment of the invention includes a cover body 1, a terminal post 2, and a protective component 7. The battery cell cover includes a substrate 11 and a boss 12, the boss 12 protruding from the substrate 11 along its thickness direction. The cover body 1 has a through hole penetrating the boss 12, and the terminal post 2 passes through the through hole and protrudes from the boss 12. The protective component 7 includes a patch 71 and a plastic part 72. The patch 71 is attached to the substrate 11 and has a through hole 710 for the boss 12 to pass through. (See also...) Figure 6 The plastic part 72 includes a retaining portion 721 and a covering portion 722. The retaining portion 721 is in contact with the side of the patch 71 away from the substrate 11 and surrounds the through hole 710. The covering portion 722 is connected to the end of the retaining portion 721 away from the patch 71 and forms a window. The pole post 2 is opposite to the window, and the covering portion 722 is attached to the top surface of the boss 12 and / or the end face of the pole post 2.

[0032] This cell cover is applied to a battery cell, which includes a cell housing, electrode assembly, and cell cover. The cell housing has an opening, and the cell cover is positioned at the opening and surrounds the cell housing to form a receiving cavity. The electrode assembly is disposed within the receiving cavity. The cell housing and cover body 1 are welded together to form the outer shell of the cell, providing protection for the internal components and withstanding certain external impacts. A terminal post 2 protrudes from the outer surface of the cover body 1 to form a terminal terminal, used for connection to a busbar, allowing multiple cells to be connected via the busbar to form a battery module. The other end of the terminal post 2 is located within the receiving cavity and connected to the electrode tabs of the electrode assembly. The battery module is assembled into a housing to form a battery pack.

[0033] See the length and width directions of substrate 11. Figure 1The thickness direction of the substrate 11 is perpendicular to the length and width directions. Specifically, the cover plate body 1 has a first side and a second side opposite to each other in the thickness direction of the substrate 11. The first side faces the outside of the cell and is provided with a boss 12. The pole post 2 protrudes from the boss 12 to form a pole post terminal. The second side faces the pole group in the receiving cavity.

[0034] The protective component 7 is disposed on the first side of the cover plate body 1. A patch 71 is attached to the side of the substrate 11 facing the boss 12, forming an insulating protection for the substrate 11. A plastic part 72 is correspondingly disposed to the boss 12, with the boss 12 passing through a through hole 710 on the patch 71. A retaining portion 721 surrounds the through hole 710, i.e., surrounds the boss 12. The retaining portion 721 has a certain height relative to the patch 71 in the thickness direction of the substrate. A covering portion 722 is connected to the retaining portion 721 and extends inwards from the retaining portion 721 in a direction parallel to the substrate 11, allowing the covering portion 722 to fit against the top surface of the boss 12 and / or the end face of the pole 2. The opening formed by the covering portion 722 faces the pole 2, facilitating the soldering of the pole 2 to the busbar.

[0035] It is understandable that the patch 71 and the plastic part 72 are two independent structural components and can be manufactured separately. During assembly, the patch 71 is first glued and fixed to the substrate 11, and then the plastic part 72 is glued and fixed to the top surface of the boss 12 and / or the end face of the pole 2. This helps to improve the bonding yield between the patch 71 and the cover plate body 1. The top surface of the boss 12 is the side away from the substrate 11, and the end face of the pole 2 is the side of the end protruding from the boss 12 that is away from the substrate 11. The wall thickness of the plastic part 72 can be set to be thicker, and it has higher rigidity than the patch 71, so as to facilitate assembly with the boss 12.

[0036] The cover plate body 1 is provided with an injection hole 1211 communicating with the receiving cavity. The protective component 7 is disposed on the side of the cover plate body 1 away from the receiving cavity, avoiding the injection hole 1211. After the cell assembly is completed, electrolyte is injected into the cell through the injection hole 1211.

[0037] In traditional battery cell cover structures, the electrolyte injection hole 1211 is located on the substrate 11, the electrode post 2 passes through the substrate 11, and a protective patch is attached to the outer surface of the cover body 1. The protective patch has holes to avoid the electrode post 2. During electrolyte injection, the pumped electrolyte can easily flow along the protective patch to the holes, and then flow into the mating gap between the electrode post 2 and the cover body 1, as well as between the protective patch and the cover body 1. This can damage the sealing of the battery cell cover, cause abnormal voltage, corrode the cover body 1, and affect the safety performance of the battery cell.

[0038] The battery cell cover plate provided in this embodiment of the invention features a boss 12 on the cover plate body 1, with the electrode post 2 protruding from the boss 12. When electrolyte is injected through the injection hole 1211 on the substrate 11, the boss 12 prevents electrolyte from flowing into the mating gap between the electrode post 2 and the cover plate body 1, thus preventing sealing failure and voltage abnormalities. Furthermore, the patch 71 provides protection for the substrate 11, and the enclosure portion 721 of the plastic component 72 blocks electrolyte from entering between the patch 71 and the cover plate body 1 through the through hole 710, thereby preventing corrosion of the cover plate body 1 by the electrolyte. The boss 12 and the protective component 7 provide reliable protection for the substrate 11 and the electrode post 2. Simultaneously, by attaching the covering portion 722 of the plastic component 72 to the top surface of the boss 12 and / or the end face of the electrode post 2, a separate design of the plastic component 72 and the patch 71 can be achieved, improving the bonding yield of the protective component 7 and the cover plate body 1.

[0039] like Figure 2 As shown, patch 71 is bonded and fixed to substrate 11 by adhesive layer. After bonding, the distance between patch 71 and the edge of substrate 11 is 'a', where 0.5mm ≤ a ≤ 1.5mm. If the value of 'a' is too small, patch 71 may easily extend beyond the edge of substrate 11 due to assembly errors in actual production, which is not conducive to the welding of substrate 11 and cell housing. If the value of 'a' is too large, patch 71 will not provide sufficient protection for substrate 11.

[0040] like Figure 4 and Figure 5 As shown, in some embodiments of the present invention, the covering portion 722 is provided with a first notch 7241, through which the busbar connected to the pole post 2 can pass. The enclosure portion 721 is provided with a second notch 7242 corresponding to the position of the first notch 7241, and the first notch 7241 and the second notch 7242 communicate to form an avoidance notch 724.

[0041] The clearance notch 724 can be oriented towards the width direction of the substrate 11, and the first notch 7241 and the second notch 7242 have the same dimensions in the length direction of the substrate 11. Alternatively, the clearance notch 724 can be oriented towards the length direction of the substrate 11, and the first notch 7241 and the second notch 7242 have the same dimensions in the width direction of the substrate 11. When the bus is connected to the terminal post 2, the bus passes through the clearance notch 724, and there is a certain distance between the blocking part 721 and the covering part 722 and the bus. During the welding of the bus and the terminal post 2, the heat of welding can be prevented from causing the plastic part 72 to melt.

[0042] like Figure 4As shown, in some embodiments of the present invention, the boss 12 has a support portion 121 and a mounting portion 122 connected along the length of the substrate 11. The pole post 2 passes through the mounting portion 122. In the thickness direction of the substrate 11, the height of the support portion 121 relative to the substrate 11 is greater than the height of the end of the pole post 2 protruding from the mounting portion 122 relative to the substrate 11. It can be understood that the height of the support portion 121 relative to the substrate 11 is greater than the height of the mounting portion 122 relative to the substrate 11, and the two are connected to form a stepped boss.

[0043] The support portion 121 is adapted to be connected to the battery pack housing for support. In the battery pack's operating state, the support portion 121 can be located on the top or side of the battery cells and abut against the housing to withstand impact forces transmitted from the housing. The portion of the housing connected to the support portion 121 can be the housing shell; alternatively, the housing includes a shell and a cold plate, with the cold plate located between the shell and the battery cells, and the support portion 121 connected to the cold plate. The height of the support portion 121 relative to the substrate 11 is greater than the height of the end of the terminal post 2 protruding from the mounting portion 122 relative to the substrate 11, so that a certain space is reserved between the terminal post 2 and the housing for the installation of a busbar.

[0044] In traditional battery pack structures, the battery pack relies solely on the casing to withstand external impacts. However, the casing plate opposite the terminal 2 has a large area, making it prone to deformation if its rigidity is insufficient. To prevent casing deformation from causing compression damage to the busbar and terminal 2, a large space needs to be reserved between the busbar and the casing in the structural design, with supporting foam installed between them. Some designs also incorporate concave and convex structures on the casing plate to enhance rigidity and prevent deformation. However, these measures result in a large gap between the cells and the casing, wasting space. Increasing the casing thickness to increase rigidity would increase the weight of the battery pack, hindering lightweight design. Furthermore, the heat from the cell cover is dissipated only through conduction between the terminal 2 and the busbar, and through its own thermal radiation, resulting in low heat dissipation efficiency and easy heat accumulation.

[0045] To address this, this embodiment incorporates a boss 12 with a support portion 121, which is connected to the casing for support, allowing the cell's outer shell to also function as a load-bearing component. The support from the outer shell prevents significant deformation of the casing, thus reducing its thickness and the weight of the battery pack. Furthermore, while ensuring the casing does not cause compression damage to the busbars and terminals 2, the distance between the busbars and the casing can be reduced, increasing the cell's volume and fully utilizing the internal space of the casing to improve cell capacity and the overall energy density of the battery pack. The cell's heat can be transferred to the casing through the support portion 121, improving the cell's heat dissipation efficiency.

[0046] In this embodiment, by disposing the pole post 2 on the mounting portion 122, the structure of the area on the cover body 1 corresponding to the pole post 2 can be strengthened through the mounting portion 122, reducing the risk of short circuit caused by the deformation of this area under impact force and squeezing the pole post 2. The supporting portion 121 and the mounting portion 122 are connected to form a stepped boss, which can save the board surface space of the cover body 1.

[0047] It should be noted that the battery cell has two pole posts 2, namely the positive pole post and the negative pole post. The number of pole posts 2 on the battery cell cover in the embodiment of the present invention can be one or two. The number of bosses 12 can be determined based on the number of pole posts 2, and each pole post 2 can correspond to one boss 12.

[0048] In the embodiment of the present invention, the boss 12 and the substrate 11 are integrally formed; or, the boss 12 is a separate structural member and is welded and fixed to the substrate 11 to form the cover body 1. The boss 12 can be a solid structure; or, the boss 12 is an internally hollow structure, that is, a stepped groove is formed on the side of the boss 12 facing the accommodating cavity, which can reduce the weight of the cover body 1 and improve the structural strength of the cover body 1.

[0049] Optionally, the boss 12 is formed by stamping a plate member. For example, the boss 12 is formed by stamping a separate plate member and then welded and fixed to the substrate 11. Or, the boss 12 and the substrate 11 are integrally formed by stamping the same plate member.

[0050] In the case where the boss 12 is an internally hollow structure, optionally, a stepped groove is formed at the position on the side of the cover body 1 away from the boss 12 corresponding to the boss 12. This stepped groove is beneficial to expanding the internal space of the battery cell, increasing the volume of the electrode group inside the battery cell, and thus increasing the capacity of the battery cell.

[0051] As Figure 2 and Figure 4 shown, the covering portion 722 includes a first frame portion 7221 and a second frame portion 7222 connected in the length direction of the substrate 11. The first frame portion 7221 surrounds and forms a first opening 7231 and covers the top periphery of the supporting portion 121, and the second frame portion 7222 surrounds and forms a second opening 7232 and covers the top periphery of the mounting portion 122.

[0052] Among them, the covering portion 722 further includes an inclined portion. The first frame portion 7221 and the second frame portion 7222 are connected through the inclined portion to form a stepped covering portion 722 similar to the shape of the Chinese character "日" (day). A first notch 7241 is provided on the second frame portion 7222, and the first frame portion 7221 surrounds the top of the supporting portion 121 in a circle. The covering portion 722 can be in contact with the top surface of the supporting portion 121 through the first frame portion 7221, and / or be in contact with the end face of the pole post 2 through the second frame portion 7222.

[0053] In this embodiment, by providing a first opening 7231, the top surface of the support portion 121 can be bonded to the housing with adhesive, ensuring the thermal conductivity of the support portion 121 and the housing. During the bonding process between the support portion 121 and the housing, the second frame portion 7222 also serves to prevent adhesive overflow, ensuring the thickness of the adhesive layer and improving the bonding reliability between the support portion 121 and the housing. The second opening 7232 is used for welding the busbar to the electrode post 2.

[0054] like Figure 5 As shown, in some embodiments of the present invention, a first adhesive layer 731 is provided on the side of the first frame portion 7221 facing the through hole 710. The first adhesive layer 731 is annularly surrounding the first opening 7231 and is bonded to the top surface of the support portion 121. In this embodiment, the injection hole 1211 can be provided on the support portion 121. The first adhesive layer 731 serves as an annular seal between the first frame portion 7221 and the support portion 121, preventing electrolyte from flowing from the gap between the plastic part 72 and the support portion 121 into the protective assembly 7 and the cover plate body 1. The injection hole 1211 is provided on the support portion 121, which avoids the injection hole 1211 occupying the space of the substrate 11.

[0055] In some embodiments of the present invention, a second adhesive layer 732 is provided on the side of the second frame portion 7222 facing the through hole 710. The second adhesive layer 732 is disposed along the circumference of the second frame portion 7222 and is bonded to the end face of the pole post 2. The second frame portion 7222 is provided with a first notch 7241, and correspondingly, the second adhesive layer 732 is also provided with a notch at the position corresponding to the first notch 7241. The length of the second adhesive layer 732 along the circumference of the second frame portion 7222 can be consistent with the circumferential length of the second frame portion 7222, thereby increasing the bonding area between the second frame portion 7222 and the pole post 2.

[0056] like Figure 6 As shown, the battery cell cover provided in this embodiment of the invention also includes an upper plastic 6. The top of the mounting part 122 is provided with a positioning groove, the upper plastic 6 is disposed in the positioning groove, and the electrode post 2 passes through the upper plastic 6.

[0057] Specifically, the through hole on the mounting part 122 for inserting the pole post 2 is located within the positioning groove. For example... Figure 8 As shown, the pole post 2 includes a connecting post 21 and a rivet block 22. The connecting post 21 passes through the cover plate body 1 and the upper plastic 6. The rivet block 22 is located on the side of the upper plastic 6 away from the cover plate body 1. The connecting post 21 and the rivet block 22 are riveted together to fix the pole post 2, the upper plastic 6, and the cover plate body 1. The upper plastic 6 is positioned in the positioning groove, serving as an insulating barrier between the rivet block 22 and the cover plate body 1. An insulating sealing ring is provided between the connecting post 21 and the cover plate body 1, serving as an insulating seal between them.

[0058] There are gaps between the rivet block 22 and the upper plastic 6, as well as between the upper plastic 6 and the positioning groove. If electrolyte enters these gaps, it can easily damage the internal insulating sealing ring, causing the seal between the electrode post 2 and the cover plate body 1 to fail. See also Figure 8 In this embodiment, the second frame portion 7222 is bonded to the end face of the pole post 2 through the second adhesive layer 732, so that part of the gap between the rivet block 22 and the upper plastic 6 and part of the gap between the upper plastic 6 and the positioning groove are covered by the second frame portion 7222, and the second adhesive layer 732 plays the role of blocking the electrolyte, reducing the risk of electrolyte entering these gaps.

[0059] like Figure 5 As shown, the plastic part 72 also includes a partition 74. The partition 74 protrudes from the side of the cover 722 facing the through hole 710, and the partition 74 is located between the pole post 2 and the support part 121.

[0060] Specifically, the partition 74 is connected to the side of the second frame portion 7222 facing the through hole 710. The partition 74 is located between the top surface of the second frame portion 7222 and the mounting portion 122, and is separated between the pole post 2 protruding from the mounting portion 122 and the support portion 121. The partition 74 extends from one side of the enclosure portion 721 to the opposite side along the width direction of the substrate 11, and the first window 7231 and the second window 7232 are located on both sides of the partition 74, respectively.

[0061] The cover plate body 1 is usually made of metal. The distance between the support part 121 and the pole post 2 is relatively close, which can easily cause creepage and arcing. In this embodiment, by setting a partition 74 on the plastic part 72 between the pole post 2 and the support part 121, a good insulation and isolation effect can be achieved between the pole post 2 and the support part 121, which can reduce the risk of creepage and arcing of the battery cell.

[0062] Furthermore, such as Figure 8 As shown, in the thickness direction of the substrate 11, the distance between the partition 74 and the mounting portion 122 is b, where 0.2mm ≤ b ≤ 0.5mm. If the value of b is too small, in actual production, due to processing and assembly errors, the partition 74 is prone to interference with the mounting portion 122, causing the plastic part 72 to fail to bond with the top surface of the boss 12 and / or the end face of the pole post 2; if the value of b is too large, it will reduce the insulation and isolation effect of the partition 74 on the pole post 2 and the support portion 121.

[0063] In some embodiments of the present invention, the distance between the enclosure portion 721 and the peripheral side surface of the boss 12 in the direction parallel to the substrate 11 is c, where 0.2mm≤c≤0.5mm. And / or, in the thickness direction of the substrate 11, the distance between the second frame portion 7222 and the top surface of the support portion 121 is d, where 0.2mm≤d≤0.5mm.

[0064] Both the support portion 121 and the mounting portion 122 have a top surface and a side surface connected to the top surface. The side surface of the mounting portion 122 connects to a portion of the side surface of the support portion 121 to form the peripheral side surface of the boss 12. Another portion of the side surface of the support portion 121 connects to its top surface and the top surface of the mounting portion 122. If the value of c is too small, interference may easily occur between the plastic part 72 and the boss 12 in the horizontal direction; if the value of c is too large, the material of the plastic part 72 will be wasted. If the value of d is too small, it will affect the setting of the first adhesive layer 731; if the value of d is too large, it may cause the first frame portion 7221 to fail to bond with the support portion 121 or the second frame portion 7222 to fail to bond with the pole post 2.

[0065] In some embodiments of the present invention, the thickness of the patch 71 is T1, where 0.2 mm ≤ T1 ≤ 0.3 mm. The wall thickness of the enclosure portion 721 and the covering portion 722 is T2, where 0.9 mm ≤ T2 ≤ 1.2 mm. If the T1 value is too small, the patch 71 is prone to wrinkling, resulting in a low bonding yield; if the T1 value is too large, material is wasted. If the T2 value is too small, the plastic part 72 has insufficient structural strength; if the T2 value is too large, material is wasted.

[0066] like Figure 6 As shown, the battery cell cover provided in this embodiment of the invention also includes an explosion-proof valve 3. The explosion-proof valve 3 is disposed on the substrate 11. Specifically, the substrate 11 is provided with an exhaust port, which communicates with the housing cavity of the battery cell, and the explosion-proof valve 3 is opposite to the exhaust port. When the battery cell experiences thermal runaway, the high-temperature gas inside can be discharged from the explosion-proof valve 3.

[0067] The explosion-proof valve 3 is located on the side of the support 121 away from the mounting part 122, thus separating the terminal post 2 and the explosion-proof valve 3. The support 121 can be used to prevent the high-temperature gas and liquid discharged from the explosion-proof valve 3 from reaching the terminal post 2 and the busbar, achieving thermoelectric isolation and improving the safety performance of the battery pack.

[0068] Optionally, there are two bosses 12. Along the length of the substrate 11, the two bosses 12 are respectively disposed on both sides of the explosion-proof valve 3, and the support portion 121 is located between the explosion-proof valve 3 and the mounting portion 122. Two pole posts 2 are respectively inserted through the mounting portions 122 of the two bosses 12. A support portion 121 is provided between each pole post 2 and the explosion-proof valve 3, and the support portion 121 separates the two pole posts 2 from the explosion-proof valve 3.

[0069] like Figure 6 As shown, in some embodiments of the present invention, the patch 71 includes an adhesive portion 711 and a separating portion 712. The separating portion 712 is opposite to the explosion-proof valve 3 in the thickness direction of the substrate 11. A scribe line 713 is provided between the separating portion 712 and the adhesive portion 711. When the explosion-proof valve 3 is opened, the patch 71 can be torn along the scribe line 713 to form an exhaust port.

[0070] Understandably, the scoring line 713 is arranged around the separation part 712 and the explosion-proof valve 3. Before the explosion-proof valve 3 is opened, the scoring line 713 is not broken, and the separation part 712 plays a role in protecting the explosion-proof valve 3, so there is no need to set up a separate explosion-proof valve 3 protection patch 71.

[0071] If the internal pressure of the battery cell exceeds the safety threshold of the explosion-proof valve 3, the explosion-proof valve 3 is opened under the action of high-pressure gas. Under the action of gas pressure, the patch 71 is torn at the scribe line 713, causing at least a portion of the separating part 712 to separate from the bonding part 711, forming an exhaust port on the patch 71, from which gas is discharged to prevent the patch 71 from affecting the exhaust effect.

[0072] The scoring line 713 can wrap around the separating portion 712, allowing the separating portion 712 to completely separate from the fitting portion 711 under air pressure. Alternatively, the scoring line 713 can wrap around a portion of the separating portion 712, allowing the separating portion 712 to partially separate from the fitting portion 711 under air pressure and fold relative to the fitting portion 711. When the scoring line 713 wraps around a portion of the separating portion 712, the scoring line 713 corresponds to the opening side of the explosion-proof valve 3.

[0073] Traditional cell cover plates have a separate patch at the explosion-proof valve. During electrolyte injection, electrolyte can easily flow to the explosion-proof valve, causing the patch to detach and leading to contamination and corrosion of the valve. This embodiment addresses this by providing a separation part 712 on the patch 71. The separation part 712 is connected to the bonding part 711 by a serrated line, which not only prevents the patch from detaching to effectively protect the explosion-proof valve 3, but also allows the vent to be opened when the explosion-proof valve 3 is opened.

[0074] Furthermore, a pre-drilled hole 714 is defined between the separating part 712 and the bonding part 711. By providing the pre-drilled hole 714, it is convenient to test the airtightness of the explosion-proof valve 3 after the battery cell assembly is completed.

[0075] like Figure 7 and Figure 8 As shown, the battery cell cover provided in some embodiments of the present invention also includes an insulating member 4. The insulating member 4 is disposed on the side of the substrate 11 away from the boss 12, and the electrode post 2 passes through the insulating member 4. The insulating member 4 is provided with an exhaust structure 43 opposite to the exhaust hole on the cover body 1. The exhaust structure 43 may be composed of multiple through holes to ensure the normal exhaust of the explosion-proof valve 3 while ensuring the structural strength of the insulating member 4.

[0076] When the cell cover is installed on the cell housing, the insulating component 4 is located between the cover body 1 and the electrode group, serving as insulation between the cover body 1 and the electrode group. The electrode post 2 passes through both the cover body 1 and the insulating component 4, with one end of the electrode post 2 located on the side of the insulating component 4 away from the cover body 1, for connection with the electrode tab of the electrode group.

[0077] In some embodiments of the present invention, a protrusion 41 is formed on the side of the insulating member 4 near the cover plate body 1. The protrusion 41 is located in a stepped groove in the cover plate body 1, and a stepped recess 42 is formed on the side of the insulating member 4 away from the substrate 11 corresponding to the position of the protrusion 41. The stepped recess 42 can be used to accommodate the tabs of the electrode assembly.

[0078] It is understandable that the insulating part 4 forms a stepped protrusion 41 on the side near the cover plate body 1. The stepped protrusion 41 and the stepped groove of the cover plate body 1 are in concave-convex fit to make full use of the internal space of the boss 12 to increase the accommodating space of the stepped groove 42.

[0079] In the cell structure, the stepped groove 42 and the electrode group define the space for accommodating the electrode tabs, allowing for a larger space inside the cell to house the electrode group body, increasing the space utilization rate inside the cell casing, and thus further increasing the cell capacity.

[0080] like Figure 7 and Figure 8 As shown, some embodiments of the present invention provide a cell cover plate that also includes a connecting piece 5. The connecting piece 5 is located within a stepped recess 42. One end of the connecting piece 5 in the length direction of the cover plate body 1 is connected to the electrode post 2, and the other end of the connecting piece 5 in the thickness direction is opposite to the support portion 121 and is adapted to connect to the electrode tab of the electrode assembly. The connecting piece 5 and the connecting post 21 of the electrode post 2 can be an integral structure or a separate structure. The connecting piece 5 being located within the stepped recess 42 further improves the space utilization rate inside the cell casing, which is beneficial for increasing the cell capacity.

[0081] Specifically, the connecting piece 5 includes a welding portion 51, a connecting portion 53, and a base portion 52 that are sequentially connected along the length of the substrate 11. The welding portion 51 is used to connect with the electrode tab and corresponds to the area of ​​the first groove, the base portion 52 is connected with the electrode post 2 and corresponds to the area of ​​the second groove, and the welding portion 51 is parallel to the base portion 52 and is set at an angle to the connecting portion 53.

[0082] like Figure 9 As shown, in some embodiments of the present invention, the angle between the sidewall of the support portion 121 and the substrate 11 is 90°+β, and the angle between the sidewall of the mounting portion 122 and the substrate 11 is 90°+γ, 15°≤β≤25°, and 15°≤γ≤25°.

[0083] Both the support portion 121 and the mounting portion 122 have a top wall and side walls connected to the top wall. By setting the angles to 15°≤β≤25° and 15°≤γ≤25°, it is beneficial to ensure the manufacturability, structural strength, and uniform stress distribution of the support portion 121 and the mounting portion 122, thereby improving production yield. If the included angle is too small, it is not conducive to the stamping process and is prone to causing large stress concentration; if the included angle is too large, the impact resistance is insufficient, and the support portion 121 and the mounting portion 122 occupy a large area, which is not conducive to the distribution of the support portion 121, the mounting portion 122, and the explosion-proof valve 3.

[0084] like Figure 9 As shown, in some embodiments of the present invention, the height of the mounting portion 122 relative to the substrate 11 in the thickness direction is H1, where 1mm ≤ H1 ≤ 2mm. Specifically, when the mounting portion 122 is formed by stamping, if the value of H1 is too low, the reinforcement effect on the pole post position structure will be poor; if the value of H1 is too high, the height of the corresponding support portion 121 needs to be higher, which is not conducive to ensuring the stamping yield of the support portion 121.

[0085] In some embodiments of the present invention, the height of the support portion 121 relative to the electrode post 2 in the thickness direction of the substrate 11 is H2, where 1.5mm ≤ H2 ≤ 2.5mm. This height difference allows for the placement of a busbar on the top of the electrode post 2, ensuring that the height of the busbar relative to the substrate 11 is lower than the height of the support portion 121 relative to the substrate 11. If the value of H2 is too small, the space between the electrode post 2 and the housing is insufficient to place the busbar; if the value of H2 is too large, it is difficult to guarantee the stamping yield and will result in wasted space, which is not conducive to improving the utilization rate of the internal space of the battery pack.

[0086] like Figure 10 As shown, this embodiment of the invention also provides a battery cell, including a battery cell housing 8, an electrode assembly, and a battery cell cover plate as described in any of the above embodiments. The battery cell housing 8 has an opening, and the battery cell cover plate is disposed at the opening and surrounds the battery cell housing 8 to form a receiving cavity. The electrode assembly is disposed within the receiving cavity, and the electrode tabs of the electrode assembly are connected to the electrode posts 2.

[0087] When assembling the battery cell, the pole posts 2 of the electrode assembly and the cell cover plate are welded together first, and the cell cover plate is assembled to one end of the electrode assembly. Then, the electrode assembly is inserted into the cell housing 8 through the opening, and the cover plate body 1 is welded to the cell housing 8. Before being inserted into the housing, the outside of the electrode assembly is usually wrapped with an insulating film to provide insulation between the electrode assembly and the cell housing 8.

[0088] The length dimension of the cover plate body is defined as L, and the width dimension is defined as W. Based on the parameter value ranges defined in this embodiment of the invention, a Design of Experiments (DOE) is conducted using cover plate bodies with dimensions of 150mm≤L≤300mm and 25mm≤W≤75mm as the test subjects. After the cover plate body is stamped, any stamping abnormalities are detected. During the assembly of the battery cell cover, the assembly of the explosion-proof valve and the terminal post with the cover plate body is checked. After the battery cells are assembled, a Z-axis (thickness direction of the substrate) stamping test is performed on the battery pack to detect the surface stress of the cover plate body. The experimental results are shown in Table 1, where H1, H2, T1, T2, a, b, and c are in mm.

[0089] Table 1: Experimental Data

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A battery cell cover plate, characterized in that, include: The cover plate body includes a base plate and a boss, the boss protruding from the base plate along the thickness direction of the base plate, and the cover plate body having a through hole penetrating the boss; The pole post passes through the through hole and protrudes from the boss; A protective component includes a patch and a plastic part. The patch is attached to the substrate and has a through hole for the boss to pass through. The plastic part includes a retaining portion and a covering portion. The retaining portion is in contact with the side of the patch away from the substrate and surrounds the through hole. The covering portion is connected to the end of the retaining portion away from the patch and forms a window. The pole is opposite to the window. The covering portion is attached to the top surface of the boss and / or the end face of the pole.

2. The cell cover plate according to claim 1, characterized in that, The covering part has a first notch, through which the busbar connected to the pole can pass; the enclosure part has a second notch corresponding to the position of the first notch, and the first notch and the second notch are connected to form an avoidance notch.

3. The cell cover plate according to claim 1, characterized in that, The boss has a support portion and a mounting portion connected in the length direction of the substrate, and the pole post passes through the mounting portion; in the thickness direction, the height of the support portion relative to the substrate is greater than the height of the end of the pole post protruding from the mounting portion relative to the substrate.

4. The cell cover plate according to claim 3, characterized in that, The covering portion includes a first frame portion and a second frame portion connected in the length direction. The first frame portion is provided with a first window and covers the top periphery of the support portion, and the second frame portion is provided with a second window and covers the top periphery of the mounting portion.

5. The cell cover plate according to claim 4, characterized in that, The first frame portion has a first adhesive layer on the side facing the through hole. The first adhesive layer is arranged in a ring around the first opening and is bonded to the top surface of the support portion. And / or, a second adhesive layer is provided on the side of the second frame portion facing the through hole, the second adhesive layer is disposed circumferentially along the second frame portion and is bonded to the end face of the pole post.

6. The cell cover plate according to claim 4, characterized in that, The plastic part also includes a partition plate, which protrudes from the side of the cover portion facing the through hole and is located between the pole post and the support portion.

7. The cell cover plate according to claim 6, characterized in that, In the thickness direction of the substrate, the distance between the partition and the mounting portion is b, where 0.2mm≤b≤0.5mm.

8. The cell cover plate according to claim 1, characterized in that, Also includes: An explosion-proof valve is disposed on the substrate. The patch includes an adhesive portion and a release portion. The release portion is opposite to the explosion-proof valve in the thickness direction of the substrate. A serration line is provided between the release portion and the adhesive portion. When the explosion-proof valve is opened, the patch can be torn along the serration line to form an exhaust port.

9. The cell cover plate according to claim 4, characterized in that, In a direction parallel to the substrate, the distance between the enclosure portion and the peripheral side surface of the boss is c, where 0.2mm≤c≤0.5mm; And / or, in the thickness direction of the substrate, the distance between the second frame portion and the top surface of the support portion is d, 0.2mm≤d≤0.5mm; And / or, the thickness of the patch is T1, and the wall thickness of the enclosure and the cover is T2, 0.2mm≤T1≤0.3mm, 0.9mm≤T2≤1.2mm.

10. A battery cell, characterized in that, include: The battery cell casing has an opening; The cell cover plate as described in any one of claims 1 to 9, wherein the cell cover plate is disposed at the opening and surrounds the cell housing to form a receiving cavity; An electrode assembly is disposed within the receiving cavity, and the electrode tabs of the electrode assembly are connected to the electrode post.

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