Cover plate and battery cell

Abstract

The application relates to the battery technical field, in particular to a cover plate and a battery cell. The cover plate comprises an insulating plastic part and a cover plate body, the insulating plastic part comprises a first supporting part and a second supporting part, the first supporting part and the second supporting part are both provided with two riveting holes penetrating through the first supporting part and the second supporting part, and the two riveting holes are arranged in alignment along the width direction; the side of the cover plate body facing the insulating plastic part is provided with a riveting boss, and the riveting boss is riveted with the riveting hole; on the first supporting part or the second supporting part, the center distance W2 of the two riveting holes in the width direction satisfies 0.6<=W2 / B<=0.7, B is the size of the insulating plastic part in the width direction; the center distance L2 of the riveting holes of the first supporting part and the second supporting part in the length direction satisfies 0.5<=L2 / A<=0.6, A is the size of the insulating plastic part in the length direction. The application solves the problems that the assembly effect of the plastic part and the light aluminum plate is poor and the fixing effect of the plastic part is poor in the existing cover plate structure.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a cover plate and a battery cell. Background Technology

[0002] Lithium-ion batteries are widely used in various fields such as transportation power supplies, power storage, new energy storage power supplies, and aerospace and military industries due to their advantages such as large capacity, high operating voltage, strong charge retention, and long cycle life. Existing energy storage cell structures generally include a cover plate (including plastic parts and plain aluminum plates), a casing, a bare cell insulating film, electrode assembly, and electrolyte. The plastic parts primarily serve as insulation and protection, and for heat-melting to fix the bare cell insulating film.

[0003] However, in the existing cover plate structure, the assembly effect of plastic parts and aluminum plate is poor, and the fixing effect of plastic parts is poor. Summary of the Invention

[0004] The purpose of this application is to provide a cover plate and a battery cell, thereby solving the problems of poor assembly effect between plastic parts and aluminum plates and poor fixing effect of plastic parts in existing cover plate structures.

[0005] According to a first aspect of this application, a cover plate is provided, the cover plate having two perpendicular length directions, width directions, and thickness directions. The cover plate includes an insulating plastic part and a cover plate body. The insulating plastic part is attached to one side of the cover plate body in the thickness direction. The insulating plastic part includes a first support portion and a second support portion connected sequentially along the length direction. Both the first support portion and the second support portion have two through-holes, and the two rivet holes are aligned along the width direction. The side of the cover plate body facing the insulating plastic part is provided with a rivet boss protruding towards the side where the insulating plastic part is located, and the rivet boss is riveted to the rivet holes. On the first support portion or the second support portion, the center distance W2 of the two rivet holes in the width direction satisfies: 0.6≤W2 / B≤0.7, where B is the dimension of the insulating plastic part in the width direction. The center distance L2 of the rivet holes of the first support portion and the second support portion in the length direction satisfies: 0.5≤L2 / A≤0.6, where A is the dimension of the insulating plastic part in the length direction.

[0006] In any of the above technical solutions, the insulating plastic part further includes a bottom wall and an edge edge disposed around the edge of the bottom wall, the edge edge fitting against the cover plate body, the bottom wall including a first support portion, an exhaust portion and a second support portion connected sequentially along the length direction; the first support portion and the second support portion each form two protrusions protruding towards one side of the cover plate body, the two protrusions are aligned along the width direction, the top wall of the protrusion is flush with the edge edge in the thickness direction, the riveting hole is opened on the top wall of the protrusion, and the protrusion forms a riveting groove open to the side opposite to the cover plate body.

[0007] In any of the above technical solutions, the edge further includes two long sides extending along the length direction and two short sides extending along the width direction. The long sides are provided with riveting notches. The side of the riveting notch facing away from the cover plate body is open. The riveting notch is connected to the riveting groove. And / or, before the riveting boss is riveted to the riveting hole, the riveting boss is cylindrical, and the height h4 of the riveting boss in the thickness direction satisfies: h4-h3=0.6mm-1.2mm, where h3 is the wall thickness of the top wall of the protrusion in the thickness direction, and the diameter Ф2 of the riveting boss satisfies: Ф2=Ф1-0.2mm, where Ф1 is the diameter of the riveting hole.

[0008] In any of the above technical solutions, further, after the riveting boss is riveted to the riveting hole, the riveting boss forms a support section and an bulging section. The support section passes through the riveting hole, and the bulging section is formed by plastic deformation of the end of the support section away from the cover plate body through riveting. The outer diameter of the bulging section is larger than the diameter of the riveting hole. The bulging section and the cover plate body together clamp the top wall. The end face of the bulging segment facing the top wall is attached to the side surface of the top wall facing away from the cover plate body, forming an annular contact surface. The sum of the areas S1 of the annular contact surfaces of all the riveting bosses satisfies: 0.2≤10S1 / S0≤0.3, where S0=AB.

[0009] In any of the above technical solutions, further, the cover plate body is provided with an explosion-proof valve, the first support part and the second support part have the same structure and are symmetrically arranged about the center line of the exhaust part, the center line is parallel to the width direction, and the exhaust part has a first exhaust hole that penetrates itself; the first support part and the second support part are also provided with a first horizontal rib and a second horizontal rib on the side facing the cover plate body, the first horizontal rib and the second horizontal rib both extend along the width direction, and the first horizontal rib and the second horizontal rib are respectively connected to the two sides of the two protrusions opposite each other in the length direction, so as to form a first groove together with the two protrusions and the bottom wall; the two long sides, one short side, the first horizontal rib and the bottom wall together form a second groove; the two long sides, the two second horizontal ribs and the exhaust part together form an exhaust groove; the first groove, the second groove and the exhaust groove are interconnected; the first support part and the second support part each have a second exhaust hole that penetrates itself at the position corresponding to the first groove and the second groove.

[0010] In any of the above technical solutions, the first horizontal rib and the second horizontal rib are both lower than the edge; both long sides are provided with exhaust notches, the side of the exhaust notch facing the cover plate body is open, and the exhaust notch is connected to the exhaust groove.

[0011] In any of the above technical solutions, the dimension L1 of the exhaust groove in the length direction satisfies: 0.45≤L1 / A≤0.55; the dimension W1 of the exhaust groove in the width direction satisfies: 1mm≤(B-W1) / 2≤3mm.

[0012] In any of the above technical solutions, the cover plate further includes a support plate. The side of the cover plate body facing the insulating plastic part is provided with a support protrusion protruding toward the side where the insulating plastic part is located. The support plate is connected to the support protrusion to form a ventilation gap with the cover plate body. The support plate, the explosion-proof valve, and the exhaust part are arranged facing each other in the thickness direction, and the support plate is provided with a ventilation hole that penetrates itself. The exhaust groove is used to accommodate the support plate.

[0013] In any of the above technical solutions, further, the dimension H1 of the support protrusion in the thickness direction is 2mm-3mm; the depth h1 of the venting groove in the thickness direction satisfies: 0.2mm≤h1-h2≤0.5mm, where h2 is the total dimension of the support protrusion and the support plate in the thickness direction.

[0014] According to a second aspect of this application, a battery cell is provided, including the cover plate as described above.

[0015] The cover plate of this application includes an insulating plastic part and a cover plate body. The insulating plastic part is attached to one side of the cover plate body in the thickness direction. The insulating plastic part includes a first support part and a second support part connected sequentially along the length direction. Each of the first and second support parts has two through-holes, which are aligned along the width direction. The side of the cover plate body facing the insulating plastic part has a riveting boss protruding towards the side where the insulating plastic part is located, and the riveting boss is riveted to the riveting holes. On the first or second support part, the center distance W2 of the two riveting holes in the width direction satisfies: 0.6≤W2 / B≤0.7, where B is the dimension of the insulating plastic part in the width direction; the center distance L2 of the riveting holes of the first support part and the second support part in the length direction satisfies: 0.5≤L2 / A≤0.6, where A is the dimension of the insulating plastic part in the length direction.

[0016] Based on the above technical features, the beneficial effects of this application are as follows: This application uses the plastic deformation of the riveting boss on the cover plate body to rivet the insulating plastic part to form a mechanical interlock. The mechanical interlock structure of the riveting can maintain stable connection strength and has excellent fatigue resistance, thereby making the assembly effect of the cover plate body and the insulating plastic part more stable.

[0017] Based on this, the positions of the two riveting holes satisfy the following conditions: 0.6≤W2 / B≤0.7, 0.5≤L2 / A≤0.6. This arrangement effectively ensures better assembly and better fit between the cover plate body and the insulating plastic part. On the first or second support part, the center distance W2 of the two riveting holes in the width direction satisfies the following condition: 0.6≤W2 / B≤0.7. If 0.6>W2 / B, the fit between the opposite edges of the insulating plastic part and the cover plate body in the width direction is poor, and the gap is too large; if W2 / B>0.7, the fit between the middle part of the insulating plastic part and the cover plate body is poor, and the gap is too large. Similarly, the center distance L2 between the rivet holes of the first support and the second support in the longitudinal direction satisfies: 0.5≤L2 / A≤0.6. If 0.5>L2 / A, the two opposite edges of the insulating plastic part in the longitudinal direction will have a poor fit with the cover plate body and the gap will be too large. If L2 / A>0.6, the middle part of the insulating plastic part will have a poor fit with the cover plate body and the gap will be too large.

[0018] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of the overall structure of the cover plate of this application is shown; Figure 2 A schematic diagram of the assembly structure of the cover plate of this application is shown; Figure 3 It shows Figure 2 Partial structural diagram; Figure 4 It shows Figure 3 Top view; Figure 5 It shows Figure 3 Side view; Figure 6 A schematic diagram of the structure of the insulating plastic part according to the first embodiment of this application is shown; Figure 7 A schematic diagram of the structure of the insulating plastic part according to the second embodiment of this application is shown; Figure 8 It shows Figure 6 Side view; Figure 9 It shows Figure 6 Top view; Figure 10 It shows Figure 9 A diagram of the back of the building; Figure 11 A schematic diagram of the structure of the riveting boss after riveting is shown.

[0021] Icons: 100 - Insulating plastic part; 110 - Bottom wall; 111 - First support part; 112 - Second support part; 113 - Protrusion; 1131 - Top wall; 114 - Vent part; 115 - Rivet hole; 116 - Second vent hole; 117 - First vent hole; 118 - Rivet groove; 120 - Edge; 121 - Long side; 122 - Short side; 123 - Rivet notch; 124 - Vent notch; 130 - First horizontal rib; 1 40 - Second horizontal rib; 150 - Vertical rib; 160 - First groove; 170 - Second groove; 180 - Exhaust groove; 200 - Cover plate body; 210 - Explosion-proof valve; 220 - Riveting boss; 221 - Support section; 222 - Bulging section; 223 - Extrusion groove; 300 - Support plate; 310 - Vent hole; 400 - Support protrusion; 410 - Vent gap; X - Length direction; Y - Width direction; Z - Thickness direction. Detailed Implementation

[0022] The following detailed embodiments are provided to help the reader gain a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will be apparent after understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein; changes that will be apparent after understanding the disclosure of this application are possible, except for operations that must occur in a specific order. Furthermore, for clarity and brevity, descriptions of features known in the art may be omitted.

[0023] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0024] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, it may be directly "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, or there may be one or more other elements in between. In contrast, when an element is described as being "directly on" another element, "directly connected to" another element, "directly bonded to" another element, "directly on" another element, or "directly covering" another element, there may be no other elements in between.

[0025] As used herein, the term “and / or” includes any one of the relevant items listed and any combination of any two or more items.

[0026] Although terms such as “first,” “second,” and “third” may be used herein to describe individual components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts are not limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Therefore, without departing from the teachings of the examples described herein, the first component, assembly, region, layer, or part referred to as the second component, assembly, region, layer, or part may also be referred to as the second component, assembly, region, layer, or part.

[0027] For ease of description, spatial relation terms such as “above,” “upper,” “below,” and “lower” are used herein to describe the relationship between one element and another, as shown in the accompanying drawings. Such spatial relation terms are intended to include not only the orientation depicted in the drawings but also different orientations of the device during use or operation. For example, if the device in the drawings is flipped, an element described as being “above” or “upper” relative to another element will subsequently be “below” or “lower” relative to that other element. Therefore, the term “above” includes both “above” and “below” orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relation terms used herein will be interpreted accordingly.

[0028] The terminology used herein is for the purpose of describing various examples only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms “comprising,” “including,” and “having” enumerate the stated features, quantities, operations, components, elements, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0029] Variations in the shapes shown in the accompanying drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include changes in shape that may occur during manufacturing.

[0030] The features of the examples described herein can be combined in various ways that will be apparent upon understanding the disclosure of this application. Furthermore, although the examples described herein have a wide variety of constructions, other constructions are possible, as will be apparent upon understanding the disclosure of this application.

[0031] The first aspect of this application provides a cover plate that solves the problems of poor assembly effect between the plastic parts and the aluminum plate, and poor fixing effect of the plastic parts in existing cover plate structures. The following will refer to... Figures 1 to 11 The cover plate described in some embodiments of this application will be described in detail below. For ease of description, the cover plate will be described as having a length direction X, a width direction Y, and a thickness direction Z that are perpendicular to each other.

[0032] like Figure 1 and Figure 2As shown, the cover plate of this application includes an insulating plastic part 100 and a cover plate body 200. The insulating plastic part 100 is attached to one side of the cover plate body 200 in the thickness direction Z. The insulating plastic part 100 includes a first support portion 111 and a second support portion 112 connected sequentially along the length direction X. Both the first support portion 111 and the second support portion 112 have two riveting holes 115 penetrating through themselves. The two riveting holes 115 are aligned along the width direction Y. A riveting boss 220 protruding towards the side of the cover plate body 200 facing the insulating plastic part 100 is provided. The riveting boss 220 is riveted to the riveting holes 115. Figure 9 and Figure 10 As shown, on the first support portion 111 or the second support portion 112, the center distance W2 of the two riveting holes 115 in the width direction Y satisfies: 0.6≤W2 / B≤0.7, where B is the dimension of the insulating plastic part 100 in the width direction Y; the center distance L2 of the riveting holes 115 of the first support portion 111 and the riveting holes 115 of the second support portion 112 in the length direction X satisfies: 0.5≤L2 / A≤0.6, where A is the dimension of the insulating plastic part 100 in the length direction X.

[0033] With this configuration, the application uses the plastic deformation of the riveting boss 220 on the cover plate body 200 to rivet with the riveting hole 115 of the insulating plastic part 100 to form a mechanical engagement. The mechanical engagement structure of the riveting can maintain a stable connection strength and has excellent fatigue resistance, thereby making the assembly effect of the cover plate body 200 and the insulating plastic part 100 more stable.

[0034] Based on this, the positions of the two riveting holes 115 satisfy the following conditions: 0.6≤W2 / B≤0.7, 0.5≤L2 / A≤0.6. This arrangement effectively ensures better assembly and better fit between the cover plate body 200 and the insulating plastic part 100. On the first support part 111 or the second support part 112, the center distance W2 of the two riveting holes 115 in the width direction Y satisfies the following condition: 0.6≤W2 / B≤0.7. If 0.6>W2 / B, the fit between the opposite edges of the insulating plastic part 100 and the cover plate body 200 in the width direction Y is poor, and the gap is too large; if W2 / B>0.7, the fit between the middle part of the insulating plastic part 100 and the cover plate body 200 is poor, and the gap is too large. Similarly, the center distance L2 of the rivet hole 115 of the first support part 111 and the rivet hole 115 of the second support part 112 in the length direction X satisfies: 0.5≤L2 / A≤0.6. If 0.5>L2 / A, the two opposite edges of the insulating plastic part 100 in the length direction X will have a poor fit with the cover plate body 200 and the gap will be too large. If L2 / A>0.6, the middle part of the insulating plastic part 100 will have a poor fit with the cover plate body 200 and the gap will be too large.

[0035] In the embodiments of this application, such as Figure 1 and Figure 6 As shown, the insulating plastic part 100 includes a bottom wall 110 and an edge 120 arranged around the edge of the bottom wall 110. The edge 120 fits against the cover plate body 200. The bottom wall 110 includes a first support part 111, an exhaust part 114 and a second support part 112 connected sequentially along the length direction X. The first support part 111 and the second support part 112 each form two protrusions 113 protruding towards one side of the cover plate body 200. The two protrusions 113 are aligned along the width direction Y. In the thickness direction Z, the top wall 1131 of the protrusion 113 is flush with the edge 120. The riveting hole 115 is opened on the top wall 1131 of the protrusion 113. The protrusion 113 forms a riveting groove 118 that opens towards the side opposite to the cover plate body 200.

[0036] With this configuration, the riveting hole 115 is located on the top wall 1131 of the protrusion 113, resulting in higher local rigidity and reducing the likelihood of dents or deformation during riveting, thus improving connection reliability and structural strength. Furthermore, after riveting, the top wall 1131 of the protrusion 113 and the edge 120 together fit against the cover plate body 200, increasing the contact area and effectively ensuring the structural strength of the insulating plastic part 100 to meet the cell design requirements. This ensures that the insulating plastic part 100 will not deform during cell assembly, subsequent vibration and impact testing, or use, thereby improving the cell's safety performance. On the other hand, the protrusion 113 forms a riveting groove 118 that opens to the side opposite to the cover plate body 200. The riveting groove 118 provides space for rivets, punches, or connectors, avoiding interference with surrounding components, ensuring a flat and compact overall structure, and improving space utilization.

[0037] Furthermore, in the embodiments of this application, such as Figure 6 As shown, the edge 120 includes two long sides 121 extending along the length direction X and two short sides 122 extending along the width direction Y. The long sides 121 have riveting notches 123, with the side of the riveting notch 123 facing away from the cover plate body 200 being open. The riveting notch 123 communicates with the riveting groove 118. Preferably, the dimension of the riveting notch 123 in the length direction X is equal to the dimension of the riveting groove 118 in the length direction X. The riveting notch 123 makes one side of the riveting groove 118 open, forming a one-sided open riveting groove 118 (through groove). This arrangement allows the riveting groove 118 to be open to the outside, facilitating the insertion and positioning of rivets, punches, or connectors from the outside, reducing assembly difficulty, improving assembly efficiency, and facilitating later maintenance and replacement.

[0038] In specific riveting operations, such as Figure 1 and Figure 11As shown, after the riveting boss 220 on the cover plate body 200 passes through the riveting hole 115, the riveting boss 220 is pressed by a punch to form a pressing groove 223 and expand the material to fix the insulating plastic part 100. It should be noted that in this embodiment, the diameter of the punch is small, so when the punch presses the riveting boss 220, a pressing groove 223 will be formed in the middle.

[0039] As an example, such as Figure 3 , Figure 4 and Figure 5 As shown, before the riveting boss 220 is riveted to the riveting hole 115, the riveting boss 220 is cylindrical. Figure 5 and Figure 8 As shown, the height h4 of the riveting boss 220 in the thickness direction Z satisfies: h4-h3=0.6mm-1.2mm, where h3 is the wall thickness of the top wall 1131 of the protrusion 113 in the thickness direction Z (i.e., the depth of the riveting hole 115), h3=0.6mm-0.8mm, and the diameter Ф2 of the riveting boss 220 satisfies: Ф2=Ф1-0.2mm, where Ф1 is the diameter of the riveting hole 115, Ф1=4mm-8mm.

[0040] After the riveting boss 220 is riveted to the riveting hole 115, as Figure 1 , Figure 2 and Figure 11 As shown, the riveting boss 220 forms a support section 221 and an bulging section 222. The support section 221 passes through the riveting hole 115. The bulging section 222 is formed by the plastic deformation of the end of the support section 221 away from the cover plate body 200 through riveting. The outer diameter of the bulging section 222 is larger than the diameter of the riveting hole 115. The bulging section 222 and the cover plate body 200 together clamp the top wall 1131. The end face of the bulging section 222 facing the top wall 1131 is attached to the side surface of the top wall 1131 away from the cover plate body 200 to form an annular contact surface.

[0041] With this setting, the lower limit of h4-h3 is 0.6mm to avoid insufficient height of the riveting boss 220, which would prevent the formation of an effective upset head (bulging section 222). This prevents loose riveting, low connection strength, and easy loosening under vibration, making it particularly suitable for scenarios with high requirements for sealing and structural reliability, such as battery covers. The upper limit of h4-h3 is 1.2mm to prevent the riveting boss 220 from being too long, which could lead to material accumulation, burrs, cracks, and wrinkles during riveting. This ensures that the riveted part has a neat shape, no obvious flash, and does not affect the overall assembly dimensions and appearance. Ф2=Ф1-0.2mm ensures full locking after riveting, resulting in high connection strength. The 0.2mm gap is moderate, allowing the riveting boss 220 to completely fill the radial gap after being compressed and plastically deformed during riveting. It fits tightly against the inner wall of the riveting hole 115, forming a reliable clamping force, avoiding riveting eccentricity and loosening due to excessive gap, and ensuring a stable and reliable connection structure.

[0042] In the embodiments of this application, the end face of the bulging segment 222 facing the top wall 1131 is attached to the side surface of the top wall 1131 away from the cover plate body 200 to form an annular contact surface. The sum of the areas S1 of the annular contact surfaces of all the riveting bosses 220 satisfies: 0.2≤10S1 / S0≤0.3, where S0=AB (i.e., the total area of ​​the insulating plastic outline).

[0043] With this configuration, if 0.2 > 10S1 / S0, the sum of the areas S1 of all annular mating surfaces will be insufficient, resulting in poor fixing of the insulating plastic part 100. If 10S1 / S0 > 0.3, the sum of the areas S1 of all annular mating surfaces will be too large, increasing the outward diffusion of material during deformation of the bulging section 222. This can easily lead to the formation of obvious burrs, rough edges, or uneven areas on the surface of the top wall 1131, affecting the appearance and subsequent assembly, and potentially scratching other components. Furthermore, the riveting pressure will be excessively concentrated in the area of ​​the insulating plastic part 100, causing it to be over-compressed, creeped, or even damaged, resulting in sealing failure and reduced insulation resistance.

[0044] In the embodiments of this application, such as Figure 2 and Figure 6 As shown, the cover body 200 is equipped with an explosion-proof valve 210. The first support part 111 and the second support part 112 have the same structure and are symmetrically arranged about the center line of the exhaust part 114. The center line is parallel to the width direction Y. The exhaust part 114 has a first exhaust hole 117 that penetrates itself. On the side of the first support part 111 and the second support part 112 facing the cover body 200, a first horizontal rib 130, a second horizontal rib 140 and a vertical rib 150 are also provided (the vertical rib 150 connects the short side 122 and the first horizontal rib 130). The first horizontal rib 130 and the second horizontal rib 140 both extend along the width direction Y, and the first horizontal rib 130 and the second horizontal rib 140 are respectively connected to the two sides of the two protrusions 113 that are opposite each other in the length direction X, so as to form a first horizontal rib 114 together with the two protrusions 113 and the bottom wall 110. A groove 160; two long sides 121, one short side 122, a first horizontal rib 130 and a bottom wall 110 are arranged together to form a second groove 170; two long sides 121, two second horizontal ribs 140 and an exhaust portion 114 are arranged together to form an exhaust groove 180; the first groove 160, the second groove 170 and the exhaust groove 180 are interconnected; the first support portion 111 and the second support portion 112 are each provided with a second exhaust hole 116 that penetrates through itself at the positions corresponding to the first groove 160 and the second groove 170.

[0045] With this configuration, the first support portion 111 and the second support portion 112 are provided with a first horizontal rib 130, a second horizontal rib 140, and a vertical rib 150 on the side facing the cover plate body 200, which can further improve the structural strength of the insulating plastic part 100. The thermal runaway venting path one of the battery cell in this application (initial stage of thermal runaway, before the insulating plastic part 100 melts): battery cell interior - first vent hole 117 (venting groove 180) - explosion-proof valve 210; the thermal runaway venting path two of the battery cell in this application (initial stage of thermal runaway, before the insulating plastic part 100 melts): battery cell interior - second vent hole 116 (first groove 160 and second groove 170) - venting groove 180 - explosion-proof valve 210, to meet the venting requirements. As an example, the first groove 160, the second groove 170, and the venting groove 180 are interconnected as follows: Figure 7 As shown, the first horizontal rib 130, the second horizontal rib 140 and the vertical rib 150 are all lower than the edge 120 (top wall 1131) to form an exhaust channel.

[0046] Additionally, in the embodiments of this application, such as Figure 1 and Figure 7 As shown, both long sides 121 are provided with venting notches 124. The side of the venting notch 124 facing the cover plate body 200 is open, and the venting notch 124 is connected to the venting groove 180. Along the thickness direction Z, the projections of the edge 120 and the cover plate body 200 are made onto a plane perpendicular to the thickness direction Z. The projected outline of the edge 120 falls completely within the projected outline range of the cover plate body 200. With this configuration, when the shell is connected to the cover plate, one end of the shell is connected to the part of the cover plate body 200 corresponding to the outer edge of its projected outline, and a venting gap is formed between the shell and the edge 120. With this configuration, the thermal runaway venting path of the battery cell in this application also includes (in the early stage of thermal runaway, before the insulating plastic part 100 melts): inside the battery cell - venting gap between the shell and the edge 120 - venting notch 124 - venting groove 180 - explosion-proof valve 210, to meet the venting requirements.

[0047] In the embodiments of this application, such as Figure 9As shown, the dimension L1 of the venting groove 180 in the length direction X satisfies: 0.45≤L1 / A≤0.55; the dimension W1 of the venting groove 180 in the width direction Y satisfies: 1mm≤(B-W1) / 2≤3mm. With this setting, if 0.45>L1 / A, the dimension of the venting groove 180 is too small, affecting its venting effect; if L1 / A>0.55, the dimension of the venting groove 180 is too large, resulting in large injection molding shrinkage deformation and insufficient flatness at the venting groove 180 position. If 1mm>(B-W1) / 2, the thickness of the long sides 121 on both sides of the venting groove 180 position is too small, affecting structural strength; if (B-W1) / 2>3mm, the thickness of the long sides 121 on both sides of the venting groove 180 position is too large, affecting the venting effect of the first venting hole 117 at the venting groove 180 position.

[0048] Another noteworthy point is that the blade energy storage cell of this application has its terminals on the same side, while the explosion-proof valve is located on the opposite side cover plate, achieving thermal-electric separation and improving the cell's safety performance. However, in conventional cells with this structure, when thermal runaway occurs, the explosion-proof valve opens to release pressure and exhaust air. As the pressure decreases, under the impact of the high-temperature, high-pressure airflow inside the cell (after the plastic parts melt), the electrode assembly will move towards the explosion-proof valve side, causing the front end of the electrode assembly to block the explosion-proof valve, greatly reducing the exhaust effect of the explosion-proof valve and lowering the cell's safety performance.

[0049] In view of this, this application solves the above-mentioned technical problems by designing a support plate 300. Specifically, in the embodiments of this application, such as... Figure 2 and Figure 3 As shown, the cover plate also includes a support plate 300 (e.g., an aluminum part). The side of the cover plate body 200 facing the insulating plastic part 100 is provided with a support protrusion 400 protruding towards the side where the insulating plastic part 100 is located. The support plate 300 is connected to the support protrusion 400 to form a ventilation gap 410 between it and the cover plate body 200. The support plate 300, the explosion-proof valve 210 and the exhaust part 114 are arranged facing each other in the thickness direction Z. The support plate 300 is provided with a vent hole 310 that penetrates itself. The exhaust groove is used to accommodate the support plate 300.

[0050] With this configuration, the cover body 200 of this application has an integrated explosion-proof valve 210. The cover body 200 is provided with a support protrusion 400 and is protected by a support plate 300, which serves to protect the explosion-proof valve 210. This prevents the explosion-proof valve 210 from being blocked by the electrode assembly and affecting the venting effect when the insulating plastic part 100 melts due to thermal runaway of the battery cell. With the support plate 300 of this application, even if the insulating plastic part 100 melts and the electrode assembly moves towards the explosion-proof valve 210, the electrode assembly will not continue to move towards the explosion-proof valve 210 due to the presence of the support plate 300, thus preventing the front end of the electrode assembly from blocking the explosion-proof valve 210. Moreover, even if the electrode assembly blocks part of the vent hole 310, the venting gap 410 between the cover body 200 and the support plate 300 can still vent, thereby improving the safety performance of the battery cell.

[0051] In the embodiments of this application, such as Figure 2 As shown, there are multiple support protrusions 400, which are arranged around the edge of the support plate 300. Preferably, there are four support protrusions 400, which are respectively arranged at the four corners of the support plate 300, such as... Figure 5 As shown, the dimension H1 of the support protrusion 400 in the thickness direction Z is between 2mm and 3mm, that is, the distance between the support plate 300 and the cover plate body 200 is between 2mm and 3mm. With this setting, if the dimension of the support protrusion 400 in the thickness direction Z is <2.0mm, it will affect the venting; if the dimension of the support protrusion 400 in the thickness direction Z is >3mm, it will affect the energy density of the battery cell.

[0052] Furthermore, such as Figure 5 and Figure 6 As shown, the depth h1 of the venting groove 180 in the thickness direction satisfies: 0.2mm ≤ h1 - h2 ≤ 0.5mm, where h2 is the total dimension of the supporting protrusion 400 and the supporting plate 300 in the thickness direction. This setting ensures that 0.2mm ≤ h1 - h2 ensures that the assembly does not interfere; h1 - h2 ≤ 0.5mm ensures the structural strength of the insulating plastic part 100 and the energy density of the battery cell.

[0053] Furthermore, such as Figure 9 As shown, the wall thickness t1 of the long side 121 at the second groove 170 position is 1.2mm-2mm, and the wall thickness t2 of the short side 122 is 1mm-1.5mm, in order to accommodate the structural strength of the insulating plastic part 100 and the internal venting effect.

[0054] Different experimental designs were used to verify the above schemes, and the results are as follows:

[0055] As can be seen, when the above design scheme is met, the structural strength of the insulating plastic component meets the requirements, the cover plate assembly is normal, and the fixing effect of the insulating plastic component is good. Ten battery cells were randomly selected for thermal runaway testing; the explosion-proof valve opened normally, and no obvious signs of electrode movement were found during cell disassembly, indicating that the cell venting meets the requirements. In other words, the structural strength of the insulating plastic component and its fixing effect with the cover plate meet the requirements. Furthermore, this cell structure effectively avoids the problem of electrode movement obstructing the explosion-proof valve and affecting its venting effect, greatly improving the cell's safety performance.

[0056] According to a second aspect of this application, a battery cell is provided, including the cover plate as described above.

[0057] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the scope of the technology disclosed in this application, or make equivalent substitutions for some of the technical features. Such modifications, changes, 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 this application, and should all be covered within the protection scope of this application.

Claims

1. A cover plate, characterized in that, The cover plate has two perpendicular length directions, width directions and thickness directions, and the cover plate includes an insulating plastic part and a cover plate body. The insulating plastic part is attached to one side of the cover plate body in the thickness direction. The insulating plastic part includes a first support part and a second support part connected sequentially along the length direction. Both the first support part and the second support part are provided with two riveting holes that penetrate through themselves. The two riveting holes are aligned along the width direction. The cover plate body has a riveting boss protruding towards the side where the insulating plastic part is located on the side facing the insulating plastic part, and the riveting boss is riveted to the riveting hole. On the first support or the second support, the center distance W2 of the two riveting holes in the width direction satisfies: 0.6≤W2 / B≤0.7, where B is the dimension of the insulating plastic part in the width direction; The center distance L2 between the riveting holes of the first support and the second support in the length direction satisfies: 0.5≤L2 / A≤0.6, where A is the dimension of the insulating plastic part in the length direction.

2. The cover plate according to claim 1, characterized in that, The insulating plastic part includes a bottom wall and an edge provided around the edge of the bottom wall. The edge is fitted with the cover plate body. The bottom wall includes a first support part, an exhaust part and a second support part connected sequentially along the length direction. Both the first support portion and the second support portion form two protrusions protruding towards one side of the cover plate body. The two protrusions are aligned along the width direction. In the thickness direction, the top wall of the protrusion is flush with the edge. The riveting hole is opened on the top wall of the protrusion. The protrusion forms a riveting groove that is open to the side opposite to the cover plate body.

3. The cover plate according to claim 2, characterized in that, The edge includes two long sides extending along the length direction and two short sides extending along the width direction. The long sides are provided with riveting notches. The side of the riveting notch facing away from the cover plate body is open. The riveting notch is connected to the riveting groove. And / or, before the riveting boss is riveted to the riveting hole, the riveting boss is cylindrical, and the height h4 of the riveting boss in the thickness direction satisfies: h4-h3=0.6mm-1.2mm, where h3 is the wall thickness of the top wall of the protrusion in the thickness direction, and the diameter Ф2 of the riveting boss satisfies: Ф2=Ф1-0.2mm, where Ф1 is the diameter of the riveting hole.

4. The cover plate according to claim 3, characterized in that, After the riveting boss is riveted to the riveting hole, the riveting boss forms a support section and an bulging section. The support section passes through the riveting hole, and the bulging section is formed by plastic deformation of the end of the support section away from the cover plate body through riveting. The outer diameter of the bulging section is larger than the diameter of the riveting hole. The bulging section and the cover plate body together clamp the top wall. The end face of the bulging segment facing the top wall is attached to the side surface of the top wall facing away from the cover plate body, forming an annular contact surface. The sum of the areas S1 of the annular contact surfaces of all the riveting bosses satisfies: 0.2≤10S1 / S0≤0.3, where S0=AB.

5. The cover plate according to claim 3, characterized in that, The cover plate body is provided with an explosion-proof valve. The first support part and the second support part have the same structure and are symmetrically arranged about the center line of the exhaust part. The center line is parallel to the width direction. The exhaust part has a first exhaust hole that penetrates itself. The first support portion and the second support portion are further provided with a first horizontal rib and a second horizontal rib on the side facing the cover plate body. The first horizontal rib and the second horizontal rib both extend along the width direction and are respectively connected to the two opposite sides of the two protrusions in the length direction, so as to form a first groove together with the two protrusions and the bottom wall; the two long sides, one short side, the first horizontal rib and the bottom wall together form a second groove; the two long sides, the two second horizontal ribs and the exhaust portion together form an exhaust groove; the first groove, the second groove and the exhaust groove are interconnected. Both the first support portion and the second support portion have a second vent hole that penetrates through them at the positions corresponding to the first groove and the second groove.

6. The cover plate according to claim 5, characterized in that, Both the first and second horizontal ribs are lower than the edge. Both long sides are provided with exhaust notches, and the side of the exhaust notch facing the cover plate body is open. The exhaust notch is connected to the exhaust groove.

7. The cover plate according to claim 5, characterized in that, The dimension L1 of the exhaust groove in the length direction satisfies: 0.45≤L1 / A≤0.55; the dimension W1 of the exhaust groove in the width direction satisfies: 1mm≤(B-W1) / 2≤3mm.

8. The cover plate according to any one of claims 5-7, characterized in that, The cover plate also includes a support plate. The side of the cover plate body facing the insulating plastic part is provided with a support protrusion protruding towards the side where the insulating plastic part is located. The support plate is connected to the support protrusion to form a ventilation gap with the cover plate body. The support plate, the explosion-proof valve and the exhaust part are arranged facing each other in the thickness direction, and the support plate has a ventilation hole that penetrates itself. The exhaust groove is used to accommodate the support plate.

9. The cover plate according to claim 8, characterized in that, The dimension of the support protrusion in the thickness direction is H1 = 2mm - 3mm; The depth h1 of the venting groove in the thickness direction satisfies: 0.2mm≤h1-h2≤0.5mm, where h2 is the total dimension of the support protrusion and the support plate in the thickness direction.

10. A battery cell, characterized in that, The cover plate included in any one of claims 1-9.

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