A battery cover plate assembly and a battery

Abstract

The application relates to the technical field of batteries, and particularly discloses a battery cover plate assembly and a battery. The battery cover plate assembly comprises a cover plate body, a combined plastic part, a connecting sheet and a pole. The combined plastic part is arranged on the cover plate body, the connecting sheet is arranged on the side of the combined plastic part away from a pole group, the tab of the pole group is connected with the connecting sheet after penetrating through the cover plate body and the combined plastic part, the pole is located on the side of the connecting sheet away from the pole group, and the pole is connected with the connecting sheet. The connecting sheet and the pole are arranged outside the shell, the arrangement space of the pole group is increased, the space utilization rate is high, and the energy density of the battery is large. In addition, the connecting sheet is in interference fit with the combined plastic part, the connecting structure between the two is relatively stable and firm, the connecting sheet is not prone to position deviation, the connection between the connecting sheet and the tab is relatively reliable, and the safety of the battery is high. The application further provides a battery comprising the above battery cover plate assembly.

Description

Technical Field

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

[0002] In lithium-ion batteries, the connecting piece and one end of the terminal are typically located inside the battery casing, while the other end of the terminal passes through the battery casing and connects to an external circuit to lead out the electrode assembly, enabling the battery to supply power or store energy. A lower plastic component is located between the end of the terminal inside the battery casing and the casing, insulating the terminal from the casing. This lower plastic component is also located inside the battery casing.

[0003] Because the connecting piece and one end of the terminal are located inside the battery casing, they occupy some of the internal space of the battery casing, resulting in less space for the electrode assembly, low space utilization within the battery casing, and low energy density. Furthermore, the two ends of the connecting piece are usually directly welded to the tabs and terminals of the electrode assembly, without any support. When the battery is shaken or subjected to impacts, the connecting piece may separate from the tabs and terminals, or the tabs may tear, leading to low battery safety. Summary of the Invention

[0004] The purpose of this invention is to provide a battery cover assembly and a battery, in which the terminals do not occupy the internal space of the casing, the volume of the electrode assembly is increased, the space utilization rate is high, and the energy density of the battery is high. Furthermore, a connecting structure is provided between the connecting piece and the assembled plastic part, ensuring a stable and secure connection and high battery safety.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] On one hand, the present invention provides a battery cover assembly, comprising:

[0007] The cover plate body is provided with a first mounting hole;

[0008] The combined plastic part is partially attached to the end face of the cover plate body on the side away from the electrode group and partially attached to the end face of the cover plate body on the side close to the electrode group. The combined plastic part is provided with through holes.

[0009] A connecting piece is located on the side of the combined plastic part away from the electrode group. The connecting piece is interference-fitted with the side of the combined plastic part away from the electrode group. The electrode lug of the electrode group passes through the first mounting hole and the through hole and is connected to the connecting piece.

[0010] The electrode post is located on the side of the connecting piece away from the electrode assembly, and the electrode post is connected to the connecting piece.

[0011] Optionally, the combined plastic part includes a first plastic part body and a second plastic part body. Both the first plastic part body and the second plastic part body are provided with the through hole. The first plastic part body is attached to the end face of the cover plate body on the side away from the electrode group, and the second plastic part body is attached to the end face of the cover plate body on the side close to the electrode group.

[0012] And / or, one of the first plastic body and the second plastic body is provided with a connecting part, the connecting part is cylindrical and located circumferentially in the through hole, the connecting part passes through the first mounting hole and fits against the inner wall of the first mounting hole, and the center of the connecting part forms a channel for the tab to pass through.

[0013] Optionally, the first plastic part body has an annular flange and a limiting flange on the side opposite to the cover plate body. The annular flange is disposed in the circumferential direction of the through hole. The annular flange, the limiting flange and the first plastic part body form a mounting groove. At least a portion of the connecting piece is embedded in the mounting groove. The connecting piece is interference-fitted with the annular flange and / or the limiting flange.

[0014] Optionally, the annular flange and / or the limiting flange are provided with a first interference rib, and the first interference rib is interference-fitted with the peripheral sidewall of the connecting piece;

[0015] And / or, the peripheral sidewall of the connecting piece is provided with a second interference rib, the second interference rib being interference-fitted with the annular flange and / or the limiting flange.

[0016] Optionally, multiple first interference ribs are provided and the first interference ribs are strip-shaped. The multiple first interference ribs extend along the axial direction of the first mounting hole and are evenly spaced on the annular flange and / or the limiting flange.

[0017] And / or, the second interference rib is provided in multiple forms and is strip-shaped, the multiple second interference ribs extend along the axial direction of the first mounting hole and are evenly spaced on the peripheral sidewall of the connecting piece.

[0018] Optionally, the end of the first interference rib facing away from the cover plate body is provided with a guide structure;

[0019] And / or, the end of the second interference rib facing the cover plate body is provided with a guide structure.

[0020] Optionally, the interference between the first interference rib and the peripheral sidewall of the connecting piece is h1, and the value of h1 is within the range of: 0.05mm≤h1≤0.5mm;

[0021] The interference between the second interference rib and the annular flange and / or the limiting flange is h2, and the value range of h2 satisfies: 0.05mm≤h2≤0.5mm.

[0022] Optionally, the first plastic part body is provided with an overlapping part in the circumferential direction, and the end face of the cover plate body opposite to the second plastic part body is provided with a groove, and the overlapping part is embedded in the groove and fits against the bottom wall of the groove.

[0023] Wherein, along the first direction, the width of the overlapping portion is c;

[0024] The range of values ​​for c satisfies: 0mm≤c≤10mm;

[0025] And / or, along the second direction, the thickness of the cover plate body is H, and the distance between the end face of the overlapping portion facing away from the second plastic body and the end face of the cover plate body facing away from the second plastic body is b.

[0026] The range of values ​​for b satisfies: -1mm≤b≤0.5H, 1mm≤H≤3mm.

[0027] Optionally, the second plastic body has an electrode ear shaping structure and a support structure on the side near the electrode assembly. The electrode ear shaping structure is arranged in the circumferential direction of the through hole and allows the electrode ear to pass through. The support structure is connected to the electrode ear shaping structure and is used to abut against the cover plate body.

[0028] On the other hand, the present invention provides a battery including a housing, an electrode assembly, and a battery cover assembly as described in any of the above embodiments, wherein the battery cover assembly is encapsulated at an opening of the housing, and the electrode assembly is disposed within the housing.

[0029] The beneficial effects of this invention are as follows:

[0030] This invention provides a battery cover assembly, including a cover body, a combined plastic component, a connecting piece, and terminals. The combined plastic component is disposed on the cover body, and the connecting piece is arranged on the side of the combined plastic component opposite to the electrode assembly. The combined plastic component insulates the connecting piece from the cover body and the cover body from the electrode assembly. The electrode tabs of the electrode assembly pass through a first mounting hole on the cover body and a through hole on the combined plastic component and connect to the connecting piece. The terminals are located on the side of the connecting piece opposite to the electrode assembly and are connected to the connecting piece. Because the connecting piece and terminals are located on the side of the combined plastic component opposite to the electrode assembly, they do not occupy internal space of the casing, increasing the space for the electrode assembly and improving space utilization, which helps to improve the energy density of the battery. Furthermore, the interference fit between the connecting piece and the side of the combined plastic component opposite to the electrode assembly ensures a stable and robust connection structure between the connecting piece and the combined plastic component, preventing the connecting piece from shifting position, ensuring reliable connection between the connecting piece and the electrode tabs, reducing the risk of tearing of the electrode tabs, and enhancing battery safety.

[0031] The present invention also provides a battery, including a casing, an electrode assembly, and the aforementioned battery cover assembly. An opening is provided on one side of the casing, through which the electrode assembly is inserted into the casing. The battery cover assembly is disposed at the opening of the casing and welded to the casing. The battery cover assembly and the casing form a closed accommodating space to encapsulate the electrode assembly within the accommodating space. The battery with this battery cover assembly has high space utilization, high energy density, and high safety. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the battery cover assembly provided in an embodiment of the present invention;

[0034] Figure 2 This is an exploded view of the battery cover assembly provided in an embodiment of the present invention;

[0035] Figure 3 This is an exploded view of the battery cover assembly provided in an embodiment of the present invention from another perspective;

[0036] Figure 4 This is a top view of the battery cover assembly provided in an embodiment of the present invention;

[0037] Figure 5 for Figure 4 Cross-sectional view of section AA;

[0038] Figure 6 for Figure 5 A magnified view of a section at point B in the middle;

[0039] Figure 7 for Figure 5 Cross-sectional view of section CC;

[0040] Figure 8 for Figure 7 A magnified view of a section at point E in the middle;

[0041] Figure 9 for Figure 7 Cross-sectional view of section DD;

[0042] Figure 10 for Figure 9 A magnified view of a section at point F in the middle;

[0043] Figure 11 This is a schematic diagram of the structure of the combined plastic part provided in the embodiment of the present invention;

[0044] Figure 12 for Figure 11 A magnified view of a section at point G.

[0045] In the picture:

[0046] 100. Cover plate body; 110. First mounting hole; 120. Settling tank; 130. Second mounting hole; 140. Support rib; 150. First injection hole;

[0047] 200. Composite plastic part; 201. Through hole; 210. First plastic part body; 211. Overlap; 212. Annular flange; 213. Limiting flange; 2131. Mounting groove; 214. First interference rib; 2141. Guide structure; 220. Second plastic part body; 221. Connecting part; 222. End tab shaping structure; 2221. Guide plate; 2222. Flared mouth; 223. Support structure; 2231. Connecting plate; 2232. Support plate; 224. Vent hole;

[0048] 300, connecting piece; 400, explosion-proof valve. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0050] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0051] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0052] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0053] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" 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 mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0054] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0055] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0056] like Figures 1-3 As shown, this embodiment provides a battery cover assembly, which is connected to a housing, and the electrode assembly is disposed inside the housing. The battery cover assembly includes a cover body 100, a combined plastic part 200, a connecting piece 300, and electrode posts, with the electrode assembly located on the side of the cover body 100 facing the housing.

[0057] The composite plastic component 200 is partially attached to the end face of the cover plate body 100 on the side away from the electrode assembly, and partially attached to the end face of the cover plate body 100 on the side closer to the electrode assembly. The connecting piece 300 is arranged on the side of the composite plastic component 200 away from the electrode assembly. The composite plastic component 200 insulates the connecting piece 300 from the cover plate body 100 and from the electrode assembly. The cover plate body 100 has a first mounting hole 110, and the composite plastic component 200 has a through hole 201. The electrode tabs of the electrode assembly pass through the first mounting hole 110 and the through hole 201 and connect to the connecting piece 300. The electrode post is located on the side of the connecting piece 300 away from the electrode assembly and is connected to the connecting piece 300. That is, the connecting piece 300 is connected to both the electrode tabs and the electrode post, and the electrode tabs and electrode post of the electrode assembly are electrically connected through the connecting piece 300.

[0058] Since the connecting piece 300 and the terminal post are located on the side of the combined plastic part 200 away from the electrode assembly, that is, both the connecting piece 300 and the terminal post are located outside the housing, they do not occupy the space inside the housing. This increases the space available for the electrode assembly, resulting in high space utilization and helping to improve the energy density of the battery. In addition, both the connecting piece 300 and the terminal post are flat, and they are arranged along... Figures 1-3 The thinner thickness along the Z-axis shown in the diagram further reduces the space occupied. The overall size of the battery cover assembly along the Z-axis is small. When the battery with this battery cover assembly is arranged in the battery pack, the space utilization is high and the energy density is large.

[0059] Furthermore, in this embodiment, the connecting piece 300 and the combined plastic part 200 are interference-fitted on the side away from the electrode assembly. As a result, the connection structure between the connecting piece 300 and the combined plastic part 200 is relatively stable and firm, and their positions are relatively fixed. The connecting piece 300 is not prone to positional displacement, and the combined plastic part 200 can provide good support for the connecting piece 300, which is conducive to improving the reliability of the connection between the connecting piece 300 and the electrode tab. The electrode tab is not prone to tearing, and the battery has high safety.

[0060] As an alternative solution, see Figures 4-6 In this embodiment, the combined plastic component 200 includes a first plastic component body 210 and a second plastic component body 220, both of which have through holes 201. The first plastic component body 210 is attached to the end face of the cover plate body 100 opposite to the electrode assembly, and the connecting piece 300 is attached to the end face of the first plastic component body 210 opposite to the electrode assembly, thus insulating the connecting piece 300 from the cover plate body 100 through the first plastic component body 210. The second plastic component body 220 is attached to the end face of the cover plate body 100 near the electrode assembly, thus insulating the electrode assembly from the cover plate body 100 through the second plastic component body 220.

[0061] See Figure 9 and Figure 10One of the first plastic body 210 and the second plastic body 220 is provided with a connecting portion 221. The connecting portion 221 is cylindrical and located circumferentially in the through hole 201. The first plastic body 210 and the second plastic body 220 are connected by the connecting portion 221, and a channel for the electrode tab to pass through is formed at the center of the connecting portion 221. The connecting portion 221 passes through the first mounting hole 110 and fits against the inner wall of the first mounting hole 110. The connecting portion 221 can insulate the electrode tab from the cover plate body 100. It should be noted that in this embodiment, the first plastic body 210, the second plastic body 220 and the connecting portion 221 can be integrally injection molded onto the cover plate body 100 using a mold. The advantage of this method is that the connection between the combined plastic body 200 and the cover plate body 100 is more reliable, the positioning is accurate, and the assembly steps of the battery cover plate assembly are simplified.

[0062] Of course, in other embodiments, the first plastic body 210 and the second plastic body 220 can also be injection molded separately, and then the first plastic body 210 and the second plastic body 220 can be assembled with the cover plate body 100. In this case, the combined plastic part 200 can be removed from the cover plate body 100, making it more convenient to replace the combined plastic part 200. Optionally, the connecting part 221 can be provided on the first plastic body 210 or on the second plastic body 220. Alternatively, both the first plastic body 210 and the second plastic body 220 can be provided with connecting parts 221, and both connecting parts 221 extend into the first mounting hole 110 and are nested together, thereby providing a double insulation structure between the electrode tab and the cover plate body 100, resulting in better insulation.

[0063] See also Figure 2 and Figure 3 In this embodiment, two electrode groups are provided. Each electrode group has a positive electrode tab and a negative electrode tab at both ends along its length. The positive electrode tabs of the two electrode groups are located on the same side, and the negative electrode tabs of the two electrode posts are located on the same side. Two first plastic parts 210, two connecting pieces 300, and two electrode posts are provided. The two first plastic parts 210 are respectively located along the cover plate body 100. Figure 2 As shown, at both ends of the X-axis direction, each first plastic part body 210 has a connecting piece 300 on the side facing away from the cover plate body 100. Each connecting piece 300 has a terminal on the side facing away from the cover plate body 100, one of which is a positive terminal and the other is a negative terminal. Each first plastic part body 210 has two through holes 201, and the two through holes 201 are along... Figure 2 The through holes 201 are arranged at intervals along the Y-axis, that is, there are four through holes 201 in total, and each through hole 201 is provided with a connecting part 221 in the circumferential direction.

[0064] The second plastic body 220 is provided with a second plastic body 220 along... Figure 2Two through holes 201 are provided at each end of the X-axis direction shown in the figure. The through holes 201 on the second plastic body 220 correspond one-to-one with the through holes 201 on the first plastic body 210. A cover plate body 100 is provided, and the cover plate body 100 is along the X-axis direction. Figure 2 Two first mounting holes 110 are provided at each end of the X-axis direction shown, meaning there are four first mounting holes 110. The through holes 201 correspond one-to-one with the first mounting holes 110. The positive electrode tab of the electrode group passes through one through hole 201 of the second plastic body 220, one first mounting hole 110 of the cover plate body 100, and one through hole 201 of the first plastic body 210, and then connects to the positive electrode post. The negative electrode tab of the electrode group passes through one through hole 201 of the second plastic body 220, one first mounting hole 110 of the cover plate body 100, and another through hole 201 of the first plastic body 210, and then connects to the negative electrode post. This allows the electrode tabs of the two electrode groups to be led out from inside the housing and connected to the connecting piece 300 on the outside of the housing, without occupying internal space of the housing, resulting in high space utilization and large volumetric energy of the electrode group.

[0065] See Figures 5-8 In this embodiment, the first plastic part body 210 is provided with an annular flange 212 and a limiting flange 213 on the side away from the cover plate body 100. Two annular flanges 212 are provided, and the two annular flanges 212 are arranged along... Figure 7 The Y-axis direction shown is spaced apart, and there are two limiting flanges 213, with the two limiting flanges 213 along the Y-axis direction. Figure 7 The arrangement is spaced along the X-axis as shown. The annular flange 212 is annular and surrounds the circumference of the through hole 201. The two ends of the limiting flange 213 are respectively connected to one of the annular flanges 212. The annular flange 212, the limiting flange 213, and the first plastic body 210 form a mounting groove 2131. At least a portion of the connecting piece 300 is embedded in the mounting groove 2131, thereby further reducing the height of the battery cover assembly along the X-axis. Figure 5 The reduced dimensions along the Z-axis decrease the space occupied by the battery cover assembly, which helps to improve the energy density of the entire battery pack. Meanwhile, the annular flange 212 and the limiting flange 213 can also limit the positioning of the connecting piece 300, ensuring accurate positioning of the connecting piece 300 in the Y-axis and X-axis directions.

[0066] Furthermore, the connecting piece 300 is interference-fitted with the annular flange 212 and / or the limiting flange 213, thereby achieving the assembly and fixation between the connecting piece 300 and the combined plastic part 200.

[0067] Optionally, in this embodiment, the annular flange 212 is provided with a first interference rib 214, and the first interference rib 214 on the annular flange 212 is connected to the connecting piece 300 along the... Figure 7The peripheral sidewalls in the Y-axis direction are interference-fitted. The interference between the first interference rib 214 and the peripheral sidewall of the connecting piece 300 is h1, and the value of h1 is within the range of 0.05mm ≤ h1 ≤ 0.5mm. For example, the value of h1 can be 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, or 0.5mm. It should be noted that the value of h1 should not be too small, otherwise the connection strength between the combined plastic part 200 and the connecting piece 300 will be low, the connection between the two will not be firm, and the connecting piece 300 may detach from the combined plastic part 200, posing a safety risk; the value of h1 should also not be too large, otherwise the assembly between the connecting piece 300 and the combined plastic part 200 will be more difficult, which is not conducive to installation, and may also cause deformation of the combined plastic part 200 and poor flatness of the battery cover assembly.

[0068] Furthermore, multiple first interference ribs 214 are provided on the annular flange 212, and the first interference ribs 214 are strip-shaped. For example, the first interference ribs 214 can be straight, wavy, etc. Multiple first interference ribs 214 are arranged along the axial direction of the first mounting hole 110. Figure 5 Extending along the Z-axis direction shown, a plurality of first interference ribs 214 are evenly spaced on the annular flange 212. Alternatively, the first interference ribs 214 may also be inclined along an axial direction offset from the first mounting hole 110. The cross-section of each first interference rib 214 (along the Z-axis direction shown) is... Figure 7 The cross-sections of the XY plane shown are all triangular. One sidewall of the first interference rib 214 is connected to the annular flange 212, and the edge opposite to this sidewall is connected to the connecting piece 300 along... Figure 7 The peripheral sidewalls in the Y-axis direction are interference-fitted. Furthermore, the edges of the first interference rib 214 opposite to the sidewall can be smoothly transitioned using a curved surface, thereby preventing the first interference rib 214 from scratching the connecting piece 300.

[0069] See Figure 11 and Figure 12 A guide structure 2141 is provided at the end of the first interference rib 214 away from the cover plate body 100. The guide structure 2141 makes it easier for the connecting piece 300 to be inserted into the mounting groove 2131, facilitating assembly. Exemplarily, the guide structure 2141 can be an inclined surface provided at the end of the first interference rib 214, which slopes towards the bottom of the mounting groove 2131 on the side facing the connecting piece 300 (the bottom of the mounting groove 2131 is the end face of the first plastic part body 210 away from the cover plate body 100). Of course, in some embodiments, the guide structure 2141 can also be an arc surface provided at the end of the first interference rib 214.

[0070] Of course, in other embodiments, not only can the first interference rib 214 be provided on the annular flange 212, but the first interference rib 214 can also be provided on the limiting flange 213. The first interference rib 214 on the limiting flange 213 is along the connecting piece 300. Figure 7 The peripheral sidewall in the X-axis direction has an interference fit. The interference between the first interference rib 214 and the peripheral sidewall of the connecting piece 300 is also h1, and the value of h1 satisfies: 0.05mm≤h1≤0.5mm. Optionally, multiple first interference ribs 214 can be provided on the limiting flange 213, and the multiple first interference ribs 214 are arranged along the axial direction of the first mounting hole 110 ( Figure 5 Extending in the Z-axis direction shown, multiple first interference ribs 214 are evenly spaced on the limiting flange 213.

[0071] The following example, which only sets the first interference rib 214 on the combined plastic part 200, illustrates the trial assembly of some samples of the battery cover assembly in specific implementation schemes to explore the influence of the value of parameter h1 on the assembly result of the connecting piece 300 and the combined plastic part 200. The results are shown in Table 1.

[0072] Table 1

[0073]

[0074] The trial assembly results show that in sample 1, the value of h1 is less than the minimum value of its set range of 0.05mm≤h1≤0.5mm. The connecting piece 300 cannot be fixedly connected to the combined plastic part 200. After assembly, the connecting piece 300 is easy to fall off the combined plastic part 200. Moreover, after the electrode tab is welded to the connecting piece 300, it is easy to shake, which will cause the electrode tab to tear and the battery cover plate assembly product to be defective.

[0075] In samples 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11, the value of h1 is within its set range of 0.05mm ≤ h1 ≤ 0.5mm. The connecting piece 300 and the combined plastic part 200 are easy to assemble, and after assembly, the connecting piece 300 and the combined plastic part 200 are stably connected. The connecting piece 300 is not easy to fall off the combined plastic part 200. After the electrode tab is welded to the connecting piece 300, the electrode tab is stably fixed and is not easy to shake. The reliability of the connection between the electrode tab and the connecting piece 300 is high, and the battery cover assembly product is good.

[0076] In sample 12, the value of h1 is greater than the maximum value of its set range of 0.05mm≤h1≤0.5mm, making it difficult to assemble the connecting piece 300 and the combined plastic part 200. During assembly, metal wires may be generated on the peripheral sidewall of the connecting piece 300, posing a short circuit risk to the electrode assembly and resulting in a defective battery cover assembly.

[0077] Furthermore, in some embodiments, a second interference rib is provided on the peripheral sidewall of the connecting piece 300, and the second interference rib is interference-fitted with the annular flange 212 and / or the limiting flange 213. For example, multiple second interference ribs may be provided, and all of the multiple second interference ribs are strip-shaped, extending along the axial direction of the first mounting hole 110, and evenly spaced on the peripheral sidewall of the connecting piece 300. By providing interference fit structures on both the connecting piece 300 and the combined plastic part 200, it is beneficial to improve the connection strength between the connecting piece 300 and the combined plastic part 200, and the fixation between the two is more stable and firm. In addition, a guide structure 2141 is also provided at the end of the second interference rib facing the cover plate body 100, and this guide structure 2141 is the same as the guide structure 2141 on the first interference rib 214. By providing a guide structure 2141 at the end of the second interference rib facing the cover plate body 100, it is easier to insert the connecting piece 300 into the mounting groove 2131 of the combined plastic part 200, thus facilitating assembly. Alternatively, in other optional embodiments, the second interference rib may be provided only on the connecting piece 300, and the first interference rib 214 may not be provided on the combined plastic part 200.

[0078] Optionally, the interference between the second interference rib and the annular flange 212 and / or the limiting flange 213 is h2, and the value of h2 is within the range of 0.05mm ≤ h2 ≤ 0.5mm. For example, the value of h2 can be 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, or 0.5mm. It should be noted that the value of h2 should not be too small, otherwise the connection strength between the combined plastic part 200 and the connecting piece 300 will be low, the connection between the two will not be firm, and the connecting piece 300 may detach from the combined plastic part 200, posing a safety risk; the value of h2 should also not be too large, otherwise the assembly between the connecting piece 300 and the combined plastic part 200 will be more difficult, which is not conducive to installation, and may also cause deformation of the combined plastic part 200 and poor flatness of the battery cover assembly.

[0079] The following example, which only sets a second interference rib on the peripheral sidewall of the connecting piece 300, illustrates the trial assembly of some specific implementation schemes of the battery cover assembly to explore the influence of the value of parameter h2 on the assembly result of the connecting piece 300 and the combined plastic part 200. The results are shown in Table 2.

[0080] Table 2

[0081]

[0082] The trial assembly results show that in sample 1, the value of h2 is less than the minimum value of its set range of 0.05mm≤h2≤0.5mm. The connecting piece 300 cannot be fixedly connected to the combined plastic part 200. After assembly, the connecting piece 300 is easy to fall off the combined plastic part 200. Moreover, after the electrode tab is welded to the connecting piece 300, it is easy to shake, which will cause the electrode tab to tear and the battery cover plate assembly product to be defective.

[0083] In samples 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11, the value of h2 is within its set range of 0.05mm ≤ h2 ≤ 0.5mm. The connecting piece 300 and the combined plastic part 200 are easy to assemble, and after assembly, the connecting piece 300 and the combined plastic part 200 are stably connected. The connecting piece 300 is not easy to fall off the combined plastic part 200. After the electrode tab is welded to the connecting piece 300, the electrode tab is stably fixed and is not easy to shake. The reliability of the connection between the electrode tab and the connecting piece 300 is high, and the battery cover assembly product is good.

[0084] In sample 12, the value of h2 is greater than the maximum value of its set range 0.05mm≤h2≤0.5mm, making it difficult to assemble the connecting piece 300 and the combined plastic part 200. During assembly, metal wires may be generated on the peripheral sidewall of the connecting piece 300, posing a short circuit risk to the electrode assembly and resulting in a defective battery cover assembly.

[0085] See also Figure 6 and Figure 10 In this embodiment, the first plastic body 210 has a circumferentially lapped portion 211, and the cover plate body 100 has a recessed groove 120 on the end face opposite to the second plastic body 220. The lapped portion 211 is embedded in the recessed groove 120 and fits against the bottom wall of the recessed groove 120. On the one hand, the lapped portion 211 can be arranged along the axial direction of the first mounting hole 110 ( Figure 2 The first plastic body 210 is limited by the Z-axis direction shown in the figure, which ensures accurate positioning between the first plastic body 210 and the cover body 100 and improves the assembly accuracy of the battery cover assembly. On the other hand, by setting the groove 120, part of the first plastic body 210 can be embedded into the cover body 100, further reducing the size of the battery cover assembly along the axial direction of the first mounting hole 110, thereby improving the space utilization of the entire battery pack and increasing the energy density.

[0086] Among them, along the first direction (that is...) Figure 9 (As shown in the Y-axis direction), the width of the overlap 211 is c, and the value of c satisfies: 0mm ≤ c ≤ 10mm. Along the third direction (i.e., Figure 5In the X-axis direction shown, the width of the overlapping portion 211 is also c, and the value of c is within the range of 0mm ≤ c ≤ 10mm. For example, the value of c can be 0mm, 1mm, 2mm, 5mm, 8mm, or 10mm, etc. The width of the overlapping portion 211 along the first direction and the width of the overlapping portion 211 along the third direction can be the same or different, as long as the value of c is within the above-mentioned range. By controlling the width c of the overlapping portion 211 within the above-mentioned range, the assembly structure between the first plastic body 210 and the cover plate body 100 can be stabilized, and the weight of the first plastic body 210 can be relatively reduced, thus reducing material costs. It should be noted that when the width c of the overlapping portion 211 is 0, the circumferential edge of the first plastic body 210 overlaps the cover plate body 100, which can also ensure successful assembly of the first plastic body 210 and the cover plate body 100. In addition, when the width c of the overlap 211 is greater than 10mm, it may occupy more space in the sink 120, affecting the assembly between the cover plate body 100 and other structural components.

[0087] Furthermore, along the second direction (i.e.) Figure 5 (In the Z-axis direction shown), the thickness of the cover body 100 is H. The distance between the end face of the overlapping portion 211 facing away from the second plastic body 220 and the end face of the cover body 100 facing away from the second plastic body 220 is b. The value of b is within the range of -1mm≤b≤0.5H, 1mm≤H≤3mm. Here, "-" indicates that the end face of the overlapping portion 211 facing away from the second plastic body 220 extends beyond the end face of the cover body 100 facing away from the second plastic body 220. For example, when H is 1mm, the value of b can be -1mm, -0.5mm, 0mm, 0.1mm, 0.3mm, or 0.5mm. It should be noted that the value of b should not be too large. If the value of b is greater than 0.5H, the depth of the recess 120 will be large, affecting the mechanical strength of the cover body 100. When the cover body 100 is subjected to impact, it is prone to deformation or breakage, leading to battery failure. Of course, the value of b should not be too small. If the value of b is less than -1mm, it indicates that the end face of the overlapping part 211 on the side away from the second plastic part body 220 extends too far beyond the groove 120, which is not conducive to improving space utilization and may affect the assembly between the first plastic part body 210 and other structural parts. Of course, in other embodiments, the value of H can also be 2mm, 2.5mm or 3mm, etc., and the value of b is taken within the above range, which will not be listed here one by one.

[0088] The following tests, using samples of battery cover assemblies, examine the dimensional design of the overlapping portion 211 and the cover body 100 to investigate the influence of the parameters H, b, and c on the insulation performance and structural strength of the battery cover assembly.

[0089] The withstand voltage test refers to applying a high voltage (e.g., 1500V) between the cover plate body 100 and the first plastic part body 210 of the combined plastic part 200 using an AC withstand voltage tester for 2 seconds, and then detecting the leakage current value. When the leakage current value is less than 2mA and the combined plastic part 200 is not broken down, the battery cover plate assembly has good insulation performance.

[0090] The thrust test refers to fixing the cover plate body 100 and applying a thrust towards the cover plate body 100 to the assembled plastic part 200. When the thrust applied to the assembled plastic part 200 is greater than 1200N, and the deformation of the cover plate body 100 along the thrust direction is less than 0.5mm, the battery cover plate assembly has high structural strength and meets the product requirements.

[0091] The detailed dimensional parameters and test results of the battery cover assembly are shown in Table 3 below.

[0092] Table 3

[0093]

[0094] In sample 1, the value of b is -2.0 mm and the value of H is 2.0 mm. The value of b is less than the minimum value of -1 mm ≤ b ≤ 0.5 H. At this time, the end face of the overlapping part 211 on the side away from the second plastic body 220 exceeds the end face of the cover plate body 100 on the side away from the second plastic body 220 by too much. This affects the height design of the electrode post along the second direction, which is not conducive to improving the energy density of the battery. It is not recommended to use it, and the product is defective.

[0095] In sample 2, the value of c is -0.5mm, which is less than the minimum value of 0mm≤c≤10mm. Other parameters H and b meet their corresponding size range limits. At this time, the insulation performance between the first plastic body 210 and the cover plate body 100 cannot be guaranteed, the pressure resistance test fails, there is a risk of pressure resistance failure, it is not recommended to use, and the product is defective.

[0096] In samples 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, and 15, the values ​​of parameters H, b, and c all meet their respective size range limitations. At this time, the insulation performance between the first plastic body 210 and the cover plate body 100 is good, the pressure resistance test is passed, and the structural strength of the cover plate body 100 is high, the thrust test is passed. It is recommended to use the product, and the product is good.

[0097] In sample 16, the value of c is 13.0 mm, which is greater than the maximum value of 0 mm ≤ c ≤ 10 mm. Other parameters H and b meet their corresponding size range limits. At this time, the insulation performance between the first plastic body 210 and the cover plate body 100 is good, and the withstand voltage test is passed. However, the width of the overlap 211 of the first plastic body 210 is large, which increases the material usage of the first plastic body 210 and the pole, resulting in higher costs. It is not recommended to use this product, which is defective.

[0098] In sample 17, the value of b is 1.5 mm and the value of H is 2.0 mm. The value of b is greater than 0.5 H, which does not meet the size limit of -1 mm ≤ b ≤ 0.5 H. At this time, the opening depth of the groove 120 on the cover plate body 100 is too large, the structural strength of the cover plate body 100 is low, the thrust test is not passed, and it is not recommended to use it. The product is defective.

[0099] See also Figure 3 , Figure 9 and Figure 10 The second plastic body 220 has an electrode lug shaping structure 222 and a support structure 223 on the side near the electrode assembly. The electrode lug shaping structure 222 is positioned circumferentially around the through hole 201, allowing the electrode lug to pass through. The electrode lug shaping structure 222 allows the electrode lug to be retracted within the through hole 201 of the combined plastic body 200, resulting in a well-formed electrode lug and preventing short circuits between the electrode lug and the cover plate body 100, thus avoiding safety risks. The support structure 223 is connected to the electrode lug shaping structure 222 and abuts against the cover plate body 100. The support structure 223 provides good support for the electrode lug shaping structure 222, which has high mechanical strength and is not easily deformed.

[0100] For example, the tab shaping structure 222 includes two guide plates 2221, which are respectively disposed along the through hole 201. Figure 9 As shown, on both sides of the Y-axis, two guide plates 2221 are inclined away from the axis of the through hole 201. Along the direction away from the through hole 201, a flared opening 2222 is formed between the two guide plates 2221. The larger end of the flared opening 2222 faces the electrode assembly, and the smaller end of the flared opening 2222 is connected to the second plastic body 220. The electrode tab is inserted into the flared opening 2222. During installation, the electrode tab is inserted into the through hole 201 from the larger end of the flared opening 2222. Along the direction close to the through hole 201, the opening of the flared opening 2222 gradually narrows. Therefore, when the electrode tab is inserted into the flared opening 2222, the guide plates 2221 on both sides of the flared opening 2222 can effectively gather the electrode tab into the through hole 201. The electrode tab has a good shape and is not prone to short-circuit contact with the cover plate body 100, resulting in high safety.

[0101] The included angle between the axis of the guide plate 2221 and the axis of the through hole 201 is α, and the value of α is in the range of 45°≤α≤87°. For example, the value of α can be 45°, 50°, 60°, 70°, 80°, 87°, etc. By controlling the value of α within the above range, it can be ensured that the tab shaping structure 222 effectively retracts the tab within the through hole 201. It should be noted that when the value of α is too large, it will not have a good shaping effect on the tab; when the value of α is too small, it will increase the length of the second plastic part body 220 along the axis of the through hole 201. Figure 9 The dimensions shown in the Z-axis direction are not conducive to improving space utilization.

[0102] The support structure 223 includes a connecting plate 2231 and a support plate 2232. The connecting plate 2231 is connected to the tab shaping structure 222, and the support plate 2232 is disposed on the end face of the connecting plate 2231 near the cover plate body 100, and abuts against the cover plate body 100. The support structure 223 provides good support for the tab shaping structure 222, ensuring that the tab shaping structure 222 has high mechanical strength and is not easily deformed.

[0103] Among them, along Figure 9 In the Y-axis direction (i.e., the first direction) shown, the distance between the end face of the support plate 2232 facing away from the guide plate 2221 and the end of the guide plate 2221 near the support plate 2232 is denoted as e. The value of e ranges from 0.5mm to e ≤ 20mm. For example, the value of e can be 0.5mm, 1.0mm, 5mm, 10mm, 15mm, or 20mm, which can be adjusted according to the dimensions of the second plastic part body 220 along the Y-axis direction. These values ​​will not be listed here. It should be noted that the value of e should not be too small, otherwise the connecting plate 2231 will be too sharp and may easily puncture the tabs or electrode assembly. Of course, the value of e should also not be too large, otherwise it will occupy the space of the tab shaping structure 222 along the Y-axis direction. Figure 9 As shown, the increased dimension in the Z-axis direction makes the electrode assembly more susceptible to damage.

[0104] Furthermore, along the second direction (i.e.) Figure 9(As shown in the Z-axis direction), the distance between the end face of the connecting plate 2231 away from the cover plate body 100 and the end face of the second plastic body 220 away from the cover plate body 100 is f, and the value of f is in the range of 0mm≤f≤5mm. For example, the value of f can be 0mm, 0.5mm, 1.0mm, 1.5mm, 2.0mm, 3.0mm, 4.0mm or 5.0mm. It should be noted that the value of f cannot be less than 0mm, otherwise the tab shaping structure 222 will protrude from the end face of the second plastic body 220 near the electrode assembly, which may easily damage the electrode assembly. The value of f should also not be too large, otherwise the tilt angle of the guide plate 2221 will be too large, the structure of the tab will be relatively loose, the shaping effect of the tab shaping structure 222 on the tab will be poor, the shape of the tab in the shell will be poor, and it will be easy for it to short-circuit with the shell.

[0105] Optionally, in this embodiment, four tab shaping structures 222 are provided, each corresponding to one of the through holes 201, with one tab shaping structure 222 provided circumferentially for each through hole 201. Multiple support structures 223 are provided, with two support structures 223 respectively disposed along the second plastic body 220. Figure 9 The two ends of the Y-axis shown are connected to the tab shaping structure 222 on one side, and the remaining support structures 223 are arranged along the Y-axis. Figure 9 As shown, between two adjacent tab shaping structures 222 in the Y-axis direction, one or more support structures 223 may be provided between each pair of tab shaping structures 222. Here, we will take one support structure 223 between each pair of tab shaping structures 222 as an example. Each tab shaping structure 222 is supported by support structures 223 on both sides along the Y-axis direction to ensure that the tab shaping structure 222 has high mechanical strength and is not easily deformed.

[0106] In some embodiments, located near the second plastic body 220 along Figure 9 In the Y-axis direction of the end support structure 223 shown, one end of its connecting plate 2231 is connected to the end of the guide plate 2221 of the electrode shaping structure 222 near the electrode assembly, and the other end of the connecting plate 2231 is connected to the support plate 2232, and the support plate 2232 is connected to the connecting plate 2231 near the end of the second plastic part body 220. Figure 9As shown, at the edge along the Y-axis, a support plate 2232 is disposed on the end face of the connecting plate 2231 near the cover plate body 100. The support plate 2232 abuts against the cover plate body 100, thereby supporting the tab shaping structure 222 connected thereto. In the support structure 223 located between two adjacent tab shaping structures 222, both ends of the connecting plate 2231 are respectively connected to the end of the guide plate 2221 of one tab shaping structure 222 near the pole group. The support plate 2232 is connected to the middle of the connecting plate 2231 and is disposed on the end face of the connecting plate 2231 near the cover plate body 100. The support plate 2232 abuts against the top cover plate body 100, thereby supporting the two adjacent tab shaping structures 222.

[0107] See also Figure 2 and Figure 3 The battery cover assembly in this embodiment also includes an explosion-proof valve 400. The cover body 100 has a second mounting hole 130, and the explosion-proof valve 400 is disposed within the second mounting hole 130; the second plastic body 220 has a vent hole 224 corresponding to the position of the second mounting hole 130, along... Figure 2 As shown in the diagram, the projection of the vent 224 onto the cover body 100 coincides with the projection of the explosion-proof valve 400 onto the cover body 100. Therefore, when the pressure on one side of the cover body 100 exceeds the opening pressure of the explosion-proof valve 400, high-temperature, high-pressure gases and liquids can be discharged from the battery through the vent 224 and the explosion-proof valve 400, avoiding the risk of explosion and ensuring high safety. Furthermore, the second mounting hole 130 is also provided with crisscrossing support ribs 140, which support the cover body 100 and improve its structural strength at the location of the second mounting hole 130. Further, multiple vent holes 224 on the second plastic body 220 can be spaced apart to increase the flow area, allowing high-temperature, high-pressure gases and liquids to be discharged quickly and smoothly.

[0108] Optionally, in some embodiments, the cover plate body 100 is further provided with a first injection hole 150, and the second plastic body 220 is provided with a second injection hole (not shown in the figure) at a position corresponding to the first injection hole 150. Figure 2 In the Z-axis direction shown, the projection of the first injection hole 150 on the cover body 100 coincides with the projection of the second injection hole on the cover body 100. After the battery cover assembly is assembled with the housing, electrolyte can be injected into the housing through the first injection hole 150 and the second injection hole to immerse the electrode assembly in the electrolyte. After injection, an injection plug can be inserted into the first injection hole 150 and / or the second injection hole to seal the first injection hole 150 and / or the second injection hole and prevent electrolyte leakage. Exemplarily, the injection plug is made of a material with elastic deformation capability, such as rubber.

[0109] This embodiment also provides a battery, including a housing, an electrode assembly, and the aforementioned battery cover assembly. An opening is provided on one side of the housing, through which the electrode assembly is inserted into the housing. The battery cover assembly is disposed at the opening of the housing and welded to the housing. The battery cover assembly and the housing form a closed accommodating space to encapsulate the electrode assembly within the accommodating space.

[0110] By adopting the aforementioned battery cover assembly, both the connecting piece 300 and the terminal post are located outside the housing, thus not occupying internal space and increasing the volume of the electrode assembly, resulting in a higher energy density for the battery. Furthermore, both the connecting piece 300 and the terminal post are flat, and the overall dimensions of the battery cover assembly along the Z-axis are relatively small. When batteries with this battery cover assembly are arranged in a battery pack, space utilization is high, and energy density is also high. In addition, by using an interference fit between the connecting piece 300 and the combined plastic part 200 on the side opposite to the electrode assembly, the connection structure between the connecting piece 300 and the combined plastic part 200 is relatively stable and robust. The connecting piece 300 is less prone to positional displacement, and the connection between the connecting piece 300 and the terminal tab has high reliability, resulting in high battery safety.

[0111] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A battery cover assembly, characterized in that, include: The cover plate body is provided with a first mounting hole; The combined plastic part is partially attached to the end face of the cover plate body on the side away from the electrode group and partially attached to the end face of the cover plate body on the side close to the electrode group. The combined plastic part is provided with through holes. A connecting piece is located on the side of the combined plastic part away from the electrode group. The connecting piece is interference-fitted with the side of the combined plastic part away from the electrode group. The electrode lug of the electrode group passes through the first mounting hole and the through hole and is connected to the connecting piece. The electrode post is located on the side of the connecting piece away from the electrode group, and the electrode post is connected to the connecting piece; The combined plastic component includes a first plastic component body and a second plastic component body. Both the first plastic component body and the second plastic component body are provided with the through hole. The first plastic component body is attached to the end face of the cover plate body on the side away from the electrode group, and the second plastic component body is attached to the end face of the cover plate body on the side close to the electrode group. And / or, one of the first plastic body and the second plastic body is provided with a connecting part, the connecting part is cylindrical and located in the circumference of the through hole, the connecting part passes through the first mounting hole and fits against the inner wall of the first mounting hole, and the center of the connecting part forms a channel for the electrode tab to pass through. The first plastic part body has an overlapping part in the circumferential direction, and the cover plate body has a groove on the end face opposite to the second plastic part body. The overlapping part is embedded in the groove and fits against the bottom wall of the groove. Wherein, along the first direction, the width of the overlapping portion is c; The range of values ​​for c satisfies: 0mm≤c≤10mm; And / or, along the second direction, the thickness of the cover plate body is H, and the distance between the end face of the overlapping portion facing away from the second plastic body and the end face of the cover plate body facing away from the second plastic body is b. The range of values ​​for b satisfies: -1mm≤b≤0.5H, 1mm≤H≤3mm.

2. The battery cover assembly according to claim 1, characterized in that, The first plastic part body has an annular flange and a limiting flange on the side opposite to the cover plate body. The annular flange is disposed in the circumference of the through hole. The annular flange, the limiting flange and the first plastic part body form a mounting groove. At least a portion of the connecting piece is embedded in the mounting groove. The connecting piece is interference-fitted with the annular flange and / or the limiting flange.

3. The battery cover assembly according to claim 2, characterized in that, The annular flange and / or the limiting flange are provided with a first interference rib, and the first interference rib is interference-fitted with the peripheral sidewall of the connecting piece. And / or, the peripheral sidewall of the connecting piece is provided with a second interference rib, the second interference rib being interference-fitted with the annular flange and / or the limiting flange.

4. The battery cover assembly according to claim 3, characterized in that, The first interference rib is provided in multiple ways and is strip-shaped. The multiple first interference ribs extend along the axial direction of the first mounting hole and are evenly spaced on the annular flange and / or the limiting flange. And / or, the second interference rib is provided in multiple forms and is strip-shaped, the multiple second interference ribs extend along the axial direction of the first mounting hole and are evenly spaced on the peripheral sidewall of the connecting piece.

5. The battery cover assembly according to claim 3, characterized in that, The end of the first interference rib that faces away from the cover plate body is provided with a guide structure; And / or, the second interference rib has a guide structure at its end facing the cover plate body.

6. The battery cover assembly according to claim 3, characterized in that, The interference between the first interference rib and the peripheral sidewall of the connecting piece is h1; The value range of h1 satisfies: 0.05mm ≤ h1 ≤ 0.5mm; The interference between the second interference rib and the annular flange and / or the limiting flange is h2; The range of h2 values ​​satisfies: 0.05mm≤h2≤0.5mm.

7. The battery cover assembly according to claim 1, characterized in that, The second plastic body has an electrode lug shaping structure and a support structure on the side near the electrode assembly. The electrode lug shaping structure is arranged in the circumference of the through hole and allows the electrode lug to pass through. The support structure is connected to the electrode lug shaping structure and is used to abut against the cover plate body.

8. A battery, characterized in that, The device includes a housing, an electrode assembly, and a battery cover assembly according to any one of claims 1-7, wherein the battery cover assembly is encapsulated at an opening of the housing, and the electrode assembly is disposed within the housing.

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