Battery cover plate and battery cell

Abstract

The utility model belongs to battery technical field discloses a kind of battery cover plate and battery monomer.Battery cover plate includes cover plate piece and protective layer component.The side of cover plate piece towards battery cell is equipped with thinning groove group;Protective layer component includes fire -retardant layer, heat-absorbing layer and heat-conducting layer, fire -retardant layer, heat-absorbing layer and heat-conducting layer are sequentially laid in thinning groove group, heat-conducting layer is used to conduct heat generated by battery cell, heat-absorbing layer is used to dissipate heat, fire -retardant layer is used to flame-retardant.The battery cover plate is light in weight, compact structure, high structural strength;And good heat dissipation effect, high flame retardance.Battery monomer includes battery cell, shell and above-mentioned battery cover plate, battery cell is located in shell, cover plate piece cover is equipped at the opening of shell, shell and cover plate piece package battery cell, heat dissipation effect is good, flame-retardant, and safety performance is high.

Description

Technical Field

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

[0002] With the widespread application of lithium-ion batteries in electric vehicles, energy storage systems, and other fields, their energy density is constantly increasing, which has drastically increased the heat generated during battery charging and discharging. If the battery's heat dissipation is inadequate, it can easily lead to high battery temperatures. Furthermore, since the electrolyte in lithium-ion batteries is mostly composed of flammable carbonate-based organic solvents, the separator is prone to shrinkage at high temperatures, leading to short circuits. Overcharging, collisions, or punctures can trigger thermal runaway, releasing flammable gases and causing combustion or explosion. To address these issues, existing batteries typically incorporate measures in the electrolyte and separator, such as adding flame retardants to the electrolyte to reduce the risk of thermal runaway. However, these methods only address heat dissipation and flame retardancy in the electrolyte and separator, neglecting the heat dissipation and flame retardancy of the battery casing, such as the battery cover. This means the heat dissipation and flame retardancy effect of these batteries cannot meet the safety requirements of current newer batteries (with higher energy densities).

[0003] Therefore, there is an urgent need to propose a battery cover and a battery cell to solve the above problems. Utility Model Content

[0004] One objective of this invention is to provide a battery cover that is lightweight, compact, and has high structural strength; it also has good heat dissipation and high flame retardancy.

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

[0006] Battery cover, including:

[0007] A cover plate, wherein the side of the cover plate facing the battery cell is provided with a thinning groove group;

[0008] A protective layer assembly includes a flame-retardant layer, a heat-absorbing layer, and a heat-conducting layer. The flame-retardant layer, the heat-absorbing layer, and the heat-conducting layer are sequentially laid on the thinning groove assembly. The heat-conducting layer is used to conduct heat generated by the battery cell, the heat-absorbing layer is used to dissipate the heat, and the flame-retardant layer is used to retard flames.

[0009] As an optional technical solution for the battery cover, the depth of the thinning groove group is h1, the thickness of the cover plate is h2, and 1 / 3≤h1 / h2≤1 / 2.

[0010] As an optional technical solution for the battery cover, the flame-retardant layer is made of a polymer material with added flame retardants; the heat-absorbing layer is made of a paraffin-based phase change material; and the heat-conducting layer is made of a CVD graphene film.

[0011] As an optional technical solution for the battery cover, the cover plate is provided with a first mounting hole, an explosion-proof valve and a second mounting hole. The first mounting hole, the explosion-proof valve and the second mounting hole are spaced apart along the length direction of the cover plate. The thinning groove group is provided between the first mounting hole and the explosion-proof valve and between the second mounting hole and the explosion-proof valve.

[0012] As an optional technical solution for the battery cover, the thinning groove assembly located between the first mounting hole and the explosion-proof valve is arranged along the outer periphery of the first mounting hole on the side facing the first mounting hole, and along the outer periphery of the explosion-proof valve on the side facing the explosion-proof valve; and / or,

[0013] The thinning groove assembly located between the second mounting hole and the explosion-proof valve is arranged along the outer periphery of the second mounting hole on the side facing the second mounting hole, and along the outer periphery of the explosion-proof valve on the side facing the explosion-proof valve.

[0014] As an optional technical solution for the battery cover, a liquid injection hole is also provided between the second mounting hole on the cover plate and the explosion-proof valve, and the thinning groove group is at least partially arranged along the outer periphery of the liquid injection hole on the side facing the explosion-proof valve, so that the thinning groove group bypasses the liquid injection hole.

[0015] As an optional technical solution for the battery cover, each group of the thinning grooves includes a groove.

[0016] As an optional technical solution for battery cover plates, each group of thinning grooves includes multiple grooves, and reinforcing ribs are provided between two adjacent grooves.

[0017] As an optional technical solution for the battery cover, the two reinforcing ribs are respectively arranged along the length and width directions of the cover plate, separating the four grooves in each group of thinning grooves.

[0018] Another objective of this invention is to provide a battery cell with good heat dissipation, strong flame retardancy, and high safety performance.

[0019] To achieve this objective, the present invention adopts the following technical solution:

[0020] A battery cell includes a battery cell, a housing, and the aforementioned battery cover plate. The battery cell is located inside the housing, and the cover plate covers the opening of the housing. The housing and the cover plate encapsulate the battery cell.

[0021] The beneficial effects of this utility model are:

[0022] The battery cover provided by this utility model includes a cover sheet and a protective layer assembly. The cover sheet is used to encapsulate the battery cell, and a thinning groove assembly is provided on the side facing the battery cell to reduce the weight of the battery cover and save materials. The protective layer assembly includes a flame-retardant layer, a heat-absorbing layer, and a heat-conducting layer sequentially laid on the thinning groove assembly. The heat-conducting layer is used to conduct heat generated by the battery cell, the heat-absorbing layer is used to dissipate heat, and the flame-retardant layer is used for flame retardancy. The heat-conducting layer quickly transfers the heat generated by the battery cell to the heat-absorbing layer, and the heat-absorbing layer absorbs and dissipates the heat in a timely manner, avoiding the accumulation of heat in the battery cell and causing local high temperature in the battery cell, which could lead to thermal runaway of the battery cell. The flame-retardant layer serves as the last line of defense, reducing the risk of fire and explosion in the event of thermal runaway of the battery cell and improving the safety performance of the battery cell. The flame-retardant layer, the heat-absorbing layer, and the heat-conducting layer are sequentially laid on the thinning groove assembly, making reasonable use of the space of the battery cover and saving the internal space of the battery cell. Moreover, the thinning groove assembly can fix the protective layer assembly, increasing the connection strength between the protective layer assembly and the cover sheet, further improving the structural performance of the battery cover, and thus improving the safety performance of the battery cell. Attached Figure Description

[0023] Figure 1 This is an exploded view of the battery cover (not all protective layer components are shown) provided in this embodiment of the utility model;

[0024] Figure 2 This is a schematic diagram of the structure of the cover plate provided in this embodiment of the utility model;

[0025] Figure 3 This is a partial cross-sectional view of the groove and protective layer assembly provided in this embodiment of the utility model.

[0026] In the picture:

[0027] 100. Cover plate; 110. Thinning groove assembly; 111. Groove; 112. Reinforcing rib; 120. First mounting hole; 130. Second mounting hole; 140. Explosion-proof valve; 150. Liquid injection hole; 200. Protective layer assembly; 210. Flame retardant layer; 220. Heat-absorbing layer; 230. Heat-conducting layer. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0029] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0030] 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.

[0031] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0032] This embodiment provides a battery cover that is lightweight, compact, and has high structural strength; it also has good heat dissipation and high flame retardancy.

[0033] Specifically, such as Figures 1 to 3As shown, the battery cover includes a cover plate 100 and a protective layer assembly 200. The cover plate 100 has a thinning groove assembly 110 on the side facing the battery cell, and the thinning groove assembly 110 is recessed on the side facing away from the battery cell. The shape of the thinning groove assembly 110 is not limited and can be square, circular, or triangular, etc. The protective layer assembly 200 includes a flame-retardant layer 210, a heat-absorbing layer 220, and a heat-conducting layer 230. The flame-retardant layer 210, the heat-absorbing layer 220, and the heat-conducting layer 230 are sequentially laid on the thinning groove assembly 110, that is, the flame-retardant layer 210 is laid at the bottom of the groove assembly 110, the heat-absorbing layer 220 is laid on the side of the flame-retardant layer 210 facing the battery cell, and the heat-conducting layer 230 is laid on the side of the heat-absorbing layer 220 facing the battery cell. In this embodiment, the outer periphery shapes of the flame-retardant layer 210, the heat-absorbing layer 220, and the heat-conducting layer 230 are all adapted to the shape of the thinning groove assembly 110, so that the outer peripheries of the flame-retardant layer 210, the heat-absorbing layer 220, and the heat-conducting layer 230 all abut against the inner sidewall of the thinning groove assembly 110. The heat-conducting layer 230 is used to conduct heat generated by the battery cell, the heat-absorbing layer 220 is used to dissipate heat, and the flame-retardant layer 210 is used for flame retardancy.

[0034] Based on the above design, the cover plate 100 is used to encapsulate the battery cell, and a thinning groove assembly 110 is provided on the side facing the battery cell to reduce the weight of the battery cover and save materials. The protective layer assembly 200 includes a flame-retardant layer 210, a heat-absorbing layer 220, and a heat-conducting layer 230 sequentially laid on the thinning groove assembly 110. The heat-conducting layer 230 is used to conduct heat generated by the battery cell, the heat-absorbing layer 220 is used to dissipate heat, and the flame-retardant layer 210 is used for flame retardancy. Figure 3 As indicated by the arrows, the heat generated by the battery cell is transferred to the heat-conducting layer 230, which then rapidly transfers the heat generated by the battery cell to the heat-absorbing layer 220. The heat-absorbing layer 220 absorbs and dissipates the heat in a timely manner, preventing heat accumulation in the battery cell and causing localized high temperatures that could lead to thermal runaway of the battery cell. The flame-retardant layer 210 serves as the last line of defense, reducing the risk of fire and explosion when the battery cell experiences thermal runaway and improving the safety performance of the battery cell. The flame-retardant layer 210, the heat-absorbing layer 220, and the heat-conducting layer 230 are sequentially laid on the thinning groove assembly 110, making reasonable use of the space of the battery cover and saving internal space of the battery cell. Furthermore, the thinning groove assembly 110 can fix the protective layer assembly 200, increasing the connection strength between the protective layer assembly 200 and the cover plate 100, further improving the structural performance of the battery cover, and thus improving the safety performance of the battery cell.

[0035] Optionally, the depth of the thinning groove group 110 is h1, and the thickness of the cover plate 100 is h2, and 1 / 3 ≤ h1 / h2 ≤ 1 / 2. For example, h1 / h2 can be 1 / 3, 2.5 / 6, or 1 / 2, etc. If the value of h1 / h2 is too large, that is, the groove depth h1 of the thinning groove group 110 is too deep, the structural strength of the cover plate 100 is too low; if the value of h1 / h2 is too small, that is, the groove depth h1 of the thinning groove group 110 is too shallow, it is inconvenient to stamp the cover plate 100, and it cannot fully accommodate the protective layer assembly 200, causing the protective layer assembly 200 to occupy the internal space of the battery cell.

[0036] Optionally, the flame retardant layer 210 is made of a polymer material with added flame retardants. Specifically, by introducing specific functional additives into the polymer matrix, the flame resistance, self-extinguishing properties and thermal stability of the polymer material under high temperature or flame conditions are significantly improved, thereby inhibiting or delaying the combustion process.

[0037] Optionally, the heat-absorbing layer 220 is made of paraffin-based phase change material, which is a functional material that uses paraffin (a mixture of alkanes) as the core functional material and achieves thermal energy storage and temperature regulation through the absorption and release of latent heat during the phase change process.

[0038] Optionally, the thermally conductive layer 230 is made of CVD (chemical vapor deposition) graphene film. CVD graphene film is a single-layer or multi-layer graphene film formed by decomposing and crystallizing carbon source gas (such as methane) on the surface of a metal substrate (copper / nickel foil) at high temperature, and has ultra-high thermal conductivity and temperature uniformity.

[0039] Optionally, the cover plate 100 is provided with a first mounting hole 120, an explosion-proof valve 140, and a second mounting hole 130. The first mounting hole 120 is used to install the negative terminal assembly, and the second mounting hole 130 is used to install the positive terminal assembly. The first mounting hole 120, the explosion-proof valve 140, and the second mounting hole 130 are spaced apart along the length of the cover plate 100. Thinning grooves 110 are provided between the first mounting hole 120 and the explosion-proof valve 140, and between the second mounting hole 130 and the explosion-proof valve 140. The thinning grooves 110, along the length of the cover plate 100, fully utilize the remaining space on the cover plate 100 after removing the first mounting hole 120, the explosion-proof valve 140, and the second mounting hole 130, thereby improving the space utilization rate of the cover plate 100 without affecting its structural strength.

[0040] To further improve the space utilization on the cover plate 100 and increase the protective coverage of the protective layer assembly 200, the thinning groove assembly 110 located between the first mounting hole 120 and the explosion-proof valve 140 is provided along the outer periphery of the first mounting hole 120 on the side facing the first mounting hole 120 and along the outer periphery of the explosion-proof valve 140 on the side facing the explosion-proof valve 140; and / or, the thinning groove assembly 110 located between the second mounting hole 130 and the explosion-proof valve 140 is provided along the outer periphery of the second mounting hole 130 on the side facing the second mounting hole 130 and along the outer periphery of the explosion-proof valve 140 on the side facing the explosion-proof valve 140.

[0041] Furthermore, an injection hole 150 is provided between the second mounting hole 130 on the cover plate 100 and the explosion-proof valve 140. The thinning groove assembly 110 is arranged at least partially along the outer periphery of the injection hole 150 on the side facing the explosion-proof valve 140, so that the thinning groove assembly 110 bypasses the injection hole 150. The above design not only avoids the injection hole 150, but also makes reasonable use of the space on both sides of the injection hole 150 along the width direction of the cover plate 100.

[0042] To improve the space utilization on the cover plate 100, the thinning groove group 110 should fill as much of the remaining space on the cover plate 100 as possible, excluding the first mounting hole 120, the explosion-proof valve 140, and the second mounting hole 130. In one specific embodiment, each thinning groove group 110 may include a groove 111, that is, a larger groove 111 is provided between the first mounting hole 120 and the explosion-proof valve 140 and between the second mounting hole 130 and the explosion-proof valve 140. In other words, one larger groove 111 fills the space between the first mounting hole 120 and the explosion-proof valve 140, and another larger groove 111 fills the space between the second mounting hole 130 and the explosion-proof valve 140.

[0043] In another specific embodiment, each group of thinning grooves 110 includes multiple grooves 111. Exemplarily, the number of grooves 111 can be two, three, four, or six, etc., and a reinforcing rib 112 is provided between two adjacent grooves 111. That is, multiple smaller grooves 111 are provided between the first mounting hole 120 and the explosion-proof valve 140, and between the second mounting hole 130 and the explosion-proof valve 140. In other words, multiple smaller grooves 111 form one group of thinning grooves 110 that fills the space between the first mounting hole 120 and the explosion-proof valve 140, and multiple smaller grooves 111 form another group of thinning grooves 110 that fills the space between the second mounting hole 130 and the explosion-proof valve 140. The reinforcing rib 112 can compensate for the problem that the thinning groove group 110 weakens the structural strength of the cover plate 100. Furthermore, in this embodiment, the reinforcing rib 112 is actually formed naturally by the recessed grooves 111 on the cover plate 100. In other words, this arrangement actually reduces the actual area of ​​the thinning groove group 110, which can prevent the thinning area of ​​the cover plate 100 from being too large and affecting the structural strength of the cover plate 100.

[0044] Furthermore, considering the structural strength, heat dissipation and flame retardancy of the cover plate 100, as well as the symmetry of structural strength and heat dissipation and flame retardancy, two reinforcing ribs 112 are respectively set along the length and width of the cover plate 100 to separate the four grooves 111 in each set of thinning grooves 110.

[0045] This embodiment also provides a battery cell with good heat dissipation, strong flame retardancy, and high safety performance.

[0046] Specifically, the battery cell includes a battery cell, a casing, and the aforementioned battery cover plate. The battery cell is located inside the casing, and the cover plate 100 covers the opening of the casing, encapsulating the battery cell with the casing and the cover plate 100. A thinning groove assembly 110 is provided on the side of the cover plate 100 facing the battery cell, reducing the weight of the battery cover plate and saving materials. The protective layer assembly 200 includes a flame-retardant layer 210, a heat-absorbing layer 220, and a heat-conducting layer 230 sequentially laid on the thinning groove assembly 110. The heat-conducting layer 230 conducts heat generated by the battery cell, the heat-absorbing layer 220 dissipates heat, and the flame-retardant layer 210 provides flame retardancy. The heat-conducting layer 230 quickly transfers the heat generated by the battery cell to the heat-absorbing layer 220, which promptly absorbs and dissipates the heat, preventing heat accumulation in the battery cell and causing localized high temperatures that could lead to thermal runaway of the battery cell. The flame-retardant layer 210 serves as... The last line of defense reduces the risk of fire and explosion in the event of thermal runaway of a battery cell, thereby improving the safety performance of the battery cell. The flame-retardant layer 210, the heat-absorbing layer 220, and the heat-conducting layer 230 are sequentially laid on the thinning groove assembly 110, making reasonable use of the space of the battery cover and saving the internal space of the battery cell. In addition, the thinning groove assembly 110 can fix the protective layer assembly 200, increasing the connection strength between the protective layer assembly 200 and the cover plate 100, further improving the structural performance of the battery cover, and thus improving the safety performance of the battery cell.

[0047] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. 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 this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A battery cover, characterized in that, include: A cover plate (100) is provided with a thinning groove group (110) on the side of the cover plate (100) facing the battery cell; A protective layer assembly (200) includes a flame-retardant layer (210), a heat-absorbing layer (220), and a heat-conducting layer (230). The flame-retardant layer (210), the heat-absorbing layer (220), and the heat-conducting layer (230) are sequentially laid on the thinning trench assembly (110). The heat-conducting layer (230) is used to conduct the heat generated by the battery cell, the heat-absorbing layer (220) is used to dissipate the heat, and the flame-retardant layer (210) is used for flame retardancy.

2. The battery cover according to claim 1, characterized in that, The depth of the thinning groove group (110) is h1, the thickness of the cover plate (100) is h2, and 1 / 3≤h1 / h2≤1 / 2.

3. The battery cover according to claim 1, characterized in that, The flame-retardant layer (210) is made of a polymer material with added flame retardant; the heat-absorbing layer (220) is made of a paraffin-based phase change material; and the heat-conducting layer (230) is made of a CVD graphene film.

4. The battery cover according to claim 1, characterized in that, The cover plate (100) is provided with a first mounting hole (120), an explosion-proof valve (140) and a second mounting hole (130). The first mounting hole (120), the explosion-proof valve (140) and the second mounting hole (130) are spaced apart along the length of the cover plate (100). The thinning groove group (110) is provided between the first mounting hole (120) and the explosion-proof valve (140) and between the second mounting hole (130) and the explosion-proof valve (140).

5. The battery cover according to claim 4, characterized in that, The thinning groove assembly (110) located between the first mounting hole (120) and the explosion-proof valve (140) is arranged along the outer periphery of the first mounting hole (120) on the side facing the first mounting hole (120), and along the outer periphery of the explosion-proof valve (140) on the side facing the explosion-proof valve (140); and / or, The thinning groove assembly (110) located between the second mounting hole (130) and the explosion-proof valve (140) is arranged along the outer periphery of the second mounting hole (130) on the side facing the second mounting hole (130) and along the outer periphery of the explosion-proof valve (140) on the side facing the explosion-proof valve (140).

6. The battery cover according to claim 5, characterized in that, A liquid injection hole (150) is also provided between the second mounting hole (130) on the cover plate (100) and the explosion-proof valve (140), and the thinning groove assembly (110) is at least partially arranged along the outer periphery of the liquid injection hole (150) on the side facing the explosion-proof valve (140), so that the thinning groove assembly (110) bypasses the liquid injection hole (150).

7. The battery cover according to claim 5 or claim 6, characterized in that, Each group of the thinning grooves (110) includes a groove (111).

8. The battery cover according to claim 5 or claim 6, characterized in that, Each group of thinning grooves (110) includes multiple grooves (111), and a reinforcing rib (112) is provided between two adjacent grooves (111).

9. The battery cover according to claim 8, characterized in that, Two reinforcing ribs (112) are respectively arranged along the length and width of the cover plate (100) to separate the four grooves (111) in each group of thinning grooves (110).

10. A single battery cell, characterized in that, The battery includes a battery cell, a housing, and a battery cover plate as described in any one of claims 1-9, wherein the battery cell is located inside the housing, and the cover plate (100) covers the opening of the housing, and the housing and the cover plate (100) encapsulate the battery cell.

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