Cells, housings, battery modules, and battery packs

Abstract

To provide a cell, a housing, a battery module, and a battery pack, in which the shear strength of a compound layer covering a cell surface is secured and the reliability at the use of the cell can be improved.SOLUTION: The present application provides a cell, a housing, a battery module, and a battery pack, and is related to a battery technology field. The cell provided by the present application includes a housing having a side surface and a bottom surface connected to each other, and a compound layer including a shear prevention layer and a connection layer, in which the shear prevention layer is connected to the housing through the connection layer. At least one of the shear prevention layer and the connection layer is an insulating layer. The compound layer covers at least one of at least a part of the side surface and at least a part of the bottom surface.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This application relates to the technical field of batteries, and in particular, to cells, housings, battery modules, and battery packs.

Background Art

[0002] With the development of new energy vehicles, the demand for power batteries has been continuously increasing. A power battery pack is usually composed of a plurality of battery modules, and a battery module is composed of a plurality of cells.

[0003] In one method known to those skilled in the art, the surface of the cell is covered with an insulating film. When the cells are connected to each other, the insulating film maintains insulation between two adjacent cells.

Summary of the Invention

Problems to be Solved by the Invention

[0004] This application provides a cell, a housing, a battery module, and a battery pack that can ensure the shear strength of the composite layer covering the cell surface and improve the reliability during the use of the cell.

Means for Solving the Problems

[0005] To achieve the above object, this application provides the following technical solutions.

[0006] The first aspect of this application provides a cell including a housing having mutually connected side surfaces and a bottom surface, and a composite layer including a shear prevention layer and a connection layer, the shear prevention layer being connected to the housing through the connection layer, at least one of the shear prevention layer and the connection layer being an insulating layer, and the composite layer covering at least one of at least a part of the side surface and at least a part of the bottom surface.

[0007] The beneficial effect of this invention is that the shear-preventing layer is connected to the housing via a connecting layer, the composite layer can form protection on the surface of the housing, and the presence of the shear-preventing layer ensures the shear strength of the composite layer covering the cell surface. Therefore, when the cell is subjected to shear force from the outside, the composite layer does not easily rupture, thereby improving the reliability of the cell during use.

[0008] In some possible embodiments, the shear protection layer and the connecting layer are each arranged as a single layer. Alternatively, both the shear protection layer and the connecting layer are arranged as multiple layers, and the multiple shear protection layers and the multiple connecting layers are stacked alternately.

[0009] Thus, when the shear prevention layer and the connecting layer are each arranged as a single layer, the processing and formation of the composite layer becomes easier. When both the shear prevention layer and the connecting layer are arranged as multiple layers, the shear strength of the composite layer can be further ensured.

[0010] In some possible embodiments, the shear-resistant layer is a PET layer, and / or the connecting layer is a photocurable layer or a temperature-curable layer, and / or, when the shear-resistant layer and the connecting layer are each arranged as one layer, the thickness range of both the shear-resistant layer and the connecting layer is 40 to 60 μm.

[0011] Thus, if the thickness of the shear protection layer is within this range, the shear strength of the shear protection layer can be ensured. If the thickness of the connecting layer is within this range, the connection strength of the connecting layer can be ensured.

[0012] In some possible embodiments, the shear strength of the composite layer is 1.4 MPa or higher, and / or the thickness range of the composite layer is 80 to 120 μm.

[0013] Thus, if the shear strength of the composite layer is within this range, the composite layer can be ensured to resist shear forces from the outside. If the thickness of the composite layer is within this range, the shear strength of the composite layer can be ensured.

[0014] In some possible embodiments, the composite layer covers the entire bottom surface, and / or the composite layer covers a portion of the sides, and the areas on the sides not covered by the composite layer are covered with gel.

[0015] In this way, the gel covering the sides can serve as a connector, allowing two adjacent cells within the battery module to be connected via the gel.

[0016] In some possible embodiments, the composite layers on the sides and bottom are arranged integrally.

[0017] In this way, by arranging the composite layers as a single unit, the shear strength and insulation properties of the entire composite layer can be improved.

[0018] In some possible embodiments, the side surface includes a first side surface and a second side surface. The housing has two first side surfaces arranged opposite each other, and two second side surfaces arranged opposite each other. The first and second side surfaces intersect each other, and the area of ​​the first side surface is greater than the area of ​​the second side surfaces. Both the first and second side surfaces are covered by the composite layer if the composite layer covers at least a portion of the side surface.

[0019] Thus, the first side is the larger side of the cell, the second side is the smaller side of the cell, and the composite layer can form protection against the first and second sides.

[0020] In some possible embodiments, the composite layer covering the first side extends to the second side, covering a portion of the second side. The area on the second side not covered by the composite layer is a window region, which is covered with gel. The area of ​​the window region occupies 40% to 80% of the area of ​​the second side. And / or, the gap between the bottom edge of the window region and the bottom surface is 5 mm or more.

[0021] Thus, when the area ratio of the window region falls within this range, the bonding area and bonding strength between the gel and the second side surface can be ensured. When the gap falls within this range, the protective capability of the composite layer against the bottom of the second side surface can be ensured.

[0022] In some possible embodiments, the composite layer has a folding region on the second side, and the composite layer is folded and arranged in the folding region.

[0023] Thus, after the composite layer is folded and arranged in the folding region, the composite layer on the second side can be flattened, and the shear strength of the composite layer in the folding region can also be improved.

[0024] In some possible embodiments, the maximum number of folded layers of the composite layer in the folding region does not exceed 5 layers.

[0025] Thus, when the maximum number of folded layers does not exceed 5 layers, the flatness of the entire composite layer on the second side can be ensured.

[0026] The second aspect of the present application provides a housing having a side surface and a bottom surface, at least a part of at least one of the side surface and at least a part of the bottom surface being covered with a composite layer. The composite layer includes a shear prevention layer and a connection layer, and the shear prevention layer is connected to the housing through the connection layer. At least one of the shear prevention layer and the connection layer is an insulating layer.

[0027] The third aspect of the present application provides a battery module including the cell described in any of the above embodiments. A plurality of cells are arranged, and the plurality of cells are connected to form a cell assembly.

[0028] The fourth aspect of the present application provides a battery pack including a battery box and the above battery module. The battery box has an accommodation cavity inside, and the battery module is arranged in the accommodation cavity.

Advantages of the Invention

[0029] Therefore, in the cell provided by this application, the shear prevention layer is connected to the housing via a connecting layer, and the composite layer can form protection against the surface of the housing. Here, the presence of the shear prevention layer ensures the shear strength of the composite layer covering the cell surface. Therefore, when the cell is subjected to shear force from the outside, the composite layer does not easily rupture under the action of the external shear force, thereby improving the reliability of the cell during use. Furthermore, the presence of the connecting layer improves the connection strength between the composite layer and the housing.

[0030] The structure of this application, as well as other objectives and advantageous effects of the invention, will be better understood by describing specific embodiments in conjunction with the accompanying drawings. [Brief explanation of the drawing]

[0031] To more clearly illustrate embodiments of the present application or technical solutions of the prior art, the drawings necessary for describing the embodiments or the prior art are briefly introduced below. Clearly, the drawings in the following description are some embodiments of the present application. Those skilled in the art can obtain other drawings based on these without any creative effort.

[0032] [Figure 1] This is a three-dimensional view of a cell provided by an embodiment of the present application. [Figure 2] This is a front view of a cell provided according to an embodiment of the present application. [Figure 3] This is a cross-sectional view of position AA in Figure 2. [Figure 4] This is a magnified view of position B in Figure 3. [Figure 5] This is another drawing corresponding to Figure 4. [Figure 6] This is a left side view of a cell provided according to an embodiment of the present application. [Figure 7] This is a drawing of Figure 6 after the composite layer has been removed. [Figure 8] This is another drawing corresponding to Figure 6. [Modes for carrying out the invention]

[0033] In methods known to those skilled in the art, when cells in a battery module are interconnected, an insulating film covering the cell surface maintains insulation between two adjacent cells. However, the insulating film covering the cell surface in the prior art suffers from low shear strength, and when a cell is subjected to shear force from the outside, the insulating film is prone to rupture, affecting the reliability of the cell during use.

[0034] Based on the above problems, embodiments of the present invention provide a cell, a housing, a battery module, and a battery pack. Both the battery module and the battery pack include a cell. Here, the cell includes a housing and a composite layer, the composite layer includes a shear-resistant layer and a connecting layer, the shear-resistant layer is connected to the housing via the connecting layer. At least one of the shear-resistant layer and the connecting layer is an insulating layer. The composite layer covers at least one of at least a portion of the side and at least a portion of the bottom surface of the housing. Therefore, after the shear-resistant layer is connected to the surface of the housing via the connecting layer, the shear strength of the composite layer covering the cell surface is ensured, thereby improving the reliability of the cell during use.

[0035] To further clarify the purpose, technical solutions, and advantages of the embodiments of this application, the technical solutions in the embodiments of this application are described below clearly and completely, together with the drawings of the embodiments. Obviously, the embodiments described are part of the embodiments of this application, but not all of them. All other embodiments obtained by those skilled in the art without creative effort based on the embodiments of this application are within the scope of protection of this application.

[0036] The technical solution of this application and how it solves the above-mentioned technical problems will be described in detail below using specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0037] The structure of the cell provided by the embodiment of this application will be described in detail below by combining Figures 1 to 8.

[0038] As shown in Figures 1 to 4, the cell provided by the embodiment of the present invention includes a housing 100. The housing 100 has a side surface 110 and a bottom surface 120. The housing 100 also has a top surface 130, and the side surface 110 is connected between the bottom surface 120 and the top surface 130. An electrolyte 600 is placed inside the housing 100.

[0039] The composite layer 200 includes a shear prevention layer 210 and a connecting layer 220. The shear prevention layer 210 is connected to the housing 100 via the connecting layer 220. At least one of the shear prevention layer 210 and the connecting layer 220 is an insulating layer. The composite layer 200 covers at least one of at least a portion of the side surface 110 and at least a portion of the bottom surface 120. The side surface 110 and bottom surface 120 of the housing 100 are susceptible to external forces, and after the composite layer 200 covers at least one of at least a portion of the side surface 110 and at least a portion of the bottom surface 120, the composite layer 200 can form protection against the side surface 110 and / or the bottom surface 120. For example, if the bottom of a cell is connected to the bottom plate of a battery box via gel, the bottom surface 120 of the housing 100 is subjected to shear force during the process of removing the cell from the bottom plate. In this case, the composite layer 200 can cover at least a portion of the bottom surface 120, thereby providing protection to the bottom surface 120. Alternatively, if the sides 110 of two adjacent cells are connected via gel, the sides 110 of the housing 100 are also subjected to shear force during the process of separating the two adjacent cells. In this case, the composite layer 200 can cover at least a portion of the sides 110, thereby providing protection to the sides 110. Alternatively, if both the sides 110 and the bottom surface 120 of the housing 100 are subjected to external shear force, the composite layer 200 can simultaneously cover at least a portion of the sides 110 and at least a portion of the bottom surface 120, thereby providing protection to both the sides 110 and the bottom surface 120 at the same time.

[0040] Specifically, either the shear prevention layer 210 or the connecting layer 220 may be an insulating layer, or both the shear prevention layer 210 and the connecting layer 220 may be insulating layers. Therefore, after the composite layer 200 covers the surface of the housing 100, insulation between two adjacent cells can be ensured.

[0041] Specifically, when the composite layer 200 covers the sides, it may cover only a portion of the side 110 or the entire side. When the composite layer 200 covers the bottom, it may cover only a portion of the bottom 120 or the entire bottom 120.

[0042] Therefore, in the cell provided by this application, the shear prevention layer 210 is connected to the housing 100 via the connecting layer 220, and the composite layer 200 can form protection against the surface of the housing 100. Here, the presence of the shear prevention layer 210 ensures the shear strength of the composite layer 200 covering the cell surface. Therefore, when the cell is subjected to shear force from the outside, the composite layer 200 does not easily rupture under the action of shear force from the outside, thereby improving the reliability of the cell during use. Furthermore, the presence of the connecting layer 220 improves the connection strength between the composite layer 200 and the housing 100.

[0043] In one specific embodiment, as shown in Figure 4, the shear prevention layer 210 and the connecting layer 220 are each arranged as a single layer. Therefore, the single layer of shear prevention layer 210 is connected to the single layer of connecting layer 220, simplifying the structure of the composite layer 200 and facilitating the processing and formation of the composite layer 200.

[0044] Specifically, when a shear prevention layer 210 and a connecting layer 220 are each arranged as a single layer, the thickness range of both the shear prevention layer 210 and the connecting layer 220 is 40 to 60 μm. When the thickness of the shear prevention layer 210 is within this range, the weight and cost of the shear prevention layer 210 can be reduced while ensuring the shear strength of the shear prevention layer 210. When the thickness of the connecting layer 220 is within this range, the weight and cost of the connecting layer 220 can be reduced while ensuring the connection strength of the connecting layer 220.

[0045] In another specific embodiment, as shown in Figure 5, both the shear prevention layer 210 and the connecting layer 220 are arranged in multiple layers, and the multiple shear prevention layers 210 and the multiple connecting layers 220 are stacked alternately in sequence. Therefore, the multiple shear prevention layers 210 and the multiple connecting layers 220 cooperate with each other to further secure the shear strength of the composite layer 200 and ensure reliability when the cell is in use. Specifically, as shown in Figure 5, both the shear prevention layer 210 and the connecting layer 220 are arranged in two layers, and the two shear prevention layers 210 and the two connecting layers 220 are stacked alternately in sequence.

[0046] Specifically, the thickness range of the composite layer 200 is 80 to 120 μm, and if the thickness of the composite layer 200 is within this range, the shear strength of the composite layer 200 can be ensured. When multiple layers of both the shear prevention layer 210 and the connecting layer 220 are arranged, the sum of the thicknesses of the multiple shear prevention layers 210 and the multiple connecting layers 220 becomes the thickness of the composite layer 200.

[0047] For example, the shear-resistant layer 210 may be a PET layer. PET has excellent shear resistance, abrasion resistance, dimensional stability, and electrical insulation properties, which can improve the performance of the composite layer 200.

[0048] Exemplary, the connecting layer 220 is a photocurable layer or a temperature-curable layer, specifically, a photocurable adhesive or a temperature-curable adhesive. If the connecting layer 220 is a photocurable adhesive, an epoxy-based cationic adhesive can be used. Thus, the connecting layer 220 can be rapidly cured under ultraviolet irradiation, and after curing, the connecting layer 220 has excellent chemical corrosion resistance, abrasion resistance, and heat resistance. If the connecting layer 220 is a temperature-curable adhesive, an epoxy resin can be used, and after thermal curing at a specific temperature, the connecting layer 220 can form a dense structure and fixed shape. Furthermore, after curing, the connecting layer 220 can withstand a certain shear force, thereby improving the shear strength of the composite layer 200.

[0049] In the embodiments of the present application, the shear strength of the composite layer 200 is 1.4 MPa or higher. Specifically, the shear strength of the composite layer 200 may be in the range of 1.4 to 5.5 MPa. Having the shear strength of the composite layer 200 within this range ensures that the composite layer 200 has the ability to resist shear forces from the outside and can also reduce the cost of the composite layer 200.

[0050] In the embodiments of the present invention, first, the surface of the housing 100 may be covered with the composite layer 200, and after covering with the composite layer 200, the housing cover 300 may be further welded to the upper part of the housing 100. Alternatively, the housing cover 300 may be first welded to the upper part of the housing 100, and then the surface of the housing 100 may be further covered with the composite layer 200.

[0051] In the embodiments of the present invention, as shown in Figures 6 and 7, the composite layer 200 covers the entire bottom surface 120. Since the bottom surface 120 of the housing 100 is subjected to large shear forces, after the composite layer 200 covers the entire bottom surface 120, the composite layer 200 can form protection over the entire bottom surface 120. In addition, the composite layer 200 covers a portion of the side surface 110, and the area on the side surface 110 not covered by the composite layer 200 is covered with gel. The gel covering the side surface 110 can serve as a connector, and two adjacent cells in the battery module may be connected via the gel, or a cell and a side plate in the battery module may be connected via the gel.

[0052] Furthermore, the bonding force between the gel and the composite layer 200 is weak. In contrast, the bonding force between the gel and the side surface 110 of the housing 100 is strong, which improves the reliability of the connection between two adjacent cells.

[0053] In the embodiment of the present application, the composite layer 200 on the side surface 110 and the bottom surface 120 is arranged integrally. For example, the composite layer 200 is a single film layer, and the film layer covers the side surface 110 and the bottom surface 120 simultaneously. After the composite layer 200 is arranged integrally, the shear strength and insulation properties of the composite layer 200 as a whole can be improved.

[0054] In embodiments of the present application, as shown in Figures 1 to 3, the side surface 110 includes a first side surface 111 and a second side surface 112. The housing 100 has two first side surfaces 111 and two second side surfaces 112 that are positioned opposite each other. The first side surfaces 111 and the second side surfaces 112 are positioned intersecting each other, and the area of ​​the first side surfaces 111 is larger than the area of ​​the second side surfaces 112. When the composite layer 200 covers at least a portion of the side surface 110, both the first side surfaces 111 and the second side surfaces 112 are covered by the composite layer 200. The first side surface 111 is the larger face of the cell, and the second side surface 112 is the smaller face of the cell, and the composite layer 200 can form protection over the first side surfaces 111 and the second side surfaces 112. Specifically, the first side surfaces 111 and the second side surfaces 112 are positioned perpendicular to each other, in which case the cell forms a square. Furthermore, the cells may be columnar, and the side surface 110 of the cell may be a columnar surface.

[0055] Specifically, as shown in Figures 1 and 6, the composite layer 200 covering the first side surface 111 extends to the second side surface 112, covering a portion of the second side surface 112. The area on the second side surface 112 not covered by the composite layer 200 is a window region 400, which is covered with gel. The gel covering the second side surface 112 can serve as a connector, and when connecting two adjacent cells in a battery module, the window regions 400 of the two cells are positioned closely facing each other, thereby connecting the two adjacent cells via the gel and improving the reliability of the connection between the two adjacent cells.

[0056] For example, the area of ​​the window region 400 occupies 40% to 80% of the area of ​​the second side surface 112. When the area ratio of the window region 400 is within this range, the bonding area and bonding strength between the gel and the second side surface 112 can be ensured, thereby improving the connection reliability between two adjacent cells and the safety and stability of the battery module and battery pack. Furthermore, the area ratio of the window region 400 is within the range of 50% to 70%. When it is within this range, the bonding area and bonding strength between the gel and the second side surface 112 can be ensured while also ensuring the covering area of ​​the composite layer 200 on the second side surface 112.

[0057] For example, the gap between the bottom edge of the window area 400 and the bottom surface 120 is 5 mm or more. As shown in Figure 6, the second side surface 112 located between the window area 400 and the bottom surface 120 is covered with the composite layer 200. The gap between the bottom edge of the window area 400 and the bottom surface 120 is the height of a portion of the composite layer 200, and when the gap is within this range, the protective capability of the composite layer 200 against the bottom of the second side surface 112 can be ensured.

[0058] Furthermore, as shown in Figures 6 and 8, the composite layer 200 has a folding region 500 on the second side surface 112, and the composite layer 200 is folded and positioned in the folding region 500. If the composite layer 200 is a film layer, excess film material is generated in the corner regions of the film layer during the process of the film layer covering the surface of the housing 100. At this time, the excess film material can be folded. With this arrangement, after the composite layer 200 is folded and positioned in the folding region 500, the composite layer 200 on the second side surface 112 can be made flat, and furthermore, the shear strength of the composite layer 200 in the folding region 500 can also be improved.

[0059] Specifically, the maximum number of folded layers of the composite layer 200 in the folding region 500 does not exceed 5 layers. By limiting the maximum number of folded layers to 5 layers, the overall flatness of the composite layer 200 on the second side surface 112 can be ensured.

[0060] As shown in Figure 6, each of the composite layers 200 has two folding regions 500 on each second side surface 112, and the two folding regions 500 do not overlap. In this case, the two folding regions 500 constitute the maximum number of folding layers region 510, and the maximum number of folding layers of the composite layer 200 in the maximum number of folding layers region 510 is 3. In this case, a window region 400 exists on the second side surface 112, and the coating on the cell corresponds to a semi-coating structure.

[0061] As shown in Figure 8, the composite layer 200 has two folded regions 500 on each second side surface 112, and the two folded regions 500 overlap. At this time, the overlapping region of the two folded regions 500 is the maximum number of folded layers region 510, and the maximum number of folded layers of the composite layer 200 in the maximum number of folded layers region 510 is 5 layers. At this time, there is no window region 400 on the second side surface 112, and the coating on the cell is a full coating structure.

[0062] An embodiment of the present invention further provides a housing 100. As shown in Figures 1 to 4, the housing 100 has a side surface 110 and a bottom surface 120. The housing 100 also has a top surface 130, and the side surface 110 is connected between the bottom surface 120 and the top surface 130. After the electrolyte 600 is placed inside the housing 100, the body of the cell is formed.

[0063] Furthermore, at least one of at least a portion of the side surface 110 and at least a portion of the bottom surface 120 is covered with the composite layer 200. The side surface 110 and bottom surface 120 of the housing 100 are susceptible to external forces, and after the composite layer 200 covers at least one of at least a portion of the side surface 110 and at least a portion of the bottom surface 120, the composite layer 200 can provide protection to the side surface 110 and / or the bottom surface 120. For example, if the bottom of the housing 100 is connected to the bottom plate of a battery box via gel, the bottom surface 120 of the housing 100 is subjected to shear force during the process of removing the housing 100 from the bottom plate. At this time, the composite layer 200 can cover at least a portion of the bottom surface 120, thereby providing protection to the bottom surface 120. Alternatively, if the side surfaces 110 of two adjacent housings 100 are connected via gel, the side surfaces 110 of the housings 100 are also subjected to shear force during the process of disassembling the two adjacent housings 100. In this case, the composite layer 200 can cover at least a portion of the side surface 110, thereby providing protection to the side surface 110. Alternatively, if both the side surface 110 and the bottom surface 120 of the housing 100 are subjected to external shear forces, the composite layer 200 can simultaneously cover at least a portion of the side surface 110 and at least a portion of the bottom surface 120, thereby providing protection to both the side surface 110 and the bottom surface 120 at the same time.

[0064] Furthermore, if the composite layer 200 covers the side surface 110, it may cover only a portion of the side surface 110 or the entire side surface. If the composite layer 200 covers the bottom surface 120, it may cover only a portion of the bottom surface 120 or the entire bottom surface 120.

[0065] Specifically, the composite layer 200 includes a shear prevention layer 210 and a connecting layer 220. The shear prevention layer 210 is connected to the housing 100 via the connecting layer 220. At least one of the shear prevention layer 210 and the connecting layer 220 is an insulating layer. For example, only one of the shear prevention layer 210 and the connecting layer 220 may be an insulating layer, or both the shear prevention layer 210 and the connecting layer 220 may be insulating layers. Therefore, after the composite layer 200 covers the surface of the housing 100, insulation between two adjacent housings 100 can be ensured.

[0066] Therefore, the presence of the shear-preventing layer 210 ensures the shear strength of the composite layer 200 covering the surface of the housing 100. Consequently, when subjected to shear force from the outside, the composite layer 200 does not easily rupture under the influence of external shear force, thereby improving the reliability of the housing 100 during use.

[0067] The specific structure of the housing 100 provided in the embodiment of this application will be described in detail below.

[0068] In one specific embodiment, as shown in Figure 4, the shear prevention layer 210 and the connecting layer 220 are each arranged as a single layer. Therefore, the single layer of shear prevention layer 210 is connected to the single layer of connecting layer 220, simplifying the structure of the composite layer 200 and facilitating the processing and formation of the composite layer 200.

[0069] Specifically, when a shear prevention layer 210 and a connecting layer 220 are each arranged as a single layer, the thickness range of both the shear prevention layer 210 and the connecting layer 220 is 40 to 60 μm. When the thickness of the shear prevention layer 210 is within this range, the weight and cost of the shear prevention layer 210 can be reduced while ensuring the shear strength of the shear prevention layer 210. When the thickness of the connecting layer 220 is within this range, the weight and cost of the connecting layer 220 can be reduced while ensuring the connection strength of the connecting layer 220.

[0070] In another specific embodiment, as shown in Figure 5, both the shear prevention layer 210 and the connecting layer 220 are arranged in multiple layers, and the multiple shear prevention layers 210 and the multiple connecting layers 220 are stacked alternately in sequence. Therefore, the multiple shear prevention layers 210 and the multiple connecting layers 220 cooperate with each other to further secure the shear strength of the composite layer 200 and ensure the reliability of the housing 100 when in use. Specifically, as shown in Figure 5, both the shear prevention layer 210 and the connecting layer 220 are arranged in two layers, and the two shear prevention layers 210 and the two connecting layers 220 are stacked alternately in sequence.

[0071] Specifically, the thickness range of the composite layer 200 is 80 to 120 μm, and if the thickness of the composite layer 200 is within this range, the shear strength of the composite layer 200 can be ensured. When multiple layers of both the shear prevention layer 210 and the connecting layer 220 are arranged, the sum of the thicknesses of the multiple shear prevention layers 210 and the multiple connecting layers 220 becomes the thickness of the composite layer 200.

[0072] For example, the shear-resistant layer 210 may be a PET layer. PET has excellent shear resistance, abrasion resistance, dimensional stability, and electrical insulation properties, which can improve the performance of the composite layer 200.

[0073] Exemplary, the connecting layer 220 is a photocurable layer or a temperature-curable layer, specifically, a photocurable adhesive or a temperature-curable adhesive. If the connecting layer 220 is a photocurable adhesive, an epoxy-based cationic adhesive can be used. Thus, the connecting layer 220 can be rapidly cured under ultraviolet irradiation, and after curing, the connecting layer 220 has excellent chemical corrosion resistance, abrasion resistance, and heat resistance. If the connecting layer 220 is a temperature-curable adhesive, an epoxy resin can be used, and after thermal curing at a specific temperature, the connecting layer 220 can form a dense structure and fixed shape. Furthermore, after curing, the connecting layer 220 can withstand a certain shear force, thereby improving the shear strength of the composite layer 200.

[0074] In the embodiments of the present application, the shear strength of the composite layer 200 is 1.4 MPa or higher. Specifically, the shear strength of the composite layer 200 may be in the range of 1.4 to 5.5 MPa. Having the shear strength of the composite layer 200 within this range ensures that the composite layer 200 has the ability to resist shear forces from the outside and can also reduce the cost of the composite layer 200.

[0075] In the embodiments of the present invention, the surface of the housing 100 may first be covered with the composite layer 200, and after covering with the composite layer 200, the housing cover 300 may be further welded to the upper part of the housing 100. Alternatively, the housing cover 300 may be first welded to the upper part of the housing 100, and then the surface of the housing 100 may be further covered with the composite layer 200.

[0076] In the embodiments of the present application, as shown in Figures 6 and 7, the composite layer 200 covers the entire bottom surface 120. Since the bottom surface 120 of the housing 100 is subjected to large shear forces, after the composite layer 200 covers the entire bottom surface 120, the composite layer 200 can form protection over the entire bottom surface 120. In addition, the composite layer 200 covers a portion of the side surface 110, and the area on the side surface 110 not covered by the composite layer 200 is covered with gel. The gel covering the side surface 110 can serve as a connector, and two adjacent housings 100 within the battery module may be connected via the gel, or the housing 100 and the side plate within the battery module may be connected via the gel.

[0077] Furthermore, the bonding force between the gel and the composite layer 200 is weak. In contrast, the bonding force between the gel and the side surface 110 of the housing 100 is strong, which improves the reliability of the connection between two adjacent housings 100.

[0078] In the embodiment of the present application, the composite layer 200 on the side surface 110 and the bottom surface 120 is arranged integrally. For example, the composite layer 200 is a single film layer, and the film layer covers the side surface 110 and the bottom surface 120 simultaneously. After the composite layer 200 is arranged integrally, the shear strength and insulation properties of the composite layer 200 as a whole can be improved.

[0079] In embodiments of the present application, as shown in Figures 1 to 3, the side surface 110 includes a first side surface 111 and a second side surface 112. The housing 100 has two first side surfaces 111 and two second side surfaces 112 that are positioned opposite each other. The first side surfaces 111 and the second side surfaces 112 are positioned intersecting each other, and the area of ​​the first side surfaces 111 is larger than the area of ​​the second side surfaces 112. When the composite layer 200 covers at least a portion of the side surface 110, both the first side surfaces 111 and the second side surfaces 112 are covered by the composite layer 200. The first side surfaces 111 are the larger surfaces of the housing 100, and the second side surfaces 112 are the smaller surfaces of the housing 100, and the composite layer 200 can form protection over the first side surfaces 111 and the second side surfaces 112. Specifically, the first side surfaces 111 and the second side surfaces 112 are positioned perpendicular to each other, in which case the housing 100 has a square shape. Furthermore, the housing 100 may be columnar, and the side surface 110 of the housing 100 may be a columnar surface.

[0080] Specifically, as shown in Figures 1 and 6, the composite layer 200 covering the first side surface 111 extends to the second side surface 112, covering a portion of the second side surface 112. The area on the second side surface 112 not covered by the composite layer 200 is a window area 400, which is covered with gel. The gel covering the second side surface 112 can serve as a connector, and when connecting two adjacent housings 100 within a battery module, the window areas 400 of the two housings 100 are positioned closely facing each other, thereby connecting the two adjacent housings 100 via the gel and improving the reliability of the connection between the two adjacent housings 100.

[0081] For example, the area of ​​the window region 400 occupies 40% to 80% of the area of ​​the second side surface 112. When the area ratio of the window region 400 is within this range, the bonding area and bonding strength between the gel and the second side surface 112 can be ensured, thereby improving the connection reliability between two adjacent housings 100, and the safety and stability of the battery module and battery pack. Furthermore, the area ratio of the window region 400 is within the range of 50% to 70%. When it is within this range, the bonding area and bonding strength between the gel and the second side surface 112 can be ensured while also ensuring the covering area of ​​the composite layer 200 on the second side surface 112.

[0082] For example, the gap between the bottom edge of the window area 400 and the bottom surface 120 is 5 mm or more. As shown in Figure 6, the second side surface 112 located between the window area 400 and the bottom surface 120 is covered with the composite layer 200. The gap between the bottom edge of the window area 400 and the bottom surface 120 is the height of a portion of the composite layer 200, and when the gap is within this range, the protective capability of the composite layer 200 against the bottom of the second side surface 112 can be ensured.

[0083] Furthermore, as shown in Figures 6 and 8, the composite layer 200 has a folding region 500 on the second side surface 112, and the composite layer 200 is folded and positioned in the folding region 500. If the composite layer 200 is a film layer, excess film material is generated in the corner regions of the film layer during the process of the film layer covering the surface of the housing 100. At this time, the excess film material can be folded. With this arrangement, after the composite layer 200 is folded and positioned in the folding region 500, the composite layer 200 on the second side surface 112 can be made flat, and furthermore, the shear strength of the composite layer 200 in the folding region 500 can also be improved.

[0084] Specifically, the maximum number of folded layers of the composite layer 200 in the folding region 500 does not exceed 5 layers. By limiting the maximum number of folded layers to 5 layers, the overall flatness of the composite layer 200 on the second side surface 112 can be ensured.

[0085] As shown in Figure 6, each of the composite layers 200 has two folding regions 500 on each second side surface 112, and the two folding regions 500 do not overlap. In this case, the two folding regions 500 constitute the maximum number of folding layers region 510, and the maximum number of folding layers of the composite layer 200 in the maximum number of folding layers region 510 is three. In this case, a window region 400 exists on the second side surface 112, and the coating on the housing 100 has a semi-coating structure.

[0086] As shown in Figure 8, the composite layer 200 has two folding regions 500 on each second side surface 112, and the two folding regions 500 overlap. At this time, the overlapping region of the two folding regions 500 is the maximum number of folding layers region 510, and the maximum number of folding layers of the composite layer 200 in the maximum number of folding layers region 510 is 5 layers. At this time, there is no window region 400 on the second side surface 112, and the coating on the housing 100 is a full coating structure.

[0087] Building upon the above embodiments, the present application further provides a battery module including cells of any of the above embodiments. Multiple cells are arranged and connected to form a cell assembly. Specifically, the window area 400 on the second side surface 112 is covered with gel. When connecting two adjacent cells in the battery module, the window areas 400 of the two cells are positioned closely facing each other, thereby connecting the two adjacent cells via the gel and improving the reliability of the connection between the two adjacent cells.

[0088] Furthermore, the present invention provides a battery pack including a battery box and the battery module of the above embodiment. The battery box has a housing cavity inside, and the battery module is arranged inside the housing cavity. The composite layer 200 on the cell can improve the cell's resistance to shear forces, thereby improving the operational reliability of the cell, battery module, and battery pack.

[0089] Furthermore, in the disclosure of this application, the descriptions of orientation such as "top" and "bottom" refer to the structure of the cells in Figures 2 and 3, and should not be understood as limitations of this application.

[0090] In this disclosure, unless otherwise explicitly defined and limited, terms such as “attachment,” “connection,” and “connection” should be understood in a broad sense. For example, this could refer to a fixed connection, an indirect connection via an intermediate medium, an internal connection between two components, or an interactive relationship between two components. A person skilled in the art will be able to understand the specific implications of these terms in this application depending on the specific circumstances.

[0091] The devices or components disclosed or implied in this application must have a specific orientation and must have a specific orientation structure and operation; therefore, this should not be understood as a limitation to this application. In the disclosures of this application, the implication of “multiple” means two or more unless specifically and precisely defined otherwise.

[0092] The terms “First,” “Second,” “Third,” “Fourth,” etc., in the specification and claims of this application and in the accompanying drawings are used to distinguish similar subjects and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this manner is interchangeable under appropriate circumstances, for example, the embodiments of this application described herein may be carried out in an order other than that illustrated or described herein. Furthermore, the terms “includes” and “have,” and their variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the explicitly listed steps or units and may include other steps or units that are not explicitly listed or specific to the process, method, product, or apparatus.

[0093] Finally, although the present invention has been described in detail with reference to the embodiments described above, it should be noted that these embodiments are used solely to illustrate the technical solutions of the present invention and are not intended to limit them. Those skilled in the art will understand that it is still possible to modify the technical solutions recorded in the embodiments described above, or to replace some or all of the technical features with equivalent ones, and that such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application. [Industrial applicability]

[0094] The cell, housing, battery module, and battery pack of the present invention can be applied in the field of battery technology. [Explanation of Symbols]

[0095] 100: Cabinet 110: Side view 111: 1st side 112:Second side 120: Bottom 130:Top surface 200: Composite layer 210: Shear prevention layer 220: Connecting Layer 300: Case cover 400: Window area 500: Foldable area 510: Maximum number of folded layers region 600: Electrolyte

Claims

1. A housing having sides and a bottom, The composite layer comprises a shear prevention layer and a connecting layer, wherein the shear prevention layer is connected to the housing via the connecting layer, and at least one of the shear prevention layer and the connecting layer is an insulating layer, and the composite layer covers at least one of at least a portion of the side surface and at least a portion of the bottom surface. The aforementioned connecting layer is a photocuring layer or a temperature curing layer. A cell characterized by the following features.

2. The shear prevention layer and the connecting layer are each arranged as a single layer. Alternatively, the shear prevention layer and the connecting layer are arranged in multiple layers, and the multiple shear prevention layers and the multiple connecting layers are arranged in an alternating stacking arrangement. The cell according to claim 1, characterized in that it is a cell according to claim 1.

3. The shear prevention layer is a PET layer. And / or, when the shear prevention layer and the connecting layer are each arranged as one layer, the thickness range of both the shear prevention layer and the connecting layer is 40 to 60 μm. The cell according to claim 2, characterized in that

4. The shear strength of the composite layer is 1.4 MPa or more. and / or, the thickness range of the composite layer is 80 to 120 μm. A cell according to any one of claims 1 to 3, characterized in that

5. The composite layer covers the entire bottom surface, and / or, the composite layer covers a portion of the side surface, and the area on the side surface not covered by the composite layer is covered with gel. A cell according to any one of claims 1 to 3, characterized in that

6. The composite layers on the side surface and the bottom surface are arranged integrally. A cell according to any one of claims 1 to 3, characterized in that

7. The aforementioned side surface includes a first side surface and a second side surface, and the housing has two of the first side surfaces arranged opposite to each other, and two of the second side surfaces arranged opposite to each other. The first side and the second side are arranged to intersect each other, the area of ​​the first side is larger than the area of ​​the second side, and the composite layer covers at least a portion of the side, so both the first side and the second side are covered by the composite layer. A cell according to any one of claims 1 to 3, characterized in that

8. The composite layer covering the first side extends to the second side, covering a portion of the second side, and the area on the second side not covered by the composite layer is a window region, and the window region is covered with gel. The area of ​​the window region occupies 40% to 80% of the area of ​​the second side surface, and / or the gap between the bottom edge of the window region and the bottom surface is 5 mm or more. The cell according to claim 7, characterized in that

9. The composite layer has a folding region on the second side surface, and the composite layer is folded and arranged in the folding region. The cell according to claim 7, characterized in that

10. The maximum number of folded layers in the aforementioned folded region of the composite layer shall not exceed five layers. The cell according to claim 9, characterized in that it is a cell according to claim 9.

11. Having sides and a bottom, at least one of at least a portion of the sides and at least a portion of the bottom is covered with a composite layer. The composite layer includes a shear prevention layer and a connecting layer, the shear prevention layer is connected to the housing via the connecting layer, and at least one of the shear prevention layer and the connecting layer is an insulating layer. The aforementioned connecting layer is a photocuring layer or a temperature curing layer. A housing characterized by the following features.

12. A cell assembly comprising a cell according to any one of claims 1 to 3, wherein a plurality of the cells are arranged and the plurality of cells are connected to form a cell assembly. A battery module characterized by the following features.

13. The invention includes a battery box and a battery module according to claim 12, wherein the battery box has a housing cavity inside, and the battery module is disposed within the housing cavity. A battery pack characterized by the following features.

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