Cell, housing, battery module, and battery pack

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] The present application relates to the technical field of batteries, and in particular to cells, housings, battery modules and battery packs. [Background technology]

[0002] With the development of new energy vehicles, the demand for power batteries continues to increase. A power battery pack is usually composed of multiple battery modules, and each battery module is composed of multiple cells.

[0003] In one method known to those skilled in the art, the surface of the cells is covered with an insulating film, which maintains insulation between two adjacent cells when the cells are interconnected. Summary of the Invention [Problem to be solved by the invention]

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

[0005] To achieve the above objectives, the present application provides the following technical proposals.

[0006] A first aspect of the present application provides a cell comprising: a housing having side and bottom surfaces connected to each other; and a composite layer including a shear prevention layer and a connecting layer, the shear prevention layer being connected to the housing via the connecting layer, at least one of the shear prevention layer and the connecting layer being an insulating layer, and the composite layer covering at least one of at least a portion of the side surfaces and at least a portion of the bottom surface.

[0007] The beneficial effect of the present invention is that the shear protection layer is connected to the housing via the connecting layer, and the composite layer can provide protection to the surface of the housing, and the shear protection layer ensures the shear strength of the composite layer covering the cell surface, so that when the cell is subjected to shear force from the outside, the composite layer will 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 in one layer, or each of the shear protection layer and the connecting layer is arranged in multiple layers, with multiple shear protection layers and multiple connecting layers being stacked alternately.

[0009] In this way, when one shear protection layer and one connecting layer are provided, the composite layer can be easily processed and formed, and when multiple shear protection layers and multiple connecting layers are provided, the shear strength of the composite layer can be further ensured.

[0010] In some possible embodiments, the shear protection layer is a PET layer, and / or the connecting layer is a photo-cured layer or a temperature-cured layer, and / or when each of the shear protection layer and the connecting layer is one layer, the thickness range of each of the shear protection layer and the connecting layer is 40 to 60 μm.

[0011] Thus, when the thickness of the shear protection layer is within this range, the shear strength of the shear protection layer can be ensured. When the thickness of the connecting layer is within this range, the connecting 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 more, and / or the thickness of the composite layer is in the range of 80 to 120 μm.

[0013] Thus, when the shear strength of the composite layer is within this range, the ability of the composite layer to resist shear forces from the outside can be ensured, and when 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 side surface, with the areas on the side surface not covered by the composite layer being covered with gel.

[0015] In this way, the gel covering the side surfaces can serve as a connection, and two adjacent cells in a battery module can be connected via the gel.

[0016] In some possible embodiments, the composite layers on the side and bottom surfaces are disposed together.

[0017] In this way, by arranging the composite layers integrally, the shear strength and insulating properties of the entire composite layer can be improved.

[0018] In some possible embodiments, the side surfaces include 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 side surfaces and the second side surfaces are arranged to intersect with each other, and the area of ​​the first side surfaces is larger than the area of ​​the second side surfaces. When the composite layer covers at least a portion of the side surfaces, both the first side surface and the second side surface are covered with the composite layer.

[0019] In this way, the first side may be the major side of the cell and the second side may be the minor side of the cell, and the composite layer may provide protection to the first side and the second side.

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

[0021] Thus, when the area ratio of the window region is within this range, the bonding area and bonding strength between the gel and the second side surface can be ensured, and when the gap is within this range, the ability of the composite layer to protect 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 arranged to fold at the folding region.

[0023] In this way, after the composite layer is folded and positioned 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 five layers.

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

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

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

[0028] A fourth aspect of the present application provides a battery pack including a battery box and the above-mentioned battery module, wherein the battery box has an accommodating cavity therein, and the battery module is disposed in the accommodating cavity. [Effects of the Invention]

[0029] Therefore, in the cell provided by the present application, the shear protection layer is connected to the housing via the connecting layer, and the composite layer can provide protection for the surface of the housing. Here, the presence of the shear protection 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 will not easily rupture under the action of the shear force from the outside, thereby improving the reliability of the cell during use. In addition, the presence of the connecting layer can improve the connection strength between the composite layer and the housing.

[0030] The structure of the present application, as well as other objects and advantages of the invention, will be more clearly understood from the following description of specific embodiments taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0031] In order to more clearly describe the embodiments of the present application or the technical solutions of the prior art, the drawings necessary for describing the embodiments or the prior art are briefly introduced below. Obviously, 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 drawings without any creative efforts.

[0032] [Figure 1] 1 is a three-dimensional view of a cell provided by an embodiment of the present application. [Figure 2] FIG. 1 is a front view of a cell provided in accordance with an embodiment of the present application. [Figure 3] FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2. [Figure 4] FIG. 4 is an enlarged view of position B in FIG. 3. [Figure 5] 5 is another drawing corresponding to FIG. 4. [Figure 6] FIG. 1 is a left side view of a cell provided in accordance with an embodiment of the present application. [Figure 7] 7 is a view of FIG. 6 after the composite layer has been removed. [Figure 8] 7 is another view corresponding to FIG. 6. DETAILED DESCRIPTION OF THE INVENTION

[0033] In a method 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 has a problem of low shear strength, and when the cell is subjected to shear force from the outside, the insulating film is prone to rupture, which affects the reliability of the cell during use.

[0034] In light of the above, embodiments of the present application provide a cell, a housing, a battery module, and a battery pack. The battery module and the battery pack each include a cell. Here, the cell includes a housing and a composite layer, which includes a shear-preventing layer and a connecting layer, and the shear-preventing layer is connected to the housing via the connecting layer. At least one of the shear-preventing layer and the connecting layer is an insulating layer. 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 of the housing. Therefore, after the shear-preventing 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] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings of the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, but are not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of the present application.

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

[0037] The structure of the cell provided by the embodiment of the present application will be described in detail below in combination with FIGS.

[0038] 1 to 4, a cell provided by an embodiment of the present application 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 disposed inside the housing 100.

[0039] The composite layer 200 includes a shear prevention layer 210 and a connection layer 220. The shear prevention layer 210 is connected to the housing 100 via the connection layer 220. At least one of the shear prevention layer 210 and the connection 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. Note that the side surface 110 and the bottom surface 120 of the housing 100 are susceptible to external forces. 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 for 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 will be subjected to shear forces during the process of removing the cell 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 for the bottom surface 120. Alternatively, if the side surfaces 110 of two adjacent cells are connected via a gel, the side surface 110 of the housing 100 is also subjected to shear force during the process of disassembling the two adjacent cells. At this time, the composite layer 200 can cover at least a portion of the side surface 110, thereby providing protection for 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 force, 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 for the side surface 110 and the bottom surface 120 simultaneously.

[0040] Specifically, only one of the shear protection layer 210 and the connection layer 220 may be an insulating layer, or both of the shear protection layer 210 and the connection 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 side surface, it may cover only a portion of the side surface 110 or the entire side surface. When the composite layer 200 covers the bottom surface, it may cover only a portion of the bottom surface 120 or the entire bottom surface 120.

[0042] Therefore, in the cell provided herein, the shear protection layer 210 is connected to the housing 100 via the connecting layer 220, and the composite layer 200 can provide protection for the surface of the housing 100. Here, the presence of the shear protection 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 will not easily rupture under the action of the shear force from the outside, thereby improving the reliability of the cell during use. Furthermore, the presence of the connecting layer 220 can improve the connection strength between the composite layer 200 and the housing 100.

[0043] In a specific embodiment, as shown in Figure 4, the shear prevention layer 210 and the connecting layer 220 are each arranged in one layer, so that one shear prevention layer 210 is connected to one connecting layer 220, which simplifies the structure of the composite layer 200 and makes it easier to process and form the composite layer 200.

[0044] Specifically, when one layer of each of the shear protection layer 210 and the connecting layer 220 is disposed, the thickness range of each of the shear protection layer 210 and the connecting layer 220 is 40 to 60 μm. When the thickness of the shear protection layer 210 is within this range, the weight and cost of the shear protection layer 210 can be reduced while ensuring the shear strength of the shear protection 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 Fig. 5, the shear prevention layers 210 and the connecting layers 220 are each arranged in multiple layers, and the multiple shear prevention layers 210 and the multiple connecting layers 220 are arranged in an alternating stacked order. Therefore, the multiple shear prevention layers 210 and the multiple connecting layers 220 cooperate with each other to further ensure the shear strength of the composite layer 200 and to ensure the reliability of the cell during use. Specifically, as shown in Fig. 5, the shear prevention layers 210 and the connecting layers 220 are each arranged in two layers, and two shear prevention layers 210 and two connecting layers 220 are arranged in an alternating stacked order.

[0046] Specifically, the thickness of the composite layer 200 is in the range of 80 to 120 μm, and when the thickness of the composite layer 200 is in this range, it is possible to ensure the shear strength of the composite layer 200. When multiple shear protection layers 210 and connecting layers 220 are arranged, the total thickness of the multiple shear protection layers 210 and multiple connecting layers 220 is the thickness of the composite layer 200.

[0047] Illustratively, the shear protection layer 210 may be a PET layer, which has excellent shear resistance, abrasion resistance, dimensional stability, and electrical insulation properties, thereby improving the performance of the composite layer 200.

[0048] For example, the connecting layer 220 may be a photo-curable layer or a temperature-curable layer. Specifically, the connecting layer 220 may be a photo-curable adhesive or a temperature-curable adhesive. If the connecting layer 220 is a photo-curable adhesive, an epoxy-based cationic adhesive may be used. Therefore, the connecting layer 220 can be rapidly cured under ultraviolet light 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 may be used. After thermal curing at a specific temperature, the connecting layer 220 can form a dense structure and a 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 an embodiment of the present application, the shear strength of the composite layer 200 is 1.4 MPa or more. Specifically, the shear strength of the composite layer 200 may be in the range of 1.4 to 5.5 MPa. When the shear strength of the composite layer 200 is in this range, the composite layer 200 can ensure its ability to resist external shear forces and can also reduce the cost of the composite layer 200.

[0050] In the embodiment of the present application, 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 welded to the top of the housing 100. Alternatively, the housing cover 300 may first be welded to the top of the housing 100, and then the surface of the housing 100 may be covered with the composite layer 200.

[0051] 6 and 7, the composite layer 200 covers the entire bottom surface 120. Because the bottom surface 120 of the housing 100 is subjected to a large shear force, after the composite layer 200 covers the entire bottom surface 120, the composite layer 200 can provide protection for 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 that is not covered by the composite layer 200 is covered with gel. The gel covering the side surface 110 can serve as a connection, and two adjacent cells in a battery module may be connected via the gel, or a cell and a side panel in a battery module may be connected via the gel.

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

[0053] In the present embodiment, the composite layer 200 on the side surface 110 and the bottom surface 120 is integrally disposed. For example, the composite layer 200 is a film layer that simultaneously covers the side surface 110 and the bottom surface 120. After the composite layer 200 is integrally disposed, the shear strength and insulating properties of the entire composite layer 200 can be improved.

[0054] In the embodiment of the present application, as shown in FIGS. 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 arranged opposite to each other and two second side surfaces 112 arranged opposite to each other. The first side surfaces 111 and the second side surfaces 112 are arranged crossing each other, and the area of ​​the first side surface 111 is larger than the area of ​​the second side surface 112. When the composite layer 200 covers at least a portion of the side surface 110, both the first side surface 111 and the second side surface 112 are covered by the composite layer 200. The first side surface 111 is the major surface of the cell, and the second side surface 112 is the minor surface of the cell, and the composite layer 200 can provide protection for the first side surface 111 and the second side surface 112. Specifically, the first side surface 111 and the second side surface 112 are arranged perpendicular to each other, and the cell has a square shape. The cells may also be columnar, and the side surfaces 110 of the cells may be columnar surfaces.

[0055] 1 and 6, the composite layer 200 covering the first side surface 111 extends to the second side surface 112 and covers a portion of the second side surface 112. The area on the second side surface 112 that is 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 connection, and when connecting two adjacent cells in a battery module, the window regions 400 of the two cells are closely arranged facing each other, so that the two adjacent cells are connected via the gel, improving the connection reliability 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 are 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 a range of 50% to 70%. When the area ratio is within this range, the bonding area and bonding strength between the gel and the second side surface 112 are ensured, while also ensuring the coverage area of ​​the composite layer 200 on the second side surface 112.

[0057] Illustratively, the gap between the bottom edge of the window region 400 and the bottom surface 120 is 5 mm or more. As shown in Fig. 6, the second side surface 112 located between the window region 400 and the bottom surface 120 is covered with the composite layer 200. The gap between the bottom edge of the window region 400 and the bottom surface 120 is the height of a portion of the composite layer 200, and when the gap is in this range, the protective ability of the composite layer 200 for the bottom of the second side surface 112 can be ensured.

[0058] 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 disposed at the folding region 500. If the composite layer 200 is a film layer, excess film material is generated at the corner regions of the film layer as the film layer covers the surface of the housing 100. At this time, the excess film material can be folded. With this arrangement, the composite layer 200 can be flattened on the second side surface 112 after being folded and disposed at the folding region 500, and the shear strength of the composite layer 200 at 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. By not exceeding 5, the flatness of the entire composite layer 200 on the second side surface 112 can be ensured.

[0060] 6, the composite layer 200 has two folding regions 500 on each second side 112, and the two folding regions 500 do not overlap. In this case, the two folding regions 500 are a maximum folding layer region 510, and the maximum number of folding layers of the composite layer 200 in the maximum folding layer region 510 is three. In this case, a window region 400 exists on the second side 112, and the coating on the cell is a half-coated structure.

[0061] 8, the composite layer 200 has two folding regions 500 on each second side 112, and the two folding regions 500 overlap. In this case, 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 five. In this case, there is no window region 400 on the second side 112, and the coating on the cell corresponds to the entire coating structure.

[0062] The embodiment of the present application 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 an electrolyte 600 is placed inside the housing 100, a body of a 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 the 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 for the side surface 110 and / or the bottom surface 120. For example, if the bottom of the housing 100 is connected to a 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 for 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 for the side surface 110. Alternatively, when both the side surface 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 side surface 110 and at least a portion of the bottom surface 120, thereby providing protection for the side surface 110 and the bottom surface 120 simultaneously.

[0064] Furthermore, when 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. When 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 top of 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 shear protection layer 210 can ensure the shear strength of composite layer 200 covering the surface of housing 100. Therefore, when subjected to shear force from the outside, composite layer 200 will not easily rupture under the action of shear force from the outside, thereby improving the reliability of housing 100 during use.

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

[0068] In a specific embodiment, as shown in Figure 4, the shear prevention layer 210 and the connecting layer 220 are each arranged in one layer, so that one shear prevention layer 210 is connected to one connecting layer 220, which simplifies the structure of the composite layer 200 and makes it easier to process and form the composite layer 200.

[0069] Specifically, when one layer of each of the shear protection layer 210 and the connecting layer 220 is disposed, the thickness range of each of the shear protection layer 210 and the connecting layer 220 is 40 to 60 μm. When the thickness of the shear protection layer 210 is within this range, the weight and cost of the shear protection layer 210 can be reduced while ensuring the shear strength of the shear protection 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 Fig. 5, the shear prevention layers 210 and the connecting layers 220 are each arranged in multiple layers, and the multiple shear prevention layers 210 and the multiple connecting layers 220 are arranged in an alternating stacked order. Therefore, the multiple shear prevention layers 210 and the multiple connecting layers 220 cooperate with each other to further ensure the shear strength of the composite layer 200 and to ensure the reliability of the housing 100 during use. Specifically, as shown in Fig. 5, the shear prevention layers 210 and the connecting layers 220 are each arranged in two layers, and two shear prevention layers 210 and two connecting layers 220 are arranged in an alternating stacked order.

[0071] Specifically, the thickness of the composite layer 200 is in the range of 80 to 120 μm, and when the thickness of the composite layer 200 is in this range, it is possible to ensure the shear strength of the composite layer 200. When multiple shear protection layers 210 and connecting layers 220 are arranged, the total thickness of the multiple shear protection layers 210 and multiple connecting layers 220 is the thickness of the composite layer 200.

[0072] Illustratively, the shear protection layer 210 may be a PET layer, which has excellent shear resistance, abrasion resistance, dimensional stability, and electrical insulation properties, thereby improving the performance of the composite layer 200.

[0073] For example, the connecting layer 220 may be a photo-curable layer or a temperature-curable layer. Specifically, the connecting layer 220 may be a photo-curable adhesive or a temperature-curable adhesive. If the connecting layer 220 is a photo-curable adhesive, an epoxy-based cationic adhesive may be used. Therefore, the connecting layer 220 can be rapidly cured under ultraviolet light 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 may be used. After thermal curing at a specific temperature, the connecting layer 220 can form a dense structure and a 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 an embodiment of the present application, the shear strength of the composite layer 200 is 1.4 MPa or more. Specifically, the shear strength of the composite layer 200 may be in the range of 1.4 to 5.5 MPa. When the shear strength of the composite layer 200 is in this range, the composite layer 200 can ensure its ability to resist external shear forces and can also reduce the cost of the composite layer 200.

[0075] In the embodiment of the present application, 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 welded to the top of the housing 100. Alternatively, the housing cover 300 may first be welded to the top of the housing 100, and then the surface of the housing 100 may be covered with the composite layer 200.

[0076] 6 and 7, the composite layer 200 covers the entire bottom surface 120. Because the bottom surface 120 of the housing 100 is subjected to a large shear force, after the composite layer 200 covers the entire bottom surface 120, the composite layer 200 can provide protection for 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 that is not covered by the composite layer 200 is covered with gel. The gel covering the side surface 110 can serve as a connection, and two adjacent housings 100 in a battery module may be connected via the gel, or the housing 100 and a side panel in a battery module may be connected via the gel.

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

[0078] In the present embodiment, the composite layer 200 on the side surface 110 and the bottom surface 120 is integrally disposed. For example, the composite layer 200 is a film layer that simultaneously covers the side surface 110 and the bottom surface 120. After the composite layer 200 is integrally disposed, the shear strength and insulating properties of the entire composite layer 200 can be improved.

[0079] In the embodiment of the present application, as shown in FIGS. 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 arranged opposite to each other and two second side surfaces 112 arranged opposite to each other. The first side surfaces 111 and the second side surfaces 112 are arranged crossing each other, and the area of ​​the first side surface 111 is larger than the area of ​​the second side surface 112. When the composite layer 200 covers at least a portion of the side surface 110, both the first side surface 111 and the second side surface 112 are covered by the composite layer 200. The first side surface 111 is the larger surface of the housing 100, and the second side surface 112 is the smaller surface of the housing 100, and the composite layer 200 can provide protection for the first side surface 111 and the second side surface 112. Specifically, the first side surface 111 and the second side surface 112 are arranged perpendicular to each other, and 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] 1 and 6, the composite layer 200 covering the first side surface 111 extends to the second side surface 112 and covers a portion of the second side surface 112. The area on the second side surface 112 that is 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 connection, and when connecting two adjacent housings 100 in a battery module, the window regions 400 of the two housings 100 are closely arranged facing each other, thereby connecting the two adjacent housings 100 via the gel and improving the connection reliability 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 are 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 a range of 50% to 70%. When the area ratio is within this range, the bonding area and bonding strength between the gel and the second side surface 112 are ensured, while also ensuring the coverage area of ​​the composite layer 200 on the second side surface 112.

[0082] Illustratively, the gap between the bottom edge of the window region 400 and the bottom surface 120 is 5 mm or more. As shown in Fig. 6, the second side surface 112 located between the window region 400 and the bottom surface 120 is covered with the composite layer 200. The gap between the bottom edge of the window region 400 and the bottom surface 120 is the height of a portion of the composite layer 200, and when the gap is in this range, the protective ability of the composite layer 200 for the bottom of the second side surface 112 can be ensured.

[0083] 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 disposed at the folding region 500. If the composite layer 200 is a film layer, excess film material is generated at the corner regions of the film layer as the film layer covers the surface of the housing 100. At this time, the excess film material can be folded. With this arrangement, the composite layer 200 can be flattened on the second side surface 112 after being folded and disposed at the folding region 500, and the shear strength of the composite layer 200 at 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. By not exceeding 5, the flatness of the entire composite layer 200 on the second side surface 112 can be ensured.

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

[0086] 8, the composite layer 200 has two folding regions 500 on each second side 112, and the two folding regions 500 overlap. In this case, 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 five. In this case, there is no window region 400 on the second side 112, and the coating on the housing 100 corresponds to the entire coating structure.

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

[0088] The present application also provides a battery pack including a battery box and the battery module of the above embodiment. The battery box has a receiving cavity therein, and the battery module is disposed in the receiving cavity. The composite layer 200 on the cell can improve the cell's ability to resist shear stress, thereby improving the operational reliability of the cell, battery module, and battery pack.

[0089] It should be noted that in the present disclosure, descriptions of orientations such as "top" and "bottom" are relative to the structure of the cells in FIGS. 2 and 3 and should not be construed as limitations on the present disclosure.

[0090] In the present disclosure, unless otherwise expressly defined or limited, terms such as "attached," "interconnected," and "connection" should be understood in a broad sense. For example, they may 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. Those skilled in the art can understand the specific implications of the above terms in the present application depending on the specific circumstances.

[0091] Any devices or components disclosed or implied herein should not be understood as limitations on the present application, as they must have a particular orientation and have a particular structure and operation. In this disclosure, the connotation of "plurality" means two or more than two, unless otherwise precisely and specifically specified.

[0092] Terms such as "first," "second," "third," "fourth," etc. in the present specification and claims, as well as in the accompanying drawings, are used to distinguish between similar objects and are not necessarily used to describe a particular order or chronological order. Such terms, as used herein, are interchangeable under appropriate circumstances; for example, it should be understood that the embodiments of the present invention described herein may be performed in an order other than that illustrated or described herein. Furthermore, the terms "comprise" and "have" and variations thereof are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus comprising a series of steps or units need not be limited to the explicitly recited steps or units, but may include other steps or units not explicitly recited or inherent in the process, method, product, or apparatus.

[0093] Finally, although the present invention has been described in detail with reference to the above embodiments, it should be noted that the above embodiments are only used to describe the technical solutions of the present invention, and do not limit it. Those skilled in the art should understand that the technical solutions recorded in the above embodiments can still be modified or some or all of the technical features can be replaced with equivalents, and these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present 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: Housing 110: Side 111: 1st side 112:Second side 120: Bottom 130:Top surface 200: Composite layer 210: Shear prevention layer 220: Connection layer 300: Housing cover 400: Window area 500: Folding area 510: Maximum number of folded layers 600: Electrolyte

Claims

1. a housing having sides and a bottom; a composite layer including a shear prevention layer and a connection layer, the shear prevention layer being connected to the housing via 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 portion of the side surface and at least a portion of the bottom surface; A cell characterized by:

2. The shear prevention layer and the connecting layer are each arranged in one layer, Alternatively, the shear protection layer and the connecting layer are each arranged in a plurality of layers, and the plurality of shear protection layers and the plurality of connecting layers are arranged in an alternating stack.

2. The cell according to claim 1, characterized in that

3. the shear protection layer is a PET layer; and / or the connecting layer is a photo-curable layer or a temperature-curable layer; and / or, when the shear protection layer and the connecting layer are each arranged in one layer, the thickness range of each of the shear protection layer and the connecting layer is 40 to 60 μm; 3. The cell of claim 2 .

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 a gel. A cell according to any one of claims 1 to 3, characterized in that

6. the composite layers on the side and bottom surfaces are disposed together; A cell according to any one of claims 1 to 3, characterized in that

7. the side surfaces include a first side surface and a second side surface, 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 surface and the second side surface are arranged to intersect with each other, the area of ​​the first side surface is larger than the area of ​​the second side surface, and when the composite layer covers at least a portion of the side surfaces, both the first side surface and the second side surface 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 surface extends to the second side surface and covers a portion of the second side surface, an area on the second side surface that is not covered by the composite layer is a window area, and the window area is covered with a 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.

8. The cell of claim 7.

9. the composite layer has a folding region on the second side, and the composite layer is folded at the folding region.

8. The cell of claim 7.

10. the maximum number of folded layers of the composite layer in the folding region does not exceed five layers; 10. The cell of claim 9.

11. having a side surface and a bottom surface, at least one of at least a portion of the side surface and at least a portion of the bottom surface being covered with a composite layer; the composite layer includes a shear prevention layer and a connection layer, the shear prevention layer is connected to the housing via the connection layer, and at least one of the shear prevention layer and the connection layer is an insulating layer. A housing characterized by:

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

13. a battery box and the battery module according to claim 12, wherein the battery box has an accommodating cavity therein, and the battery module is disposed in the accommodating cavity; A battery pack characterized by:

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