Battery cell and electric equipment

Abstract

The invention provides a battery cell. The battery cell comprises a membrane shell, an electrode assembly, a first bonding piece, a second bonding piece and a third bonding piece, a mounting cavity is formed in the membrane shell, and the electrode assembly is arranged in the mounting cavity. The membrane shell is provided with a first outer wall face used for being bonded with the connecting base body, the electrode assembly is provided with a first surface facing the first outer wall face, and the first bonding piece is bonded to the first surface. And the second bonding piece is bonded with the first bonding piece and the membrane shell. And the third bonding piece is bonded with the electrode assembly and the membrane shell. The adhesive force between the first bonding piece and the second bonding piece is F1, the adhesive force between the third bonding piece is F2, the adhesive force between the first bonding piece and the electrode assembly is F3, and the adhesive force between the second bonding piece and the membrane shell is F4. F1, F2, F3 and F4 meet the following conditions: F2 is greater than F1, F3 is greater than F1, F2 is greater than F4, and F3 is greater than F4. According to the technical scheme, the risk that the electrode assembly is torn is reduced.

Description

Technical Field

[0001] This disclosure relates to the field of new energy technology, specifically to a battery cell and an electrical device. Background Technology

[0002] The structure of a pouch cell mainly consists of an electrode assembly and a housing, with the housing encapsulating the electrode assembly inside. The electrode assembly is bonded and fixed to the inner wall of the housing using adhesive to ensure the relative stability of the electrode assembly within the housing.

[0003] Some electrical appliances use battery cells as their power source. However, when these appliances are dropped or impacted, the foil inside the battery cells can easily tear or detach, which may damage the battery cells, leading to battery cell failure or safety risks. Summary of the Invention

[0004] In view of this, the present disclosure aims to provide a battery cell and an electrical device to solve the problem that when the electrical device is subjected to vibration or drops, the battery cell used in it may fail or pose a safety risk due to the aluminum foil of the electrode assembly being torn.

[0005] In a first aspect, this disclosure provides a battery cell, including a membrane housing, an electrode assembly, a first adhesive member, a second adhesive member, and a third adhesive member. The membrane housing has an internal mounting cavity, and the electrode assembly is disposed within the mounting cavity. The membrane housing has a first outer wall surface and a second outer wall surface disposed opposite each other along a first direction. The first outer wall surface is used for bonding and fixing to a connecting substrate. The electrode assembly has a first surface facing the first outer wall surface, and the first adhesive member is bonded to the first surface. The first adhesive member has a third surface facing away from the electrode assembly, and the second adhesive member is bonded to the third surface and fixed to the inner wall surface of the membrane housing. The third adhesive member is disposed on the side of the electrode assembly facing the second outer wall surface and is bonded to both the electrode assembly and the inner wall surface of the membrane housing. The area of ​​the second adhesive member is smaller than the area of ​​the first adhesive member. The adhesive force between the first and second adhesive members is F1, the adhesive force of the third adhesive member is F2, the adhesion between the first adhesive member and the electrode assembly is F3, and the adhesive force between the second adhesive member and the membrane housing is F4. F1, F2, F3, and F4 satisfy the following conditions: F2 > F1, F3 > F1, F2 > F4, and F3 > F4. Wherein, the thickness direction refers to the thickness direction of the battery cell.

[0006] In the above technical solution, by designing the adhesive structure and limiting the different adhesive forces generated by different adhesive components, the order in which different components detach when the battery cell is impacted can be controlled and adjusted. As the relative force between the electrode assembly and the membrane housing increases, the second adhesive component detaches from the first adhesive component, and the second adhesive component detaches from the membrane housing first. The adhesive force between the first adhesive component and the electrode assembly, and the adhesive force of the third adhesive component, are even greater, making it less likely for their corresponding components to detach. Thus, when the battery cell is bumped or dropped, the electrode assembly and the membrane housing tend to separate under the influence of relative forces. As this relative force increases, the initial limit reached is F1 or F4. Further increases are needed to reach greater limits F2 and F3. Therefore, the first to separate are the second adhesive component and the first adhesive component, or the second adhesive component and the membrane housing, rather than the first and third adhesive components directly bonded to the electrode assembly. Thus, in testing and actual use scenarios, if impacts or drops occur, the resulting force will increase to a certain limit, causing the second adhesive to detach from the adjacent component first, while ensuring stable adhesion between the first adhesive and the electrode assembly. This reduces the risk of tearing damage to the electrode assembly surface caused by the separation of the first adhesive from the electrode assembly. The multiple adhesives provided in this embodiment of the present disclosure can effectively protect the electrode assembly, reducing the problem of tearing damage to the electrode assembly surface caused by impacts or drops, improving the stability of the battery cell operation, and reducing the risk of equipment failure. Furthermore, through the above-mentioned design of this solution, even if the electrode assembly separates due to large interaction forces in the event of impacts or drops, the integrity of the electrode assembly structure can be maintained, reducing adverse effects on subsequent use.

[0007] In one specific implementation, the film shell includes a first packaging section and a second packaging section, which are connected to each other and together enclose an installation cavity. The first packaging section includes a first bottom wall, a first annular wall, and a first sealing wall. The first annular wall surrounds the first bottom wall. The first sealing wall surrounds at least a portion of the first annular wall. The first bottom wall, the first annular wall, and the first sealing wall together enclose a first recess. The second packaging section includes a second bottom wall, a second annular wall, and a second sealing wall. The second annular wall surrounds the second bottom wall. The second sealing wall surrounds at least a portion of the second annular wall. The second bottom wall, the second annular wall, and the second sealing wall together enclose a second recess. A first outer wall surface is located on the side of the first bottom wall away from the first recess, and a second outer wall surface is located on the side of the second bottom wall away from the second recess. The first sealing wall and the second sealing wall are sealed together, and the first and second recesses together enclose the installation cavity. Along the thickness direction, the depth of the first recess is less than the depth of the second recess.

[0008] In one specific implementation, the projection of the second adhesive member onto the set plane is at least partially located inside the projection of the first adhesive member onto the set plane. The area of ​​the bonding region between the first and second adhesive members is S1. The projected area of ​​the second adhesive member onto the set plane is S2. The area of ​​the first surface is S3. S1, S2, and S3 satisfy: 20% ≤ S1 / S2 ≤ 75%, and / or, S2 / S3 ≥ 65%. The set plane is perpendicular to the thickness direction.

[0009] In a specific feasible implementation, S1, S2 and S3 satisfy: 35%≤S1 / S2≤50%, and / or, S2 / S3≥85%.

[0010] In one specific implementation, the first adhesive member includes a first substrate layer and a first adhesive layer, the first adhesive layer being connected to the side of the first substrate layer facing the electrode assembly. The second adhesive member includes a second substrate layer, a second adhesive layer, and a third adhesive layer. The second adhesive layer and the third adhesive layer are respectively connected to opposite sides of the second substrate layer in the thickness direction. Alternatively, The first adhesive component includes a first substrate layer and a first adhesive layer, the first adhesive layer being connected to the side of the first substrate layer facing the electrode assembly. The second adhesive component is an adhesive layer, which is connected to the side of the first substrate layer facing away from the electrode assembly.

[0011] In one specific implementation scheme, the elastic modulus E of the first substrate layer satisfies: 0.2 GPa ≤ E ≤ 10 GPa; and / or, the elongation δ of the first substrate layer satisfies: 120% ≤ δ ≤ 500%; and / or, the yield strength σ of the first substrate layer... s Satisfy: 30 MPa ≤ σ s ≤250 MPa; and / or, the tensile strength σ of the first substrate layer b Satisfy: 50 MPa ≤ σ b ≤550 MPa. Preferably, the elastic modulus E of the first substrate layer satisfies: 0.5 GPa ≤ E ≤ 3 GPa. Preferably, the elastic modulus E of the first substrate layer satisfies: 0.7 GPa ≤ E ≤ 1.2 GPa.

[0012] In one specific implementation, multiple second adhesive members are provided, and the multiple second adhesive members are bonded to the surface of the first adhesive member opposite to the electrode assembly. Alternatively, Multiple first adhesive members are provided, and second adhesive members are bonded to the surfaces of the electrode assembly that are opposite to the surfaces of the multiple first adhesive members. Alternatively, Multiple first adhesive components and multiple second adhesive components are provided, and the multiple first adhesive components and multiple second adhesive components are arranged in a one-to-one correspondence.

[0013] In one specific embodiment, a portion of the first adhesive is bonded to a first surface of the electrode assembly, and another portion is bonded to a second surface of the electrode assembly. The second surface is a surface of the electrode assembly that faces away from the first surface. A third adhesive is at least partially bonded to the first adhesive located on the second surface of the electrode assembly.

[0014] In one specific feasible implementation, the membrane shell is an aluminum-plastic film. And / or, The edges and corners of the second adhesive component are chamfered. And / or, The edges and corners of the third adhesive component are chamfered. And / or, The second adhesive component has multiple spaced adhesive zones.

[0015] Secondly, this disclosure also provides an electrical device, including a device body and a battery cell as described in any of the above claims. The device body has a mounting surface for fixing the battery cell, and a first outer wall surface of the battery cell is adhered to the mounting surface. Attached Figure Description

[0016] Figure 1 The diagram shown is a schematic representation of the overall structure of a pouch battery according to an embodiment of this disclosure.

[0017] Figure 2 The diagram shown is a schematic representation of the adhesion force between multiple adhesive components and adjacent components according to an embodiment of this disclosure.

[0018] Figure 3 The diagram shown is a structural schematic of a membrane shell provided in an embodiment of this disclosure.

[0019] Figure 4 The diagram shown is a schematic diagram of a first adhesive member and a second adhesive member provided in an embodiment of this disclosure.

[0020] Figure 5 The diagram shown is a schematic diagram of a first adhesive member and a second adhesive member provided in another embodiment of this disclosure.

[0021] Figure 6 The diagram shown is a schematic representation of the mating relationship between the first adhesive member and the second adhesive member provided in one embodiment of this disclosure.

[0022] Figure 7 The diagram shows the mating relationship between the first adhesive and the second adhesive provided in two embodiments of this disclosure.

[0023] Figure 8 The diagram shown illustrates the mating relationship between the first adhesive member and the second adhesive member provided in three embodiments of this disclosure.

[0024] Figure 9 The diagram shows the mating relationship between the first adhesive and the second adhesive provided in four embodiments of this disclosure.

[0025] Figure 10 The diagram shown illustrates the mating relationship between the first adhesive member and the second adhesive member provided in five embodiments of this disclosure.

[0026] Figure 11 The diagram shown illustrates the mating relationship between the first adhesive member and the second adhesive member provided in the sixth embodiment of this disclosure.

[0027] Figure 12 The diagram shown is a structural schematic of the first adhesive member provided in the first embodiment of this disclosure.

[0028] Figure 13 The diagram shown is a structural schematic of the first adhesive component provided in the second embodiment of this disclosure.

[0029] Figure 14 The diagram shown is a structural schematic of the first adhesive component provided in the third embodiment of this disclosure.

[0030] The attached figures are labeled as follows: 1. Membrane housing; 101. Mounting cavity; 1011. First recessed cavity; 1012. Second recessed cavity; 102. First outer wall surface; 103. Second outer wall surface; 11. First mounting part; 111. First bottom wall; 112. First annular wall; 113. First sealing wall; 12. Second mounting part; 121. Second bottom wall; 122. Second annular wall; 123. Second sealing wall; 2. Electrode assembly, 201, first surface, 202, second surface, 21, tab; 3. First adhesive component; 301. Third surface; 31. First substrate layer; 32. First adhesive layer; 4. Second adhesive component; 41. Second substrate layer; 42. Second adhesive layer; 43. Third adhesive layer; 5. Third adhesive component. Detailed Implementation

[0031] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure are within the scope of protection of this disclosure.

[0032] To facilitate understanding of the battery cell and power-consuming device provided in the embodiments of this disclosure, a brief description of the relevant content is provided first. Taking a mobile phone as an example, the battery cell is used as the power supply for the mobile phone. The battery cell is fixedly installed inside the battery compartment of the mobile phone and is fixedly connected to the compartment wall or cover of the battery compartment by adhesive bonding.

[0033] Specifically, the battery cell includes an electrode assembly and a membrane housing. The electrode assembly can be a wound core or a stacked structure. The membrane housing is usually preferably an aluminum-plastic membrane. As the outer shell structure of the battery cell, the membrane housing encapsulates the electrode assembly inside the membrane housing. The electrode assembly is bonded and fixed to the inner wall of the membrane housing with adhesive, so that the electrode assembly remains stable inside the membrane housing.

[0034] Considering the various harsh working conditions that may occur during later use, such as phone drops and impacts, in order to ensure the stable and normal operation of the battery cells, relevant tests are also required during the production process to ensure that the battery cells meet the requirements and are not easily damaged during subsequent actual use.

[0035] For example, one sidewall of the battery cell (usually the large sidewall of the cell) is bonded to the wall or cover of the battery compartment. To ensure the stability of the battery cell installation, the bonding between the cell and the phone is sufficiently firm. In the event of impacts or drops, relative forces will occur between the battery cell and the phone, and between the electrode assembly and the casing. These relative forces will cause a tendency for displacement between the corresponding components. Once these relative forces reach a certain limit, they will damage the structure of the battery cell and electrode assembly, mostly causing tearing. Due to the inherent structural strength limitations of the battery cell and electrode assembly, the structural strength of the casing is usually greater than that of the electrode assembly to fulfill the function of encapsulating and protecting the electrode assembly.

[0036] Therefore, compared to the membrane housing structure, the electrode assembly is more likely to be damaged. Specifically, even when the electrode assembly is bonded to the inner wall of the membrane housing, it tends to shift relative to the membrane housing under external force, similar to tearing the electrode assembly off the membrane housing. In the cell manufacturing process, to ensure the stability of the electrode assembly within the membrane housing, the bond between the electrode assembly and the membrane housing needs to be sufficiently strong. Thus, when the aforementioned relative force reaches a certain limit, the electrode assembly may tear.

[0037] For example, the electrode assembly has a foil on its outer periphery, and the foil is bonded to the inner wall of the membrane housing by adhesive. Under the action of the above-mentioned relative forces, the adhesive will separate from the electrode assembly foil. The separation of the adhesive from the electrode assembly foil can easily cause the surface of the electrode assembly to be torn.

[0038] For example, when the electrode assembly is a wound core structure, it is formed by stacking and winding a positive electrode sheet, a separator, and a negative electrode sheet. At the tail end of the winding direction, the tail end of the positive electrode sheet exposes an empty aluminum foil that does not cover the positive electrode active layer, and the empty aluminum foil covers the outermost ring of the electrode assembly. Alternatively, the tail end of the negative electrode sheet exposes an empty copper foil that does not cover the negative electrode active layer, and the empty copper foil covers the outermost ring of the electrode assembly. One side of the adhesive is bonded to the empty aluminum foil or empty copper foil, and the other side is bonded to the inner wall of the membrane housing using hot melt adhesive or the like. Under the action of the aforementioned relative forces, the outermost empty aluminum foil or empty copper foil may tear or fall off, thereby causing the electrode assembly to loosen or fall off from the membrane housing, and further aggravating the relative displacement between the electrode assembly and the membrane housing.

[0039] It is also understandable that when the electrode assembly is a core structure, the outermost ends of its thickness direction are usually exposed with empty aluminum foil or empty copper foil. A hot melt adhesive layer is also attached between its surface and the membrane shell to bond with the inner wall of the membrane shell. Its drop failure principle is the same as or similar to that of the core structure mentioned above, and will not be elaborated on here.

[0040] The electrode assembly can be damaged by tearing of the foil, rendering the battery cell unusable. Even if the battery cell is still usable, damage to the electrode assembly structure significantly increases the risk of malfunctions, short circuits, and gas generation during use.

[0041] To overcome the aforementioned problems, this disclosure provides a battery cell and an electrical device, which designs the bonding structure between the electrode assembly and the membrane housing in the battery cell. In scenarios involving impacts or drops, the bonding structure is designed to separate first, or the bonding structure detaches from the membrane housing first, under the interaction force between the electrode assembly and the membrane housing, rather than the non-bonded structure separating from the electrode assembly, thereby reducing the risk of damage to the electrode assembly. A detailed description is provided below with reference to the accompanying drawings and embodiments.

[0042] refer to Figure 1 The main structure of the battery cell provided in this embodiment is shown, including a membrane housing 1, an electrode assembly 2, a first adhesive component 3, a second adhesive component 4, and a third adhesive component 5. The membrane housing 1 has an internal mounting cavity 101 for mounting the electrode assembly 2; the membrane housing 1 has a first outer wall surface 102 and a second outer wall surface 103 disposed opposite each other along the thickness direction, the first outer wall surface 102 being the adhesive surface. Exemplarily, the membrane housing 1 is an aluminum-plastic film.

[0043] Here, the thickness direction refers to the thickness direction of the battery cell, that is... Figure 1Unless otherwise specified, the thickness direction in this embodiment is the same as the thickness direction of the battery cell. Where otherwise specified, the corresponding description shall prevail. The battery cell is bonded and fixed to the connecting substrate via an adhesive surface. The connecting substrate refers to the part of the electrical equipment used to install the battery cell, such as the wall or cover of the battery compartment in a mobile phone. It can also refer to the structure used to fix the battery cell during testing.

[0044] It should also be noted that the adhesive surface is the surface used to glue and fix the device to the electrical equipment, for example, the adhesive surface is glued to the wall or cover of the battery compartment of a mobile phone.

[0045] Furthermore, it should be noted that the first outer wall surface 102 is limited to being used for bonding and fixing with the connecting substrate in this embodiment of the present disclosure. It is not limited to fixing through the first outer wall surface 102. It also includes the method of bonding and fixing the battery cell to the connecting substrate simultaneously through the first outer wall surface 102 and the second outer wall surface 103.

[0046] Electrode assembly 2 is disposed in mounting cavity 101 and is bonded and fixed to the inner wall of membrane housing 1. Electrode assembly 2 has a first surface 201 and a second surface 202 disposed opposite to each other along the thickness direction. The first surface 201 and the second surface 202 of electrode assembly 2 are bonded and fixed to membrane housing 1 by an adhesive structure. The first surface 201 is the surface of electrode assembly 2 facing the first outer wall surface 102, and the second surface 202 is the surface of electrode assembly 2 facing the second outer wall surface 103.

[0047] The aforementioned adhesive structure refers to the first adhesive component 3, the second adhesive component 4, and the third adhesive component 5. The first adhesive component 3 is bonded to the first surface 201 of the electrode assembly 2. The second adhesive component 4 is bonded to the third surface 301 of the electrode assembly 2, which is opposite to the first adhesive component 3, and is bonded to the inner wall surface of the membrane housing 1. The area of ​​the second adhesive component 4 is smaller than the area of ​​the first adhesive component 3.

[0048] The third adhesive member 5 is disposed on the side of the electrode assembly 2 facing the second outer wall surface 103, and the electrode assembly 2 is bonded to the inner wall surface of the membrane housing 1 through the third adhesive member 5. It should be noted that the bonding between the electrode assembly 2 and the inner wall surface of the membrane housing 1 through the third adhesive member 5 can be a direct bonding or an indirect connection. An indirect connection means that other structures besides the third adhesive member 5 can be provided between the electrode assembly 2 and the inner wall surface of the membrane housing 1.

[0049] For example, the first adhesive 3 is a large-area single-sided adhesive bonded to the electrode assembly 2, and the second adhesive 4 and the third adhesive 5 are double-sided hot melt adhesives. In other embodiments, the first adhesive 3, the second adhesive 4, and the third adhesive 5 may also be other types of adhesive structures commonly used in the art, and this part will not be described in detail in this embodiment.

[0050] refer to Figure 2 and combined Figure 1 The adhesion force between the first adhesive component 3 and the second adhesive component 4 is F1, the adhesion force between the third adhesive component 5 and F2, the adhesion force between the first adhesive component 3 and the electrode assembly 2 is F3, and the adhesion force between the second adhesive component 4 and the membrane shell 1 is F4. F1, F2, F3, and F4 satisfy the following conditions: F2 > F1, F3 > F1, F2 > F4, F3 > F4. The adhesion force of the third adhesive component 5 refers to the adhesion force generated when the adhesive layer of the third adhesive component 5 is in contact with other structures.

[0051] By designing the aforementioned adhesive structure, different adhesive components generate different adhesive forces, enabling controllable adjustment of the order in which different components detach when the battery cell is subjected to an impact. As the relative force between the electrode assembly 2 and the membrane shell 1 increases, the second adhesive component 4 detaches from the first adhesive component 3, and the second adhesive component 4 detaches from the membrane shell 1 first. The adhesive forces between the first adhesive component 3 and the electrode assembly 2, and the third adhesive component 5, are even greater, making it less likely for their corresponding components to detach.

[0052] Specifically, the second adhesive component 4 has the first adhesive component 3 and the membrane shell 1 on its two sides, with corresponding adhesion forces of F1 and F4, respectively. The first adhesive component 3 is directly bonded to the electrode assembly 2, with an adhesion force of F2. In some cases, the third adhesive component 5 can also be directly bonded to the electrode assembly 2, with an adhesion force of F3.

[0053] When the battery cell is subjected to impacts or drops, the electrode assembly 2 and the membrane housing 1 tend to separate under the influence of relative forces. As this relative force increases, it first reaches a limit of F1 or F4, and then continues to increase before reaching greater limits of F2 and F3. Therefore, the first to separate is the second adhesive component 4 and the first adhesive component 3, or the second adhesive component 4 and the membrane housing 1, rather than the first adhesive component 3 and the third adhesive component 5 which are directly bonded to the electrode assembly 2.

[0054] Thus, in testing and actual use scenarios, if impacts or drops occur, the resulting force will increase to a certain limit, causing the second adhesive component 4 to detach from the adjacent component first, while ensuring stable adhesion between the first adhesive component 3 and the electrode assembly 2. This reduces the risk of tearing damage to the surface of the electrode assembly 2 due to the separation of the first adhesive component 3 from the electrode assembly 2.

[0055] In some cases, the third adhesive 5 is directly bonded to the electrode assembly 2. Similarly, the second adhesive 4 is first separated from the adjacent component, while the third adhesive 5 remains bonded to the electrode assembly 2 to avoid the electrode assembly being torn.

[0056] It should be further explained that the first outer wall surface 102 is bonded and fixed to the connecting substrate. In the event of an impact or drop, the main stress point of the relative force generated between the electrode assembly 2 and the membrane shell 1 is the bonding structure between the electrode assembly 2 and the first outer wall surface 102. For example, with the first outer wall surface 102 facing upwards, the battery cell is in a suspended state. An impact or drop causes the battery cell to shake. Taking the connection point between the battery cell and the connecting substrate as the stress point, the lower half of the battery cell has a longer lever arm and generates a greater force. This causes the electrode assembly 2 to shake inside the membrane shell 1. The electrode assembly 2 and the lower half of the membrane shell 1 are largely in a state of synchronous movement; that is, the connection point between the third adhesive 5 and the electrode assembly 2 and the membrane shell 1 experiences less force, while the connection points of the first adhesive 3 and the second adhesive 4 experience greater force. As the force increases, the second adhesive 4 detaches from the adjacent adhesive component, while the first adhesive 3 remains bonded to the electrode assembly 2 and the third adhesive 5 remains bonded to the adjacent adhesive component.

[0057] In some other embodiments, the second outer wall surface 103 is also bonded and fixed to the connecting substrate, and the lower half of the battery cell is also in a state of relative fixation to the connecting substrate. In this case, the bonding structures of the electrode assembly 2 facing both the first outer wall surface 102 and the second outer wall surface 103 are subjected to a large force. However, by setting multiple adhesives with different adhesion forces between them and adjacent structures, as the above-mentioned forces increase, the second adhesive 4 will still be the first to detach from the adjacent component.

[0058] In summary, the multiple adhesive components provided in this embodiment can provide better protection for the electrode assembly 2, reduce the problem of tearing and damage to the surface of the electrode assembly 2 caused by bumps, drops, etc., improve the stability of the battery cell operation, and reduce the risk of equipment failure.

[0059] Furthermore, through the above-mentioned design of this scheme, even if the electrode assembly 2 separates due to large interaction forces in the event of adverse factors such as bumps or drops, the integrity of the electrode assembly 2 structure can be guaranteed, reducing the adverse effects on subsequent use.

[0060] refer to Figure 1 and Figure 3 The membrane shell 1 includes a first packaging part 11 and a second packaging part 12 that are connected to each other, and the first packaging part 11 and the second packaging part 12 together enclose the mounting cavity 101.

[0061] The first packaging section 11 includes a first bottom wall 111, a first annular wall 112, and a first sealing wall 113. The first bottom wall 111 is generally a planar plate structure. In other embodiments, the first bottom wall 111 may also be provided with a certain curvature as needed. Exemplarily, the first bottom wall 111 is rectangular, and the corners may be rounded as needed. The first annular wall 112 is disposed around the edge of the first bottom wall 111 and is fixedly connected to the first bottom wall 111. Exemplarily, the first annular wall 112 is perpendicular to the first bottom wall 111. In some other embodiments, the first annular wall 112 may be adjusted within a certain angle range on both sides of the vertical state relative to the first bottom wall 111. The first sealing wall 113 is disposed around at least a portion of the first annular wall 112. The first sealing wall 113 is located on the side edge of the first annular wall 112 away from the first bottom wall 111 and is used to connect with the second packaging section 12. In the embodiments of this disclosure, the first sealing wall 113 is disposed around the entire circumference of the first annular wall 112. In some other embodiments, the first sealing wall 113 may be provided to surround the first annular wall 112.

[0062] The first bottom wall 111, the first annular wall 112, and the first sealing wall 113 together form the first concave cavity 1011, wherein the first outer wall surface 102 is the side of the first bottom wall 111 away from the first concave cavity 1011.

[0063] The second packaging section 12 includes a second bottom wall 121, a second annular wall 122, and a second sealing wall 123. The second bottom wall 121 is generally a planar plate structure. In other embodiments, the second bottom wall 121 may also be provided with a certain curvature as needed. Exemplarily, the second bottom wall 121 is rectangular, and the corners may be rounded as needed. The second annular wall 122 is disposed around the edge of the second bottom wall 121 and is fixedly connected to the second bottom wall 121. Exemplarily, the second annular wall 122 is perpendicular to the second bottom wall 121. In some other embodiments, the second annular wall 122 may be adjusted within a certain angle range on both sides of the vertical state relative to the second bottom wall 121. The second sealing wall 123 is disposed around at least a portion of the second annular wall 122. The second sealing wall 123 is located on the side edge of the second annular wall 122 away from the second bottom wall 121 and is used to connect with the first packaging section 11. In the embodiments of this disclosure, the second sealing wall 123 is disposed around the entire circumference of the second annular wall 122. In some other embodiments, a second sealing wall 123 may be provided to surround the second annular wall 122.

[0064] The second bottom wall 121, the second annular wall 122, and the second sealing wall 123 together enclose the second cavity 1012, wherein the second outer wall surface 103 is the side of the second bottom wall 121 away from the second cavity 1012.

[0065] As shown above, the first sealing wall 113 and the second sealing wall 123 are hot-pressed and melted to form a sealing edge, so that the first cavity 1011 and the second cavity 1012 together enclose the mounting cavity 101.

[0066] In the thickness direction, the depth of the first cavity 1011 is less than the depth of the second cavity 1012.

[0067] Alternatively, it can be stated that the width of the first annular wall 112 is smaller than the width of the second annular wall 122. This width comparison is performed under the following conditions: one is that the first annular wall 112 is perpendicular to the first bottom wall 111, and the second annular wall 122 is perpendicular to the second bottom wall 121. The second condition is that the inclination angle of the first annular wall 112 relative to the first bottom wall 111 is the same as the inclination angle of the second annular wall 122 relative to the second bottom wall 121.

[0068] When the battery cell is in use, the first outer wall surface 102 is bonded and fixed to the connecting substrate. The sides of the battery cell are adapted to the installation position. According to the structure of the battery cell, the outermost perimeter of the battery cell is the outer edge of the first sealing wall 113 and the second sealing wall 123. Taking the battery cell installed in a mobile phone as an example, the outermost perimeter of the battery cell abuts against the side wall of the installation space inside the mobile phone. Therefore, the connection between the first sealing wall 113 and the second sealing wall 123 is a rigid structure. For ease of explanation, in this embodiment, the connection between the first sealing wall 113 and the second sealing wall 123 is simply referred to as the dividing point.

[0069] In the thickness direction, the distance from the dividing point to the first outer wall surface 102 is smaller than the distance from the dividing point to the second outer wall surface 103. In the above-mentioned collision and drop scenarios, the battery cell relative to the connecting substrate and the electrode assembly 2 relative to the membrane shell 1 tend to have relative displacement. Since the distance from the dividing point to the first outer wall surface 102 is smaller, when the relative forces generated by the electrode assembly 2 relative to the membrane shell 1 due to the collision and drop are of the same magnitude, the electrode assembly 2 overcomes the above-mentioned relative forces through the reverse force generated by contact with the dividing point.

[0070] With the same magnitude of the generated reverse force, the distance from the dividing point to the first outer wall surface 102 is smaller, resulting in a smaller torque and reducing the risk of the electrode assembly 2 being torn.

[0071] refer to Figure 4 The first adhesive 3 includes a first substrate layer 31 and a first adhesive layer 32, with the first adhesive layer 32 connected to the side of the first substrate layer 31 facing the electrode assembly 2.

[0072] The second adhesive 4 includes a second substrate layer 41, a second adhesive layer 42, and a third adhesive layer 43, wherein the second adhesive layer 42 and the third adhesive layer 43 are respectively connected to the two opposite sides of the second substrate layer 41 in the thickness direction.

[0073] refer to Figure 5 In another embodiment, the second adhesive 4 is an adhesive layer, exemplarily a second adhesive layer 42; the second adhesive layer 42 is directly bonded to the side of the first substrate layer 31 facing away from the electrode assembly 2.

[0074] In actual design, the configuration of the second adhesive component 4 can be adjusted according to actual needs. That is, the second adhesive component 4 can be configured as a double-sided adhesive structure with a second substrate layer 41, or it can be configured as an adhesive structure without a substrate layer. The adhesive structure without a substrate layer can be configured as a fluid adhesive structure, or refer to a common double-sided adhesive structure.

[0075] The elastic modulus E of the first substrate layer 31 satisfies: 0.2 GPa ≤ E ≤ 10 GPa. For example, the elastic modulus of the first substrate layer 31 may be selected from, but is not limited to, the following values: 0.2 GPa, 0.3 GPa, 0.4 GPa, 0.5 GPa, 0.6 GPa, 0.7 GPa, 0.8 GPa, 0.9 GPa, 1.0 GPa, 1.2 GPa, 1.5 GPa, 1.8 GPa, 2.0 GPa, 2.2 GPa, 2.5 GPa, 2.8 GPa, 3.0 GPa, 3.5 GPa, 4.0 GPa, 4.5 GPa, 5.0 GPa, 5.5 GPa, 6.0 GPa, 7.5 GPa, 8.0 GPa, 8.5 GPa, 9.0 GPa, 9.5 GPa, and 10.0 GPa.

[0076] If the elastic modulus of the first substrate layer 31 is lower, it will be softer, resulting in poor relative positional stability of the electrode assembly 2 relative to the membrane shell 1, causing unnecessary shaking. As unnecessary shaking increases, the adhesion between the electrode assembly 2 and the membrane shell 1 will decrease. Therefore, the elastic modulus of the first substrate layer 31 is set to be no less than 0.2 GPa to ensure the stability between the electrode assembly 2 and the membrane shell 1, reduce unnecessary shaking, and improve the quality of the battery cell.

[0077] Conversely, the higher the elastic modulus of the first substrate layer 31, the greater its stiffness, i.e., the "harder" it is. This causes the connection between the electrode assembly 2 and the membrane shell 1 to be closer to a rigid connection, failing to provide any shock absorption or cushioning effect. The inability to buffer the force between the membrane shell 1 and the electrode assembly 2 results in the force being directly transmitted from the membrane shell 1 to the electrode assembly 2. This lack of necessary buffering increases the risk of the electrode assembly 2 or the first adhesive 3 being torn.

[0078] Therefore, setting the elastic modulus of the first substrate layer 31 to be no higher than 10 GPa can effectively buffer the force transmitted between the membrane shell 1 and the electrode assembly 2. This reduces the risk of the electrode assembly 2 or the first adhesive 3 being torn, providing better protection for the electrode assembly 2.

[0079] Furthermore, the elastic modulus E of the first substrate layer 31 satisfies: 0.5Gpa≤E≤3Gpa.

[0080] Furthermore, the elastic modulus E of the first substrate layer 31 satisfies: 0.7 Gpa ≤ E ≤ 1.2 Gpa.

[0081] This improves the stability between electrode assembly 2 and membrane housing 1, reduces unnecessary shaking, and enhances the quality of the battery cell. Simultaneously, it buffers the forces between membrane housing 1 and electrode assembly 2, reducing the risk of electrode assembly 2 tearing.

[0082] Furthermore, the elongation δ of the first substrate layer 31 satisfies: 120% ≤ δ ≤ 500%. Exemplarily, the elongation of the first substrate layer 31 can be: 120%, 150%, 180%, 200%, 230%, 250%, 280%, 300%, 320%, 350%, 380%, 400%, 420%, 450%, 470%, 500%. In some other embodiments, the elongation of the first substrate layer can be set to satisfy: 200% ≤ δ ≤ 400%, 300% ≤ δ ≤ 500%, 200% ≤ δ ≤ 500%, 200% ≤ δ ≤ 300%, 400% ≤ δ ≤ 500%.

[0083] The first substrate layer 31 has good elongation, and under the action of external force, it can stretch and deform without being easily torn or damaged. At the same time, it avoids the problem of insufficient stable support due to excessive elongation.

[0084] Yield strength σ of the first substrate layer 31 s Satisfy: 30 MPa ≤ σ s ≤250 MPa. For example, the yield strength of the first substrate layer can be: 30 MPa, 40 MPa, 50 MPa, 60 MPa, 70 MPa, 80 MPa, 80 MPa, 100 MPa, 110 MPa, 120 MPa, 130 MPa, 140 MPa, 150 MPa, 160 MPa, 170 MPa, 180 MPa, 190 MPa, 200 MPa, 210 MPa, 220 MPa, 230 MPa, 240 MPa, 250 MPa.

[0085] Preferably, the yield strength σ of the first substrate layer 31 s Satisfy: 50 MPa ≤ σ s ≤200Mpa.

[0086] More preferably, the yield strength σ of the first substrate layer 31 s Satisfy: 100 MPa ≤ σ s ≤150Mpa.

[0087] Setting the yield strength to greater than 30 MPa provides good flexibility, making it less prone to deformation under pressure and reducing the risk of deformation and failure during assembly. It also enhances the ability to resist the deformation and expansion forces generated during the charging and discharging of the battery cell, extending its lifespan. Simultaneously, it avoids excessively high yield strength, as this can easily lead to cracking under external impact. Furthermore, it ensures that the first substrate layer 31 possesses sufficient toughness over a wide temperature range, reducing the risk of damage.

[0088] Tensile strength σ of the first substrate layer 31 b Satisfy: 50 MPa ≤ σ b ≤550 MPa. For example, the tensile strength of the first substrate layer 31 can be 50 MPa, 70 MPa, 100 MPa, 120 MPa, 150 MPa, 180 MPa, 200 MPa, 230 MPa, 250 MPa, 280 MPa, 300 MPa, 330 MPa, 350 MPa, 380 MPa, 400 MPa, 430 MPa, 450 MPa, 480 MPa, 500 MPa, 530 MPa, or 550 MPa.

[0089] Preferably, the tensile strength σ of the first substrate layer 31 b Satisfy: 100 MPa ≤ σ b ≤500Mpa.

[0090] More preferably, the tensile strength σ of the first substrate layer 31 b Satisfy: 200 MPa ≤ σ b ≤400Mpa.

[0091] The first substrate layer 31 has a tensile strength greater than 50 MPa, which can effectively resist the stress generated by the volume expansion of the battery cell during charge and discharge cycles. Under stress, it maintains its structural stability and is not prone to breakage or damage, thus maintaining good adhesive strength. In addition, it avoids excessive tensile strength, which could restrict the expansion of the battery cell too much, reducing the stress on the battery cell structure and making it less likely to cause battery cell damage. It can adapt to large expansion deformation of the battery cell, buffer the stress generated by expansion, and maintain adhesive stability.

[0092] refer to Figure 6 The illustration exemplarily shows a schematic diagram of a first adhesive member 3 and a second adhesive member 4 bonded to the surface of an electrode assembly 2. Two tabs 21 extend from one end face of the electrode assembly 2, designated as a positive tab and a negative tab, respectively. The first adhesive member 3 and the second adhesive member 4 are disposed on the first surface 201 of the electrode assembly 2. Specifically, the configuration of the first adhesive 3 and the second adhesive 4 includes, but is not limited to, the following.

[0093] Firstly: Reference Figure 6 Each component has one first adhesive member 3 and one second adhesive member 4. The second adhesive member 4 is adhered to the first surface 201 of the first adhesive member 3 facing away from the electrode assembly. The corners of the first adhesive member 3 and the second adhesive member 4 can be rounded as needed. In other possible embodiments, the third adhesive member 5 can also be rounded accordingly. The details of the rounding and chamfering will not be elaborated further in this disclosure.

[0094] Secondly: Reference Figure 7 Multiple first adhesive members 3 are provided, and one second adhesive member 4 is provided. All first adhesive members 3 are adhered to the first surface 201 of the electrode assembly 2. The second adhesive member 4 is adhered to the surface of the electrode assembly 2 opposite to the multiple first adhesive members 3. The second adhesive member 4 can be configured to be bonded to one or more of the first adhesive members 3, or it can be configured to maintain bonded connection between the second adhesive member 4 and all of the multiple first adhesive members 3.

[0095] Thirdly: Reference Figure 8 There is one first adhesive component 3 and multiple second adhesive components 4. The multiple second adhesive components 4 are adhered to the surface of the first adhesive component 3 that is away from the electrode assembly 2.

[0096] Fourthly: Reference Figure 9 Multiple first adhesives 3 and multiple second adhesives 4 are provided, and the multiple first adhesives 3 and multiple second adhesives 4 are arranged in a one-to-one correspondence. Each second adhesive 4 is bonded to the surface of the corresponding first adhesive 3 that is away from the electrode assembly 2.

[0097] Fifth: Reference Figure 10 Multiple first adhesive members 3 and multiple second adhesive members 4 are provided. In one part, each first adhesive member 3 is bonded with one second adhesive member 4, while in another part, each first adhesive member 3 is bonded with multiple second adhesive members 4. Alternatively, each first adhesive member 3 may be bonded with multiple second adhesive members 4.

[0098] Sixth: Reference Figure 11 Multiple first adhesive members 3 and multiple second adhesive members 4 are provided. In one part, each second adhesive member 4 is bonded to one first adhesive member 3, and in another part, each second adhesive member 4 is bonded to multiple first adhesive members 3 simultaneously. Alternatively, each second adhesive member 4 is bonded to multiple first adhesive members 3.

[0099] In some other embodiments, for the first adhesive member 3, the second adhesive member 4, and the third adhesive member 5, each adhesive member may also have multiple spaced-apart connectors. For example, a plurality of first adhesive layers 32 are provided on the first substrate layer 31, and the plurality of first adhesive layers 32 are spaced apart on the first substrate layer 31.

[0100] With the total bonding area between the first adhesive component 3 and the electrode assembly 2 remaining unchanged (i.e., the total area of ​​the first adhesive layer 32 remaining unchanged), the coverage area of ​​the adhesive surface can be increased, which is beneficial to improving the stability of the bond. If the coverage area of ​​the first adhesive layer 32 is not limited, the failure of some adhesive potentials is less likely to cause the failure of other adhesive points as well, which is beneficial to improving the overall stability of the structure.

[0101] refer to Figure 6 and Figure 7 The projection of the second adhesive 4 onto the set plane is at least partially located inside the projection of the first adhesive 3 onto the set plane, and the set plane is perpendicular to the thickness direction. That is, the second adhesive 4 is at least partially bonded to the first adhesive 3, but not entirely bonded to the electrode assembly 2.

[0102] refer to Figure 6 The following example illustrates the application of one first adhesive member 3 and one second adhesive member 4. The second adhesive member 4 is bonded to the surface of the first adhesive member 3 facing away from the electrode assembly 2, and the outer periphery of the second adhesive member 4 does not extend beyond the outer periphery of the first adhesive member 3. The area of ​​the vertical projection of the first adhesive member 3 onto the designated plane is S1, and the area of ​​the vertical projection of the second adhesive member 4 onto the designated plane is S2. S1 and S2 satisfy: 20% ≤ S2 / S1 ≤ 75%. For example, the value of S2 / S1 can be: 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%.

[0103] Furthermore, S1 and S2 satisfy the condition: 35%≤S2 / S1≤50%.

[0104] In some other embodiments, reference is made to Figure 7 and Figure 9 When there are multiple first adhesive members 3 and second adhesive members 4, the area of ​​the above projection refers to the sum of the areas of multiple projections. Correspondingly, S1 is the area of ​​the vertical projection of the first adhesive member 3 on the set plane, and S2 is the area of ​​the vertical projection of the part of the second adhesive member 4 that is bonded to the first adhesive member 3 on the set plane.

[0105] Furthermore, to ensure the strong adhesion of the adhesive to the electrode assembly 2 and the membrane housing 1, and to avoid the problem of insufficient bonding area and weak fixation due to the adhesive being too small, the area of ​​the first surface 201 of the electrode assembly 2 projected vertically onto the designated plane is set to S3, where S2 and S3 satisfy: S2 / S3 ≥ 65%. For example, the value of S2 / S3 can be: 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100%.

[0106] Preferably, S2 and S3 satisfy: S2 / S3≥85%.

[0107] By limiting the relative size ratio between the first adhesive component 3 and the electrode assembly 2, the problem of weak bonding between the electrode assembly 2 and the membrane shell 1 is avoided due to the area of ​​the first adhesive component 3 and the second adhesive component 4 being too small. This improves the stability of the electrode assembly 2 fixedly connected inside the membrane shell 1 and enhances the quality of the battery.

[0108] refer to Figure 12 In some embodiments, a portion of the first adhesive member 3 may be bonded to the first surface 201 of the electrode assembly 2, and another portion may be bonded to the second surface 202 of the electrode assembly 2. The third adhesive member 5 may be at least partially bonded to the first adhesive member 3 located on the second surface 202.

[0109] For example, the two sides of the first adhesive member 3 extend to the outer side of the first surface 201, bend and extend towards the second surface 202, and finally partially extend onto the second surface 202, where they are bonded and fixed. The two ends of the first adhesive member 5 are joined on the second surface 202, so that the first adhesive member 3 as a whole forms a ring structure.

[0110] refer to Figure 13 In another embodiment, the two ends of the first adhesive member 3 may be spaced apart on the second surface 202. That is, the first adhesive member 3 does not form a complete annular structure, but has a partial gap.

[0111] Furthermore, in response to the design where the first adhesive component 3 forms a ring structure with a partial notch, the third adhesive component 5 is differentiated. (See reference) Figure 13 The third adhesive component 5 is a single unit, and it is bonded and fixed to both ends of the first adhesive component 3. (Reference) Figure 14 Alternatively, the number of third adhesive parts 5 can be set to two, which are respectively bonded and fixed to both ends of the first adhesive part 3.

[0112] For ease of explanation, the following description will take the formation of a ring structure by the first adhesive component 3 as an example.

[0113] With the above settings, the bonding area between the first adhesive component 3 and the electrode assembly 2 is larger, which improves the bonding and fixing firmness between the first adhesive component 3 and the electrode assembly 2, and makes it less likely to loosen or detach.

[0114] Furthermore, when the electrode assembly 2 and the membrane housing 1 vibrate under external force, the first adhesive 3 and the electrode assembly 2, in addition to preventing separation based on their adhesive force, also form a ring structure, creating a contact force between the first adhesive 3 and the electrode assembly. Compared to simply placing the first adhesive 3 on the first surface 201, this further enhances the firmness of the connection between the first adhesive 3 and the electrode assembly 2.

[0115] In other embodiments, the first adhesive member 3 may extend from the second surface 202 toward the first surface 201, thereby forming a ring-like structure. That is, based on Figure 12 , 13 14, wherein the first adhesive component 3 is flipped up and down, where up and down refers to the up and down direction in the attached drawing.

[0116] Adhesion force test method: Testing environment: Preferably conducted in a standard laboratory environment (e.g., 23±2°C, 50±5% RH).

[0117] Commonly used testing equipment: Universal testing machine: used for shear strength and peel strength testing. Requires specialized fixtures (such as tensile shear fixtures and peel fixtures).

[0118] Sample Preparation: Based on the requirements of the testing equipment, prepare test samples of appropriate size. Set up the following groups for bonding: first adhesive component to battery cell, second adhesive component to first adhesive component, second adhesive component to membrane housing, third adhesive component to battery cell, and third adhesive component to membrane housing. Prepare at least 5 valid samples for each group of tests. Take the average result to improve statistical reliability. Adhesion force test between the first adhesive component and the battery cell: Using a testing machine, the first adhesive component and the battery cell material are peeled off at a specific angle (45°, 90°, or 180°). During the peeling process, the testing machine maintains a constant speed, such as 300 mm / min. The force value curve is recorded. After testing multiple samples sequentially, the average peeling force is calculated.

[0119] Adhesion test between the second adhesive and the first adhesive assembly: Using a testing machine, the second adhesive and the substrate layer of the first adhesive are peeled at a specific angle (45°, 90°, or 180°). During the peeling process, the testing machine maintains a constant speed, such as 300 mm / min. The force curve is recorded. After testing multiple samples sequentially, the average peel force is calculated.

[0120] The tests for the adhesion strength between the second adhesive component and the membrane housing, the adhesion strength between the third adhesive component and the battery cell, and the adhesion strength between the third adhesive component and the membrane housing are similar to those for the adhesion strength between the first adhesive component and the battery cell. The standard also adopts GB / T 2792-2014.

[0121] In addition, this disclosure also provides an electrical device, which includes a device body and a battery cell provided in the above embodiments of this disclosure. The device body is provided with a mounting surface for fixing the battery cell, and the first outer wall surface 102 of the battery cell is bonded to the mounting surface to achieve a fixed connection between the battery cell and the device body.

[0122] By bonding the first outer wall surface 102 (i.e., the adhesive surface) to the mounting surface, the torque generated between the electrode assembly 2 and the first bottom wall 111 of the membrane housing 1 can be reduced, thus lowering the risk of tearing the electrode assembly 2 and providing better protection for it. This reduces the probability of damage and improves the stability of the battery cell and electrical equipment.

[0123] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Any modifications or equivalent substitutions made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A battery cell, characterized in that, include: The membrane shell has an internal mounting cavity. The membrane shell has a first outer wall surface and a second outer wall surface that are arranged opposite to each other along the thickness direction. The first outer wall surface of the membrane shell is an adhesive surface. Electrode assembly is disposed within the mounting cavity; The first adhesive is bonded to the first surface of the electrode assembly facing the first outer wall surface; The second adhesive is bonded to the third surface of the first adhesive that is away from the electrode assembly and is bonded to the inner wall surface of the membrane shell. The area of ​​the second adhesive is smaller than the area of ​​the first adhesive. The third adhesive component is located on the side of the electrode assembly facing the second outer wall surface, and the electrode assembly is bonded to the inner wall surface of the membrane shell through the third adhesive component. The adhesion force between the first adhesive and the second adhesive is F1, the adhesion force of the third adhesive is F2, the adhesion between the first adhesive and the electrode assembly is F3, and the adhesion force between the second adhesive and the membrane shell is F4. F1, F2, F3 and F4 satisfy: F2>F1, F3>F1, F2>F4, F3>F4; Wherein, the thickness direction is the thickness direction of the battery cell.

2. The battery cell according to claim 1, characterized in that, The membrane shell includes a first packaging part and a second packaging part that are connected to each other, and the first packaging part and the second packaging part together enclose the mounting cavity; The first packaging section includes a first bottom wall, a first annular wall, and a first sealing wall. The first annular wall is disposed around the first bottom wall, and the first sealing wall is disposed around at least a portion of the first annular wall. The first bottom wall, the first annular wall, and the first sealing wall together form a first cavity. The second packaging section includes a second bottom wall, a second annular wall, and a second sealing wall. The second annular wall is disposed around the second bottom wall, and the second sealing wall is disposed around at least a portion of the second annular wall. The second bottom wall, the second annular wall, and the second sealing wall together form a second cavity. The first outer wall surface is located on the side of the first bottom wall away from the first cavity, and the second outer wall surface is located on the side of the second bottom wall away from the second cavity. The first sealing wall and the second sealing wall are sealed together, and the first cavity and the second cavity together form the mounting cavity. Along the thickness direction, the depth of the first cavity is less than the depth of the second cavity.

3. The battery cell according to claim 1, characterized in that, The projection of the second adhesive member on the set plane is at least partially located inside the projection of the first adhesive member on the set plane; The area of ​​the bonding region between the first adhesive and the second adhesive is S1; The projected area of ​​the second adhesive member on the designated plane is S2; The area of ​​the first surface is S3; S1, S2 and S3 satisfy: 20%≤S1 / S2≤75%, and / or, S2 / S3≥65%; The set plane is perpendicular to the thickness direction.

4. The battery cell according to claim 3, characterized in that, The conditions S1, S2 and S3 satisfy: 35%≤S1 / S2≤50%, and / or, S2 / S3≥85%.

5. The battery cell according to claim 1, characterized in that, The first adhesive includes a first substrate layer and a first adhesive layer, wherein the first adhesive layer is connected to the side of the first substrate layer facing the electrode assembly; The second adhesive component includes a second substrate layer, a second adhesive layer, and a third adhesive layer, wherein the second adhesive layer and the third adhesive layer are respectively connected to two opposite sides of the second substrate layer in the thickness direction; or, The first adhesive includes a first substrate layer and a first adhesive layer, wherein the first adhesive layer is connected to the side of the first substrate layer facing the electrode assembly; The second adhesive is an adhesive layer, which is connected to the side of the first substrate facing away from the electrode assembly.

6. The battery cell according to claim 5, characterized in that, The elastic modulus E of the first substrate layer satisfies: 0.2 GPa ≤ E ≤ 10 GPa; and / or, The elongation δ of the first substrate layer satisfies: 120% ≤ δ ≤ 500%; and / or, The yield strength σ of the first substrate layer s Satisfy: 30 MPa ≤ σ s ≤250Mpa; and / or, The tensile strength σ of the first substrate layer b Satisfy: 50 MPa ≤ σ b ≤550Mpa; Preferably, the elastic modulus E of the first substrate layer satisfies: 0.5 GPa ≤ E ≤ 3 GPa; Preferably, the elastic modulus E of the first substrate layer satisfies: 0.7 Gpa ≤ E ≤ 1.2 Gpa.

7. The battery cell according to claim 1, characterized in that, The second adhesive is provided in multiple parts, and the multiple second adhesives are bonded to the surface of the first adhesive that is away from the electrode assembly; or, The first adhesive is provided in multiple forms, and the second adhesive is bonded to the surface of the multiple first adhesives that is away from the electrode assembly. or, Multiple first adhesive members and multiple second adhesive members are provided, and the multiple first adhesive members and multiple second adhesive members are arranged in a one-to-one correspondence.

8. The battery cell according to claim 1, characterized in that, A portion of the first adhesive is bonded to a first surface of the electrode assembly, and another portion is bonded to a second surface of the electrode assembly, wherein the second surface is a surface of the electrode assembly that is opposite to the first surface; The third adhesive is at least partially bonded to the first adhesive located on the second surface of the electrode assembly.

9. The battery cell according to claim 1, characterized in that, The membrane shell is an aluminum-plastic film; and / or, The edges and corners of the second adhesive component are chamfered; and / or, The edges and corners of the third adhesive component are chamfered; and / or, The second adhesive component has multiple spaced adhesive areas.

10. An electrical appliance, characterized in that, Includes the main body of the device and the battery cell as described in any one of claims 1-9; The main body of the device is provided with a mounting surface for fixing the battery cell; The first outer wall surface of the battery cell is bonded to the mounting surface.

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