Electrode assembly and battery cell

Abstract

The application relates to the technical field of batteries, in particular to an electrode assembly and a battery monomer. A diaphragm and an anode sheet are attached along the thickness direction of the electrode assembly; the diaphragm has an isolation part and a protection part connected with each other; the isolation part and the protection part are arranged along a first direction; the first direction is perpendicular to the thickness direction of the electrode assembly; at least part of the structure of the protection part protrudes from the anode sheet along the first direction; and the thickness of the protection part is greater than that of the isolation part. In the embodiment of the application, the protection part protrudes from the anode sheet along the first direction, and the thickness of the protection part is greater than that of the isolation part. The electrode assembly may be folded under external impact, thereby causing the anode sheet and the cathode sheet to be short-circuited. The protection part can reduce the direct contact between the anode sheet and the cathode sheet to a certain extent; the thickness of the protection part is greater than that of the isolation part; the bending stiffness of the protection part is relatively large; the protection part is less likely to be folded; and the short-circuiting between the cathode sheet and the anode sheet can be reduced.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to an electrode assembly and a battery cell. Background Technology

[0002] With the development of new energy sources, more and more fields are adopting new energy as a power source. Due to its advantages such as high energy density, rechargeability, safety, and environmental friendliness, battery devices are widely used in new energy vehicles, consumer electronics, energy storage systems, and other fields. However, when battery devices are used in electrical equipment, the vibrations or impacts generated by the equipment can affect the electrode components within the battery device to some extent.

[0003] In related technologies, electrode assemblies may experience short circuits. Utility Model Content

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes an electrode assembly and a battery cell that can reduce the occurrence of short circuits in the electrode assembly.

[0005] The electrode assembly according to a first aspect embodiment of this application includes: Anode plate; A diaphragm is attached to the anode sheet along the thickness direction of the electrode assembly. The diaphragm has an isolation portion and a protective portion connected to each other. The isolation portion and the protective portion are arranged along a first direction, which is perpendicular to the thickness direction of the electrode assembly. At least a portion of the structure of the protective portion protrudes from the anode sheet along the first direction. The thickness of the protective portion is greater than the thickness of the isolation portion.

[0006] The electrode assembly according to the embodiments of this application has at least the following beneficial effects: In the embodiments of this application, the diaphragm has an isolation portion and a protective portion arranged along a first direction. The protective portion protrudes from the anode sheet along the first direction, and the thickness of the protective portion is greater than the thickness of the isolation portion. During use, the electrode assembly may bend under external impact, leading to a short circuit between the anode sheet and the cathode sheet. The protective portion protruding from the anode sheet along the first direction can reduce direct contact between the anode sheet and the cathode sheet to a certain extent. Furthermore, the thickness of the protective portion is greater than the thickness of the isolation portion, resulting in greater bending stiffness and making it less prone to bending, thereby reducing the possibility of a short circuit between the cathode sheet and the anode sheet. Moreover, the greater thickness of the protective portion reduces the possibility of burrs from the anode sheet piercing the diaphragm due to the cutting process.

[0007] According to some embodiments of this application, a portion of the structure of the protective part is attached to the anode sheet along the thickness direction of the electrode assembly.

[0008] According to some embodiments of this application, the electrode assembly further includes a cathode sheet, and along the thickness direction of the electrode assembly, the diaphragm is located between the anode sheet and the cathode sheet, and along the first direction, the protective portion is arranged at intervals from the cathode sheet.

[0009] According to some embodiments of this application, the diaphragm includes a base film and a coating layer that are bonded together, the base film and the coating layer are arranged along the thickness direction of the electrode assembly, and the thickness of the coating layer at the position corresponding to the protective part is greater than the thickness of the coating layer at the position corresponding to the isolation part.

[0010] According to some embodiments of this application, the protective portion is connected to both opposite ends of the isolation portion along the first direction.

[0011] According to some embodiments of this application, the electrode assembly further includes a cathode sheet, and along the thickness direction of the electrode assembly, the diaphragm is located between the anode sheet and the cathode sheet. Along the first direction, the size difference between the anode sheet and the diaphragm is a, the size difference between the anode sheet and the cathode sheet is b, and the size of the protective part is c, wherein a / 2 < c < (a+b) / 2.

[0012] According to some embodiments of this application, the size of the protective portion ranges from 8 μm to 20 μm along the thickness direction of the electrode assembly.

[0013] According to some embodiments of this application, the protective portion extends from one end of the diaphragm to the opposite end of the diaphragm along a second direction, the second direction being perpendicular to both the first direction and the thickness direction of the electrode assembly.

[0014] According to some embodiments of this application, the protective portion includes a first sub-portion and a second sub-portion, which are located on opposite sides of the diaphragm along the thickness direction of the electrode assembly.

[0015] This application also provides a single battery cell, comprising: case; The electrode assembly of any of the above is disposed inside the housing.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a simplified structural diagram of an electrode assembly in one embodiment of this application; Figure 2 This is a simplified structural diagram of the diaphragm in one embodiment of this application.

[0018] Figure label: 100, Anode plate; 200, Diaphragm; 200a, Isolation section; 200b, Protection section; 200c, First sub-section; 200d, Second sub-section; 210, Base film; 220, Coating layer; 300, Cathode plate. Detailed Implementation

[0019] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0020] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0021] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0022] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0023] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0024] Currently, judging from market trends, the application of battery devices is becoming increasingly widespread. Battery devices are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely applied in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields. With the continuous expansion of the application areas of battery devices, the market demand is also constantly increasing.

[0025] In related technologies, in order for the diaphragm to effectively isolate the anode and cathode plates, the length of the diaphragm is generally set to be longer than the length of the anode plate. When the electrical equipment vibrates, is subjected to external impact, or is washed by electrolyte, the diaphragm may fold, causing the anode and cathode plates on both sides of the diaphragm to short-circuit, leading to a short circuit and thermal runaway inside the electrode assembly.

[0026] The diaphragm 200 of this application has an isolation portion 200a and a protective portion 200b connected to each other. At least a portion of the structure of the protective portion 200b protrudes from the anode plate 100, and the thickness of the protective portion 200b is greater than the thickness of the isolation portion 200a. The thicker protruding portion of the diaphragm 200 results in higher bending stiffness of the protective portion 200b, making it less prone to folding, thereby reducing the possibility of short circuits in the electrode assembly.

[0027] This application provides an electrical device, which includes a device body and a battery pack, the battery pack being used to supply power to the device body.

[0028] Electrical devices can be, for example, mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft.

[0029] The technical solutions described in this application are not limited to the devices described above, but can also be applied to all devices that use battery devices.

[0030] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar.

[0031] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0032] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0033] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0034] This application also provides a battery pack, which includes a housing and at least one battery cell, with the battery cell located inside the housing.

[0035] In some embodiments of this application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0036] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0037] This application also provides a battery cell, which includes a housing and an electrode assembly disposed inside the housing. The battery cell also includes an electrolyte located inside the housing, which is capable of wetting the electrode assembly.

[0038] This application also provides an electrode assembly; please refer to [link to relevant documentation]. Figure 1 and Figure 2 The electrode assembly includes an anode plate 100 and a diaphragm 200. The diaphragm 200 is attached to the anode plate 100 along the thickness direction of the electrode assembly. Exemplarily, the thickness directions of the electrode assembly, the anode plate 100, and the diaphragm 200 are arranged parallel to each other. The diaphragm 200 has an isolation portion 200a and a protective portion 200b connected to each other. The isolation portion 200a and the protective portion 200b are arranged along a first direction, and the isolation portion 200a is attached to the anode plate 100 along the thickness direction of the electrode assembly. Exemplarily, the first direction is orthogonal to the thickness direction of the electrode assembly, and the dimension of the electrode assembly along the thickness direction is much smaller than the dimension of the electrode assembly along the first direction. The thickness direction of the electrode assembly is as follows: Figure 1 The direction indicated by the middle arrow R1, the first direction is as follows: Figure 1 The direction indicated by the middle arrow R2. At least a portion of the protective portion 200b protrudes from the anode plate 100 along the first direction, and the thickness of the protective portion 200b is greater than the thickness of the insulating portion 200a. It is understood that the electrode assembly can be any of the following: laminated cell, square wound cell, or cylindrical wound cell.

[0039] In this embodiment, the diaphragm 200 has an isolation portion 200a and a protective portion 200b arranged along a first direction. The protective portion 200b protrudes from the anode plate 100 along the first direction, and its thickness is greater than that of the isolation portion 200a. During use, the electrode assembly may bend under external impact, causing a short circuit between the anode plate 100 and the cathode plate 300. The protective portion 200b protruding from the anode plate 100 along the first direction can reduce direct contact between the anode plate 100 and the cathode plate 300 to a certain extent. Furthermore, the greater thickness of the protective portion 200b compared to the isolation portion 200a results in greater bending stiffness, making it less prone to bending and thus reducing the likelihood of a short circuit between the cathode plate 300 and the anode plate 100. Moreover, the greater thickness of the protective portion 200b reduces the possibility of burrs from the anode plate 100 puncturing the diaphragm 200 due to the cutting process.

[0040] In one embodiment, please refer to Figure 1 A portion of the structure of the protective portion 200b is attached to the anode plate 100 along the thickness direction of the electrode assembly. Exemplarily, along a first direction, the protective portion 200b is located at the end of the diaphragm 200, extending from one end of the diaphragm 200 towards the other end and to the corresponding position on the anode plate 100. The protective portion 200b is relatively long, and the area of ​​the reinforced region of the diaphragm 200 that partially attaches to the anode plate 100 is large, thereby further reducing the likelihood of the diaphragm 200 folding.

[0041] It is understood that other embodiments of this application are not limited to the protective portion 200b being partially attached to the anode sheet 100 along the thickness direction of the electrode assembly. Exemplarily, the protective portion 200b and the anode sheet 100 are arranged at a distance along the first direction.

[0042] In one embodiment, please refer to Figure 1 The electrode assembly also includes a cathode plate 300, and a separator 200 is located between the anode plate 100 and the cathode plate 300 along the thickness direction of the electrode assembly. Exemplarily, the thickness direction of the cathode plate 300 is arranged parallel to the thickness direction of the electrode assembly, and along a first direction, the size of the anode plate 100 is larger than the size of the cathode plate 300. Along the first direction, a protective portion 200b is spaced apart from the cathode plate 300. This edge-spaced arrangement of the protective portion 200b and the cathode plate 300 reduces the increase in the thickness of the electrode assembly due to the protective portion 200b, thus minimizing the impact of the separator 200 on the energy density of the electrode assembly. Furthermore, a shorter protective portion 200b of the separator 200 also reduces the influence of the separator 200 on lithium-ion migration.

[0043] It is understood that other embodiments of this application are not limited to the arrangement of the protective portion 200b and the cathode plate 300 at a distance. Exemplarily, along the first direction, the protective portion 200b is attached to both the cathode plate 300 and the anode plate 100.

[0044] In one embodiment, please refer to Figure 1 Along the thickness direction of the electrode assembly, the diaphragm 200 is located between the anode plate 100 and the cathode plate 300. Exemplarily, along the first direction, both ends of the anode plate 100 protrude beyond the opposite ends of the cathode plate 300, and the distances at both ends of the anode plate 100 protruding are equal, i.e., the distances at both ends of the anode plate 100 protruding beyond the cathode plate 300 along the first direction are both b / 2. Along the first direction, the size difference between the anode plate 100 and the diaphragm 200 is a, the size difference between the anode plate 100 and the cathode plate 300 is b, and the size of the protective portion 200b is c, where a / 2 < c < (a+b) / 2. The size of the protective portion 200b is within a suitable range, which allows for a small possibility of folding while also reducing the impact of the protective portion 200b on energy density. Exemplarily, the value of a ranges from 1.8mm to 2.4mm, and the value of b ranges from 1.2mm to 1.8mm, where the dimensions of a, b, and c are as follows: Figure 1 As shown.

[0045] In one embodiment, the size of the protective portion 200b ranges from 8 μm to 20 μm along the thickness direction of the electrode assembly. Exemplarily, the size of the protective portion 200b along the thickness direction of the electrode assembly is 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, or 20 μm. Having the thickness of the protective portion 200b within a suitable range allows it to have high bending stiffness while also reducing the degree of energy density reduction caused by the base film 210.

[0046] In one embodiment, please refer to Figure 2The diaphragm 200 includes a base membrane 210 and a coating layer 220 bonded together. Exemplarily, the base membrane 210 is made of PP (polypropylene) or PE (polyethylene), and the coating layer 220 is made of one or more of Al2O3, Al(OH)3, AlOOH (boehmite), Mg(OH)2, MgO, SiO2, or TiO. The base membrane 210 and the coating layer 220 are arranged along the thickness direction of the electrode assembly, and the thickness of the coating layer 220 at the corresponding position of the protective portion 200b is greater than the thickness of the coating layer 220 at the corresponding position of the insulating portion 200a. Exemplarily, along the thickness direction of the electrode assembly, the size of the base membrane 210 ranges from 4 μm to 10 μm, and both the thickness directions of the base membrane 210 and the coating layer 220 are arranged parallel to the thickness direction of the diaphragm 200. The coating layer 220 at the location corresponding to the protective part 200b is relatively thick. The manufacturing process of the diaphragm 200 is relatively simple. During the manufacturing process of the diaphragm 200, multiple layers of the coating layer 220 material need to be coated on the base film 210 to form a thicker coating layer 220, thereby achieving the formation of a thicker protective part 200b. For example, the thickness of the coating layer 220 at the location corresponding to the isolation part 200a is 1μm to 8μm.

[0047] It is understood that other embodiments of this application are not limited to the coating layer 220 at the position corresponding to the protective part 200b having a thickness greater than the coating layer 220 at the position corresponding to the isolation part 200a. For example, the base film 210 at the position corresponding to the protective part 200b has a thickness greater than the base film 210 at the position corresponding to the isolation part 200a.

[0048] In one embodiment, please refer to Figure 1 and Figure 2 Along the first direction, protective portions 200b are connected to both ends of the isolation portion 200a. When the electrode assembly is subjected to a load along the first direction, the protective portions 200b on both sides can further reduce the risk of the diaphragm 200 folding, thereby making it more difficult for the electrode assembly to short-circuit.

[0049] It is understood that other embodiments of this application are not limited to having protective portions 200b connected to both opposite ends of the isolation portion 200a along the first direction. Exemplarily, along the first direction, one end of the isolation portion 200a is connected to the protective portion 200b.

[0050] In one embodiment, the protective portion 200b extends from one end of the diaphragm 200 to the opposite end of the diaphragm 200 along a second direction, and the second direction is orthogonal to both the first direction and the thickness direction of the electrode assembly. Exemplarily, both the first and second directions are arranged parallel to the large surface of the electrode assembly. The continuous extension of the protective portion 200b along the second direction further enhances the bending stiffness of the diaphragm 200.

[0051] It is understood that other embodiments of this application are not limited to the provision that, along the second direction, the protective portion 200b extends from one end of the diaphragm 200 to the opposite end of the diaphragm 200. Exemplarily, a single diaphragm 200 has a plurality of protective portions 200b, which are spaced apart along the second direction.

[0052] In one embodiment, please refer to Figure 2 The protective portion 200b includes a first sub-portion 200c and a second sub-portion 200d, which are located on opposite sides of the diaphragm 200 along the thickness direction of the electrode assembly. Exemplarily, along the thickness direction of the electrode assembly, the electrode assembly has opposite first and second sides. The first sub-portion 200c is located on the side of the base membrane 210 facing the first side, and the second sub-portion 200d is located on the side of the base membrane 210 facing the second side. Along the thickness direction of the electrode assembly, the size of the first sub-portion 200c is equal to the size of the second sub-portion 200d. The protective portion 200b is provided on both the portion of the base membrane 210 facing the first and second sides, thereby providing the diaphragm 200 with bending stiffness from the first side to the second side and bending stiffness from the second side to the first side.

[0053] It is understood that other embodiments of this application are not limited to the first sub-part 200c and the second sub-part 200d located on opposite sides of the diaphragm 200 along the thickness direction of the electrode assembly. Exemplarily, the protective part 200b is located on the side of the base film 210 facing the first side or on the side of the base film 210 facing the second side.

[0054] The above embodiments are merely illustrative of the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and all should be covered within the scope of the specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of protection.

Claims

1. An electrode assembly, characterized in that, include: Anode plate; A diaphragm is attached to the anode sheet along the thickness direction of the electrode assembly. The diaphragm has an isolation portion and a protective portion connected to each other. The isolation portion and the protective portion are arranged along a first direction, which is perpendicular to the thickness direction of the electrode assembly. At least a portion of the structure of the protective portion protrudes from the anode sheet along the first direction. The thickness of the protective portion is greater than the thickness of the isolation portion.

2. The electrode assembly according to claim 1, characterized in that, A portion of the protective structure is attached to the anode sheet along the thickness direction of the electrode assembly.

3. The electrode assembly according to claim 2, characterized in that, The electrode assembly further includes a cathode sheet. Along the thickness direction of the electrode assembly, the diaphragm is located between the anode sheet and the cathode sheet. Along the first direction, the protective portion is arranged at intervals from the cathode sheet.

4. The electrode assembly according to claim 1, characterized in that, The diaphragm includes a base film and a coating layer that are bonded together. The base film and the coating layer are arranged along the thickness direction of the electrode assembly. The thickness of the coating layer at the position corresponding to the protective part is greater than the thickness of the coating layer at the position corresponding to the isolation part.

5. The electrode assembly according to claim 1, characterized in that, Along the first direction, the protective part is connected to both opposite ends of the isolation part.

6. The electrode assembly according to claim 1, characterized in that, The electrode assembly further includes a cathode sheet. Along the thickness direction of the electrode assembly, the diaphragm is located between the anode sheet and the cathode sheet. Along the first direction, the size difference between the anode sheet and the diaphragm is a, the size difference between the anode sheet and the cathode sheet is b, and the size of the protective part is c, where a / 2 < c < (a+b) / 2.

7. The electrode assembly according to claim 1, characterized in that, Along the thickness direction of the electrode assembly, the size of the protective portion ranges from 8μm to 20μm.

8. The electrode assembly according to claim 1, characterized in that, Along a second direction, the protective portion extends from one end of the diaphragm to the opposite end of the diaphragm, and the second direction is perpendicular to both the first direction and the thickness direction of the electrode assembly.

9. The electrode assembly according to claim 1, characterized in that, The protective portion includes a first sub-portion and a second sub-portion, which are located on opposite sides of the diaphragm along the thickness direction of the electrode assembly.

10. A single battery cell, characterized in that, include: case; The electrode assembly as claimed in any one of claims 1 to 9, wherein the electrode assembly is disposed inside the housing.

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