Battery monomer, battery pack and power utilization device

Abstract

The utility model discloses a battery monomer, a battery pack and a power utilization device, and relates to the technical field of batteries. The electrode assembly comprises a pole piece and a pole lug which are connected with each other. The buffer member is connected to the electrode assembly, and at least partial structure of the small surface of the electrode assembly is covered with the buffer member. The shell is provided with a containing cavity, the electrode assembly and the buffering piece are located in the containing cavity, and the buffering piece is located between the electrode assembly and the shell. In the embodiment of the invention, at least part of the structure of the small surface of the electrode assembly is covered with the buffer piece. The buffer part is connected to the side face of the electrode assembly, and under the condition that the electrode assembly is arranged in the shell, the buffer part can reduce the collision degree between the electrode assembly and the shell, and the situation that the electrode assembly is damaged due to external force is reduced. In the working process of the single battery, the electrode assembly can generate the circulation effect of volume expansion and volume shrinkage within a certain time, so that the stress fatigue generated by the shell is reduced.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, battery pack and power supply device. Background Technology

[0002] With the development of new energy sources, more and more fields are adopting new energy as their power source. Due to their advantages such as high energy density, rechargeability, safety, and environmental friendliness, battery devices are widely used in new energy vehicles, consumer electronics, and energy storage systems. Each battery cell typically has an outer casing that encloses the electrode assembly, thereby reducing the impact of the external environment on the electrode assembly.

[0003] In related technologies, the electrode assembly may shake inside the casing, potentially causing damage to the electrode assembly. 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 a battery cell, a battery pack, and an electrical device that can reduce the occurrence of damage to the electrode components in the battery cell.

[0005] The battery cell according to the first aspect of this application includes:

[0006] An electrode assembly includes an electrode plate and a tab, wherein the tab is connected to the electrode plate;

[0007] A buffer element is connected to the electrode assembly. At least a portion of the structure of the small facet of the electrode assembly is covered by the buffer element. The buffer element includes an adhesive layer, a buffer layer, and a substrate layer that are interconnected. The adhesive layer is bonded to the electrode assembly. The buffer layer is connected to both the adhesive layer and the substrate layer. The substrate layer is located on the side of the buffer layer opposite to the adhesive layer.

[0008] The housing has a receiving cavity, the electrode assembly and the buffer are located within the receiving cavity, and the buffer is located between the electrode assembly and the housing.

[0009] The battery cell according to the embodiments of this application has at least the following beneficial effects:

[0010] In the embodiments of this application, a buffer is connected to the electrode assembly, and at least a portion of the structure of the electrode assembly's small facet is covered by the buffer. The buffer is connected to the side of the electrode assembly. When the electrode assembly is inside the housing, the buffer can reduce the degree of collision between the electrode assembly and the housing, thereby reducing the possibility of damage to the electrode assembly due to significant external forces. Furthermore, during the operation of a single battery cell, the battery cell undergoes a "breathing" effect, and the electrode assembly experiences cyclical expansion and contraction over a certain period. The buffer can absorb the deformation of the electrode assembly to a certain extent, reducing the pulling force exerted by the electrode assembly on the housing, thereby reducing stress fatigue of the housing under repeated tension and thrust, which could lead to housing damage.

[0011] According to some embodiments of this application, the buffer layer is made of foam.

[0012] According to some embodiments of this application, the volume expansion rate of the buffer layer ranges from 0.05 to 0.20.

[0013] According to some embodiments of this application, the buffer includes a first buffer portion, a second buffer portion, and a third buffer portion that are connected to each other. The first buffer portion and the third buffer portion are respectively connected to two opposite large surfaces of the electrode assembly, and the second buffer portion is connected to a small surface of the electrode assembly.

[0014] According to some embodiments of this application, the small faces of the buffer are all connected to the buffer.

[0015] According to some embodiments of this application, the buffer has a plurality of micropores that penetrate the buffer along its thickness direction.

[0016] According to some embodiments of this application, the ratio between the area of ​​the opening size of all the micropores and the surface area of ​​the buffer is in the range of 5% to 50%.

[0017] According to some embodiments of this application, the outer shell has a groove on the side facing the receiving cavity, and at least a portion of the micropores communicate with the groove.

[0018] A second aspect of this application provides a battery pack, comprising:

[0019] Box;

[0020] The battery cell of any of the above, wherein the battery cell is located inside the casing.

[0021] A third aspect of this application provides an electrical device, comprising:

[0022] Main body of the device;

[0023] The battery pack of any of the above is used to power the main body of the device.

[0024] 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

[0025] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0026] Figure 1 This is a top view of the battery cell structure according to the first embodiment of this application; the outer casing is not shown in the figure.

[0027] Figure 2 This is a structural side view of a battery cell according to the first embodiment of this application, showing the outer casing;

[0028] Figure 3 This is a top view of the battery cell structure according to the second embodiment of this application; the outer casing is not shown in the figure.

[0029] Figure 4 This is a structural side view of a battery cell according to a second embodiment of this application, showing the outer casing;

[0030] Figure 5 This is a simplified structural diagram of a buffer component according to an embodiment of this application.

[0031] Figure label:

[0032] 100, Electrode assembly; 100a, Large surface; 100b, Small surface; 110, Electrode sheet; 120, Electrode tab; 200, Buffer component; 200a, Micropore; 200b, First buffer section; 200c, Second buffer section; 200d, Third buffer section; 210, Adhesive layer; 211, First adhesive layer; 212, Second adhesive layer; 220, Buffer layer; 230, Substrate layer; 300, Outer shell; 300a, Receiving cavity. Detailed Implementation

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] In related technologies, battery cells are typically equipped with a casing to protect the internal electrode components, and the casing also prevents the internal electrolyte from flowing to the outside. Normally, there is a certain gap between the casing and the electrode components. During the operation of the battery cell, the electrode components may move within the casing, causing collisions between the electrode components and the casing, resulting in damage to the electrode components.

[0040] In this embodiment of the application, a buffer member 200 connected to the electrode assembly 100 is provided inside the battery cell. The buffer member 200 can protect the sides of the electrode assembly 100, thereby reducing the degree of collision between the electrode assembly 100 and the outer casing 300, and thus reducing the possibility of damage to the electrode assembly 100.

[0041] 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.

[0042] Electrical devices can be, for example, mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft.

[0043] 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.

[0044] 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.

[0045] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] This application provides a single battery cell; please refer to [link / reference]. Figure 1 and Figure 2 The battery cell includes an electrode assembly 100, a buffer 200, and a housing 300. The electrode assembly 100 includes interconnected electrode plates 110 and tabs 120. The buffer 200 is connected to the electrode assembly 100, and at least a portion of the structure of the small facet 100b of the electrode assembly 100 covers the buffer 200. The buffer 200 is arranged in a direction that intersects the arrangement direction and thickness direction of the electrode assembly 100. The housing 300 has a receiving cavity 300a, within which both the electrode assembly 100 and the buffer 200 are located, with the buffer 200 positioned between the electrode assembly 100 and the housing 300. The housing 300 can be an aluminum-plastic film. For example, at least a portion of the structure of the buffer 200 is arranged orthogonally to the arrangement direction and thickness direction of the electrode assembly 100. Two large surfaces 100a of the electrode assembly 100 are arranged opposite each other along the thickness direction of the electrode assembly 100, and the surface area of ​​the large surfaces 100a is much larger than the surface area of ​​the other surfaces of the electrode assembly 100. A small surface 100b of the electrode assembly 100 is connected to the side of the large surface 100a. A tab 120 of the electrode assembly 100 extends from one of the small surfaces 100b.

[0052] For example, the thickness direction of the electrode assembly 100 is as follows: Figure 2 The direction indicated by the middle arrow R1.

[0053] In the embodiments of this application, the buffer 200 is connected to the electrode assembly 100, and at least a portion of the structure of the buffer 200 is arranged intersecting the arrangement direction and thickness direction of the electrode assembly 100. The buffer 200 is connected to the side of the electrode assembly 100. When the electrode assembly 100 is inside the housing 300, the buffer 200 can reduce the degree of collision between the electrode assembly 100 and the housing 300, thereby reducing the possibility of the electrode assembly 100 being damaged by a large external force. Furthermore, during the operation of the battery cell, the battery cell undergoes a "breathing" effect, and the electrode assembly 100 will experience a cycle of volume expansion and contraction over a certain period of time. The buffer 200 can absorb the deformation of the electrode assembly 100 to a certain extent, reducing the pulling force of the electrode assembly 100 on the housing 300, thereby reducing stress fatigue of the housing 300 under repeated tension and thrust, which could lead to damage to the housing 300.

[0054] In one embodiment, please refer to Figure 1 and Figure 2 The buffer 200 extends from one large surface 100a of the electrode assembly 100, through the side surface of the electrode assembly 100, to the other large surface 100a. The side surface of the electrode assembly 100 refers to the surface that connects the two large surfaces 100a of the electrode assembly 100 respectively. Along the thickness direction of the electrode assembly 100, the buffer 200 has opposing portions.

[0055] In the first embodiment, please refer to Figure 1 and Figure 2 The buffer 200 includes a first buffer portion 200b, a second buffer portion 200c, and a third buffer portion 200d that are connected to each other. The first buffer portion 200b and the third buffer portion 200d are respectively connected to two opposing large surfaces 100a of the electrode assembly 100, and the second buffer portion 200c is connected to the small surface 100b of the electrode assembly 100.

[0056] In the embodiment of this application, the buffer 200 extends from one large surface 100a of the electrode assembly 100 to another large surface 100a. Both large surfaces 100a of the electrode assembly 100 are connected to the buffer 200. The buffer 200 can protect both sides of the electrode assembly 100 along the thickness direction, thereby further reducing the impact of the outer casing 300 on the electrode assembly 100 along the thickness direction. Furthermore, the buffer 200 can also reduce the pulling effect of the electrode assembly 100 on the outer casing 300 in the thickness direction.

[0057] It is understood that the embodiments of this application are not limited to the buffer 200 extending from one large surface 100a of the electrode assembly 100 to the other large surface 100a. Exemplarily, the buffer 200 is only connected to the side of the electrode assembly 100.

[0058] In the first embodiment, please refer to Figure 1 Projecting along the thickness direction of the battery cell, the ratio between the area of ​​the projected region of the buffer 200 and the area of ​​the projected region of the electrode assembly 100 ranges from 5% to 50%. When the ratio between the buffer 200 and the electrode assembly 100 is within a suitable range, the buffer 200 can provide good buffering for the electrode assembly 100 while also controlling the manufacturing cost of the battery cell to a certain extent.

[0059] For example, the ratio between the area of ​​the projected region of the buffer 200 and the area of ​​the projected region of the electrode assembly 100 projected along the thickness direction of the battery cell is 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%.

[0060] In the first embodiment, please refer to Figure 1 There are multiple buffer elements 200, which are arranged at intervals along the circumference of the electrode assembly 100. The multiple buffer elements 200 can protect multiple positions of the electrode assembly 100, thereby further reducing the possibility of damage to the electrode assembly 100 caused by the housing 300.

[0061] Please refer to the first and second embodiments. Figures 1 to 4 The buffer members 200 are connected to the circumferential side surfaces of the large surface 100a of the electrode assembly 100. The buffer members 200 are connected to the circumference of the electrode assembly 100, and the buffer members 200 can provide a buffering effect on all four sides of the electrode assembly 100. The buffer members 200 have a good buffering effect.

[0062] Please refer to the first and second embodiments. Figures 1 to 4 All small faces 100b of the buffer 200 are connected to the buffer 200.

[0063] It is understood that when there are multiple buffers 200, in the first embodiment, the multiple buffers 200 are arranged at intervals along the circumference of the electrode assembly 100, and the four sides of the electrode assembly 100 are connected to the buffers 200.

[0064] When the number of buffers 200 is single, in the second embodiment, a single buffer 200 can extend continuously along the circumference of the electrode assembly 100, the electrode assembly 100 being located inside the area enclosed by the buffers 200.

[0065] In one embodiment, please refer to Figure 5 The buffer element 200 includes an adhesive layer 210, a buffer layer 220, and a substrate layer 230 connected to each other. The adhesive layer 210 is bonded to the electrode assembly 100. The buffer layer 220 is connected to both the adhesive layer 210 and the substrate layer 230. The substrate layer 230 is located on the side of the buffer layer 220 opposite to the adhesive layer 210. The adhesive layer 210 includes a first adhesive layer 211 and a second adhesive layer 212. The first adhesive layer 211 is bonded to both the electrode assembly 100 and the buffer layer 220, and the second adhesive layer 212 is connected to both the buffer layer 220 and the substrate layer 230. The substrate layer 230 is made of a material capable of elastic deformation. For example, the substrate layer 230 can be made of polyurethane, EPDM rubber, or ethylene-vinyl acetate copolymer.

[0066] In one embodiment, the buffer layer 220 is made of foam.

[0067] For example, the material of the buffer layer 220 is polyurethane foam or CR (Chloroprene Rubber) foam.

[0068] In the embodiment of this application, the buffer layer 220, being made of foam, effectively protects the electrode assembly 100 and reduces interference between the outer shell 300 and the electrode assembly 100. Furthermore, the foam can withstand high temperatures and chemical corrosion to a certain extent, and the buffer 200 has a long service life, thus providing extended protection for the electrode assembly 100.

[0069] It is understood that other embodiments of this application do not limit the material of the buffer layer 220. For example, the material of the buffer layer 220 may be rubber.

[0070] In one embodiment, the volume expansion rate of the buffer layer 220 is in the range of 0.05 to 0.20.

[0071] For example, the volume expansion rate of the buffer layer 220 is 0.05, 0.10, 0.15 or 0.20.

[0072] Understandably, the volume expansion rate can be obtained by measuring the volume of the material of the buffer layer 220 before and after expansion. The volume expansion rate is equal to the volume before expansion divided by the volume after expansion.

[0073] In the embodiments of this application, the volume expansion rate of the buffer layer 220, within a suitable range, can provide a good buffering effect on the electrode assembly 100 while keeping the manufacturing cost of the battery cell low, thereby reducing the impact of external loads on the electrode assembly 100. Furthermore, the buffer layer 220 can effectively absorb the deformation of the electrode assembly 100 under the action of breathing, reducing the stress transmitted from the electrode assembly 100 to the outer casing 300 due to the breathing action.

[0074] It is understood that other embodiments of this application do not limit the volume expansion rate of the buffer layer 220.

[0075] In one embodiment, please refer to Figure 5 The buffer member 200 has multiple micropores 200a, which penetrate the buffer member 200 along its thickness direction. When electrolyte is injected into the housing 300, the electrolyte can flow along the micropores 200a to the electrode assembly 100, thereby wetting the electrode sheet 110. The micropores 200a can accelerate the flow of electrolyte to a certain extent and reduce the obstruction effect of the buffer member 200 on the electrolyte.

[0076] It is understood that other embodiments of this application do not limit whether the buffer 200 has micropores 200a.

[0077] In one embodiment, the ratio between the area of ​​the opening size of all the micropores 200a and the surface area of ​​the buffer 200 ranges from 5% to 50%. A suitable ratio between the area of ​​the opening size of the micropores 200a and the surface area of ​​the buffer 200 allows the electrolyte to flow smoothly through the buffer 200 to the electrode assembly 100, thus wetting the electrode 110. It also provides a certain degree of strength to the buffer 200, reducing the risk of damage to the buffer 200 due to external loads, which could lead to the electrode assembly 100 losing its protection. It should be noted that when there is only one buffer 200, the surface area of ​​the buffer 200 is the surface area of ​​a single buffer 200. When there are multiple buffers 200, the surface area of ​​the buffer 200 is the sum of the surface areas of all the buffers 200.

[0078] For example, the ratio between the area of ​​the opening size of all micropores 200a and the surface area of ​​the buffer 200 is 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%.

[0079] It is understood that other embodiments of this application do not limit the ratio between the area of ​​the opening size of the micropore 200a and the surface area of ​​the buffer 200.

[0080] In one embodiment, the outer casing 300 has a groove on the side facing the receiving cavity 300a, and at least a portion of the micropores 200a communicate with the groove. When an electrolyte is injected into the receiving cavity 300a, the electrolyte can flow inside the groove, thereby flowing into the plurality of micropores 200a communicating with the groove, so that the electrolyte can enter the interior of the electrode assembly 100 through the micropores 200a and wet the electrode sheet.

[0081] In one embodiment, the electrode assembly 100 is a laminated battery cell. The thickness direction of the electrode assembly 100 is arranged parallel to the stacking direction of the laminated battery cell.

[0082] It is understood that other embodiments of this application do not limit the type of electrode assembly 100. Exemplarily, the electrode assembly 100 can be a cylindrical wound cell. The buffer 200 can be connected to the cylindrical surface of the cylindrical wound cell, thereby reducing interference of the housing 300 with the cylindrical wound cell. When there are multiple buffers 200, the multiple buffers 200 are arranged at intervals along the length direction of the cylindrical wound cell.

[0083] 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. A battery cell, characterized in that, include: An electrode assembly includes an electrode plate and a tab, wherein the tab is connected to the electrode plate; A buffer element is connected to the electrode assembly. At least a portion of the structure of the small facet of the electrode assembly is covered by the buffer element. The buffer element includes an adhesive layer, a buffer layer, and a substrate layer that are interconnected. The adhesive layer is bonded to the electrode assembly. The buffer layer is connected to both the adhesive layer and the substrate layer. The substrate layer is located on the side of the buffer layer opposite to the adhesive layer. The housing has a receiving cavity, the electrode assembly and the buffer are located within the receiving cavity, and the buffer is located between the electrode assembly and the housing.

2. The battery cell according to claim 1, characterized in that, The buffer layer is made of foam.

3. The battery cell according to claim 2, characterized in that, The volume expansion rate of the buffer layer ranges from 0.05 to 0.

20.

4. The battery cell according to claim 1, characterized in that, The buffer has a first buffer portion, a second buffer portion, and a third buffer portion that are connected to each other. The first buffer portion and the third buffer portion are respectively connected to two opposite large surfaces of the electrode assembly, and the second buffer portion is connected to a small surface of the electrode assembly.

5. The battery cell according to claim 1, characterized in that, The small facets of the electrode assembly are all connected to the buffer.

6. The battery cell according to any one of claims 1 to 5, characterized in that, The buffer has multiple micropores that penetrate the buffer along its thickness direction.

7. The battery cell according to claim 6, characterized in that, The ratio between the area of ​​the opening size of all the micropores and the surface area of ​​the buffer is in the range of 5% to 50%.

8. The battery cell according to claim 6, characterized in that, The outer shell has a groove on the side facing the receiving cavity, and at least a portion of the micropores communicate with the groove.

9. A battery pack, characterized in that, include: Box; At least one battery cell as described in any one of claims 1 to 8, wherein the battery cell is located within the housing.

10. An electrical device, characterized in that, include: Main body of the device; The battery pack of claim 9 is used to power the main body of the device.

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