Single battery, and battery device, energy storage device, energy storage system, power utilization device and charging network with single battery

Abstract

The utility model discloses a single battery and a battery device, an energy storage device, an energy storage system, a power utilization device and a charging network with the single battery, the single battery comprises a shell, an electrode assembly and a buffer layer, the electrode assembly and the buffer layer are located in the shell, the electrode assembly comprises a straight section and a corner section, and the straight section is connected with the corner section; the buffer layer covers the outer side of the electrode assembly along the winding direction of the electrode assembly, the buffer layer comprises a straight part and a corner part which are connected, the straight part covers at least part of the straight section, and the corner part covers at least part of the corner section. According to the electrode assembly provided by the embodiment of the invention, the buffer layer is arranged, the buffer layer can well limit expansion of the straight section, the corner section and the corner connecting part, and the buffer layer can well separate the straight section, the corner section and the corner connecting part from the shell; therefore, the risk of breakage of the straight sections, the corner sections and the corner joints can be well reduced.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell and a battery device, energy storage device, energy storage system, power consumption device, and charging network having the same. Background Art

[0002] Electric vehicles, due to their energy-saving and environmentally friendly advantages, have become a crucial component of the automotive industry's sustainable development. Battery technology is a crucial factor in the development of electric vehicles. Batteries typically consist of a housing and an electrode assembly within the housing. The electrode assembly is manufactured by winding a stack of positive electrode sheets, a separator, and a negative electrode sheet, followed by hot pressing.

[0003] However, during the battery cycle, the outermost electrode sheet of the electrode assembly is prone to breakage. Utility Model Content

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the first aspect of the present application provides a battery cell, which can effectively reduce the risk of fracture of the outermost electrode sheet of the electrode assembly.

[0005] A second aspect of the present application further provides a battery device having the battery cell.

[0006] A third aspect of the present application further provides an energy storage device having the battery cell or battery device.

[0007] A fourth aspect of the present application further provides an energy storage system having the energy storage device.

[0008] A fifth aspect of the present application further proposes an electrical device having the battery cell, the battery device, the energy storage device or the energy storage system.

[0009] A sixth aspect of the present application further provides a charging network having the energy storage device or energy storage system.

[0010] According to the battery cell of the embodiment of the first aspect of the present application, the battery cell includes a shell, an electrode assembly and a buffer layer; the electrode assembly is located in the shell, the electrode assembly includes a straight section and a corner section, and the straight section and the corner section are connected; the buffer layer covers the outside of the electrode assembly along the winding direction of the electrode assembly, the buffer layer includes a connected straight portion and a corner portion, the straight portion covers at least part of the straight section, and the corner portion covers at least part of the corner section.

[0011] According to the battery cell of the embodiment of the present application, a buffer layer is provided, and the buffer layer includes a connected straight portion and a corner portion. The straight portion can cover the outside of the straight section, and the corner portion can cover the outside of the corner section. The buffer layer can better limit the expansion of the straight section, the corner section and the corner connection. Moreover, the buffer layer can better separate the straight section, the corner section and the corner connection from the shell, thereby better reducing the risk of fracture of the straight section, the corner section and the corner connection.

[0012] In addition, the battery cell according to the present application may also have the following additional technical features:

[0013] In some embodiments of the present application, in the winding direction of the electrode assembly, the size D1 of the corner segment and the size D2 of the corner portion satisfy: 1 / 2<D2 / D1≤1.

[0014] In the above technical solution, by meeting the above conditions, when the corner portion covers the corner section starting from the corner connection, the corner portion can cover the corner tip, thereby better reducing the risk of deformation of the electrode assembly after the corner tip abuts against the shell when it expands.

[0015] In some embodiments of the present application, in the winding direction of the electrode assembly, the dimension D2 of the corner portion satisfies: [Πc+2*] / 4<D2<c, wherein A is the dimension value of the buffer layer in the winding direction of the electrode assembly, a is the dimension value of the electrode assembly in the length direction of the straight segment, and c is the dimension value of the electrode assembly in the length direction perpendicular to the straight segment.

[0016] In the above technical solution, by satisfying the above conditions, the risk of deformation of the electrode assembly due to contact between the corner tip and the shell during expansion can be effectively reduced.

[0017] In some embodiments of the present application, the number of the straight sections is two, the number of the corner sections is two, and the two straight sections are arranged at intervals; the two ends of one of the corner sections are respectively connected to the ends of the two straight sections on the same side, and the two ends of the other corner section are respectively connected to the ends of the two straight sections on the other side; wherein, at least one buffer layer is provided, and each buffer layer covers at least a portion of the outside of at least one straight section and at least a portion of the outside of at least one corner section.

[0018] In the above technical solution, the buffer layer can be flexibly covered on the outside of the electrode assembly, thereby better protecting the electrode assembly and reducing the risk of breakage of the outermost electrode sheet of the electrode assembly.

[0019] In some embodiments of the present application, the buffer layer includes two corner portions, the two corner portions are connected to both sides of the straight portion, the straight portion covers the outside of any one of the two straight segments, and the two corner portions respectively cover at least part of the outside of the two corner segments.

[0020] In the above technical solution, by making the buffer layer have a straight portion and two corner portions, the electrode assembly can be better protected by the corner portions at both ends in the length direction and by the straight portion on one side. While protecting the electrode assembly, the use of the buffer layer can be reduced and the cost of the buffer layer can be reduced.

[0021] In some embodiments of the present application, a plurality of electrode assemblies are provided, and the buffer layer covers the outside of one of the electrode assemblies, and / or the buffer layer covers the outsides of at least two adjacent electrode assemblies.

[0022] In the above technical solution, when multiple electrode assemblies are provided, the multiple electrode assemblies can be better protected by arranging the buffer layer.

[0023] In some embodiments of the present application, the buffer layer covers the outer sides of two adjacent electrode assemblies, and the two adjacent electrode assemblies are respectively the first winding core and the second winding core, the outermost electrode piece of the first winding core is the first electrode piece, and the outermost electrode piece of the second winding core is the second electrode piece, the first electrode piece includes a first straight section and a first corner section, and the second electrode piece includes a second straight section and a second corner section, the first straight section and the second straight section are respectively located on the opposite side of the first winding core and the second winding core, the straight portion is arranged between the first straight section and the second straight section, and the corner portion covers at least part of the first corner section and / or at least part of the second corner section.

[0024] In the above technical solution, when multiple electrode assemblies are provided, the arrangement of the buffer layer in the above example can better protect the multiple electrode assemblies, and each electrode assembly does not need to be covered with a buffer layer in each straight section. Therefore, the electrode assembly can be better thinned.

[0025] In some embodiments of the present application, in the length direction of the electrode assembly, the first pole piece includes two first corner segments located at both ends of the first straight segment, the second pole piece includes two second corner segments located at both ends of the second straight segment, and the corner portions include two, wherein one corner portion covers at least a portion of the first corner segment and at least a portion of the second corner segment at one end in the length direction of the electrode assembly, and the other corner portion covers at least a portion of the first corner segment and at least a portion of the second corner segment at the other end in the length direction of the electrode assembly.

[0026] In the above technical solution, through the morphological design of the above-mentioned buffer layer, the two corner sections of the first pole piece and the second pole piece can be better protected, and the corner connection between the straight section and the corner section can also be effectively protected, which can better reduce the risk of electrode assembly breakage.

[0027] In some embodiments of the present application, the two adjacent electrode assemblies are respectively the first roll core and the second roll core, the buffer layer covering the first roll core is the first buffer layer, and the buffer layer covering the second roll core is the second buffer layer, the first buffer layer and the second buffer layer are respectively covered on the opposite sides of the first roll core and the second roll core, and the two ends of the first buffer layer respectively extend to at least part of the outside of the two corner sections of the first roll core, and the two ends of the second buffer layer respectively extend to at least part of the outside of the two corner sections of the second core.

[0028] In the above technical solution, by covering the outermost side of the electrode assembly with a buffer layer, complete protection of the electrode assembly can be formed, which can not only limit the expansion of the electrode assembly as a whole, but also effectively reduce the mutual extrusion between the electrode assembly and the shell, thereby effectively reducing the risk of breakage of the electrode assembly.

[0029] In some embodiments of the present application, the thickness H1 of the corner portion and the thickness H2 of the straight portion satisfy: 0.5 mm < H2 ≤ H1 ≤ 8 mm.

[0030] In the above technical solution, by making the thickness of the corner portion greater than or equal to the thickness of the straight portion, the corner portion obtains a compression deformation greater than or equal to that of the straight portion, thereby better protecting the corner section of the electrode assembly.

[0031] In some embodiments of the present application, the compression capacity of the buffer layer is greater than or equal to 60% / 1 MPa.

[0032] In the above technical solution, by making the buffer layer meet the above conditions, the electrode assembly can be better protected.

[0033] In some embodiments of the present application, the buffer layer is integrally formed of PE, PP, PVC or PET.

[0034] In the above technical solution, the buffer layer is integrally formed, has good uniformity, can better cover the outer peripheral side of the electrode assembly, and can better protect the electrode assembly, thereby reducing the risk of breakage of the electrode assembly.

[0035] In some embodiments of the present application, in the wound state, the electrode assembly has a length, b height, and c width, a height of the active layer on the outermost electrode of the electrode assembly is d, a length of the buffer layer covering the electrode assembly is x, and a height of y, satisfying: a+2c>x>a+c, b>y>d.

[0036] In the above technical solution, by designing the dimensions of the electrode assembly and the buffer layer, the buffer layer can better cover the outer peripheral side of the electrode assembly and better protect the electrode assembly, thereby reducing the risk of breakage of the electrode assembly.

[0037] In some embodiments of the present application, at least one electrode assembly is disposed in the shell, and a buffer layer between the electrode assembly and the shell is a bonding buffer layer, and the electrode assembly is bonded to the shell via the bonding buffer layer.

[0038] In the above technical solution, the electrode assembly can be fixedly connected to the shell through the bonding buffer layer and form a whole with the shell. The Mylar film between the electrode assembly and the shell can also be reduced, which is beneficial to reducing costs.

[0039] The present application also provides a battery device having the battery cell of the above embodiment.

[0040] According to the second embodiment of the present application, the battery device includes a box and a battery cell. There is at least one battery cell installed in the box. The battery cell includes a shell and an electrode assembly. The electrode assembly is located in the shell.

[0041] According to the battery device of the embodiment of the present application, by providing the battery cell of the above embodiment, the electrode assembly of the battery cell can better reduce the risk of electrode assembly breakage. Therefore, the battery of the present application can have higher reliability and good safety.

[0042] The present application also proposes an energy storage device.

[0043] The energy storage device according to the third embodiment of the present application includes a plurality of battery cells or a plurality of battery devices, and the battery cells or battery devices are used to store or provide electrical energy.

[0044] The energy storage device in the above examples is provided with the battery cells or battery devices in the above examples for storing or providing electrical energy, so that the energy storage device of the present application can have high reliability and good safety.

[0045] The present application also proposes an energy storage system having the energy storage device of the above embodiment.

[0046] According to the fourth aspect of the present application, the energy storage system includes a power conversion device and an energy storage device, and the power conversion device is used to electrically connect the power generation device and the energy storage device.

[0047] In the above example, the energy storage system is provided with the energy storage device of the above example, so that the energy storage system of the present application can have higher reliability and good safety.

[0048] The present application also provides an electrical device.

[0049] According to the electrical device of the embodiment of the present application, the electrical device may include a battery cell, a battery device, an energy storage device or an energy storage system, and the battery cell or battery device is used to store or provide electrical energy.

[0050] In the above examples, by providing the battery cells, battery devices, energy storage devices or energy storage systems of the above examples, the electrical device of the present application can have higher reliability and better safety.

[0051] This application also proposes a charging network.

[0052] According to the charging network of the embodiment of the present application, the charging network may include charging piles, and the charging network may further include an energy storage device or an energy storage system, where the energy storage device is used to provide electrical energy to the charging piles.

[0053] In the above examples, the charging network is provided with the energy storage device or energy storage system according to the above embodiments, so that the charging network has high reliability and good safety.

[0054] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0056] Figure 1 FIG. 4 is a schematic structural diagram of a vehicle according to an embodiment.

[0057] Figure 2 FIG. 1 is a schematic diagram of an exploded structure of a battery according to an embodiment.

[0058] Figure 3 FIG. 1 is a schematic diagram of the exploded structure of a battery cell according to an embodiment.

[0059] Figure 4 FIG. 4 is a transverse cross-sectional view of an electrode assembly according to one embodiment.

[0060] Figure 5 This is a cross-sectional view of an electrode assembly according to one embodiment, wherein the positive electrode sheet, separator, and negative electrode sheet are stacked and then rolled along the Z direction and hot-pressed.

[0061] Figure 6 is a cross-sectional view of a buffer layer of an electrode assembly according to one embodiment.

[0062] Figure 7 is a cross-sectional view of an electrode assembly according to one embodiment.

[0063] Figure 8 is a cross-sectional view of a buffer layer of an electrode assembly according to one embodiment.

[0064] Figure 9 FIG. 4 is a longitudinal cross-sectional view of an electrode assembly according to one embodiment.

[0065] Figure 10 is a schematic diagram of an energy storage system according to one embodiment.

[0066] Figure 11 FIG. 1 is a schematic diagram of a charging network according to an embodiment.

[0067] Reference numerals:

[0068] 1000, vehicle; 100, battery device; 200, controller; 300, motor;

[0069] 1. Energy storage device; 2. Power conversion device; 3. Power generation device; 4. Charging pile; 5. Connector;

[0070] 10. Box; 11. First box; 12. Second box;

[0071] 20. Battery cell; 21. Top cover; 22. Housing;

[0072] 30. Electrode assembly; 311. First winding core; 312. Second winding core; 313. Straight section; 314. Corner section; 315. Corner connection; 316. Corner tip; 32. Buffer layer; 321. Straight section; 322. Corner section. DETAILED DESCRIPTION

[0073] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0074] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0075] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0076] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0077] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0078] Currently, market developments indicate that power batteries are becoming increasingly widely used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As power battery applications continue to expand, market demand is also growing.

[0079] In the related art, a battery cell includes a shell and an electrode assembly. The electrode assembly is made by stacking a positive electrode sheet, a separator, and a negative electrode sheet, and then winding and hot pressing them. The electrode sheet in the middle of the electrode assembly is straight, and the electrode sheet in the end of the electrode assembly is arc-shaped. The end is also called the corner of the electrode assembly. The arc-shaped part on the electrode sheet is the corner of the electrode sheet. The outermost electrode sheet of the electrode assembly refers to a circle of negative electrode sheets wound around the outermost part of the electrode assembly. This circle of negative electrode sheets includes a straight section and a corner section. The straight section is located in the middle of the electrode assembly, and the corner section is located at the end of the electrode assembly. The connection between the corner section and the straight section is called a corner connection. During the cycle of the battery, the temperature inside the battery changes. On the one hand, the temperature change will cause the electrode sheets in the electrode assembly to expand and contract. On the other hand, the electrode sheets will undergo lithium removal and lithium insertion during the charge and discharge process, which will also cause the electrode sheets to expand and contract. The expansion and contraction of the electrode sheets will cause the electrode assembly to expand in the width and thickness directions. and shrinkage; with the increase of the number of cycles, the rebound of the negative electrode sheet increases, and the side reaction products accumulate, resulting in the thickening of the negative electrode sheet, which causes the negative electrode sheet to expand irreversibly, thereby causing the electrode assembly to expand irreversibly in the width and thickness directions; however, during the cycle, the principal strains and stresses of the electrode sheets at various positions in the electrode assembly are different, among which the corner sections and corner connections are subjected to greater forces, and are prone to fracture at the corner sections and corner connections, causing failure of the electrode assembly, and when the electrode assembly is placed in the shell, the expanded corner sections of the electrode assembly are prone to abut against the shell during the cycle of the electrode assembly, which is easy to cause the electrode sheets to break, and is also easy to cause failure of the electrode assembly.

[0080] In order to alleviate the above problems, the inventors have found that the buffer layer 32 is wrapped around the outside of the electrode assembly 30 along the winding direction of the electrode assembly 30. At the same time, the buffer layer 32 can limit the expansion of the electrode assembly 30. In this way, during the cycle of the battery device 100, the buffer layer 32 can restrain the electrode assembly 30, and can reduce the expansion force on the outermost electrode sheet of the electrode assembly 30 in the corner section 314 and at the corner connection 315. In addition, when the electrode assembly 30 is placed in the shell 22, the buffer layer 32 separates the corner section 314 of the electrode assembly 30 from the inner wall of the shell 22, and can also reduce the friction force of the shell 22 on the outermost electrode sheet of the electrode assembly 30 in the corner section 314, thereby reducing the risk of electrode sheet breakage.

[0081] In the embodiment of the present application, the battery cell 20 may be a secondary battery. A secondary battery refers to a battery cell 20 that can be continuously used by activating active materials by charging after the battery cell 20 is discharged.

[0082] The battery cell 20 can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel metal hydride battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiment of the present application.

[0083] The present invention provides an electrical device that uses a battery cell 20 as a power source. The electrical device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0084] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0085] Please refer to Figure 1 , Figure 1 A schematic structural diagram of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery cell 20 is provided inside the vehicle 1000. The battery cell 20 may be provided at the bottom, head or tail of the vehicle 1000. The battery cell 20 may be used to power the vehicle 1000. For example, the battery cell 20 may serve as an operating power source for the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300. The controller 200 is used to control the battery cell 20 to power the motor 300, for example, for starting, navigating and operating power requirements of the vehicle 1000 during driving.

[0086] In some embodiments of the present application, the battery cell 20 can serve not only as the operating power source of the vehicle 1000 , but also as the driving power source of the vehicle 1000 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000 .

[0087] Please refer to Figure 2 , Figure 2 An exploded view of a battery device 100 provided in some embodiments of the present application. The battery device 100 described in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells 20, which are connected in series, parallel, or in parallel via a busbar.

[0088] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells 20 .

[0089] As an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing a plurality of battery cells 20 to form an independent module. As an example, the battery module may be formed by bundling a plurality of battery cells 20 with a cable tie.

[0090] In some embodiments, the battery device 100 may be a battery pack, which includes a case and one or more battery cell assemblies, wherein the battery cell assemblies are housed in the case 10 .

[0091] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box body 10 by fixing the battery module in the box body 10 .

[0092] As an example, the battery cell assembly may also be housed in the case 10 by directly fixing a plurality of battery cells to the case 10 .

[0093] As an example, the housing 10 may include a first housing 11 and a second housing 12. The first housing 11 and the second housing 12 engage to form an enclosed space within the housing 10 for accommodating the battery cell assembly. Enclosed here means covered or closed, and can be either sealed or unsealed. The first housing 11 may be a top cover or a bottom plate.

[0094] As an example, the box body 10 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that a closed space is formed inside the box body 10 to accommodate the battery cell assembly.

[0095] In some embodiments, the box 10 can be used as part of the chassis structure of the vehicle. For example, part of the box 10 can become at least a part of the floor of the vehicle 1000, or part of the box 10 can become at least a part of the crossbeam and longitudinal beam of the vehicle 1000.

[0096] The technical solutions described in the embodiments of the present application are applicable to various electrical devices that use battery cells 20, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, electric tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0097] Please refer to Figure 3 , Figure 3This is a schematic diagram of the exploded structure of a battery cell 20 provided in some embodiments of the present application. The battery cell 20 is the smallest unit that constitutes the battery device 100. The battery cell 20 includes a housing 22 and an electrode assembly 30.

[0098] For example, Figure 3 The battery cell 20 includes a top cover 21, a shell 22, an electrode assembly 30 and other functional components.

[0099] The housing 22 is a component used to cooperate with the top cover 21 to form an internal environment of the battery cell 20 , wherein the formed internal environment can be used to accommodate the electrode assembly 30 , electrolyte and other components.

[0100] The electrode assembly 30 is the component where the electrochemical reaction occurs in the battery cell 20. One or more electrode assemblies 30 may be contained within the housing 22. The electrode assembly 30 is primarily formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and a separator is typically provided between the positive electrode sheet and the negative electrode sheet.

[0101] Combine Figure 4 and Figure 5 As shown, Figure 4 FIG. 4 is a transverse cross-sectional view of an electrode assembly 30 according to an embodiment. Figure 5 1 is a cross-sectional view of an electrode assembly 30 according to an embodiment, wherein the positive electrode sheet, the separator, and the negative electrode sheet are stacked and then rolled along the Z direction and hot-pressed.

[0102] In one embodiment of the present application, an electrode assembly 30 is provided, which includes a straight section 313 and a corner section 314. The straight section 313 and the corner section 314 are connected, and a buffer layer 32 covers the outside of the electrode assembly 30 along the winding direction of the electrode assembly 30. The buffer layer 32 includes a connected straight portion 321 and a corner portion 322. The straight portion 321 covers at least a portion of the straight section 313, and the corner portion 322 covers at least a portion of the corner section 314.

[0103] For example, the connection between the straight section 313 and the corner section 314 is a corner connection 315. When the buffer layer 32 covers the outermost pole piece, the buffer layer 32 can better cover the outside of the corner connection 315. When the corner connection 315 expands, the buffer layer 32 can better limit the expansion of the corner connection 315. At the same time, since the straight portion 321 covers the outside of the straight section 313, the straight portion 321 can better limit the expansion of the straight section 313. The corner portion 322 covers the outside of the corner section 314, and the corner portion 322 can better limit the expansion of the corner section 314. In addition, the buffer layer 32 can also better separate the straight section 313, the corner section 314 and the corner connection 315 from the shell 22, reducing the extrusion of the shell 22 on the straight section 313, the corner section 314 and the corner connection 315, thereby better reducing the risk of breakage of the straight section 313, the corner section 314 and the corner connection 315.

[0104] For example, the straight portion 321 may completely cover the straight section 313 , or the straight portion 321 may only cover a portion of the straight section 313 .

[0105] For example, the corner portion 322 may completely cover the outside of the corner section 314 , or the corner portion 322 may only cover a portion of the outside of the corner section 314 .

[0106] For example, the straight portion 321 may only cover the outside of a portion of the straight section 313, and the corner portion 322 may only cover the outside of a portion of the corner section 314. In this way, the buffer layer 32 can reduce the length of the buffer layer 32 while protecting the electrode assembly 30, thereby better improving the coverage efficiency of the buffer layer 32 and reducing the use cost of the buffer layer 32.

[0107] According to the electrode assembly 30 of the embodiment of the present application, a buffer layer 32 is provided, and the buffer layer 32 includes a connected straight portion 321 and a corner portion 322. The straight portion 321 can cover the outside of the straight section 313, and the corner portion 322 can cover the outside of the corner section 314. The buffer layer 32 can better limit the expansion of the straight section 313, the corner section 314 and the corner connection 315. Moreover, the buffer layer 32 can also better separate the straight section 313, the corner section 314 and the corner connection 315 from the shell 22, thereby better reducing the risk of fracture of the straight section 313, the corner section 314 and the corner connection 315.

[0108] In some embodiments of the present application, in the winding direction of the electrode assembly 30 , the dimension D1 of the corner segment 314 and the dimension D2 of the corner portion 322 satisfy: 1 / 2<D2 / D1≤1.

[0109] For example, the dimension D1 of the corner section 314 may be the dimension of the corner section 314 in a straight state or an unwound state, and the dimension D2 of the corner portion 322 may be the dimension of the corner portion 322 in a straight state or an unwound state. Figure 5 As shown, in the length direction of the straight section 313, the end of the corner section 314 in the wound state away from the straight section 313 is the corner tip 316. By satisfying the above conditions, when the corner portion 322 starts to cover the corner section 314 from the corner connection 315, the corner portion 322 can cover the corner tip 316. As a result, the risk of deformation of the corner tip 316 after abutting against the shell 22 when the electrode assembly 30 expands can be better reduced.

[0110] For example, the values of D2 / D1 may be: 5 / 8, 3 / 4, 7 / 8, or 1. It is understandable that the value of D2 / D1 may also have other values, which are not limited in this application.

[0111] In the above technical solution, by satisfying the above conditions, the risk of deformation of the electrode assembly 30 due to the contact between the corner tip 316 and the shell 22 during expansion can be effectively reduced.

[0112] In some embodiments of the present application, in the winding direction of the electrode assembly 30, the dimension D2 of the corner portion 322 satisfies: [Πc+2*] / 4<D2<c, where A is the dimension value of the buffer layer 32 in the winding direction of the electrode assembly 30, a is the dimension value of the electrode assembly 30 in the length direction of the straight section 313, and c is the dimension value of the electrode assembly 30 in the length direction perpendicular to the straight section 313.

[0113] In the above technical solution, by satisfying the above conditions, the risk of deformation of the electrode assembly 30 due to the contact between the corner tip 316 and the shell 22 during expansion can be effectively reduced.

[0114] In some embodiments of the present application, Figure 4 and Figure 5 As shown, there are two straight sections 313 and two corner sections 314, and the two straight sections 313 are arranged at intervals; the two ends of one corner section 314 are respectively connected to the ends of the two straight sections 313 on the same side, and the two ends of the other corner section 314 are respectively connected to the ends of the two straight sections 313 on the other side; wherein, at least one buffer layer 32 is provided, and each buffer layer 32 covers at least a portion of the outside of at least one straight section 313 and at least a portion of the outside of at least one corner section 314.

[0115] Exemplarily, the buffer layer 32 is provided with a buffer layer 32 including a straight portion 321 and a corner portion 322 . The straight portion 321 may cover an outside of a straight section 313 , and the corner portion 322 may cover an outside of a corner section 314 .

[0116] For example, Figure 8 As shown, the buffer layer 32 is provided with a buffer layer 32 including a straight portion 321 and two corner portions 322 . The straight portion 321 can cover the outside of a straight section 313 , and the two corner portions 322 can cover the outside of two corner sections 314 respectively.

[0117] Exemplarily, the buffer layer 32 is provided with one, and the buffer layer 32 includes two straight portions 321 and two corner portions 322 . The two straight portions 321 can respectively cover the outside of the two straight sections 313 , and the two corner portions 322 can respectively cover the outside of the two corner sections 314 .

[0118] Exemplarily, two buffer layers 32 are provided, each buffer layer 32 includes a straight portion 321 and a corner portion 322, the straight portions 321 of the two buffer layers 32 can both cover the outside of the same straight segment 313, and the corner portions 322 of the two buffer layers 32 can respectively cover the outside of the two corner segments 314, wherein the two straight portions 321 can be connected or not connected. When the two straight portions 321 are connected, in the winding direction of the electrode assembly 30, the sum of the sizes of the two straight portions 321 can be equal to the size of the straight segment 313.

[0119] Exemplarily, two buffer layers 32 are provided, each buffer layer 32 includes a straight portion 321 and a corner portion 322, the straight portions 321 of the two buffer layers 32 can respectively cover the outside of the two straight sections 313, and the corner portions 322 of the two buffer layers 32 can respectively cover the outside of the two corner sections 314, wherein in the winding direction of the electrode assembly 30, the two buffer layers 32 can be connected or not connected.

[0120] Exemplarily, two buffer layers 32 are provided. For the convenience of description, the two buffer layers 32 are respectively referred to as the first buffer layer 32 and the second buffer layer 32. The first buffer layer 32 includes two straight portions 321 and one corner portion 322. The second buffer layer 32 includes one straight portion 321 and one corner portion 322. One straight portion 321 of the first buffer layer 32 and the straight portion 321 of the second buffer layer 32 are both covered outside the same straight segment 313. The corner portions 322 of the two buffer layers 32 can respectively cover outside the two corner segments 314. The other straight portion 321 of the first buffer layer 32 can be covered outside the other straight segment 313 of the electrode assembly 30.

[0121] For the above example, it should be noted that the straight portion 321 can completely cover the outside of the straight section 313, and the corner portion 322 can completely cover the outside of the corner section 314. Alternatively, the straight portion 321 can cover part of the straight section 313, and the corner portion 322 can cover part of the corner section 314. In addition, when two buffer layers 32 are provided, the two buffer layers 32 can overlap or not overlap in the winding direction of the electrode assembly 30, and this application does not impose any restrictions on this.

[0122] For the above example, the electrode assembly 30 of the present application can flexibly cover the outer side of the electrode assembly 30 with a buffer layer 32, thereby better protecting the electrode assembly 30 and better reducing the risk of fracture of the outermost electrode sheet of the electrode assembly 30.

[0123] In addition, in the above example, one buffer layer 32 is provided, and the buffer layer 32 includes a straight portion 321, or two buffer layers 32 are provided, and each buffer layer 32 includes a straight portion 321 and a corner portion 322. The straight portions 321 of the two buffer layers 32 can both cover the outside of the same straight segment 313. Since the straight portion 321 is covered only in one straight segment 313 of the electrode assembly 30, and the other straight segment 313 does not cover the straight portion 321, the size of the electrode assembly 30 in the thickness direction can be better reduced, which is also conducive to the thinning design of the electrode assembly 30.

[0124] In some embodiments of the present application, Figure 7 and Figure 8 As shown, Figure 7 FIG. 4 is a cross-sectional view of an electrode assembly 30 according to an embodiment. Figure 8 FIG. 4 is a cross-sectional view of a buffer layer 32 of an electrode assembly 30 according to an embodiment.

[0125] The buffer layer 32 includes two corner portions 322 connected to both sides of the straight portion 321 . The straight portion 321 covers any one of the two straight sections 313 , and the two corner portions 322 cover at least part of the two corner sections 314 .

[0126] Exemplarily, the buffer layer 32 is provided with a straight portion 321 and two corner portions 322, so that the electrode assembly 30 can be better protected by the corner portions 322 at both ends in the length direction and by the straight portion 321 on one side. While protecting the electrode assembly 30, the use of the buffer layer 32 can be reduced, thereby reducing the cost of the buffer layer 32.

[0127] In the above technical solution, by making the buffer layer 32 have a straight portion 321 and two corner portions 322, the electrode assembly 30 can be better protected by the corner portions 322 at both ends in the length direction, and by the straight portion 321 on one side. While protecting the electrode assembly 30, the use of the buffer layer 32 can be reduced, thereby reducing the cost of the buffer layer 32.

[0128] In some embodiments of the present application, multiple electrode assemblies 30 are provided, and the buffer layer 32 covers the outermost pole piece of one electrode assembly 30, and / or the buffer layer 32 covers the outermost pole pieces of at least two adjacent electrode assemblies 30.

[0129] For example, Figure 7 and Figure 8 As shown, a plurality of electrode assemblies 30 are provided, a plurality of buffer layers 32 are provided, and the plurality of buffer layers 32 are covered on the outside of the plurality of electrode assemblies 30 in a one-to-one correspondence.

[0130] Exemplarily, multiple electrode assemblies 30 are provided, multiple buffer layers 32 are provided, and the number of buffer layers 32 is less than the number of assembled winding cores. In a part of the electrode assemblies 30, each electrode assembly 30 is protected by a buffer layer 32, and in another part of the electrode assemblies 30, two electrode assemblies 30 can be protected by a buffer layer 32, or three or more electrode assemblies 30 can be protected by a buffer layer 32. This application does not impose any restrictions.

[0131] Exemplarily, there are multiple electrode assemblies 30, and one buffer layer 32 can be provided. All electrode assemblies 30 are wrapped in one buffer layer 32. There can also be two or more buffer layers 32. Two electrode assemblies 30 can be protected by one buffer layer 32, or three or more electrode assemblies 30 can be protected by one buffer layer 32. This application does not impose any restrictions.

[0132] Therefore, in the above example, when a plurality of electrode assemblies 30 are provided, the arrangement of the buffer layer 32 in the above example can better protect the plurality of electrode assemblies 30 .

[0133] In some embodiments of the present application, the buffer layer 32 covers the outermost pole pieces of two adjacent electrode assemblies 30, and the two adjacent electrode assemblies 30 are respectively the first winding core 311 and the second winding core 312. The outermost pole piece of the first winding core 311 is the first pole piece, and the outermost pole piece of the second winding core 312 is the second pole piece. The first pole piece includes a first straight section and a first corner section, and the second pole piece includes a second straight section and a second corner section. The first straight section and the second straight section are respectively located on the opposite sides of the first winding core 311 and the second winding core 312, the straight portion 321 is arranged between the first straight section and the second straight section, and the corner portion 322 covers at least part of the first corner section and / or at least part of the second corner section.

[0134] For example, Figure 4 and Figure 6 As shown, Figure 6 FIG3 is a cross-sectional view of a buffer layer 32 of an electrode assembly 30 according to an embodiment. The buffer layer 32 includes a straight portion 321 and four corner portions 322. The straight portion 321 is arranged between the first straight section and the second straight section, and the four corner portions 322 can respectively cover the outside of the two first corner sections and the outside of the two second corner sections. As a result, in the thickness direction of the electrode assembly 30, only one layer of straight portion 321 is added between the two electrode assemblies 30, which can effectively reduce the size of the electrode assembly 30 in the thickness direction, that is, it can facilitate the thinning design of the electrode assembly 30. At the same time, the four corner sections 314 of the two electrode assemblies 30 and the corner connection 315 where the corner section 314 connects to the straight section 313 are also well protected, which can effectively reduce the risk of electrode fracture.

[0135] Exemplarily, the buffer layer 32 includes a straight portion 321 and two corner portions 322, one corner portion 322 covers at least a portion of a first corner segment at one end of the electrode assembly 30 in the longitudinal direction, and the other corner portion 322 covers at least a portion of a second corner segment at the other end of the electrode assembly 30 in the longitudinal direction, that is, each buffer layer 32 can be arranged in an "S" shape between two adjacent electrode assemblies 30.

[0136] In the above example, when multiple electrode assemblies 30 are provided, the arrangement of the buffer layer 32 in the above example can better protect the multiple electrode assemblies 30, and each straight section 313 of each electrode assembly 30 does not need to be covered with the buffer layer 32. Therefore, the electrode assembly 30 can be better designed to be thinned.

[0137] In some embodiments of the present application, in the longitudinal direction of the electrode assembly 30, the first pole piece includes two first corner segments located at both ends of the first straight segment, the second pole piece includes two second corner segments located at both ends of the second straight segment, and the corner portions 322 include two, wherein one corner portion 322 covers at least a portion of the first corner segment located at one end of the longitudinal direction of the electrode assembly 30 and at least a portion of the second corner segment, and the other corner portion 322 covers at least a portion of the first corner segment located at the other end of the longitudinal direction of the electrode assembly 30 and at least a portion of the second corner segment.

[0138] That is to say, if Figure 4 and Figure 6 As shown, in this example, the buffer layer 32 can include a straight portion 321 and four corner portions 322. The four corner portions 322 can cover only part of the corner section 314 or all of the corner section 314 according to actual needs, and this application does not impose any restrictions. In addition, through the morphological design of the buffer layer 32, the two corner sections 314 of the first and second pole pieces can be well protected. The corner connection 315 between the straight section 313 and the corner section 314 can also be effectively protected, which can effectively reduce the risk of fracture of the electrode assembly 30.

[0139] In some embodiments of the present application, two adjacent electrode assemblies 30 are respectively the first roll core 311 and the second roll core 312, the buffer layer 32 covering the first roll core 311 is the first buffer layer, and the buffer layer 32 covering the second roll core 312 is the second buffer layer. The first buffer layer and the second buffer layer respectively cover the opposite sides of the first roll core 311 and the second roll core 312, and the two ends of the first buffer layer respectively extend to at least part of the outside of the two corner sections 314 of the first roll core 311, and the two ends of the second buffer layer respectively extend to at least part of the outside of the two corner sections 314 of the second roll core 312.

[0140] For example, Figure 7 and Figure 8 As shown, the electrode assembly 30 includes two electrode assemblies 30, and the first buffer layer and the second buffer layer are equivalent to covering the two straight sections 313 exposed on the outside of the electrode assembly 30, and then the two corner portions 322 of the first buffer layer cover the two corner sections 314 of the first winding core 311, and the two corner portions 322 of the second buffer layer cover the two corner sections 314 of the second winding core 312, which can form protection for the outer peripheral side of the electrode assembly 30. Here, the first buffer layer and the second buffer layer can be connected or not connected, and this application does not impose any restrictions.

[0141] In the above example, by covering the outermost side of the electrode assembly 30 with the buffer layer 32, complete protection of the electrode assembly 30 can be formed, which can not only limit the expansion of the electrode assembly 30 as a whole, but also effectively reduce the mutual extrusion between the electrode assembly 30 and the shell 22, thereby effectively reducing the risk of fracture of the electrode assembly 30.

[0142] In some embodiments of the present application, the thickness H1 of the corner portion 322 and the thickness H2 of the straight portion 321 satisfy the following conditions: 0.5 mm < H2 ≤ H1 ≤ 8 mm.

[0143] Exemplarily, the thickness of the corner portion 322 is greater than the thickness of the straight portion 321 ; exemplary, the thickness of the corner portion 322 is equal to the thickness of the straight portion 321 .

[0144] Illustratively, the thickness H2 of the straight portion 321 may be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, or 8 mm.

[0145] For example, the thickness H1 of the corner portion 322 may be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, or 8 mm.

[0146] In the above example, by making the thickness of the corner portion 322 greater than or equal to the thickness of the straight portion 321 , the corner portion 322 obtains a compression deformation greater than or equal to that of the straight portion 321 , thereby better protecting the corner section 314 of the electrode assembly 30 .

[0147] In some embodiments of the present application, the compressibility of the buffer layer 32 is greater than or equal to 60% / 1 MPa, where 60% / 1 MPa means that the deformation degree of the buffer layer 32 under 1 MPa reaches 60%.

[0148] In the above example, by making the buffer layer 32 meet the above conditions, the electrode assembly 30 can be better protected.

[0149] In some embodiments of the present application, the buffer layer 32 is integrally formed using PE (polyethylene), PP (polypropylene), PVC (polyvinyl chloride) or PET (polyethylene terephthalate). The polymer has excellent mechanical properties and mechanical properties, a small thermal expansion coefficient, and at the same time, the advantages of uniform pores, acid and alkali corrosion resistance, odorlessness, good thermal insulation, and good air permeability and aging performance are also suitable for the lithium battery device 100 system.

[0150] In the above example, the buffer layer 32 is integrally formed, has good uniformity, can better cover the outer peripheral side of the electrode assembly 30, and can better protect the electrode assembly 30, thereby reducing the risk of breakage of the electrode assembly 30.

[0151] In some embodiments of the present application, Figure 5 and Figure 9 As shown, Figure 9 Figure 2 is a longitudinal cross-sectional view of an electrode assembly 30 according to one embodiment. In the wound state, the electrode assembly 30 has a length a, a height b, and a width c. The height of the active layer on the outermost electrode sheet of the electrode assembly 30 is d. The length of the buffer layer 32 covering the electrode assembly 30 is x, and the height is y. These conditions satisfy: a + 2c > x > a + c, and b > y > d.

[0152] In the above example, by designing the dimensions of the electrode assembly 30 and the buffer layer 32 , the buffer layer 32 can better cover the outer periphery of the electrode assembly 30 and better protect the electrode assembly 30 , thereby reducing the risk of fracture of the electrode assembly 30 .

[0153] In some embodiments of the present application, Figure 3 and Figure 7 As shown, at least one electrode assembly 30 is disposed in the shell 22 , and a buffer layer 32 between the electrode assembly 30 and the shell 22 is a bonding buffer layer, and the electrode assembly 30 is bonded and connected in the shell 22 via the bonding buffer layer.

[0154] For example, Figure 3 and Figure 7 As shown, two electrode assemblies 30 are disposed within the shell 22. The two electrode assemblies 30 are a first core 311 and a second core 312. The buffer layer 32 covering the first core 311 is a first buffer layer, and the buffer layer 32 covering the second core 312 is a second buffer layer. The first buffer layer and the second buffer layer respectively cover the opposite sides of the first core 311 and the second core 312. The ends of the first buffer layer extend to at least a portion of the outside of the two corner sections 314 of the first core 311, and the ends of the second buffer layer extend to at least a portion of the outside of the two corner sections 314 of the second core 312. In this example, both the first buffer layer and the second buffer layer can serve as adhesive buffer layers. After the first core 311 and the second core 312 are placed in the shell, the first core 311, the second core 312, the first buffer layer, the second buffer layer, and the shell 22 can form a whole, and the Mylar film between the electrode assembly 30 and the shell 22 can also be reduced.

[0155] If the arrangement of the buffer layer 32 is Figure 4 As shown, the Mylar film can completely wrap the electrode assembly 30 and the buffer layer 32 and then be placed in the shell 22.

[0156] In addition, if the arrangement of the buffer layer 32 is Figure 7As shown, in one embodiment, the Mylar film can be used to wrap the two electrode assemblies 30, and then the two buffer layers 32 are respectively covered at corresponding positions outside the Mylar film, and then they can be bonded to the shell 22 through the buffer layer 32; in another embodiment, the Mylar film can be used to completely wrap the electrode assembly 30 and the buffer layer 32, and then they can be installed in the shell 22.

[0157] In the above example, the electrode assembly 30 can be fixedly connected to the shell 22 through the bonding buffer layer and form a whole with the shell 22. The Mylar film between the electrode assembly 30 and the shell 22 can also be reduced, which can help reduce costs.

[0158] The present application also provides a battery device 100 having the battery cell 20 according to the above embodiment.

[0159] like Figure 2 As shown, the battery device 100 according to an embodiment of the present application includes a box body 10 and a battery cell 20. There is at least one battery cell 20, which is installed in the box body 10. The battery cell 20 includes a shell 22 and an electrode assembly 30. The electrode assembly 30 is located in the shell 22.

[0160] According to the battery device 100 of the embodiment of the present application, by providing the battery cell 20 of the above embodiment, the electrode assembly 30 of the battery cell 20 can effectively reduce the risk of the electrode assembly 30 breaking. Therefore, the battery device 100 of the present application can have higher reliability and good safety.

[0161] The battery device 100 can be applied to, but is not limited to, mobile phones, tablets, laptop computers, electric toys, electric tools, electric vehicles, electric cars, ships, spacecraft, and the like. Electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, among others.

[0162] Since the battery device 100 of the embodiment of the present application adopts all the technical solutions of all the above embodiments, it also has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described in detail here.

[0163] This application also proposes an energy storage device 1 .

[0164] The energy storage device 1 according to the present application includes a plurality of battery cells or a plurality of battery devices 100 , and the battery cells or battery devices 100 are used to store or provide electrical energy.

[0165] An embodiment of the present application provides an energy storage device 1 comprising one or more battery clusters to increase the voltage and capacity of the energy storage device 1. The battery cluster may include multiple battery devices 100, which are connected in series via a busbar to increase the voltage of the energy storage device 1. When the energy storage device 1 comprises multiple battery clusters, the battery clusters are connected in parallel to increase the capacity of the energy storage device 1.

[0166] The energy storage device 1 can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. The energy storage device 1 can store electrical energy as needed and output it at the appropriate time. For example, the energy storage device 1 can store electrical energy during low-power periods and provide electrical energy to relevant users or electrical equipment during peak power periods. The energy storage system provided in the embodiments of the present application can be any power system that requires the energy storage device 1.

[0167] In some embodiments, the energy storage device 1 is an energy storage container or an energy storage cabinet.

[0168] In some embodiments, the energy storage device 1 may include a cabinet and one or more battery clusters, where the battery clusters are housed in the cabinet.

[0169] In some embodiments, the energy storage device 1 may include modules such as a thermal management module, a main control module, a master control module, a power distribution module, and a fire protection module.

[0170] As an example, the thermal management module may include a liquid cooling unit that provides cooling liquid for regulating the temperature of the battery cells to each battery device 100 through a pipeline.

[0171] For example, the master control module can serve as the battery management unit (BMU) of a battery cluster, monitoring and managing the cluster. The master control module can monitor information such as the battery cluster's current, voltage, power, or temperature. For example, it can control the battery cluster's charge and discharge current and voltage. The master control module includes modules such as the slave battery management unit (SBMU) and a fusion switch.

[0172] As an example, the master control module can serve as the battery management unit of the energy storage device 1, used to monitor and manage the energy storage device 1. The master control module can monitor information such as the current, voltage, power, state of charge, or temperature of the energy storage device 1. For example, it can control the charge and discharge current and voltage of the energy storage device 1. As an example, the master control module includes modules such as an insulation monitoring module (IMM), a master battery management unit (MBMU), an Ethernet (ETH), and a fiber optic conversion module.

[0173] As an example, the fire protection system includes a control panel, detectors, alarm devices, etc., which are used to detect, alarm or extinguish fires in the energy storage system.

[0174] As an example, the power distribution device can be used to distribute power to the power modules of the energy storage device 1 .

[0175] The energy storage device 1 in the above example is provided with the battery cell or battery device 100 in the above example for storing or providing electrical energy, so that the energy storage device 1 of the present application can have high reliability and good safety.

[0176] The present application also proposes an energy storage system having the energy storage device 1 of the above embodiment.

[0177] like Figure 10 As shown, Figure 10 Schematic diagram of an energy storage system according to an embodiment. The energy storage system according to the present application includes a power conversion device 2 and an energy storage device 1 , wherein the power conversion device 2 is used to electrically connect the power generation device 3 and the energy storage device 1 .

[0178] In some embodiments, the energy storage system may include one or more energy storage devices 1 and a power converter system 2 (PCS). The power converter 2 is connected between the power generation device 3 and the energy storage device 1. The power generation device 3 is used to generate electrical energy, and the electrical energy generated by the power generation device 3 can be stored in the energy storage device 1 through the power converter 2. As an example, the power generation device 3 can be a solar panel, a hydropower generation device 3, a thermal power generation device 3, a wind power generation device 3, etc. The specific type of the power generation device 3 is not limited in this application.

[0179] In the above example, the energy storage system is provided with the energy storage device 1 of the above example, so that the energy storage system of the present application can have higher reliability and good safety.

[0180] The present application also provides an electrical device.

[0181] According to the electrical device of the embodiment of the present application, the electrical device may include a battery cell, a battery device 100 , an energy storage device 1 or an energy storage system, and the battery cell or the battery device 100 is used to store or provide electrical energy.

[0182] In the above examples, by providing the battery cells, battery devices 100, energy storage devices 1 or energy storage systems of the above examples, the electrical device of the present application can have higher reliability and better safety.

[0183] This application also proposes a charging network.

[0184] like Figure 11 , Figure 11 FIG2 is a schematic diagram of a charging network according to an embodiment of the present application. The charging network according to the embodiment of the present application may include a charging pile 4 and an energy storage device 1 or an energy storage system. The energy storage device 1 is used to provide electrical energy to the charging pile 4.

[0185] An embodiment of the present application provides a charging network, including a charging pile 4 and an energy storage device 1. The charging pile 4 is electrically connected to the energy storage device 1, and the energy storage device 1 is used to provide electrical energy to the charging pile 4. The charging pile 4 is electrically connected to the battery device 100 in the energy storage device 1 via a cable, and the battery device 100 can provide its stored electrical energy to the charging pile 4. The charging pile 4 has one or more connectors 5, which are used to connect to electrical equipment (such as a vehicle 1000) to replenish energy to the electrical equipment.

[0186] The energy storage device 1 can be located inside the charging pile 4 (for example, an integrated storage and charging device), or outside the charging pile 4 .

[0187] In the above example, the charging network is provided with the energy storage device 1 or the energy storage system according to the above embodiment, so that the charging network has high reliability and good safety.

[0188] Other structures and operations of the battery cell 20, battery device 100, energy storage device, energy storage system, power device and power network according to the embodiments of the present application are well known to those skilled in the art and will not be described in detail here.

[0189] In the description of this specification, reference to the terms "some embodiments," "optionally," "further," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples.

[0190] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A battery cell (20), characterized in that: include: Housing (22); An electrode assembly (30) is located in the housing, the electrode assembly (30) comprising a straight section (313) and a corner section (314), the straight section (313) and the corner section (314) being connected; A buffer layer (32), the buffer layer (32) covering the outside of the electrode assembly (30) along the winding direction of the electrode assembly (30), the buffer layer (32) comprising a connected straight portion (321) and a corner portion (322), the straight portion (321) covering at least a portion of the straight section (313), and the corner portion (322) covering at least a portion of the corner section (314).

2. The battery cell (20) according to claim 1, characterized in that In the winding direction of the electrode assembly (30), the dimension D1 of the corner section (314) and the dimension D2 of the corner portion (322) satisfy the following relationship: 1 / 2<D2 / D1≤1.

3. The battery cell (20) according to claim 2, characterized in that In the winding direction of the electrode assembly (30), the dimension D2 of the corner portion (322) satisfies: [Πc+2*(Aac)] / 4<D2<c, wherein, A is the dimension of the buffer layer (32) in the winding direction of the electrode assembly (30), a is the dimension of the electrode assembly (30) in the length direction of the straight section (313), and c is the dimension of the electrode assembly (30) in the length direction perpendicular to the straight section (313).

4. The battery cell (20) according to claim 1, characterized in that There are two straight sections (313) and two corner sections (314), and the two straight sections (313) are arranged at intervals; the two ends of one corner section (314) are respectively connected to the ends of the two straight sections (313) on the same side, and the two ends of the other corner section (314) are respectively connected to the ends of the two straight sections (313) on the other side; wherein, At least one buffer layer (32) is provided, and each buffer layer (32) covers at least a portion of the outside of at least one straight section (313) and at least a portion of the outside of at least one corner section (314).

5. The battery cell (20) according to claim 4, characterized in that The buffer layer (32) comprises two corner portions (322), the two corner portions (322) are connected to both sides of the straight portion (321), the straight portion (321) covers the outside of any one of the two straight sections (313), and the two corner portions (322) respectively cover at least part of the outside of the two corner sections (314).

6. The battery cell (20) according to claim 1, characterized in that A plurality of the electrode assemblies (30) are provided, the buffer layer (32) covers the outside of one of the electrode assemblies (30), and / or the buffer layer (32) covers the outside of at least two adjacent electrode assemblies (30).

7. The battery cell (20) according to claim 6, characterized in that The buffer layer (32) covers the outer sides of two adjacent electrode assemblies (30), the two adjacent electrode assemblies (30) are respectively a first winding core (311) and a second winding core (312), the outermost electrode piece of the first winding core (311) is a first electrode piece, the outermost electrode piece of the second winding core (312) is a second electrode piece, the first electrode piece includes a first straight section and a first corner section, and the second electrode piece includes a second straight section and a second corner section. The first straight section and the second straight section are respectively located on opposite sides of the first winding core (311) and the second winding core (312), the straight portion (321) is arranged between the first straight section and the second straight section, and the corner portion (322) covers at least part of the first corner section and / or at least part of the second corner section.

8. The battery cell (20) according to claim 7, characterized in that In the length direction of the electrode assembly (30), the first pole piece includes two first corner segments located at both ends of the first straight segment, the second pole piece includes two second corner segments located at both ends of the second straight segment, and the corner portion (322) includes two, wherein: One of the corner portions (322) covers at least a portion of the first corner segment and at least a portion of the second corner segment at one end of the electrode assembly (30) in the longitudinal direction, and the other of the corner portions (322) covers at least a portion of the first corner segment and at least a portion of the second corner segment at the other end of the electrode assembly (30) in the longitudinal direction.

9. The battery cell (20) according to claim 4, characterized in that The two adjacent electrode assemblies (30) are respectively a first winding core (311) and a second winding core (312). The buffer layer (32) covering the first winding core (311) is a first buffer layer, and the buffer layer (32) covering the second winding core (312) is a second buffer layer. The first buffer layer and the second buffer layer respectively cover the opposite sides of the first winding core (311) and the second winding core (312), and both ends of the first buffer layer respectively extend to at least a portion of the outside of the two corner sections (314) of the first winding core (311), and both ends of the second buffer layer respectively extend to at least a portion of the outside of the two corner sections (314) of the second winding core (312).

10. The battery cell (20) according to any one of claims 1 to 9, characterized in that: The thickness H1 of the corner portion (322) and the thickness H2 of the straight portion (321) satisfy the following relationship: 0.5 mm < H2 ≤ H1 ≤ 8 mm.

11. The battery cell (20) according to any one of claims 1 to 9, characterized in that: The compression capacity of the buffer layer (32) is greater than or equal to 60% / 1 MPa.

12. The battery cell (20) according to claim 9, characterized in that The buffer layer (32) is integrally formed from PE, PP, PVC or PET.

13. The battery cell (20) according to claim 1, characterized in that In a wound state, the electrode assembly (30) has a length a, a height b, and a width c; the height of the active layer on the outermost pole piece of the electrode assembly (30) is d; the length of the buffer layer (32) covering the electrode assembly (30) is x, and the height is y, satisfying the following: a+2c>x>a+c, b>y>d.

14. The battery cell (20) according to claim 1, characterized in that At least one electrode assembly (30) is arranged in the shell (22); the buffer layer (32) between the electrode assembly (30) and the shell (22) is a bonding buffer layer; and the electrode assembly (30) is bonded and connected in the shell (22) via the bonding buffer layer.

15. A battery device (100), characterized in that: include: Box (10): A battery cell (20), wherein there is at least one battery cell (20), the battery cell (20) is installed in the box (10), and the battery cell (20) is the battery cell (20) according to any one of claims 1 to 14.

16. An energy storage device (1), characterized in that The invention comprises a plurality of battery cells (20) according to any one of claims 1 to 14 or a plurality of battery devices (100) according to claim 15, wherein the battery cells (20) or the battery devices (100) are used for storing or providing electrical energy.

17. An energy storage system, characterized in that: It comprises a power conversion device (2) and an energy storage device (1) as claimed in claim 16, wherein the power conversion device (2) is used to electrically connect a power generation device (3) and the energy storage device (1).

18. An electrical device, characterized in that: The invention comprises a battery cell (20) according to any one of claims 1 to 14, a battery device (100) according to claim 15, an energy storage device (1) according to claim 16, or an energy storage system according to claim 17, wherein the battery cell (20) or the battery device (100) is used for storing or providing electrical energy.

19. A charging network, characterized in that: It comprises a charging pile (4) and an energy storage device (1) as claimed in claim 16 or an energy storage system as claimed in claim 17, wherein the energy storage device (1) is used to provide electrical energy to the charging pile (4).

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