Battery cells, batteries and electrical devices

Abstract

The present application discloses a battery cell, a battery and an electrical device, wherein the battery cell includes two electrode plates and an isolating member. The two electrode plates are stacked along a first direction. The isolating member includes an isolating portion arranged opposite to the two electrode plates and an insulating portion connected to one side of the isolating portion along a second direction, wherein at least a portion of the thickness of the isolating portion is less than the thickness of the isolating portion, and the second direction intersects with the first direction. The insulating portion in the isolating member is arranged on the outside of the isolating member, which can reduce the risk of short circuit between the electrode assembly and the outer shell of the battery cell. Furthermore, at least a portion of the insulating portion is not provided with a thermal insulation coating, so as to reduce the thickness of the insulating portion, reduce the weight of the isolating member and the space occupied, and improve the energy density of the battery cell.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a battery cell, a battery and an electrical device. Background Art

[0002] Batteries are widely used in electronic devices, such as mobile phones, laptops, electric vehicles, electric cars, electric ships, electric toy cars, electric toy ships, electric toy planes, electric tools, and energy storage systems, etc. Batteries usually include multiple battery cells, which may include cadmium nickel battery cells, hydrogen nickel battery cells, lithium-ion battery cells, sodium-ion battery cells, and secondary alkaline zinc-manganese battery cells.

[0003] At present, how to improve the energy density of battery cells is also one of the research issues in this field. Utility Model Content

[0004] In view of the above problems, the present application provides a battery cell, a battery and an electrical device, which can improve the energy density of the battery cell.

[0005] In a first aspect, the present application provides a battery cell, comprising two electrode plates and a separator. The two electrode plates are stacked along a first direction. The separator comprises a separator arranged opposite to the two electrode plates and an insulating portion connected to one side of the separator along a second direction, at least a portion of the insulating portion has a thickness less than that of the separator, and the second direction intersects the first direction.

[0006] In the technical solution of the embodiment of the present application, the battery cell is charged and discharged by setting electrode plates in the battery cell to release and store electrical energy in the battery. The isolating portion in the isolating member is arranged between the electrode plates to achieve insulation between the plates and reduce the risk of short circuit between the two plates. In particular, the insulating portion in the isolating member is arranged outside the isolating member, which can reduce the risk of short circuit between the electrode assembly and the outer shell of the battery cell. In addition, at least part of the insulating portion is not provided with a thermal insulation coating to reduce the thickness of the insulating portion, reduce the weight of the isolating member and the space occupied, and improve the energy density of the battery cell.

[0007] In some embodiments, the battery cell further comprises an outer shell, the outer shell comprises a shell and an end cap, the shell has a receiving cavity, and the end cap and the shell are arranged along the second direction. In the above structure, the insulating part is arranged on the side of the isolation part facing the end cap, which can reduce the space occupied by the isolation part in the height direction of the battery cell and improve the energy density of the battery cell.

[0008] In some embodiments, the isolating member includes a first isolating sheet and a second isolating sheet, the first isolating sheet is disposed between the two electrode sheets, the number of the second isolating sheets is two, and the two electrode sheets are disposed between the two second isolating sheets. In the above structure, the two electrode sheets are insulated and isolated by arranging the first isolating sheet, thereby improving the insulation performance of the electrode assembly. The second isolating sheet is arranged to wrap the outside of the two electrode sheets, further increasing the creepage distance between the two electrode sheets, improving the insulation protection performance, and improving the stability of the battery cell operation.

[0009] In some embodiments, the number of the insulating parts is two, and the two insulating parts are arranged on opposite sides of the isolation part along the second direction. In the above structure, two insulating parts are arranged to reduce the weight of both sides of the isolation part, and further improve the energy density of the battery cell.

[0010] In some embodiments, the first isolation sheet includes a first insulating base film and a first thermal insulation coating. The first insulating base film includes a first sub-portion and a second sub-portion connected to each other, the first sub-portion is arranged between the two electrode plates, and the second sub-portion protrudes from one side of the first sub-portion along the second direction. The first thermal insulation coating is arranged on two opposite sides of the first sub-portion. The first sub-portion and the first thermal insulation coating are isolation portions, and the second sub-portion is an insulation portion.

[0011] In the above structure, the creepage distance between the two electrode sheets is increased by providing the first insulating base film, the insulation performance is improved, and the risk of short circuit between the two electrode sheets is reduced. The first sub-section is used to isolate the two electrode sheets, and the second sub-section is used to achieve insulation between the electrode sheets and the shell. In addition, the first thermal insulation coating is provided on the isolating member, which can effectively prevent heat from being conducted between the two electrode sheets, reduce the temperature inside the battery, and thus improve the operating stability of the battery cell.

[0012] In some embodiments, the first isolation sheet further includes a second heat-insulating coating, and the second heat-insulating coating is disposed on a portion of the surface of the second sub-section. In the above structure, the conduction of heat inside the battery cell can be further reduced, and the stability of the operation of the battery cell can be improved.

[0013] In some embodiments, the thickness of the first sub-portion of the second sub-portion of the second thermal insulation coating is less than the thickness of the first thermal insulation coating. The above structure can reduce the space occupied by the second thermal insulation coating and improve the energy density of the battery cell.

[0014] In some embodiments, the electrode plate includes a current collector and an active material layer. The current collector is disposed between the first isolation sheet and the second isolation sheet. The active material layer is disposed on two opposite surfaces of the current collector. The orthographic projection of the active material layer on the current collector completely falls within the range of the orthographic projection of the first thermal insulation coating on the current collector. In the above structure, the heat dissipated by the active material layer is relatively large. Completely covering the active material layer with the first thermal insulation coating can reduce heat conduction between electrode assemblies, reduce the risk of reduced operating efficiency due to rapid increase in the temperature of the electrode assemblies, and improve the efficiency of battery cell operation.

[0015] In some embodiments, the electrode plate is a cathode plate, and the cathode plate further includes an insulating coating, which is disposed on two opposite sides of the current collector, and is connected to one side of the active material layer along the second direction, and the orthographic projection of the insulating coating on the first insulating base film completely falls within the range of the orthographic projection of the first thermal insulation coating on the first insulating base film. In the above structure, the insulating coating is disposed on the cathode plate, which can further improve the insulation performance of the cathode plate, and the first thermal insulation coating covers the cathode insulating coating, which reduces the heat transfer from the cathode plate to the anode plate, and improves the stability of the battery cell operation.

[0016] In a second aspect, the present application provides a battery, which includes the battery cell in the above embodiment.

[0017] In a third aspect, the present application provides an electrical device, which includes the battery in the above embodiment, and the battery is used to provide electrical energy.

[0018] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0020] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0021] Figure 2 An exploded schematic diagram of a battery provided in some embodiments of the present application;

[0022] Figure 3 An exploded schematic diagram of a battery cell provided in some embodiments of the present application;

[0023] Figure 4 A schematic diagram of the structure of the electrode plates and the isolation member provided in some embodiments of the present application;

[0024] Figure 5 A schematic diagram of the structure of electrode plates and isolation members provided in other embodiments of the present application;

[0025] Figure 6 A schematic diagram of the structure of a first isolation sheet provided in some embodiments of the present application;

[0026] Figure 7 Schematic diagram of the structure of electrode plates and isolation components provided in some other embodiments of the present application.

[0027] Detailed description of reference numerals:

[0028] 1. Vehicle; 2. Battery; 10. Electrode assembly; 101. Electrode plate; 102. Spacer; 103. Spacer; 104. Insulation; 105. First spacer; 106. Second spacer; 107. First insulating base film; 108. First thermal insulation coating; 109. First sub-unit; 110. Second sub-unit;

[0029] 111, second heat-insulating coating; 112, current collector; 113, active material layer; 114, insulating coating;

[0030] 20. Shell; 25. Electrode terminal; 30. End cap; 40. Housing; 3. Controller; 4. Motor;

[0031] 5. Box body; 51. First box body part; 52. Second box body part; 53. Accommodation space; X. First direction; Y. Second direction; 7. Battery cell. DETAILED DESCRIPTION

[0032] The following embodiments of the technical solution of the present application will be described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0034] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0035] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0036] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0037] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0038] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0039] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0040] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0041] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0042] The term "plurality" used in the present application refers to two or more (including two).

[0043] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0044] Battery cells may include but are not limited to lithium ion battery cells, sodium ion battery cells, sodium lithium ion battery cells, lithium metal battery cells, sodium metal battery cells, lithium sulfur battery cells, magnesium ion battery cells, nickel metal hydride battery cells, nickel cadmium battery cells, lead storage battery cells, etc.

[0045] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell or a battery cell of other shapes. The prismatic battery cell includes a square shell battery cell, a blade-shaped battery cell, a polygonal battery, such as a hexagonal battery, etc. There is no particular limitation in the present application.

[0046] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0047] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module. Figure 2 As shown, a plurality of battery cells are stacked along the thickness direction to form a battery module.

[0048] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are accommodated in the case.

[0049] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0050] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0051] The battery disclosed in the embodiments of the present application can be used in an electrical device that uses the battery as a power source or in various energy storage systems that use the battery as an energy storage element. The electrical device can be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, and the like. Among them, the electric toy can include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like, and the spacecraft can include an airplane, a rocket, a space shuttle, and a spacecraft, and the like.

[0052] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0053] Figure 1 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application.

[0054] like Figure 1 As shown, a battery 2 is disposed inside the vehicle 1, and the battery 2 may be disposed at the bottom, head, or tail of the vehicle 1. The battery 2 may be used to power the vehicle 1, for example, the battery 2 may be used as an operating power source for the vehicle 1.

[0055] The vehicle 1 may further include a controller 3 and a motor 4 , wherein the controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1 .

[0056] In some embodiments of the present application, the battery 2 can not only serve as an operating power source for the vehicle 1, but also serve as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0057] Figure 2 Schematic diagram of an explosion of a battery provided in some embodiments of the present application. Figure 2 As shown, the battery 2 includes a box body 5 and a battery cell 7 , and the battery cell 7 is accommodated in the box body 5 .

[0058] The box body 5 is used to accommodate the battery cell 7, and the box body 5 can be a variety of structures. In some embodiments, the box body 5 can include a first box body part 51 and a second box body part 52, the first box body part 51 and the second box body part 52 cover each other, and the first box body part 51 and the second box body part 52 jointly define a storage space 53 for accommodating the battery cell. The second box body part 52 can be a hollow structure with one end open, the first box body part 51 is a plate-like structure, and the first box body part 51 covers the open side of the second box body part 52 to form a box body 5 with a storage space 53; the first box body part 51 and the second box body part 52 can also be a hollow structure with one side open, and the open side of the first box body part 51 covers the open side of the second box body part 52 to form a box body 5 with a storage space 53. Of course, the first box body part 51 and the second box body part 52 can be a variety of shapes, such as a cylinder, a cuboid, etc.

[0059] In order to improve the sealing performance after the first box body 51 and the second box body 52 are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 51 and the second box body 52 .

[0060] Assuming that the first box body portion 51 covers the top of the second box body portion 52 , the first box body portion 51 can also be referred to as an upper box cover, and the second box body portion 52 can also be referred to as a lower box body.

[0061] In the battery 2, the battery cell 7 can be one or more. If there are more than one battery cell 7, the battery cells 7 can be connected in series, in parallel or in mixed connection. Mixed connection means that the battery cells 7 are both connected in series and in parallel. The battery cells 7 can be directly connected in series, in parallel or in mixed connection, and then the whole formed by the battery cells 7 can be accommodated in the box 5; of course, the battery cells 7 can also be connected in series, in parallel or in mixed connection to form a battery module, and then the battery modules can be connected in series, in parallel or in mixed connection to form a whole, and then accommodated in the box 5.

[0062] Exemplarily, the battery cell 7 may be the smallest unit constituting the battery 2 .

[0063] Figure 3 An exploded schematic diagram of a battery cell provided in some embodiments of the present application.

[0064] like Figure 3 As shown, in some embodiments, the battery cell 7 includes a housing 40 and an electrode assembly 10 accommodated in the housing 40 .

[0065] The electrode assembly 10 includes a positive electrode and a negative electrode. During the charge and discharge process of the battery cell 7, active ions (such as lithium ions) are inserted and removed back and forth between the positive electrode and the negative electrode. Optionally, the electrode assembly 10 also includes a separator disposed between the positive electrode and the negative electrode, which can reduce the risk of short circuit between the positive and negative electrodes while allowing active ions to pass through.

[0066] The housing 40 is used to encapsulate the electrode assembly 10 and the electrolyte and other components. The housing 40 can be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing 40), or an aluminum-plastic film.

[0067] In some embodiments, the housing 40 includes a shell 20 and an end cover 30 . The shell 20 has an opening, and the end cover 30 is used to cover the opening.

[0068] The housing 20 is a component used to cooperate with the end cover 30 to form an internal cavity of the battery cell 7. The formed internal cavity can be used to accommodate the electrode assembly 10, electrolyte and other components.

[0069] The housing 20 and the end cap 30 may be independent components. For example, an opening may be provided on the housing 20, and the end cap 30 may be closed at the opening to form an internal cavity of the battery cell 7.

[0070] The end cover 30 is connected to the housing 20 by welding, bonding, clamping or other methods.

[0071] In some embodiments, the battery cell 7 includes an electrode terminal 25 . The electrode terminal 25 is electrically connected to the electrode assembly 10 to output or input electrical energy of the battery cell 7 .

[0072] In some embodiments, the battery cell 7 further includes an electrolyte contained in the housing 40. The electrolyte plays a role in conducting ions between the positive and negative electrodes. The electrolyte may be in a liquid, gel or solid state.

[0073] During the operation of the electrode assembly, a large amount of heat is released. Usually, a thermal insulation coating is set in the separator to insulate and reduce the heat transfer between the electrode assemblies. However, the thermal insulation coating will increase the thickness of the separator, especially the thickness of the separator outside the electrode sheet is large, which will occupy the space in the height direction of the wound electrode assembly, resulting in a decrease in the energy density of the battery cell.

[0074] Based on the above considerations, the present application proposes a battery cell, in which the battery cell is charged and discharged by setting electrode plates to release and store electrical energy in the battery. The isolating portion in the isolating member is arranged between the electrode plates to achieve insulation between the plates and reduce the risk of short circuit between the two plates. In particular, the insulating portion in the isolating member is arranged on the outside of the isolating member, which can reduce the risk of short circuit between the electrode assembly and the outer shell of the battery cell. In addition, at least part of the insulating portion is not provided with a thermal insulation coating to reduce the thickness of the insulating portion, reduce the weight of the isolating member and the space occupied, and improve the energy density of the battery cell.

[0075] The following is a detailed description of the battery cell provided in the embodiment of the present application in conjunction with the accompanying drawings. Figure 3 to Figure 4 , Figure 3 Schematic diagram of an explosion of a battery cell provided in some embodiments of the present application, Figure 4 A schematic diagram of the structure of electrode plates and isolation components provided in some embodiments of the present application.

[0076] As shown in the figure, an embodiment of the present application provides a battery cell 7, including two electrode plates 101 and a separator 102. The two electrode plates 101 are stacked along a first direction X. The separator 102 includes a separator 103 arranged opposite to the two electrode plates 101 and an insulating portion 104 connected to one side of the separator 103 along a second direction Y, at least part of the thickness of the insulating portion 104 is less than the thickness of the separator 103, and the second direction Y intersects with the first direction X.

[0077] Optionally, the two electrode sheets 101 and the separator 102 are stacked and can be directly assembled into the housing 40, or can be wound to form the electrode assembly 10 and then placed into the housing 40, which is not limited here.

[0078] The separator 102 is used to insulate and isolate the two electrode plates 101, and the separator 102 is provided with micropores for active ions to pass through, so as to realize charge transfer on the basis of ensuring insulation and isolation. In the electrode assembly 10, when the heat generation of the two electrode plates 101 is uneven, the electrode plate 101 with a higher temperature can easily transfer heat to the electrode plate 101 with a lower temperature. In order to reduce the thermal damage of the high-temperature electrode plate 101 to the low-temperature electrode plate 101 and improve the overall efficiency of the electrode assembly 10, a thermal insulation coating is usually provided on the separator 102 to reduce the heat conduction between the electrode plates 101 and improve the heat transfer efficiency between the electrode plates 101 and the housing 40, so as to reduce the overall temperature of the electrode assembly 10.

[0079] Optionally, the first direction X may be a thickness direction of the electrode plate 101 , and the second direction Y may be a width direction or a height direction of the electrode plate 101 .

[0080] The surface area of ​​the separator 102 is usually larger than the surface area of ​​the electrode plate 101. In the width direction, the two sides of the separator 102 are wider than the two sides of the electrode plate 101; in the height direction, the two ends of the separator 102 are also higher than the two ends of the electrode plate 101. The portion of the separator 102 that is higher than the electrode plate 101 or wider than the electrode plate 101 is usually also provided with a thermal insulation coating. The thickness of the thermal insulation coating occupies the space in the outer shell 40, reducing the energy density of the battery cell 7. The inventor noticed that the above-mentioned extra space is not provided with the electrode plate 101, so it does not need to play the role of heat insulation. The energy density of the battery cell 7 can be improved by reducing the thickness of the above-mentioned width portion.

[0081] In the technical solution of the embodiment of the present application, the battery cell 7 is charged and discharged by setting the electrode plate 101 in the battery 2. The isolating portion 103 in the isolating member 102 is arranged between the electrode plates 101 to achieve insulation between the plates and reduce the risk of short circuit between the two plates. In particular, the insulating portion 104 in the isolating member 102 is arranged outside the isolating member 102, which can reduce the risk of short circuit between the electrode assembly 10 and the outer shell 40 of the battery cell 7. In addition, at least part of the insulating portion 104 is not provided with a thermal insulation coating to reduce the thickness of the insulating portion 104, reduce the weight of the isolating member 102 and the space occupied, and improve the energy density of the battery cell 7.

[0082] In some embodiments of the present application, the battery cell 7 further includes an outer shell 40 , the outer shell 40 includes a shell body 20 and an end cover 30 , the shell body 20 has a receiving cavity, and the end cover 30 and the shell body 20 are arranged along the second direction Y.

[0083] In the above structure, since the insulating portion 104 is located between the isolating portion 103 and the end cover 30, the size of the battery cell 7 in the height direction will not be increased. This helps to reduce the space occupied by the battery cell 7 in the height direction, making the battery 2 more compact. By optimizing the spatial layout, the proportion of inactive materials (such as isolating members 102 and insulating materials) in the battery cell 7 is reduced, thereby increasing the proportion of active materials (such as electrode materials). This means that in a battery 2 of the same volume, more active materials can be accommodated, thereby increasing the energy density of the battery 2. In addition, the presence of the insulating portion 104 still ensures the electrical safety inside the battery cell 7 and prevents the occurrence of current leakage or short circuit.

[0084] In some embodiments of the present application, the isolation member 102 includes a first isolation sheet 105 and a second isolation sheet 106 , the first isolation sheet 105 is disposed between two electrode sheets 101 , there are two second isolation sheets 106 , and the two electrode sheets 101 are disposed between the two second isolation sheets 106 .

[0085] In the above structure, the first separator 105 is placed between the two electrode plates 101. The electrode plates 101 are the key parts of the battery 2 responsible for charge storage and transmission, so the insulation isolation between them is crucial. The main function of the first separator 105 is to prevent direct contact between the two electrode plates 101, thereby avoiding the occurrence of short circuit. This not only improves the safety of the battery 2, but also prevents the battery 2 from being damaged prematurely due to short circuit. The number of the second separators 106 is two, which are wrapped around the outside of the two electrode plates 101, further increasing the creepage distance between the two electrode plates 101. The creepage distance refers to the shortest distance on the surface of a solid insulating material, which determines the ability of the material surface to prevent current from passing under given working voltage and pollution conditions. Therefore, increasing the creepage distance helps to improve the insulation protection performance. By setting the second separator 106, the battery cell 7 can better resist the influence of external pollution and humid environment during operation, thereby improving the stability and reliability of the battery 2.

[0086] like Figure 5 As shown, in some embodiments of the present application, the number of the insulating portions 104 is two, and the two insulating portions 104 are disposed on opposite sides of the isolation portion 103 along the second direction Y.

[0087] In the above structure, the separator 102 in the battery cell not only includes a separator 103 for separating the electrode plates 101, but also includes two insulating parts 104. The two insulating parts 104 are arranged on opposite sides of the separator 103 along the second direction Y. The main purpose of providing the two insulating parts 104 is to ensure the electrical safety inside the battery cell 7 and prevent current leakage or short circuit. At the same time, this layout also helps to reduce the weight on both sides of the separator 102, thereby improving the energy density of the battery cell 7.

[0088] Specifically, since the insulating parts 104 are usually made of lightweight materials, they are relatively light in weight compared to other components of the battery 2 (such as the electrode plates 101, electrolyte, etc.). By arranging the insulating parts 104 on both sides of the isolating part 103 instead of attaching them to the isolating member 102 as an integral structure, the total weight of the isolating member 102 can be significantly reduced.

[0089] Reducing the weight of the separator 102 means that more active materials (such as electrode materials) can be accommodated in the battery cell 7 of the same volume, thereby improving the energy density of the battery 2. Energy density is one of the important indicators of the performance of the battery 2, which indicates the electrical energy that can be stored in the battery 2 per unit volume or per unit mass. Therefore, increasing the energy density can enable the battery 2 to have a higher energy output capacity under the same volume or mass.

[0090] like Figure 6As shown, in some embodiments of the present application, the first isolation sheet 105 includes a first insulating base film 107 and a first thermal insulation coating 108. The first insulating base film 107 includes a first sub-portion 109 and a second sub-portion 110 that are connected to each other. The first sub-portion 109 is arranged between the two electrode plates 101, and the second sub-portion 110 protrudes from one side of the first sub-portion 109 along the second direction Y. The first thermal insulation coating 108 is arranged on the opposite side surfaces of the first sub-portion 109. Among them, the first sub-portion 109 and the first thermal insulation coating 108 are the isolation portion 103, and the second sub-portion 110 is the insulation portion 104. It can be understood that the first sub-portion 109 and the first thermal insulation coating 108 form the isolation portion 103 of the first isolation sheet 105, and the second sub-portion 110 forms the insulation portion 104 of the first isolation sheet 105.

[0091] In the above structure, the first insulating base film 107 includes a first sub-portion 109 and a second sub-portion 110 which are connected to each other. The first sub-portion 109 is arranged between the two electrode plates 101, and serves to directly isolate the two electrode plates 101, thereby preventing direct contact and short circuit between them. The second sub-portion 110 protrudes from one side of the first sub-portion 109 along the second direction Y. This part serves as an insulating portion 104, which is used to achieve insulation between the electrode plates 101 and the outer shell 40. By ensuring that the positive projection of any electrode plate 101 on the isolation member 102 does not overlap with the insulating portion 104, direct contact between the electrode plate 101 and the outer shell 40 can be effectively avoided, thereby improving the safety of the battery 2.

[0092] The first thermal insulation coating 108 is disposed on the opposite side surfaces of the first sub-portion 109 of the first insulating base film 107. This coating can effectively prevent heat from being conducted between the two electrode plates 101, thereby reducing the temperature inside the battery 2. During the operation of the battery 2, the electrode plates 101 may generate heat due to chemical reactions and current transmission. If this heat cannot be effectively isolated and dissipated, it may cause the temperature inside the battery 2 to be too high, thereby affecting the performance and life of the battery 2. The provision of the first thermal insulation coating 108 can effectively solve this problem and improve the operating stability of the battery cell 7.

[0093] In some optional embodiments, the first sub-section 109 and the second sub-section 110 are integrally formed structures. Integral forming refers to completing the molding process of the entire part in one mold at one time. The first sub-section 109 and the second sub-section 110 can be made of the same insulating material, and the insulating material can form the isolation part 103 on the convex part of the corresponding electrode plate 101, and the second sub-section 110 is not coated with the insulating material to form the insulating part 104. The above structure improves manufacturing efficiency.

[0094] like Figure 5 as well as Figure 6As shown, in some embodiments of the present application, the first isolation sheet 105 further includes a second thermal insulation coating 111 , and the second thermal insulation coating 111 is disposed on a portion of the surface of the second sub-portion 110 .

[0095] The above structure can effectively reduce the heat conducted from the electrode plate 101 through the first sub-section 109 to the second sub-section 110 and further to other parts of the battery cell 7 or the housing 40. This helps to reduce the temperature inside the battery 2 and prevent performance degradation or safety hazards caused by overheating.

[0096] In some embodiments of the present application, the thickness of the second thermal insulation coating 111 is less than the thickness of the first thermal insulation coating 108. The above structure reduces the space occupied by the second thermal insulation coating 111 while realizing the function of reducing heat conduction of the second thermal insulation coating 111, thereby improving the energy density of the battery cell 7.

[0097] like Figure 7 As shown, in some embodiments of the present application, the electrode plate 101 includes a current collector 112 and an active material layer 113. The current collector 112 is disposed between the first separator 105 and the second separator 106. The active material layer 113 is disposed on two opposite surfaces of the current collector 112. The orthographic projection of the active material layer 113 on the current collector 112 completely falls within the range of the orthographic projection of the first thermal insulation coating 108 on the current collector 112.

[0098] In the above structure, first, the current collector 112 is arranged between the first separator 105 and the second separator 106, which is to ensure the stable position and electrical connection of the electrode plate 101 in the battery cell 7. As a carrier of current, the good conductivity of the current collector 112 is crucial to the performance of the battery 2. In addition, the active material layer 113 is arranged on two opposite surfaces of the current collector 112. The active material layer 113 is the main part of the battery 2 for storing and releasing electrical energy, so it usually dissipates a large amount of heat. During the operation of the battery 2, if the heat generated by the active material layer 113 cannot be dissipated in time, the temperature of the electrode assembly 10 will rise rapidly, thereby affecting the performance and operating efficiency of the battery 2. In order to reduce this risk, the design of the present application specifically considers the position and coverage of the first thermal insulation coating 108. Specifically, the positive projection of the active material layer 113 on the current collector 112 completely falls within the range of the positive projection of the first thermal insulation coating 108 on the current collector 112. This means that the first thermal insulation coating 108 completely covers the active material layer 113, forming an effective thermal insulation barrier.

[0099] Since the first heat-insulating coating 108 has good heat-insulating properties, it can effectively prevent the heat generated by the active material layer 113 from being conducted to the surroundings, thereby reducing the heat conduction between the electrode assemblies 10. This can not only reduce the temperature of the electrode assembly 10, reduce the performance degradation and safety hazards caused by overheating, but also improve the operating efficiency of the battery cell 7. Therefore, the above structure reduces the additional space occupied by the separator 102 while ensuring the operating efficiency of the battery cell 7, and improves the energy density of the battery cell 7.

[0100] In some embodiments of the present application, the electrode plate 101 is a cathode plate, and the cathode plate also includes an insulating coating 114. The insulating coating 114 is arranged on two opposite sides of the current collector 112. The insulating coating 114 is arranged on one side of the active material layer 113 along the second direction Y. The insulating coating 114 is within the range of the orthographic projection of the first insulating base film 107 and the orthographic projection of the first thermal insulation coating 108 on the first insulating base film 107.

[0101] In the above structure, the cathode electrode sheet includes a current collector 112, an active material layer 113 and an insulating coating 114. The current collector 112, as a carrier of current, is located between the first isolation sheet 105 and the second isolation sheet 106 to ensure stable transmission of current. The active material layer 113 is located on two opposite surfaces of the current collector 112 and is the main part for storing and releasing electrical energy in the battery 2. In particular, the insulating coating 114 is arranged on two opposite sides of the current collector 112 and is located on one side of the active material layer 113 along the second direction Y (usually the side facing the other electrode sheet 101). The insulating coating 114 can effectively isolate the current collector 112 from other potential conductive parts to prevent the occurrence of short circuits.

[0102] In particular, the orthographic projection of the insulating coating 114 on the first insulating base film 107 (i.e., the first sub-portion 109 of the first isolation sheet 105) completely falls within the range of the orthographic projection of the first thermal insulation coating 108 on the first insulating base film 107. That is, the first thermal insulation coating 108 not only covers the heat area that may be generated by the active material layer 113, but also further covers the insulating coating 114. Since the insulating coating 114 itself may also be affected by heat to a certain extent, the performance of the insulating coating 114 is not damaged, and the insulating performance of the cathode electrode is further improved.

[0103] At the same time, since the first thermal insulation coating 108 effectively covers the insulating coating 114, it can reduce the risk of heat from the cathode electrode piece being transferred to the anode electrode piece. During the operation of the battery 2, there may be a certain temperature difference between the cathode electrode piece and the anode electrode piece. If heat can be easily transferred between the two, it may cause performance degradation or safety hazards of the battery 2. Through the thermal insulation effect of the first thermal insulation coating 108, the heat of the cathode electrode piece is effectively isolated inside, reducing the impact on the anode electrode piece, thereby improving the stability of the operation of the battery cell 7.

[0104] In summary, by providing an insulating coating 114 on the cathode electrode and completely covering its orthographic projection within the range of the first thermal insulation coating 108, the embodiment of the present application provides a battery cell 7 structure with excellent insulation and thermal insulation properties, further improving the performance and safety of the battery 2 and meeting the standard requirements for higher power and higher charging rate.

[0105] like Figure 7 As shown, in some optional embodiments, along the second direction Y, the extension length of the second sub-portion 110 is H, and the value range of H is: 1mm≤H≤10mm. Preferably, 2mm≤H≤5mm. Exemplarily, H is 2.0mm, 2.5mm, 3.0mm, 3.5mm, 4.0mm, 4.5mm or 5.0mm.

[0106] The embodiment of the present application provides a battery 2, which includes the battery cell 7 in the above embodiment. The embodiment of the present application also provides an electrical device, which includes the battery 2 in the above embodiment, and the battery 2 is used to provide electrical energy. In the above technical solution, the battery cell 7 is charged and discharged by setting the electrode plate 101 in the battery 2. The isolation part 103 in the isolation member 102 is arranged between the electrode plates 101 to achieve insulation between the plates and reduce the risk of short circuit between the two plates. In particular, the insulating part 104 in the isolation member 102 is arranged on the outside of the isolation member 102, which can reduce the risk of short circuit between the electrode assembly 10 and the outer shell 40 of the battery cell 7. In addition, at least part of the insulating part 104 is not provided with a thermal insulation coating to reduce the thickness of the insulating part 104, reduce the weight of the isolation member 102 and the space occupied, and improve the energy density of the battery cell 7.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell (7), characterized in that: include: Two electrode plates (101) are stacked along a first direction (X); The isolating member (102) comprises an isolating portion (103) arranged opposite to the two electrode plates (101) and an insulating portion (104) connected to one side of the isolating portion (103) along a second direction (Y), wherein at least a portion of the thickness of the insulating portion (104) is smaller than the thickness of the isolating portion (103), and the second direction (Y) intersects with the first direction (X).

2. The battery cell (7) according to claim 1, characterized in that: The battery cell (7) further comprises an outer shell (40), wherein the outer shell (40) comprises a shell (20) and an end cover (30), wherein the shell (20) has a receiving cavity, and the end cover (30) and the shell (20) are arranged along the second direction (Y).

3. The battery cell (7) according to claim 1 or 2, characterized in that: The isolation member (102) comprises a first isolation sheet (105) and a second isolation sheet (106), wherein the first isolation sheet (105) is arranged between the two electrode sheets (101), and the number of the second isolation sheets (106) is two, and the two electrode sheets (101) are arranged between the two second isolation sheets (106).

4. The battery cell (7) according to claim 3, characterized in that: The number of the insulating parts (104) is two, and the two insulating parts (104) are arranged on two opposite sides of the isolation part (103) along the second direction (Y).

5. The battery cell (7) according to claim 4, characterized in that: The first isolation sheet (105) comprises: A first insulating base film (107) comprises a first sub-portion (109) and a second sub-portion (110) which are connected to each other, wherein the first sub-portion (109) is arranged between the two electrode plates (101), and the second sub-portion (110) protrudes from one side of the first sub-portion (109) along the second direction (Y); A first heat-insulating coating (108) is provided on two opposite surfaces of the first sub-portion (109), The first sub-portion (109) and the first thermal insulation coating (108) are the isolation portion (103), and the second sub-portion (110) is the insulating portion (104).

6. The battery cell (7) according to claim 5, characterized in that: The first isolation sheet (105) further comprises a second thermal insulation coating (111), wherein the second thermal insulation coating (111) is disposed on a portion of the surface of the second sub-section (110).

7. The battery cell (7) according to claim 6, characterized in that: The thickness of the second thermal insulation coating (111) is smaller than the thickness of the first thermal insulation coating (108).

8. The battery cell (7) according to claim 5, characterized in that: The electrode plate (101) comprises: A current collector (112) is disposed between the first isolation sheet (105) and the second isolation sheet (106); An active material layer (113) is disposed on two opposite surfaces of the current collector (112); The orthographic projection of the active material layer (113) on the current collector (112) completely falls within the range of the orthographic projection of the first thermal insulation coating (108) on the current collector (112).

9. The battery cell (7) according to claim 8, characterized in that: The electrode plate (101) is a cathode plate, and the cathode plate further comprises an insulating coating (114). The insulating coating (114) is arranged on two opposite sides of the current collector (112), and the insulating coating (114) is connected to one side of the active material layer (113) along the second direction (Y). The orthographic projection of the insulating coating (114) on the first insulating base film (107) completely falls within the range of the orthographic projection of the first thermal insulation coating (108) on the first insulating base film (107).

10. A battery (2), characterized in that: The invention comprises a battery cell (7) as claimed in any one of claims 1 to 9.

11. An electrical device, characterized in that: The electrical device comprises the battery (2) as claimed in claim 10, and the battery (2) is used to provide electrical energy.

Images