Battery monomer, battery device and power utilization device

Abstract

The utility model discloses a battery monomer, a battery device and a power utilization device, and belongs to the technical field of batteries. An electrode terminal arranged on the first wall is electrically connected with an electrode assembly located in the shell, the electrode terminal is located between the electrode assembly and a corresponding target surface, the target surface is located in an area defined by the heat dissipation surface, and the target surface is used for installing a convergence piece. The phase change device is laid on the outer side of the first wall and the outer side of the heat dissipation face. Through the arrangement of the phase change device, heat dissipation is performed on the electrode terminal and the shell wall, facing one side of the corresponding electrode terminal, of the shell.

Description

Technical Field

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

[0002] Batteries are being used more and more widely in daily life and industry. For example, new energy vehicles equipped with batteries are already widely used. In addition, batteries are increasingly being used in the field of energy storage.

[0003] In related technologies, during the normal operation of a battery cell, the electrode terminals of the battery cell and the shell wall on the side facing the corresponding electrode terminals generate a large amount of heat. Summary of the Invention

[0004] To solve the above-mentioned technical problems, this application provides a battery cell, a battery device, and an electrical device to dissipate heat from the electrode terminals and the casing wall on the side of the casing facing the corresponding electrode terminals during normal operation of the battery cell.

[0005] This application is achieved through the following technical solution.

[0006] A first aspect of this application provides a battery cell, comprising:

[0007] The outer shell, including the first wall;

[0008] The electrode assembly is located inside the housing;

[0009] An electrode terminal is disposed on the first wall and electrically connected to the electrode assembly. The electrode terminal has a target surface and a heat dissipation surface exposed on the housing. The electrode terminal is located between the electrode assembly and the corresponding target surface. The target surface is located within the area enclosed by the heat dissipation surface. The target surface is used to install a busbar.

[0010] A phase change device is installed on the outer side of the first wall and the outer side of the heat dissipation surface.

[0011] In this embodiment, a phase change device is provided on the outer side of the first wall. During normal operation of the battery cell, the phase change device generates a phase change, carrying away the heat released from the structure on the first wall used to electrically connect the electrode assembly and electrode terminals. Since the target surface is located within the area enclosed by the heat dissipation surface, and the heat dissipation surface is positioned relatively far outward from the electrode terminals in a direction perpendicular to the arrangement direction of the electrode assembly and corresponding electrode terminals, the heat dissipation surface of the electrode terminals has a large heat dissipation area, which is beneficial for heat dissipation. The phase change device is arranged on the heat dissipation surface and positioned on its outer side. During normal operation of the battery cell, the phase change device on the heat dissipation surface generates a phase change, which carries away the heat released from the electrode terminals. Because the heat dissipation surface is exposed to the outer casing, the phase change generated by the phase change device on the heat dissipation surface does not significantly affect the contact between the electrode terminals and the outer casing, and the battery cell can still maintain normal operation during the phase change process. Therefore, in this embodiment of the application, the phase change device is positioned in a manner that does not substantially affect the normal operation of the battery cell. The phase change device can dissipate heat from the heat dissipation surface with a large heat dissipation area on the electrode terminal, which is beneficial for better heat dissipation of the electrode terminal. The phase change device on the first wall can also effectively dissipate heat from the structure used to electrically connect the electrode assembly and the electrode terminal.

[0012] In some embodiments, the phase change device includes a phase change body for generating a phase change to dissipate heat from the electrode terminals in normal operation, wherein the phase change temperature of the phase change body is 28°C to 78°C.

[0013] In this embodiment, the phase change temperature of the phase change body is 28°C to 78°C, which makes the phase change temperature of the phase change body more suitable. The temperature conditions under normal working conditions of the battery cell are basically sufficient for the phase change body to generate phase change and absorb heat.

[0014] In some embodiments, the phase change device includes a phase change body for generating a phase change to dissipate heat from the electrode terminals in normal operation, the phase change body being made of a hydrated crystalline salt or an organic phase change material.

[0015] In this embodiment, the phase transition temperatures of crystalline hydrated salts and organic phase change materials are suitable, enabling them to undergo phase transitions during normal operation of the battery cell to better dissipate heat from the battery cell.

[0016] In some embodiments, the battery cell further includes an insulating film covering the outer side of the housing. The insulating film has a clearance opening for avoiding the electrode terminals. Along the opening direction of the clearance opening, the projection area of ​​the electrode terminals and the projection area of ​​the phase change device are both located within the projection area of ​​the clearance opening.

[0017] In this embodiment, an insulating film covering the outer surface of the outer casing protects the casing and provides a certain degree of insulation. Since the projection area of ​​the electrode terminals is located within the projection area of ​​the clearance opening, the insulating film avoids the electrode terminals through the clearance opening, allowing the electrode terminals to be exposed. Because the projection area of ​​the phase change device is located within the projection area of ​​the clearance opening, the phase change device avoids the insulating film, reducing the warping of the insulating film at the edge of the clearance opening and improving the insulation of the outer casing.

[0018] In some embodiments, the first wall is an end cap, the outer casing further includes a housing, the end cap covers the housing, the electrode assembly is located within the space enclosed by the end cap and the housing, and the phase change device includes a phase change body for generating a phase change to dissipate heat from the electrode terminals in normal operation, the phase change body including:

[0019] The first phase change body covers the side of the end cap opposite to the electrode assembly;

[0020] The second phase change body covers the outer side of the heat dissipation surface, and the second phase change body protrudes from the side of the first phase change body away from the electrode assembly.

[0021] In this embodiment, the second phase change body protrudes from the side of the first phase change body away from the electrode assembly, allowing the second phase change body to effectively dissipate heat from the heat dissipation surface located on the side of the cover away from the electrode assembly, thereby effectively dissipating heat from the electrode terminals. By dissipating heat from the heat dissipation surface of the electrode terminals through the protruding second phase change body, the thickness of the first phase change body along the arrangement direction of the electrode terminals and electrode assembly is almost unaffected by the heat dissipation requirements of the heat dissipation surface. The thickness of the first phase change body along the arrangement direction of the electrode terminals and electrode assembly can be set according to actual needs.

[0022] In some embodiments, the first wall has an injection hole for injecting electrolyte into the housing, the battery cell further includes a pressure relief mechanism mounted on the first wall, and the phase change device is located outside the area where the injection hole is located and the area where the pressure relief mechanism is located.

[0023] In this embodiment, the phase change device is located outside the areas where the injection port and the pressure relief mechanism are located. The phase change device avoids the injection port and the pressure relief mechanism, thus essentially not affecting the injection of liquid through the injection port and essentially not affecting the pressure relief mechanism's ability to release pressure in the event of thermal runaway.

[0024] In some embodiments, the electrode terminals include:

[0025] First insulating component;

[0026] A supporting frame is partially located within the first insulating member, and the supporting frame is connected to the first wall;

[0027] The main terminal is electrically connected to the electrode assembly. The main terminal portion is installed between the first wall and the first insulating member, and the outward portion of the main terminal is exposed in the first insulating member.

[0028] In this embodiment, the main terminal is electrically connected to the electrode assembly, and the electrode assembly provides or releases electrical energy through the main terminal. The first insulating member is supported by a support frame partially located within it, and the support frame is connected to the first wall, allowing the main terminal to be securely clamped between the first wall and the first insulating member.

[0029] In some embodiments, the phase change device further includes a retainer, wherein the phase change body is disposed in the retainer to prevent the phase change body from detaching from the retainer.

[0030] In this embodiment, the phase change body is placed in the retainer. By preventing the phase change body from detaching from the retainer, the dissipation of the phase change body during the phase change process can be reduced, which is beneficial for the phase change body in the phase change device to repeatedly perform phase change heat dissipation.

[0031] In some embodiments, the retainer has a receiving cavity in which the phase change body is located; or, the retainer is a porous carrier capable of generating a fuzzy response.

[0032] In this embodiment, the phase change subject is contained in the receiving cavity. After the phase change subject undergoes a phase change, it can remain essentially within the receiving cavity of the retainer, thereby reducing the dissipation of the phase change subject during the phase change process.

[0033] In some embodiments, the electrode assembly has a flat region, and the electrode assembly includes a positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode. The positive electrode, the separator, and the negative electrode are stacked in the thickness direction in the flat region, and the size of the battery cell along the thickness direction is 25mm to 35mm.

[0034] In this embodiment, the size of the battery cell along the thickness direction is 25mm to 35mm. The size of the battery cell along the thickness direction is suitable. On the one hand, the smaller size of the battery cell along the thickness direction is conducive to heat dissipation of the electrode assembly in the thickness direction. On the other hand, the size of the battery cell along the thickness direction is not too small.

[0035] In some embodiments, the first wall is the bottom wall of the outer casing along the direction of gravity.

[0036] In this embodiment, along the direction of gravity, the first wall is the bottom wall of the outer shell. Under the action of gravity, the electrode liquid inside the outer shell can be as close as possible to the electrode terminals, so that the electrolyte can dissipate heat from the structure of the electrode assembly and the electrode terminals that are electrically connected to the electrode terminals.

[0037] In some embodiments, the electrode assembly has tabs that are electrically connected to the electrode terminals.

[0038] In this embodiment, the electrode assembly can be conveniently electrically connected to the electrode terminals via the tabs.

[0039] In some embodiments, the battery cell further includes an adapter that is connected to the tab and the electrode terminal respectively to electrically connect the tab and the electrode terminal.

[0040] In this embodiment, the adapter is connected to the tab and the electrode terminal respectively, so that the position of the tab is not constrained by the position of the electrode end, and the position of the tab can be arranged according to actual needs.

[0041] In some embodiments, the portion of the electrode terminal located within the area enclosed by the heat dissipation surface is a solid structure.

[0042] In this embodiment, since the portion of the electrode terminal located within the area enclosed by the heat dissipation surface is a solid structure, the portion of the electrode terminal located within the area enclosed by the heat dissipation surface has a large current-carrying cross section, which is beneficial to reduce the resistance of the electrode terminal and reduce the heat generation of the electrode terminal.

[0043] A second aspect of this application provides a battery device, comprising:

[0044] Box;

[0045] The battery cell of any of the above types is installed in the housing and is used to store or provide electrical energy;

[0046] A busbar is electrically connected to at least two of the battery cells, and the busbar is in contact with the target surface.

[0047] In some embodiments, the busbar is welded to the electrode terminal at the target surface;

[0048] The phase change device is partially disposed in the busbar and located outside the welding area of ​​the busbar, or the phase change device is disconnected from the busbar.

[0049] In this embodiment, the welding zone is avoided to reduce the impact of the welding zone on the phase change device.

[0050] A third aspect of this application provides an electrical device, which is a battery cell or a battery device of any of the above types, wherein the battery cell or the battery device is used to store or provide electrical energy.

[0051] Beneficial effects

[0052] In the battery cell of this embodiment, a phase change device is provided on the outer side of the first wall. During normal operation of the battery cell, the phase change device generates a phase change, carrying away the heat released from the structure on the first wall used to electrically connect the electrode assembly and electrode terminals. Since the target surface is located within the area enclosed by the heat dissipation surface, and the heat dissipation surface is positioned relatively far outward from the electrode terminals in a direction perpendicular to the arrangement direction of the electrode assembly and corresponding electrode terminals, the heat dissipation surface of the electrode terminals has a large heat dissipation area, which is beneficial for heat dissipation. The phase change device is arranged on the heat dissipation surface and positioned on its outer side. During normal operation of the battery cell, the phase change device on the heat dissipation surface generates a phase change, which carries away the heat released from the electrode terminals. Because the heat dissipation surface is exposed to the outer casing, the phase change generated by the phase change device on the heat dissipation surface does not significantly affect the contact between the electrode terminals and the outer casing, and the battery cell can still maintain normal operation essentially during the phase change process. Therefore, in this embodiment of the application, the phase change device is positioned in a manner that does not substantially affect the normal operation of the battery cell. The phase change device can dissipate heat from the heat dissipation surface with a large heat dissipation area on the electrode terminal, which is beneficial for better heat dissipation of the electrode terminal. The phase change device on the first wall can also effectively dissipate heat from the structure used to electrically connect the electrode assembly and the electrode terminal. Attached Figure Description

[0053] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0054] Figure 1 This is a schematic diagram of the structure of the electrical device according to an embodiment of this application;

[0055] Figure 2 This is a schematic diagram of the battery device according to an embodiment of this application;

[0056] Figure 3 This is a schematic diagram of the structure of a single battery cell according to an embodiment of this application;

[0057] Figure 4 This is an assembly diagram of the insulating film, end cap, electrode terminals, pressure relief mechanism, and phase change device according to an embodiment of this application.

[0058] Figure 5 for Figure 4Sectional view at position AA in the middle;

[0059] Figure 6 for Figure 5 A magnified view at position B in the middle;

[0060] Figure 7 This is a schematic diagram of the structure in an embodiment of this application where at least two battery cells are electrically connected via a busbar.

[0061] Figure 8 This is a schematic diagram of the structure of the electrode assembly according to an embodiment of this application. The electrode assembly in the figure is a wound structure.

[0062] Figure 9 This is a schematic diagram of the structure of the electrode assembly according to an embodiment of this application. The electrode assembly in the figure is a stacked structure.

[0063] Explanation of reference numerals in the attached figures

[0064] 1000, Vehicle; 100, Battery Unit; 200, Controller; 300, Motor; 400, Housing; 401, First Housing; 402, Second Housing; 500, Battery Cell; 1, Outer Shell; 11, First Wall; 12, Shell; 131, Cover; 132, Insulator; 1321, First Insulator; 1322, Second Insulator; 2, Electrode Assembly; 21, Straight Area; 22, Corner Area; 23, Tab; 24, Positive Electrode; 25, Negative Electrode; 26, Isolator; 3, Electrode Terminal; 31, Target Surface; 32, Heat Dissipation Surface; 33, Main Terminal; 34, Support Frame; 4, Phase Change Device; 41, Phase Change Main Body; 411, First Phase Change Main Body; 412, Second Phase Change Main Body; 5, Insulating Film; 51, Clearance Opening; 6, Adapter; 7, Busbar; 8, Pressure Relief Mechanism; 9, Injection Hole. Detailed Implementation

[0065] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0066] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0067] In the description of the embodiments of this application, technical terms such as "first," "second," and "third" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0068] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0069] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects are in an "or" relationship.

[0070] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0071] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical term "contact" should be interpreted broadly, and can be direct contact, contact through an intermediate medium layer, contact between two contacting parties with substantially no interaction force, or contact between two contacting parties with interaction force.

[0072] In related technologies, the electrode assembly has a flat region. The electrode assembly includes a positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode. The positive electrode, separator, and negative electrode are stacked in the thickness direction in the flat region. The outer shell of some battery cells has a smaller size in the thickness direction, which results in a smaller size in the electrode terminals and the part of the structure that electrically connects the electrode terminals to the electrode assembly. This increases the internal resistance. During normal operation of the battery cell, the electrode terminals and the shell wall of the outer shell located on the side of the shell wall facing the corresponding electrode terminal generate a large amount of heat.

[0073] For example, the electrode assembly has tabs that are directly connected to the electrode terminals to make the electrode assembly electrically connected to the electrode terminals. The tabs have a small dimension in the thickness direction and generate a large amount of heat. The heat from the tabs is transferred to the shell wall on the side of the housing facing the corresponding electrode terminal, so that the shell wall on the side of the housing facing the corresponding electrode terminal generates a large amount of heat.

[0074] For example, the electrode assembly has tabs, and the battery cell also includes an adapter. The adapter is connected to the tabs and the electrode terminals respectively to make the electrode assembly electrically connected to the electrode terminals. The tabs have a smaller dimension in the thickness direction, and the adapter has a smaller dimension in the thickness direction. The heat generated by the tabs and the adapter is relatively large. The heat from the tabs and the adapter is transferred to the shell wall on the side of the housing facing the corresponding electrode terminal, resulting in a larger heat generation on the shell wall on the side of the housing facing the corresponding electrode terminal.

[0075] This embodiment of the application dissipates heat from the electrode terminals via a phase change device at the heat dissipation surface of the electrode terminals. Since the heat dissipation surface is located on the side of the preset contact surface away from the electrode assembly along the arrangement direction of the electrode assembly and the corresponding electrode terminals, the phase change device laid on the heat dissipation surface hardly affects the contact between the electrode terminals and the preset contact surface during the phase change process, and thus hardly affects the normal operation of the battery cell. The heat dissipation surface surrounds the target surface, which is located within the area enclosed by the heat dissipation surface. This results in the heat dissipation surface being relatively far from the center of the electrode terminals, and a large area of ​​the heat dissipation surface, which is beneficial for better heat dissipation from the electrode terminals. The shell wall of the outer casing, on the side of the electrode assembly facing the corresponding electrode terminal, is the first wall. The phase change device, laid on the outer side of the first wall, dissipates heat from the first wall of the outer casing, carrying away the heat from the shell wall on the side of the outer casing facing the corresponding electrode terminal.

[0076] The solutions in this application are not limited to battery cells, but can also be used in battery devices and electrical devices.

[0077] This application provides an electrical device; please refer to [link / reference]. Figure 1 This includes individual battery cells or battery devices used to store or provide electrical energy.

[0078] In one embodiment, the electrical device further includes a device body, and a battery device or battery cell is mounted on the device body to supply power to the device body.

[0079] Electrical devices are devices that use electrical energy as their energy source to perform corresponding functions by consuming electrical energy. For example, electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0080] The main body of a device refers to the main structure that consumes electrical energy to perform its corresponding functions. For example, an electrical device can be a mobile phone, where the main body is the part that enables communication and other functions, powered by individual battery cells or battery packs. Similarly, an electrical device can be a car, where the main body is the part that provides seating and allows the vehicle to move on the road, powered by individual battery cells or battery packs.

[0081] The following description will be based on an embodiment of the present application where the electrical device is a vehicle 1000.

[0082] One embodiment of this application provides a vehicle 1000 that can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended vehicle, etc. Please refer to... Figure 2 The vehicle 1000 has a battery device 100 installed inside, which can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, it can serve as the vehicle 1000's operating power source. The vehicle 1000 may also include a controller 200 and a motor 300, whereby the controller 200 can control the battery device 100 to supply power to the motor 300. For example, the battery device 100 can meet the power needs of the vehicle 1000 during startup, navigation, and operation.

[0083] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0084] In one embodiment, the battery device 100 may be a battery pack.

[0085] In one embodiment, the battery device 100 can be an energy storage device.

[0086] The battery device 100 of this application embodiment includes a battery cell 500. The battery cell 500 is used to store or provide electrical energy.

[0087] In this embodiment of the application, the battery cell 500 can be a secondary battery. A secondary battery refers to a battery cell 500 that can be used again after being discharged by recharging to activate the active materials.

[0088] The battery cell 500 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0089] The battery cell 500 includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator, with the separator disposed between the negative and positive electrodes. During the charging and discharging process of the battery cell 500, active ions (e.g., lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, disposed between the positive and negative electrodes, prevents short circuits between the positive and negative electrodes while allowing active ions to pass through. In some embodiments, the positive electrode can be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0090] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0091] As an example, the positive current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0092] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.8 Co 0.15 Al 0.05 At least one of O2 and its modified compounds. Modified compounds refer to substances obtained by modification methods such as doping or coating based on the above-mentioned substances.

[0093] In one embodiment, please refer to Figure 2 The battery device 100 also includes a housing 400, and individual battery cells 500 are installed inside the housing 400.

[0094] For example, the housing 400 may include a first housing 401 and a second housing 402. The first housing 401 and the second housing 402 are fastened together to form a closed space inside the housing 400 to accommodate the battery cells 500. Here, "closed" refers to covering or closing, and can be sealed or unsealed. The first housing 401 may be a top cover or a bottom plate.

[0095] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0096] As an example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material substrate and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0097] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0098] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0099] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cell 500. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for battery cell 500 may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0100] In some embodiments, the negative electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the negative electrode sheet, the surface of the foamed metal may or may not have a negative electrode active material.

[0101] As an example, negative electrode active materials can be filled or / and deposited within the negative electrode current collector.

[0102] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0103] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0104] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0105] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a single component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can also be applied to the surface of the separator.

[0106] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0107] In some embodiments, the battery cell 500 also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0108] Liquid electrolytes include electrolyte salts and solvents.

[0109] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0110] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0111] In some embodiments, the electrolyte may optionally include additives. For example, additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain performance of the battery cell 500, such as additives that improve the overcharge / fast charge performance of the battery cell 500, additives that improve the high-temperature performance of the battery cell 500, additives that improve the low-temperature performance of the battery cell 500, etc.

[0112] The gel electrolyte includes a polymer as a backbone network and can be used in conjunction with an ionic liquid-lithium salt.

[0113] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0114] As an example, the polymers of polymeric solid electrolytes may include polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids, cellulose, etc.

[0115] As an example, inorganic solid electrolytes can be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphorus sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0116] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0117] The electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0118] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0119] In some implementations, the electrode assembly is a stacked structure.

[0120] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0121] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0122] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0123] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0124] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0125] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0126] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0127] For the battery cell 500 in this embodiment, please refer to [link / reference needed]. Figures 3-6 The battery cell 500 includes a housing 1, an electrode assembly 2, electrode terminals 3, and a phase change device 4. The housing 1 includes a first wall 11. The electrode assembly 2 is located inside the housing 1. The electrode terminals 3 are disposed on the first wall 11 and electrically connected to the electrode assembly 2. The electrode terminals 3 have a target surface 31 and a heat dissipation surface 32 exposed on the housing 1. The electrode terminals 3 are located between the electrode assembly 2 and the corresponding target surface 31. The target surface 31 is located within the area enclosed by the heat dissipation surface 32 and is used to mount a busbar 7. The phase change device 4 is disposed on the outer side of the first wall 11 and the outer side of the heat dissipation surface 32.

[0128] The target surface 31 and the heat dissipation surface 32 are exposed outside the housing 1. The target surface 31 and the heat dissipation surface 32 are located on the outside of the housing 1, that is, the target surface 31 and the heat dissipation surface 32 are located on the side of the housing 1 away from the electrode assembly.

[0129] The target surface 31 is used to install the busbar 7. It can be that part of the target surface 31 is welded to the busbar 7, or the entire target surface 31 is welded to the busbar 7.

[0130] The target surface 31 is used to install the busbar 7, and the busbar 7 is in contact with the target surface 31 at least.

[0131] For example, the busbar 7 contacts the target surface 31, but the busbar 7 does not contact any other surface of the electrode terminal 3 other than the target surface 31.

[0132] For example, the bus 7 contacts the target surface 31 and other surfaces of the electrode terminal 3 besides the target surface 31.

[0133] The outer side of the first wall 11, that is, the side of the first wall 11 that is away from the electrode assembly 2.

[0134] The outer side of the heat dissipation surface 32, that is, the side of the heat dissipation surface 32 that is away from the area enclosed by the heat dissipation surface 32.

[0135] For example, please refer to Figure 3 , Figure 6 as well as Figure 7 The electrode assembly 2 and the corresponding electrode terminal 3 are arranged in the direction shown by arrow R1 in the figure.

[0136] For example, the phase change device 4 is surrounded around the heat dissipation surface 32.

[0137] The outer casing 1 is a structure for housing the electrode assembly 2, and the outer casing 1 is used to protect the electrode assembly 2.

[0138] The electrode assembly 2 includes a positive electrode 24, a negative electrode 25, and an insulating member 26. The insulating member 26 is disposed between the positive electrode 24 and the negative electrode 25.

[0139] For example, in addition to the isolation member 26 being provided between the positive electrode 24 and the negative electrode 25, the isolation member 26 may be provided on the side of the positive electrode 24 away from the negative electrode 25.

[0140] For example, in addition to the isolation member 26 being provided between the positive electrode 24 and the negative electrode 25, the isolation member 26 may be provided on the side of the negative electrode 25 away from the positive electrode 24.

[0141] For example, electrode terminal 3 can be a pole post.

[0142] Electrode terminal 3 is located between electrode assembly 2 and corresponding target surface 31. Target surface 31 is the end face of electrode terminal 3 facing away from electrode assembly 2 along the arrangement direction of electrode assembly 2 and corresponding electrode terminal 3. In other words, target surface 31 is the end face of electrode terminal 3 away from electrode assembly 2. Along the arrangement direction of electrode assembly 2 and corresponding electrode terminal 3, electrode terminal 3 is basically located on the side of target surface 31 facing electrode assembly 2.

[0143] The heat dissipation surface 32 surrounds the target surface 31, and the target surface 31 is located within the area enclosed by the heat dissipation surface 32. The heat dissipation surface 32 is approximately located at the edge of the target surface 31. The portion of the electrode terminal 3 between the two ends of the heat dissipation surface 32 along the arrangement direction of the electrode assembly 2 and the corresponding electrode terminal 3 is basically located within the area enclosed by the heat dissipation surface 32. The heat dissipation surface 32 is located at a relatively outer position of the electrode terminal 3 in a direction perpendicular to the arrangement direction of the electrode assembly 2 and the corresponding electrode terminal 3.

[0144] The phase change device 4 generates phase change heat absorption through the phase change body 41 of the phase change device 4.

[0145] For example, the phase change body 41 can be made of a material that is capable of undergoing a phase change between a solid phase and a liquid phase.

[0146] For example, the material of the phase change body 41 can be a material that can undergo a phase change between a solid phase and a gas phase.

[0147] For example, the phase change body 41 can be made of a material that is capable of undergoing a phase change between a liquid phase and a gas phase.

[0148] The outer side of the first wall 11 is the side of the first wall 11 that is away from the electrode assembly 2 along the arrangement direction of the electrode assembly 2 and the corresponding electrode terminal 3.

[0149] Battery cell 500 is working normally, meaning that battery cell 500 is undergoing a normal charging or discharging process without any major faults and without thermal runaway.

[0150] Contact between electrode terminal 3 and housing 1 means that electrode terminal 3 is in contact with the insulating part of housing 1.

[0151] The target surface 31 is located within the area enclosed by the heat dissipation surface 32, which surrounds the target surface 31.

[0152] The phase change device 4 is located on the side of the heat dissipation surface 32 away from the target surface 31, that is, the phase change device 4 is located on the side of the heat dissipation surface 32 away from the area enclosed by the heat dissipation surface 32.

[0153] In this embodiment, a phase change device 4 is provided on the outer side of the first wall 11. During normal operation of the battery cell 500, the phase change device 4 generates a phase change, carrying away the heat released from the structure on the first wall 11 used to electrically connect the electrode assembly 2 and the electrode terminal 3. Since the target surface 31 is located within the area enclosed by the heat dissipation surface 32, and the heat dissipation surface 32 is positioned relatively far outward from the electrode terminal 3 in a direction perpendicular to the arrangement direction of the electrode assembly 2 and the corresponding electrode terminal 3, the heat dissipation surface 32 of the electrode terminal 3 has a large heat dissipation surface area, which is beneficial for heat dissipation. The phase change device 4 is arranged on the heat dissipation surface 32 and positioned on its outer side. During normal operation of the battery cell 500, the phase change device 4 on the heat dissipation surface 32 generates a phase change, which carries away the heat released from the electrode terminal 3. Since the heat dissipation surface 31 is exposed to the outer casing 1, the phase change generated by the phase change device 4 arranged on the heat dissipation surface 32 does not substantially affect the contact between the electrode terminal 3 and the outer casing 1. The battery cell 500 can still maintain normal operation substantially during the phase change generated by the phase change device 4. Therefore, in this embodiment of the application, the phase change device 4 is positioned so as not to affect the normal operation of the battery cell 500. The phase change device 4 can dissipate heat from the heat dissipation surface 32 with a large area on the electrode terminal 3, which is beneficial to the better heat dissipation of the electrode terminal 3. The phase change device 4 on the first wall 11 can also better dissipate heat from the structure used to electrically connect the electrode assembly 2 and the electrode terminal 3.

[0154] In some embodiments, the phase change device 4 includes a phase change body 41 for generating a phase change to dissipate heat from the electrode terminal 3 in normal operation, and the phase change temperature of the phase change body 41 is 28°C to 78°C.

[0155] Phase transition temperature refers to the temperature at which the phase transition subject 41 undergoes a phase transition.

[0156] For example, the material of the phase change body 41 can be a material capable of undergoing a phase change between a solid phase and a liquid phase, and the temperature at which the phase change body 41 undergoes a phase change is the temperature at which the phase change body 41 transitions between a solid phase and a liquid phase.

[0157] For example, the material of the phase change body 41 can be a material that can generate a phase change between a solid phase and a gas phase, and the temperature at which the phase change body 41 generates a phase change is the temperature at which the phase change body 41 transitions between a solid phase and a gas phase.

[0158] For example, the material of the phase change body 41 can be a material that can generate a phase change between a liquid phase and a gas phase, and the temperature at which the phase change body 41 generates a phase change is the temperature at which the phase change body 41 transitions between a liquid phase and a gas phase.

[0159] For example, the phase change temperature of the phase change body 41 can be 28°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C or 78°C.

[0160] In this embodiment, the phase change temperature of the phase change body 41 is 28°C to 78°C, which makes the phase change temperature of the phase change body 41 more suitable. The temperature conditions of the battery cell 500 under normal operating conditions are basically sufficient to enable the phase change body 41 to generate phase change and absorb heat.

[0161] It is understood that the specific phase change temperature of the phase change body 41 is not limited, as long as it does not exceed the maximum normal operating temperature of the battery cell 500. For example, the phase change temperature of the phase change body 41 can be slightly less than 28°C. For example, the phase change temperature of the phase change body 41 can be slightly greater than 78°C.

[0162] In some embodiments, the phase change device 4 includes a phase change body 41 for generating a phase change to dissipate heat from the electrode terminal 3 in normal operation. The phase change body 41 is made of hydrated salt or paraffin.

[0163] Most hydrated salts can undergo a phase transition between the solid and liquid phases.

[0164] The latent heat of phase transition refers to the heat absorbed or released when a substance transforms from one phase to another under isothermal and isobaric conditions.

[0165] For example, a hydrated salt can be:

[0166] CaCl2·6H2O, calcium chloride hexahydrate, phase transition temperature 29℃, latent heat of phase transition 190.8J / g;

[0167] Na2SO4·10H2O, sodium sulfate decahydrate, phase transition temperature 32.4℃, latent heat of phase transition 241.0J / g;

[0168] Na2HPSO4·12H2O, sodium hydrogen phosphate dodecahydrate, phase transition temperature 35.0℃, latent heat of phase transition 256.6J / g;

[0169] CH3COONa·3H2O, sodium acetate trihydrate, phase transition temperature 58.6℃, latent heat of phase transition 286.3J / g;

[0170] Ba(OH)2·8H2O, barium hydroxide octahydrate, phase transition temperature 78.0℃, latent heat of phase transition 278.0J / g.

[0171] For example, organic phase change materials can be paraffin-based, and the phase change temperature can be changed by adjusting the number of carbon atoms, with a latent heat of phase change of approximately 200 J / g.

[0172] For example, organic phase change materials can be non-paraffinic. For instance, polyethylene glycol has a phase change temperature of 35.5°C and a latent heat of phase change of 265.0 J / g. Another example is hexadecanoic acid, which has a melting point of 57.8°C and a latent heat of phase change of 185.4 J / g.

[0173] In this embodiment, the phase transition temperatures of the crystalline hydrated salt and the organic phase change material are suitable, and they can generate a phase transition during the normal operation of the battery cell 500 to better dissipate heat from the battery cell 500.

[0174] It is understood that the specific material of the phase change body 41 is not limited, as long as it can generate phase change and absorb heat under the normal operating temperature conditions of the battery cell 500. For example, the material of the phase change body 41 can be other inorganic phase change materials other than hydrated salts.

[0175] In some embodiments, the phase change device 4 further includes a retainer, wherein the phase change body 41 is disposed in the retainer to prevent the phase change body 41 from detaching from the retainer.

[0176] For example, the retainer is at least laid on the heat dissipation surface 32.

[0177] For example, the retainer spans the heat dissipation surface 32 and the first wall 11.

[0178] For example, retainers are provided on the heat dissipation surface 32 and the first wall 11 respectively.

[0179] In this embodiment, the phase change body 41 is placed in the retainer. The retainer prevents the phase change body 41 from detaching from the retainer, which can reduce the dissipation of the phase change body 41 during the phase change process and facilitate the phase change body 41 in the phase change device 4 to repeatedly perform phase change heat dissipation.

[0180] It is understood that the specific structure of the phase change device 4 is not limited. For example, the phase change device 4 may not have a retainer, and the phase change body 41 may be directly laid on the first wall 11 or the heat dissipation surface 32.

[0181] In some embodiments, the retainer has a receiving cavity in which the phase change body 41 is located.

[0182] For example, the retainer can be a sealed container with a receiving cavity, and the phase change body 41 is disposed inside the sealed container. The liquid or gas generated after the phase change body 41 undergoes a phase change can be sealed inside the container to reduce the escape and loss of the phase change material.

[0183] In this embodiment, the phase change body 41 is contained in a receiving cavity. After the phase change occurs, the phase change body 41 remains essentially within the receiving cavity of the retainer, which reduces the leakage of the phase change body 41 during the phase change process. The capillary force between the retainer and the liquid generated after the phase change of the phase change body 41 ensures that the liquid is adsorbed within the retainer as much as possible, further reducing the leakage of the phase change body 41 during the phase change process.

[0184] In some embodiments, the retainer is a porous carrier capable of generating capillary action.

[0185] Capillary action is an adsorption phenomenon driven by the surface tension of a liquid.

[0186] In this embodiment, the capillary force between the retainer and the liquid generated after the phase change of the phase change body 41 makes the liquid adsorbed in the retainer as much as possible, thereby reducing the loss of the phase change body 41 during the phase change process.

[0187] In some embodiments, please refer to Figures 3-6 The first wall 11 is an end cap, and the outer shell 1 also includes a housing 12. The end cap covers the housing 12, and the electrode assembly 2 is located within the space enclosed by the end cap and the housing 12.

[0188] For example, the heat dissipation surface 32 may be located on the side of the end cap away from the electrode assembly 2 along the arrangement direction of the electrode assembly 2 and the corresponding electrode terminal 3.

[0189] The housing 12 is the main structure of the outer shell 1, and the housing 12 is used to house the electrode assembly 2.

[0190] For example, the housing 12 can be made of metal.

[0191] For example, the housing 12 may be made of aluminum or aluminum alloy.

[0192] For example, please refer to Figure 5 and Figure 6 The end cap includes a cover 131 that covers the housing 12, and the electrode assembly 2 is located within the space enclosed by the cover 131 and the housing 12.

[0193] The first wall 11 is an end cap, which includes a cap body 131, that is, the first wall 11 includes a cap body 131.

[0194] The cover 131 is the main structure of the end cap.

[0195] Electrode terminals 3 are inserted into the corresponding cover 131.

[0196] For example, the cover 131 can be made of metal.

[0197] For example, the cover 131 may be made of aluminum or aluminum alloy.

[0198] For example, the end cap also includes a second insulating member 1322, which is at least partially located on the side of the cap body 131 facing the electrode assembly 2. The cap body 131 may be made of a conductive material.

[0199] The first wall 11 is an end cap, and the end cap also includes a second insulating element 1322, that is, the first wall 11 also includes a second insulating element 1322.

[0200] For example, the electrode assembly 2 and the corresponding electrode terminal 3 are arranged in the vertical direction, and the second insulating member 1322 is made of plastic.

[0201] The end cap and the housing 12 are two parts manufactured independently. The end cap and the housing 12 are assembled together after they are manufactured separately.

[0202] The cover 131 and the shell 12 are two components manufactured independently. The cover 131 and the shell 12 are assembled together after they are manufactured separately.

[0203] For example, the battery cell 500 also includes a pressure relief mechanism 8, which is mounted on the end cap. Projected along the arrangement direction of the electrode assembly 2 and the corresponding electrode terminals 3, the projection area of ​​the pressure relief mechanism 8 is outside the projection area of ​​the phase change device 4. The pressure relief mechanism 8 is offset from the phase change device 4, so that in the event of thermal runaway of the battery cell 500, the thermal runaway ejection material discharged by the pressure relief mechanism 8 is less obstructed by the phase change device 4, allowing the pressure relief mechanism 8 to relieve pressure more effectively.

[0204] For example, the pressure relief mechanism 8 is installed on the cover 131.

[0205] In this embodiment, the heat released by the structure electrically connected to the electrode assembly 2 and the electrode terminal 3 is transferred to the end cover. The phase change device 4 is laid on the side of the end cover away from the electrode assembly 2, which can better absorb the heat released by the structure electrically connected to the electrode assembly 2 and the electrode terminal 3 to the end cover, and promote better heat dissipation of the structure electrically connected to the electrode assembly 2 and the electrode terminal 3.

[0206] It is understandable that the specific structure of the outer casing 1 is not limited. The outer casing 1 is a single, integral structure without independently assembled end caps.

[0207] In some embodiments, please refer to Figure 3 and Figure 6The first wall 11 is an end cap, and the outer shell 1 also includes a housing 12. The end cap covers the housing 12. The electrode assembly 2 is located within the space enclosed by the end cap and the housing 12. The phase change device 4 includes a phase change body 41 for generating a phase change to dissipate heat from the electrode terminal 3 in normal operation. The phase change body 41 includes a first phase change body 411 and a second phase change body 412. The first phase change body 411 covers the side of the end cap away from the electrode assembly 2. The second phase change body 412 covers the outer side of the heat dissipation surface 32 and protrudes from the side of the first phase change body 411 away from the electrode assembly 2.

[0208] The second phase change body 412 covers the outer side of the heat dissipation surface 32, and dissipates heat from the heat dissipation surface 32 through the second phase change body 412.

[0209] The cover 131 is the main structure of the end cap. The cover 131 covers the opening of the housing 12 to block the opening of the housing 12 as much as possible.

[0210] The heat dissipation surface 32 is located on the side of the end cover away from the electrode assembly 2. Along the arrangement direction of the electrode assembly 2 and the corresponding electrode terminal 3, the distance between the end cover and the electrode assembly 2 is smaller than the distance between the heat dissipation surface 32 and the electrode assembly 2.

[0211] For example, the phase change body 41 can be offset from the first insulating member 1321, and the phase change body 41 is not provided on the first insulating member 1321.

[0212] For example, the second phase change body 412 is laid on the heat dissipation surface 32.

[0213] For example, the second phase change body 412 is located inside the retainer, which is laid on the heat dissipation surface 32.

[0214] In this embodiment, the second phase change body 412 protrudes from the side of the first phase change body 411 away from the electrode assembly 2, allowing the second phase change body 412 to effectively dissipate heat from the heat dissipation surface 32 located on the side of the end cap away from the electrode assembly 2, thereby effectively dissipating heat from the electrode terminal 3. By dissipating heat from the heat dissipation surface 32 of the electrode terminal 3 through the protruding second phase change body 412, the thickness of the first phase change body 411 along the arrangement direction of the electrode terminal 3 and the electrode assembly 2 is almost unaffected by the heat dissipation requirements of the heat dissipation surface 32. The thickness of the first phase change body 411 along the arrangement direction of the electrode terminal 3 and the electrode assembly 2 can be set according to actual needs.

[0215] It is understood that the specific structure of the phase change body 41 is not limited. For example, the surface of the first phase change body 411 facing away from the electrode assembly 2 along the arrangement direction of the electrode assembly 2 and the corresponding electrode terminal 3, and the surface of the second phase change body 412 facing away from the electrode assembly 2 along the arrangement direction of the electrode assembly 2 and the corresponding electrode terminal 3, can be flush.

[0216] In some embodiments, please refer to Figures 3-6 The battery cell 500 also includes an insulating film 5, at least part of which covers the outside of the first wall 11. The insulating film 5 has a clearance opening 51 provided in the first wall 11, and the electrode terminal 3 and the phase change device 4 are both located within the clearance opening 51.

[0217] For example, the insulating film 5 can be a blue film.

[0218] For example, the blue film can be polyethylene terephthalate or a polyolefin material.

[0219] For example, the polyolefin material can be polypropylene or polyethylene.

[0220] For example, the insulating film 5 has a flange that covers the side of the end cap opposite to the electrode assembly 2 along the arrangement direction of the electrode assembly 2 and the corresponding electrode terminal 3. The flange forms a clearance opening 51.

[0221] In this embodiment, the insulating film 5 covering the outside of the first wall 11 protects the first wall 11 and provides insulation. Since both the electrode terminal 3 and the phase change device 4 are located within the clearance opening 51, the insulating film 5 avoids the electrode terminal 3 through the clearance opening 51, allowing the electrode terminal 3 to be exposed. Because both the electrode terminal 3 and the phase change device 4 are located within the clearance opening 51, the phase change device 4 avoids the insulating film 5, reducing the warping of the insulating film 5 at the edge of the clearance opening 51, which is beneficial for the insulating film 5 to better insulate the outer casing 1.

[0222] It is understood that the specific arrangement of the insulating film 5 is not limited. For example, the insulating film 5 may cover part of the phase change device 4.

[0223] In some embodiments, please refer to Figure 4 The first wall 11 has an injection hole 9 for injecting electrolyte into the housing 1. The battery cell also includes a pressure relief mechanism 8 installed on the first wall 11. The phase change device 4 is located outside the area where the injection hole 9 is located and the area where the pressure relief mechanism 8 is located.

[0224] For example, please refer to Figure 4 Projecting along the thickness direction of the first wall 11, the projection areas of the injection hole 9 and the pressure relief mechanism 8 are both located outside the projection area of ​​the phase change device 4.

[0225] In this embodiment, the phase change device 4 is located outside the area where the injection port 9 is located and the area where the pressure relief mechanism 8 is located. The phase change device 4 avoids the injection port 9 and the pressure relief mechanism 8, so the phase change device 4 will not affect the injection of liquid through the injection port 9, and will not affect the pressure relief mechanism 8 in the event of thermal runaway.

[0226] In some embodiments, please refer to Figure 6 The electrode terminal 3 includes a first insulating member 1321, a support frame 34, and a main terminal 33. The support frame 34 is partially located within the first insulating member 1321 and is connected to the first wall 11. The main terminal 33 is electrically connected to the electrode assembly 2, and is partially installed between the first wall 11 and the first insulating member 1321, with the outward portion of the main terminal protruding from the first insulating member.

[0227] The main terminal 33 is partially installed between the first wall 11 and the first insulating member 1321, and is held by the first wall 11 and the first insulating member 1321, which has a support frame 34 inside.

[0228] For example, the support frame 34 is welded to the first wall 11. The support frame 34 is made of metal, and the welded portion of the first wall 11 welded to the support frame 34 is also made of metal.

[0229] For example, the support frame 34 is partially exposed outside the first insulator 1321.

[0230] For example, please refer to Figure 6 The heat dissipation surface 32 includes the upper surface of the first insulating member that covers the surface of the support frame 34.

[0231] For example, the electrode assembly 2 and the first wall 11 are arranged along the direction of gravity, and the first insulating member 1321 is located on the upper side of the first wall 11. The first insulating member 1321 is made of plastic.

[0232] For example, the support frame 34 is embedded within the first insulating member 1321.

[0233] In this embodiment, the main terminal 33 is electrically connected to the electrode assembly 2, and the electrode assembly 2 provides or releases electrical energy through the main terminal 33. The first insulating member 1321 is supported by a support frame 34 located partially in the first insulating member 1321, and the support frame 34 is connected to the first wall 11, so that the main terminal 33 can be clamped relatively firmly between the first wall 11 and the first insulating member 1321.

[0234] It is understood that the specific structure of the electrode terminals is not limited. Exemplarily, the electrode terminals may include a main terminal 33 and a rivet block riveted to the main terminal 33. The main terminal 33 is electrically connected to the electrode assembly 2. The heat dissipation surface 32 includes the sidewall surface of the rivet block.

[0235] In some embodiments, please refer to Figure 8 and Figure 9The electrode assembly 2 has a flat region 21. The electrode assembly 2 includes a positive electrode 24, a negative electrode 25, and a separator 26 located between the positive electrode 24 and the negative electrode 25. The positive electrode 24, the separator 26, and the negative electrode 25 are stacked in the thickness direction in the flat region 21. The size of the battery cell 500 along the thickness direction is 25mm to 35mm.

[0236] For example, please refer to Figure 4 , Figure 8 and Figure 9 The thickness direction is as shown by arrow R2 in the figure.

[0237] For example, please refer to Figure 4 The thickness dimension of a single battery cell 500 is D1, where 25mm ≤ D1 ≤ 35mm.

[0238] For example, the dimensions of the battery cell 500 along the thickness direction can be 25mm, 27mm, 29mm, 30mm, 32mm, 34mm or 35mm.

[0239] For example, the direction perpendicular to the arrangement direction of the electrode assembly 2 and the electrode terminal 3 and the thickness direction is the width direction, and the dimension of the battery cell 500 in the width direction is 300mm to 340mm.

[0240] For example, please refer to Figure 3 , Figure 4 and Figure 8 The width direction is as shown by arrow R3 in the figure.

[0241] For example, please refer to Figure 3 The dimension of the battery cell 500 along the width direction is D2, 300mm≤D2≤340mm.

[0242] For example, the dimensions of the battery cell 500 along the width direction can be 300mm, 305mm, 310mm, 315mm, 320mm, 325mm, 330mm, 335mm or 340mm.

[0243] For example, the electrode assembly 2 is a stacked electrode assembly 2, in which the positive electrode 24, the separator 26 and the negative electrode 25 are stacked in the flat region 21.

[0244] For example, the electrode assembly 2 and the corresponding electrode terminal 3 are arranged in a cross direction in terms of both arrangement and thickness.

[0245] For example, the electrode assembly 2 is perpendicular to the arrangement direction and thickness direction of the corresponding electrode terminal 3.

[0246] For example, the electrode assembly 2 is a wound electrode assembly 2, and the electrode assembly 2 also has a corner area 22. Corner areas 22 are provided on both sides of the straight area 21. The arrangement direction of the corner areas 22 on both sides is intersected with the thickness direction and the arrangement direction of the electrode assembly 2 and the corresponding electrode terminal 3, respectively.

[0247] For example, the arrangement direction of the two corner areas 22 is perpendicular to the thickness direction and the arrangement direction of the electrode assembly 2 and the corresponding electrode terminal 3, respectively.

[0248] In this embodiment, the size of the battery cell 500 along the thickness direction is 25mm to 35mm. The size of the battery cell 500 along the thickness direction is suitable. On the one hand, the smaller size of the battery cell 500 along the thickness direction is conducive to heat dissipation of the electrode assembly 2 in the thickness direction. On the other hand, the size of the battery cell 500 along the thickness direction is not too small.

[0249] It is understood that the specific dimensions of the battery cell 500 along the thickness direction are not limited. For example, the dimension of the battery cell 500 along the thickness direction can be appropriately less than 25mm, or the dimension of the battery cell 500 along the thickness direction can be greater than 35mm.

[0250] In some embodiments, please refer to Figure 7 Along the direction of gravity, the first wall 11 is the bottom wall of the outer shell 1.

[0251] Along the direction of gravity, the first wall 11 is the bottom wall of the outer shell 1, and the electrode assembly 2 and the electrode terminal 3 are arranged along the direction of gravity.

[0252] In this embodiment, along the direction of gravity, the first wall 11 is the bottom wall of the outer shell 1. Under the action of gravity, the electrode liquid inside the outer shell 1 can get as close as possible to the electrode terminal 3, so that the electrolyte can dissipate heat from the structure of the electrode assembly 2 and the electrode terminal 3 that are electrically connected.

[0253] It is understood that the specific structure of the electrode terminal 3 is not limited. For example, the electrode terminal 3 may be located on the upper side of the housing 1.

[0254] In some embodiments, please refer to Figure 3 The electrode assembly 2 has a tab 23, which is electrically connected to the electrode terminal 3.

[0255] In this embodiment, the electrode assembly 2 can be conveniently electrically connected to the electrode terminal 3 via the tab 23.

[0256] It is understood that the specific structure of the electrode assembly 2 is not limited. For example, the electrode assembly 2 may not have tab 23, and the electrode assembly 2 may be connected to the electrode terminal 3 via a positive electrode 24 or a negative electrode 25 to make the electrode assembly 2 electrically connected to the electrode terminal 3.

[0257] In some embodiments, please refer to Figure 3 , Figure 5 and Figure 6 The battery cell 500 also includes an adapter 6, which is connected to the tab 23 and the electrode terminal 3 respectively to make the tab 23 and the electrode terminal 3 electrically connected.

[0258] For example, adapter 6 can be an adapter piece.

[0259] In this embodiment, the adapter 6 is connected to the tab 23 and the electrode terminal 3 respectively, so that the position of the tab 23 is not constrained by the position of the electrode end, and the position of the tab 23 can be arranged according to actual needs.

[0260] It is understood that the specific structure for the electrical connection between the tab 23 and the electrode terminal 3 is not limited. For example, the battery cell 500 may not have the adapter 6, and the tab 23 may be connected to the electrode terminal 3 to make the tab 23 electrically connected to the electrode terminal 3.

[0261] In some embodiments, please refer to Figure 6 The portion of the electrode terminal 3 located within the area enclosed by the heat dissipation surface 32 is a solid structure.

[0262] The portion of electrode terminal 3 within the area enclosed by heat dissipation surface 32 is a solid structure, and there are no machined cavities in this portion. Uncontrollable voids or porosity generated during the molding process of the material itself are not considered machined cavities.

[0263] In this embodiment, since the portion of the electrode terminal 3 located within the area enclosed by the heat dissipation surface 32 is a solid structure, the portion of the electrode terminal 3 located within the area enclosed by the heat dissipation surface 32 has a large current-carrying cross section, which is beneficial to reduce the resistance of the electrode terminal 3 and reduce the heat generation of the electrode terminal 3.

[0264] In some embodiments, the battery device 100 further includes a busbar 7 electrically connected to at least two battery cells 500, and the busbar 7 is in contact with the target surface 32.

[0265] In some embodiments, please refer to Figure 7 The busbar 7 is welded to the electrode terminal 3 at the target surface 32. The phase change device 4 is partially disposed on the busbar 7 and located outside the welding area of ​​the busbar 7, or the phase change device 4 is not in contact with the busbar 7.

[0266] For example, the bus 7 can be a bus.

[0267] For example, the busbar 7 can be a copper busbar or an aluminum busbar.

[0268] For example, at least two battery cells 500 are connected in series, in parallel, or in a mixed configuration via the busbar 7.

[0269] In this embodiment, the phase change device 4 is partially disposed on the busbar 7 and located outside the welding area of ​​the busbar 7. The phase change device 4 can better dissipate heat from the busbar and reduce the influence of the welding area of ​​the busbar 7 on the phase change of the phase change device 4. The phase change device 4 is disengaged from the busbar 7, thus avoiding the welding area on the busbar 7.

[0270] It is understood that the arrangement of the busbar 7 and the electrode terminal 3 is not limited. For example, the busbar 7 may be in contact with the heat dissipation surface 32.

[0271] In some embodiments, please refer to Figures 1-9The battery cell 500 includes a housing 1, an electrode assembly 2, electrode terminals 3, and a phase change device 4. The electrode assembly 2 is located inside the housing 1. The electrode terminals 3 are electrically connected to the electrode assembly 2 and are mounted on the housing 1. The electrode terminals 3 have a target surface 31 and a heat dissipation surface 32, and are located between the electrode assembly 2 and the corresponding target surface 31. The target surface 31 is located within the area enclosed by the heat dissipation surface 32. The phase change device 4 is located on the side of the housing 1 facing the corresponding electrode terminal 3 of the electrode assembly 2, forming a first wall 11. The phase change device 4 is laid on the outer side of the first wall 11 and the heat dissipation surface 32, surrounding the heat dissipation surface 32. The phase change device 4 is located on the side of the heat dissipation surface 32 away from the target surface 31. The phase change device 4 includes a phase change body 41 for generating a phase change to dissipate heat from the electrode terminals 3 during normal operation. The battery cell 500 has a thickness of 25mm to 35mm and a width of 300mm to 340mm. The thickness of the first phase change body 411 is less than or equal to 50% of the distance between the target surface 31 of the electrode terminal 3 and the cover 131. The battery device 100 also includes a busbar 7 electrically connected to at least two battery cells 500. The busbar 7 is welded to the electrode terminal 3 to achieve electrical connection between the busbar 7 and the electrode terminal 3, and the busbar 7 contacts the target surface 31. Each battery cell 500 also includes an insulating film 5 covering the outer side of the housing 1. The insulating film 5 has a clearance opening 51 for avoiding the electrode terminal 3. Along the opening direction of the clearance opening 51, the projection area of ​​the electrode terminal 3 and the projection area of ​​the phase change device 4 are both located within the projection area of ​​the clearance opening 51. The insulating film 5 has a flange covering the end cap on the side opposite to the electrode assembly 2 along the arrangement direction of the electrode assembly 2 and the corresponding electrode terminal 3. The flange forms the clearance opening 51. The phase change device 4 is located within the clearance opening 51. The phase change host 41 can be made of the following materials: CaCl2·6H2O (calcium chloride hexahydrate, phase change temperature 29℃, latent heat of phase change 190.8 J / g); Na2SO4·10H2O (sodium sulfate decahydrate, phase change temperature 32.4℃, latent heat of phase change 241.0 J / g); Na2HPSO4·12H2O (sodium hydrogen phosphate dodecahydrate, phase change temperature 35.0℃, latent heat of phase change 256.6 J / g); CH3COONa·3H2O (sodium acetate trihydrate, phase change temperature 58.6℃, latent heat of phase change 286.3 J / g); or Ba(OH)2·8H2O (barium hydroxide octahydrate, phase change temperature 78.0℃, latent heat of phase change 278.0 J / g). The phase change host 41 can also be made of paraffin wax, and the phase change temperature can be changed by adjusting the number of carbon atoms; the latent heat of phase change is approximately 200 J / g. The phase change substrate 41 can be made of a non-paraffinic material. For example, polyethylene glycol has a phase change temperature of 35.5℃ and a latent heat of phase change of 265.0 J / g. For example, hexadecanoic acid has a melting point of 57.8℃ and a latent heat of phase change of 185.4 J / g.

[0272] The above embodiments are merely illustrative of the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The outer shell, including the first wall; The electrode assembly is located inside the housing; An electrode terminal is disposed on the first wall and electrically connected to the electrode assembly. The electrode terminal has a target surface and a heat dissipation surface exposed in the housing. The electrode terminal is located between the electrode assembly and the corresponding target surface. The target surface is located in the area enclosed by the heat dissipation surface. The target surface is used to install a busbar. A phase change device is installed on the outer side of the first wall and the outer side of the heat dissipation surface.

2. The battery cell according to claim 1, characterized in that, The phase change device includes a phase change body for generating a phase change to dissipate heat from the electrode terminals in normal operation, wherein the phase change temperature of the phase change body is 28°C to 78°C.

3. The battery cell according to claim 1, characterized in that, The phase change device includes a phase change body for generating a phase change to dissipate heat from the electrode terminals in normal operation. The phase change body is made of hydrated crystalline salt or organic phase change material.

4. The battery cell according to any one of claims 1 to 3, characterized in that, The battery cell also includes an insulating film, at least a portion of which covers the outside of the first wall. The insulating film has a clearance opening in the first wall, and the electrode terminals and the phase change device are both located within the clearance opening.

5. The battery cell according to any one of claims 1 to 3, characterized in that, The first wall is an end cap, and the outer shell further includes a housing. The end cap covers the housing, and the electrode assembly is located within the space enclosed by the end cap and the housing. The phase change device includes a phase change body for generating a phase change to dissipate heat from the electrode terminals during normal operation. The phase change body includes: The first phase change body covers the side of the end cap opposite to the electrode assembly; The second phase change body covers the outer side of the heat dissipation surface, and the second phase change body protrudes from the side of the first phase change body away from the electrode assembly.

6. The battery cell according to any one of claims 1 to 3, characterized in that, The first wall has an injection hole for injecting electrolyte into the housing. The battery cell also includes a pressure relief mechanism installed on the first wall. The phase change device is located outside the area where the injection hole is located and the area where the pressure relief mechanism is located.

7. The battery cell according to any one of claims 1 to 3, characterized in that, The electrode terminals include: First insulating component; A supporting frame is partially located within the first insulating member, and the supporting frame is connected to the first wall; The main terminal is electrically connected to the electrode assembly. The main terminal portion is installed between the first wall and the first insulating member, and the outward portion of the main terminal is exposed in the first insulating member.

8. The battery cell according to any one of claims 1 to 3, characterized in that, The phase change device further includes a retainer and a phase change body for generating a phase change to dissipate heat from the electrode terminals in normal operation, the phase change body being disposed in the retainer to prevent the phase change body from detaching from the retainer.

9. The battery cell according to claim 8, characterized in that, The retainer has a receiving cavity, and the phase change body is located in the receiving cavity; or, the retainer is a porous carrier capable of generating capillary action.

10. The battery cell according to any one of claims 1 to 3, characterized in that, The electrode assembly has a flat region. The electrode assembly includes a positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode. The positive electrode, the separator, and the negative electrode are stacked in the thickness direction in the flat region. The size of the battery cell along the thickness direction is 25mm to 35mm.

11. The battery cell according to any one of claims 1 to 3, characterized in that, Along the direction of gravity, the first wall is the bottom wall of the outer shell.

12. The battery cell according to any one of claims 1 to 3, characterized in that, The electrode assembly has tabs that are electrically connected to the electrode terminals.

13. The battery cell according to claim 12, characterized in that, The battery cell also includes an adapter, which is connected to the tab and the electrode terminal respectively to make the tab and the electrode terminal electrically connected.

14. The battery cell according to any one of claims 1 to 3, characterized in that, The portion of the electrode terminal located within the area enclosed by the heat dissipation surface is a solid structure.

15. A battery device, characterized in that, include: Box; The battery cell according to any one of claims 1 to 14 is installed in the housing and is used to store or provide electrical energy; A busbar is electrically connected to at least two of the battery cells, and the busbar is in contact with the target surface.

16. The battery device according to claim 15, characterized in that, The busbar is welded to the electrode terminal at the target surface; The phase change device is partially disposed in the busbar and located outside the welding area of ​​the busbar, or the phase change device is disconnected from the busbar.

17. An electrical device, characterized in that, Includes a battery cell according to any one of claims 1 to 14 or a battery device according to claim 15 or 16, wherein the battery cell or the battery device is used to store or provide electrical energy.

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