Battery device and power device

Abstract

The embodiment of the present application provides a battery device and an electric device, wherein the battery device includes a box, a battery cell assembly and a plurality of connection units, wherein the battery cell assembly is located in the box, the battery cell assembly includes a plurality of busbars and a plurality of battery cells connected in series, the battery cell includes at least two battery cells connected in parallel through two busbars, and the battery cell includes an end cap, an electrode assembly, a connector and an electrode terminal; the plurality of connection units are arranged on at least one battery cell, and the two connectors of the battery cell and the end cap of the battery cell are both insulated and provided with connection units, or the two busbars connected to the battery cell and the end cap of the battery cell are both insulated and provided with connection units, and the connection units are configured to make the end cap and the adapter or the end cap and the busbar conductively connected when thermal runaway occurs in the battery cell. The present application can improve the reliability of the battery device.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and more specifically, to a battery device and an electrical device. Background Art

[0002] Battery monomers are widely used in electronic devices, such as mobile phones, laptop computers, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools, etc.

[0003] In the development of battery technology, how to improve the reliability of battery devices is a research direction in battery technology. Summary of the invention

[0004] The present application provides a battery device and an electrical device, which can improve the reliability of the battery device.

[0005] An embodiment of the present application provides a battery device, including a case, a battery cell assembly and a plurality of connection units, wherein the battery cell assembly is located in the case, the battery cell assembly includes a plurality of busbars and a plurality of battery cells connected in series, the battery cell includes at least two battery cells connected in parallel via two busbars, the battery cell includes an end cap, an electrode assembly, a adapter and an electrode terminal, the electrode assembly is electrically connected to the electrode terminal via the adapter, the electrode terminal is insulated on the end cap, and the adapter and the busbar are insulated from the end cap, respectively; a plurality of connection units are arranged on at least one battery cell, a connection unit is insulated between two adapters of the battery cell and the end cap of the battery cell, or a connection unit is insulated between two busbars connected to the battery cell and the end cap of the battery cell, and the connection unit is configured to conductively connect the end cap and the adapter or the end cap and the busbar when thermal runaway occurs in the battery cell.

[0006] In the above technical scheme, the battery device of the embodiment of the present application is provided with a connecting unit. When a battery cell has thermal runaway, the connecting unit makes the end cover and the adapter or the end cover and the busbar conductively connected of the battery cell in thermal runaway, so that the two battery cells form a short-circuit loop with a large current. The large current causes the busbar or the adapter in the short-circuit loop to melt. After the busbar or the adapter melts, the short-circuit loop is disconnected, and the loop formed when the battery cell in thermal runaway is regarded as a resistor is also disconnected. The parallel battery cells almost no longer generate heat, which reduces the risk of thermal runaway and improves the reliability of the battery device.

[0007] In some embodiments, the connecting unit includes a connected conductive member and an insulating member; the conductive member is electrically connected to the end cap, and the insulating member is connected to the adapter or the bus, or the conductive member is electrically connected to the adapter or the bus, and the insulating member is connected to the end cap; the melting point of the insulating member is lower than the melting point of the conductive member, and when the insulating member melts, the conductive member deforms and becomes conductively connected to the component to which the insulating member was connected before melting.

[0008] In the above technical solution, the connection unit is configured to include a conductive member and an insulating member, and the conductive member is deformed during thermal runaway to achieve conductive connection between the end cap and the adapter or between the end cap and the busbar. This connection unit is not only more reliable to use.

[0009] In some embodiments, the conductive member includes an elastic portion, which is configured to be in a compressed state and store elastic potential energy before the insulating member melts, and the elastic portion is configured to release the elastic potential energy and stretch when the insulating member melts, so that the conductive member can achieve a conductive connection between the end cap and the transition member or the end cap and the busbar.

[0010] In the above technical solution, the elastic part is used to release elastic potential energy and stretch to achieve conductive connection between the end cover and the adapter or the end cover and the busbar. This arrangement is more reliable and has lower cost.

[0011] In some embodiments, the elastic portion is a conductive structure and is used for conductive connection between the end cap and the adapter or between the end cap and the busbar.

[0012] In the above technical solution, the elastic part is set as a conductive structure, which is conductively connected to the component connected to the insulating part before melting after deformation, which can simplify the structure of the connecting unit.

[0013] In some embodiments, the conductive member includes a deformable portion, and the deformable portion is configured to be deformed by heat when the insulating member is melted, so as to conductively connect the end cap and the transition member or the end cap and the busbar.

[0014] In the above technical solution, the deformable portion is deformed by temperature to achieve conductive connection between the end cap and the adapter or between the end cap and the busbar. This method is more reliable to use.

[0015] In some embodiments, the insulating member includes a protective cover, the conductive member includes a conductive seat body, the protective cover is disposed on the conductive seat body and is surrounded by the conductive seat body to form a receiving cavity, the deformable portion of the conductive member is electrically connected to the conductive seat body and is located in the receiving cavity, one of the conductive seat body and the insulating member is connected to the end cap, and the other is connected to the adapter or the busbar.

[0016] In the above technical solution, a protective cover is provided, and a receiving cavity is formed by the protective cover and the conductive seat to accommodate the deformable part of the conductive member. In this way, not only the deformable part is well protected, but the protective cover can also reduce the possibility of the conductive member moving or deforming during use and causing a short circuit, thereby improving the reliability of the battery device.

[0017] In some embodiments, the protective cover is disposed on a side of the conductive base body facing the deformable portion of the conductive member.

[0018] In the above technical solution, the area of ​​the conductive base can be increased, and the reliability of the electrical connection between the conductive base and the corresponding components can be improved.

[0019] In some embodiments, the conductive member further includes a conductive cover plate, which is disposed in the accommodating cavity and connected to an end of the deformable portion of the conductive member away from the conductive seat body. The conductive cover plate is configured to abut against the component connected to the insulating member before the insulating member melts when the insulating member melts.

[0020] In the above technical solution, a conductive cover plate is provided, and when the insulating member melts, the contact area between the conductive member and the component connected before the insulating member melts is increased, thereby improving the current carrying capacity of the connection unit.

[0021] In some embodiments, a plurality of conductive protrusions are disposed on a side of the conductive cover plate facing away from the conductive base body, and the plurality of conductive protrusions are configured to abut against components connected to the insulating member before the insulating member melts when the insulating member melts.

[0022] In the above technical solution, the conductive protrusion is provided so that after the conductive cover plate is tilted, it can still be in good contact with the components connected before the insulating member melts, thereby improving the reliability of the connection unit.

[0023] In some embodiments, all battery cells of at least one battery unit are provided with a connection unit.

[0024] In the above technical solution, no matter which battery cell in the battery unit experiences thermal runaway, a short circuit can be formed and then cut off, further reducing the possibility of thermal runaway of the battery cell and improving the reliability of the battery device.

[0025] In some embodiments, the melting point of the insulating member is T1, and T1 satisfies: 200°C≤T1≤400°C.

[0026] In the above technical solution, the melting point of the insulating member is set to be greater than or equal to 200°C to meet the insulation requirements of the battery device during normal use. The melting point of the insulating member is limited to less than or equal to 400°C so that the insulating member can melt in time when thermal runaway occurs.

[0027] In some embodiments, T1 satisfies: 200°C≤T1≤250°C.

[0028] In the above technical solution, the melting point of the insulating member is further limited to greater than or equal to 200°C to further meet the insulation requirements of the battery device during normal use. The melting point of the insulating member is further limited to less than or equal to 250°C so that the insulating member can melt faster when thermal runaway occurs.

[0029] In some embodiments, the battery cells are prismatic battery cells.

[0030] In the above technical solution, the adapter of the square shell battery cell is more easily melted by heat and is more applicable.

[0031] In a second aspect, an embodiment of the present application further provides an electrical device, comprising the above-mentioned battery device, and the battery device is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without paying creative work.

[0033] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0034] Figure 2 A schematic diagram of the structure of a battery device provided in some embodiments of the present application;

[0035] Figure 3 A schematic diagram of an exploded structure of a battery unit and a busbar provided in some embodiments of the present application;

[0036] Figure 4 A top view of a battery cell and a busbar provided in some embodiments of the present application;

[0037] Figure 5 for Figure 4 A cross-sectional view of the battery cell and the busbar at AA is shown;

[0038] Figure 6 for Figure 5 Enlarged view at B;

[0039] Figure 7 Another structural schematic diagram of a battery unit and a busbar provided in some embodiments of the present application;

[0040] Figure 8 Another top view of a battery cell and a busbar provided in some embodiments of the present application;

[0041] Fig. 9 for Figure 8 A cross-sectional view of the battery cell and the busbar at CC is shown;

[0042] Fig.10 for Fig. 9 Enlarged view at D;

[0043] Fig.11 A schematic diagram of a structure of a connection unit in a battery device provided in some embodiments of the present application;

[0044] Fig.12 for Fig.11 The structural schematic diagram of the connecting unit shown is from another angle;

[0045] Fig.13 Another structural schematic diagram of a connection unit in a battery device provided in some embodiments of the present application;

[0046] Fig.14 A schematic diagram of a partial structure of a connection unit in a battery device provided in some embodiments of the present application.

[0047] The reference numerals of the specific embodiments are as follows:

[0048] 100, vehicle; 200, battery device; 300, controller; 400, motor;

[0049] 1. Box body;

[0050] 2. Battery cell assembly; 21. Busbar; 22. Battery unit; 23. Battery cell; 231. End cap; 232. Electrode assembly; 233. Adapter; 234. Electrode terminal; 235. Lower plastic; 236. Shell;

[0051] 3. Connecting unit; 31. Conductive member; 311. Elastic portion; 312. Deformable portion; 313. Conductive seat; 314. Conductive cover plate; 315. Conductive protrusion; 32. Insulating member; 321. Protective cover; 322. Top wall; 323. Side wall. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0053] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0054] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0055] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0056] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0057] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0058] The term “plurality” used in this application refers to two or more (including two).

[0059] In the present application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell or a magnesium-ion battery cell, etc., and the embodiments of the present application do not limit this. The battery cell may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this.

[0060] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode sheet, a negative electrode sheet and a separator. A battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. The positive current collector includes a positive coating area and a positive electrode ear connected to the positive coating area. The positive coating area is coated with a positive active material layer, and the positive electrode ear is not coated with a positive active material layer. Taking a lithium-ion battery cell as an example, the material of the positive current collector can be aluminum, and the positive active material layer includes a positive active material. The positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer is coated on the surface of the negative electrode current collector; the negative electrode current collector includes a negative electrode coating area and a negative electrode tab connected to the negative electrode coating area, and the negative electrode coating area is coated with a negative electrode active material layer, and the negative electrode tab is not coated with a negative electrode active material layer. The material of the negative electrode current collector can be copper, and the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material can be carbon or silicon, etc. The material of the separator can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc.

[0061] In a battery device, usually two or more battery cells are connected in parallel to form a battery unit and then connected in series in the entire circuit. In such a battery device, when one of the battery cells in the battery unit experiences thermal runaway, the battery cell in thermal runaway can be regarded as a resistor, and the battery cells connected in parallel with it form a circuit through the resistor to discharge. The battery cells in parallel continue to generate heat due to continuous discharge, which can easily cause thermal runaway, thereby causing heat diffusion.

[0062] In view of this, the present application provides a battery device, which, by setting a connection unit, configures the connection unit to be insulated during normal use, and makes the end cover and the adapter or the end cover and the busbar conductively connected when thermal runaway occurs in the battery cell, thereby forming a short-circuit loop with a larger current, and then melting the mechanical parts (such as the busbar or the adapter) in the formed short-circuit loop, cutting off the loop, so that the parallel battery cells no longer continue to generate heat, reducing the risk of thermal runaway, and improving the reliability of the battery device.

[0063] The technical solutions described in the embodiments of the present application are applicable to various electrical devices using battery devices, such as mobile phones, portable devices, laptop computers, electric vehicles, electric toys, electric tools, vehicles, ships and spacecraft, for example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0064] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0065] Figure 1 A schematic diagram of the structure of a vehicle 100 provided in some embodiments of the present application, Figure 2 A schematic diagram of the structure of a battery device provided in some embodiments of the present application.

[0066] like Figure 1 As shown, a battery device 200 is disposed inside the vehicle 100, and the battery device 200 may be disposed at the bottom, head, or tail of the vehicle 100. The battery device 200 may be used to power the vehicle 100, for example, the battery device 200 may be used as an operating power source for the vehicle 100.

[0067] The vehicle 100 may further include a controller 300 and a motor 400 . The controller 300 is used to control the battery device 200 to supply power to the motor 400 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 100 .

[0068] In some embodiments of the present application, the battery device 200 can not only serve as an operating power source for the vehicle 100, but also serve as a driving power source for the vehicle 100, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 100.

[0069] See also Figure 2 The battery apparatus 200 (Battery Apparatus) mentioned in the embodiment of the present application may include one or more battery cell assemblies 2 for providing voltage and capacity.

[0070] In some embodiments, the battery device 200 may be a battery pack, which includes a box body 1 and one or more battery cell assemblies 2 , wherein the battery cell assemblies 2 are accommodated in the box body 1 .

[0071] As an example, the battery cell assembly 2 may be a battery module, and the battery cell assembly 2 may be accommodated in the box body 1 by fixing the battery module in the box body 1 .

[0072] As an example, the battery cell assembly 2 may also be accommodated in the housing 1 by directly fixing the plurality of battery cells 23 to the housing 1 .

[0073] As an example, the box 1 may include a first box and a second box. The first box and the second box are buckled together to form a closed space inside the box to accommodate the battery cell assembly 2. The closed space here means covered or closed, which may be sealed or unsealed. The first box may be a top cover or a bottom plate.

[0074] As an example, the box body 1 may include a top cover, a frame and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that a closed space is formed inside the box body 1 to accommodate the battery cell assembly 2.

[0075] As an example, the box 1 can be used as a part of the chassis structure of the vehicle 100. For example, the roof of the box 1 can become at least a part of the floor of the vehicle 100, or the frame of the box 1 can become at least a part of the cross beam and longitudinal beam of the vehicle 100.

[0076] In some embodiments, the battery device 200 refers to an energy storage device, which includes a box 1, at least one side of which is provided with a door. The energy storage device includes an energy storage container, an energy storage cabinet, and the like.

[0077] Figure 3 A schematic diagram of an exploded structure of a battery unit and a busbar provided in some embodiments of the present application; Figure 4 A top view of a battery cell and a busbar provided in some embodiments of the present application; Figure 5 for Figure 4 A cross-sectional view of the battery cell and the busbar at AA is shown; Figure 6 for Figure 5 Enlarged view at B; Figure 7 Another structural schematic diagram of a battery unit and a busbar provided in some embodiments of the present application; Figure 8 Another top view of a battery cell and a busbar provided in some embodiments of the present application; Fig. 9 for Figure 8 A cross-sectional view of the battery cell and the busbar at CC is shown; Fig.10 for Fig. 9 Enlarged view at D.

[0078] like Figure 2-Figure 10As shown, the embodiment of the present application provides a battery device 200, the battery device 200 includes a box body 1, a battery cell assembly 2 and a connecting unit 3, the battery cell assembly 2 is located in the box body 1, the battery cell assembly 2 includes a plurality of busbars 21 and a plurality of battery cells 22 connected in series, the battery cell 22 includes at least two battery cells 23 connected in parallel through two busbars 21, the battery cell 23 includes an end cap 231, an electrode assembly 232, a transition piece 233 and an electrode terminal 234, the electrode assembly 232 and the electrode terminal 234 are connected in parallel, and the battery cell 22 includes at least two battery cells 23 connected in parallel through two busbars 21, and the battery cell 23 includes an end cap 231, an electrode assembly 232, a transition piece 233 and an electrode terminal 234. The terminal 234 is electrically connected through the adapter 233, the electrode terminal 234 is insulated and arranged on the end cover 231, and the adapter 233 and the busbar 21 are respectively insulated and arranged on the end cover 231; a plurality of connection units 3 are arranged on at least one battery cell 23, and a connection unit 3 is insulated and arranged between the two adapters 233 of the battery cell 23 and the end cover 231 of the battery cell 23; or, a connection unit 3 is insulated and arranged between the two busbars 21 connected to the battery cell 23 and the end cover 231 of the battery cell 23. The connection unit 3 is configured to make the end cover 231 and the adapter 233 or the end cover 231 and the busbar 21 conductively connected when the battery cell 23 has thermal runaway.

[0079] The battery unit 22 of the embodiment of the present application includes at least two or more battery cells 23, and the two or more battery cells 23 are connected in parallel through two busbars 21. Exemplarily, the busbar 21 is a busbar, and its material can be copper or aluminum.

[0080] The multiple battery cells 22 of the embodiment of the present application are connected in series, which can be as follows Figure 2 As shown, the series connection is achieved through the busbars 21 , and the series connection can also be achieved through structures such as wires, and the two ends of the wires are conductively connected to the two busbars 21 respectively.

[0081] The electrode assembly 232 of the embodiment of the present application may be a wound electrode assembly, a laminated electrode assembly, or a mixed structure of winding and lamination.

[0082] The connection unit 3 of the embodiment of the present application can be made of semiconductor materials, such as silicon, germanium, etc. The semiconductor material is an insulator at room temperature, but when the temperature exceeds a certain temperature, the electrons will be activated, resulting in the conductive property of the semiconductor material, and the connection unit 3 conducts the end cap 231 and the adapter 233 or the end cap 231 and the busbar 21.

[0083] Exemplarily, the battery cell 23 may be a square-shell battery cell or a cylindrical battery cell.

[0084] Optionally, the battery cell 23 further includes a housing 236 , wherein the housing 236 has an opening, and the end cover 231 covers the opening. The electrode assembly 232 and the adapter 233 are both disposed in the housing 236 .

[0085] In the embodiment of the present application, a connection unit 3 is insulated between the two adapters 233 of the battery cell 23 and the end cover 231 of the battery cell 23 , and one or more connection units 3 may be provided between the end cover 231 of the battery cell 23 and the adapter 233 of the battery cell 23 .

[0086] In the embodiment of the present application, a connection unit 3 is insulated between the two busbars 21 connected to the battery cells 23 and the end caps 231 of the battery cells 23 . One or more connection units 3 may be provided between the end caps 231 and the busbars 21 .

[0087] Exemplarily, take the example that the battery unit 22 includes two parallel battery cells 23, and the connecting unit 3 is arranged between the end cover 231 and the adapter 233 of the battery cell 23 that has thermal runaway, the connecting unit 3 conducts the end cover 231 and the adapter 233 of the battery cell 23 that has thermal runaway, and the short circuit loop formed is, the positive pole of the battery cell 23 that is not out of control → the bus 21 → the positive electrode terminal 234 of the out-of-control battery cell 23 → the adapter 233 at the positive pole of the out-of-control battery cell 23 → the connecting unit 3 at the positive pole of the out-of-control battery cell 23 → the end cover 231 of the out-of-control battery cell 23 → the connecting unit 3 at the negative pole of the out-of-control battery cell 23 → the adapter 233 at the negative pole of the out-of-control battery cell 23 → the negative electrode terminal 234 of the out-of-control battery cell 23 → another bus 21 → the negative pole of the battery cell 23 that is not out of control. After the short circuit is formed, the larger current can melt the adapter 233 or the busbar 21 in the entire circuit, so that after the short circuit is disconnected, the circuit formed when the out-of-control battery cell 23 is regarded as a resistor is also disconnected. The short circuit includes the internal circuit of the battery cell 23 that is not out of control, and the internal circuit of the battery cell 23 that is not out of control has the adapter 233.

[0088] For example, the battery unit 22 includes two parallel battery cells 23, and the connection unit 3 is arranged between the end cap 231 and the busbar 21 of the battery cell 23 that has thermal runaway, and the connection unit 3 conducts the end cap 231 and the busbar 21, and the short circuit formed is: the positive electrode of the battery cell 23 that is not out of control → busbar 21 → the connection unit 3 at the positive electrode of the out-of-control battery cell 23 → the end cap 231 of the out-of-control battery cell 23 → the connection unit 3 at the negative electrode of the out-of-control battery cell 23 → another busbar 21 → the negative electrode of the battery cell 23 that is not out of control. After the short circuit is formed, a large current can fuse the busbar 21 or the adapter 233 in the entire circuit, so that after the short circuit is disconnected, the circuit formed when the original out-of-control battery cell 23 is regarded as a resistor is also disconnected. Among them, the short circuit includes the internal circuit of the battery cell 23 that is not out of control, and the internal circuit of the battery cell 23 that is not out of control has the adapter 233.

[0089] Even if the connecting unit 3 in the battery cell 23 connected in parallel with the out-of-control battery cell 23 conducts the end cap 231 and the adapter 233 or the end cap 231 and the bus 21 of the parallel battery cell 23, the battery cell 23 short-circuits itself through the end cap 231, forming a large current to melt the adapter 233 or the bus 21, and also disconnects the circuit formed by the parallel battery cells 23 and the out-of-control battery cell 23.

[0090] Exemplarily, a connection unit 3 is insulated between the end cap 231 of the battery cell 23 and the two adapters 233 of the battery cell 23. The battery cell 23 also includes a lower plastic 235, which is located between the end cap 231 and the electrode assembly 232 and has a through hole for the connection unit 3 to pass through.

[0091] The triggering condition of thermal runaway in the embodiment of the present application can be temperature or pressure, that is, excessive pressure can trigger thermal runaway.

[0092] The battery device 200 of the embodiment of the present application is provided with a connection unit 3. When a battery cell 23 has thermal runaway, the connection unit 3 makes the end cover 231 and the adapter 233 of the battery cell 23 with thermal runaway or the end cover 231 and the bus 21 conductively connected, so that the two battery cells 23 form a short-circuit loop with a large current. The large current causes the bus 21 or the adapter 233 in the short-circuit loop to melt. After the bus 21 or the adapter 233 melts, the short-circuit loop formed by the runaway battery cell 23 and the parallel battery cells 23 is disconnected, and the loop formed when the original thermal runaway battery cell 23 is regarded as a resistor is also disconnected. The parallel battery cells 23 almost no longer generate heat, which reduces the risk of thermal runaway and improves the reliability of the battery device 200.

[0093] In some embodiments, the connecting unit 3 includes a connected conductive member 31 and an insulating member 32; the conductive member 31 is electrically connected to the end cover 231, and the insulating member 32 is connected to the adapter 233 or the bus 21, or the conductive member 31 is electrically connected to the adapter 233 or the bus 21, and the insulating member 32 is connected to the end cover 231; the melting point of the insulating member 32 is lower than the melting point of the conductive member 31, and when the insulating member 32 melts, the conductive member 31 is deformed and conductively connected to the component to which the insulating member 32 is connected before melting.

[0094] The material of the conductive member 31 in the embodiment of the present application may be aluminum, copper, nickel, etc.; the material of the insulating member 32 may be rubber, polypropylene (PP), polyethylene (PE), polyimide (PI).

[0095] The conductive member 31 and the insulating member 32 of the embodiment of the present application can be arranged along the arrangement direction of the two components connected to them, the conductive member 31 is used for deformation, and the insulating member 32 provides insulation under normal working conditions. The conductive member 31 and the insulating member 32 of the embodiment of the present application can be offset or fixedly connected, for example, by bonding or welding.

[0096] The conductive member 31 of the embodiment of the present application can be abutted against the connected component to achieve conductive connection, or can be fixedly connected to the connected component to achieve conductive connection, for example, by bolt locking, welding or clamping.

[0097] The insulating member 32 of the embodiment of the present application may be abutted against the connected component, or may be fixedly connected to the connected component, for example, by bonding or welding.

[0098] The conductive member 31 of the embodiment of the present application is electrically connected to the end cover 231, and the insulating member 32 is connected to the adapter 233 or the bus 21, or the conductive member 31 is electrically connected to the adapter 233 or the bus 21, and the insulating member 32 is connected to the end cover 231, including the following solutions:

[0099] The conductive member 31 is electrically connected to the end cap 231, and the insulating member 32 is connected to the adapter 233. Figure 6 As shown;

[0100] The conductive member 31 is electrically connected to the end cap 231, and the insulating member 32 is connected to the busbar 21. Fig.10 As shown;

[0101] The conductive member 31 is electrically connected to the adapter 233 , and the insulating member 32 is connected to the end cap 231 ;

[0102] The conductive member 31 is electrically connected to the busbar 21 , and the insulating member 32 is connected to the end cover 231 .

[0103] The connection unit 3 is configured to include a conductive member 31 and an insulating member 32. The conductive member 31 is deformed during thermal runaway to achieve conductive connection between the end cap 231 and the adapter 233 or the end cap 231 and the busbar 21. This type of connection unit 3 is not only more reliable to use, but also has a lower cost.

[0104] Fig.11 A schematic diagram of a structure of a connection unit in a battery device provided in some embodiments of the present application; Fig.12 for Fig.11 A schematic structural diagram of the connecting unit shown at another angle.

[0105] See also Fig.11 and Fig.12In some embodiments, the conductive member 31 includes an elastic portion 311, which is configured to be in a compressed state and store elastic potential energy before the insulating member 32 melts, and the elastic portion 311 is configured to release the elastic potential energy and stretch after the insulating member 32 melts, so that the conductive member 31 can achieve a conductive connection between the end cap 231 and the adapter 233 or the end cap 231 and the bus 21.

[0106] The elastic portion 311 of the embodiment of the present application may be a spring, or a metal spring folded in a Z-shape along the length direction, or other structures that can be extended.

[0107] Exemplarily, the elastic portion 311 is stretched due to the release of elastic potential energy, and counteracts the component connected to the insulating member 32 before melting, thereby achieving a conductive connection between the end cap 231 and the adapter 233 or the end cap 231 and the busbar 21 .

[0108] Exemplarily, the elastic part 311 may also be an insulating elastic body such as rubber, the upper end of which is connected to a conductive cover plate structure, and the lower end is connected to a conductive bottom plate structure, the cover plate structure and the bottom plate structure are electrically connected via a wire, the length of the wire is sufficient, and the insulating member 32 is connected to the cover plate structure. When the insulating member 32 melts, the elastic part 311 releases elastic potential energy and stretches, driving the cover plate structure to counteract the components connected to the insulating member 32 before melting to achieve conductive connection.

[0109] The elastic portion 311 is extended by releasing elastic potential energy to realize the conductive connection between the end cover 231 and the adapter 233 or the end cover 231 and the busbar 21 . This arrangement is more reliable and has lower cost.

[0110] In some embodiments, the elastic portion 311 is a conductive structure and is used for conductive connection between the end cap 231 and the adapter 233 or the end cap 231 and the busbar 21 .

[0111] Exemplarily, the elastic portion 311 is a metal conductive structure, such as a spring.

[0112] The elastic portion 311 of the embodiment of the present application may directly abut against the component of the insulating member 32 before it is melted, or may not abut against the component.

[0113] The elastic portion 311 is configured as a conductive structure, which after deformation is conductively connected to the component connected to the insulating member 32 before melting, thereby simplifying the structure of the connecting unit 3 .

[0114] Fig.13 Another structural schematic diagram of a connection unit in a battery device provided in some embodiments of the present application.

[0115] See also Fig.13In some embodiments, the conductive member 31 includes a deformable portion 312 , and the deformable portion 312 is configured to be deformed by heat when the insulating member 32 melts, so as to conductively connect the end cap 231 and the transition member 233 or the end cap 231 and the busbar 21 .

[0116] The deformable portion 312 of the embodiment of the present application may be a memory alloy, which stretches or undergoes other deformations after being heated, such as changing from a bent state to a straight state, so that the end cover 231 and the adapter 233 or the end cover 231 and the busbar 21 are conductively connected.

[0117] By utilizing the property of the deformable portion 312 to deform due to temperature, the end cap 231 and the adapter 233 or the end cap 231 and the busbar 21 are electrically connected. This method is more reliable to use.

[0118] In some embodiments, the insulating member 32 includes a protective cover 321, the conductive member 31 includes a conductive seat body 313, the protective cover 321 is covered on the conductive seat body 313 and is surrounded by the conductive seat body 313 to form a receiving cavity, the deformable portion of the conductive member 31 is electrically connected to the conductive seat body 313 and is located in the receiving cavity, one of the conductive seat body 313 and the insulating member 32 is connected to the end cover 231, and the other is connected to the adapter 233 or the bus 21.

[0119] Exemplarily, the protective cover 321 includes a side wall 323 and a top wall 322, wherein the side wall 323 is connected to the outer periphery of the top wall 322, wherein the side wall 323 may be a curved wall arranged in a circle; the side wall 323 may also be a straight wall, wherein a plurality of straight walls are connected in sequence at an angle.

[0120] The deformable portion of the conductive member 31 in the embodiment of the present application may be the elastic portion 311 mentioned above, or may be the deformable portion 312 mentioned above.

[0121] The protective cover 321 of the embodiment of the present application may or may not be offset against the component connected to the conductive member 31 .

[0122] Exemplarily, the protective cover 321 and the connected component may be connected in a fixed manner, such as bonding or welding.

[0123] Exemplarily, the conductive base body 313 is a plate-shaped member, and the conductive base body 313 is fixed and conductively connected to the connected component, for example, by welding or bonding with conductive adhesive.

[0124] A protective cover 321 is provided, and a receiving cavity is formed by the protective cover 321 and the conductive base body 313 to receive the deformable portion of the conductive member 31. In this way, not only the deformable portion is well protected, but the protective cover 321 can also reduce the possibility of the conductive member 31 moving or deforming during use and causing a short circuit, thereby improving the reliability of the battery device 200.

[0125] In some embodiments, the protection cover 321 is disposed on a side of the conductive base 313 facing the deformable portion of the conductive member 31 .

[0126] Exemplarily, the protective cover 321 is fixedly connected to the conductive base body 313 , for example, by welding or bonding.

[0127] Such a configuration can increase the area of ​​the conductive base 313 and improve the reliability of the electrical connection between the conductive base 313 and the corresponding components.

[0128] In some embodiments, the conductive member 31 also includes a conductive cover plate 314, which is disposed in the accommodating cavity and connected to an end of the deformable portion of the conductive member 31 that is away from the conductive seat body 313. The conductive cover plate 314 is configured to abut against the component to which the insulating member 32 is connected before it melts when the insulating member 32 melts.

[0129] Exemplarily, the conductive cover plate 314 is configured to be disposed in contact with the component to which the insulating member 32 is connected before the insulating member 32 is melted when the insulating member 32 is melted.

[0130] Exemplarily, the conductive cover plate 314 is integrally formed or welded with the deformable portion of the conductive member 31 .

[0131] The conductive cover plate 314 is provided to increase the contact area between the conductive member 31 and the components connected before the insulating member 32 melts, thereby improving the current carrying capacity of the connecting unit 3 .

[0132] Fig.14 A schematic diagram of a partial structure of a connection unit in a battery device provided in some embodiments of the present application.

[0133] See also Fig.14 In some embodiments, a plurality of conductive protrusions 315 are provided on a side of the conductive cover plate 314 facing away from the conductive base body 313 , and the plurality of conductive protrusions 315 are configured to abut against components connected to the insulating member 32 before the insulating member 32 melts when the insulating member 32 melts.

[0134] The shapes of the plurality of conductive protrusions 315 in the embodiment of the present application may be the same or different.

[0135] The conductive protrusion 315 is provided so that after the conductive cover plate 314 is tilted, it can still be in good contact with the connected components before the insulating member 32 is melted, thereby improving the reliability of the connection unit 3 in use.

[0136] In some embodiments, all battery cells 23 of at least one battery unit 22 are provided with a connection unit.

[0137] Optionally, one battery unit 22 has two battery cells 23 , and both battery cells 23 are provided with a connecting unit 3 .

[0138] With such configuration, no matter which battery cell 23 in the battery unit 22 experiences thermal runaway, a short circuit can be formed and then cut off, thereby further improving the reliability of the battery device 200 .

[0139] In some embodiments, the component connected to the insulating member 32 is fixedly connected to the insulating member 32 , and / or the component connected to the conductive member 31 is fixedly connected to the conductive member 31 .

[0140] The components corresponding to the insulating member 32 in the embodiment of the present application can be connected to the insulating member 32 by welding or bonding.

[0141] The components corresponding to the conductive member 31 in the embodiment of the present application can be connected to the conductive member 31 by means of clamping, welding or locking with fasteners.

[0142] Such an arrangement can improve the tightness of the connection between the connection unit 3 and other components in the battery device 200, thereby reducing the possibility of displacement of the connection unit 3 during use.

[0143] In some embodiments, the melting point of the insulating member 32 is T1, and T1 satisfies: 200°C≤T1≤400°C.

[0144] Optionally, the value of T1 may be 200°C, 250°C, 300°C, 350°C or 400°C.

[0145] The melting point of the insulating member 32 is set to be greater than or equal to 200° C. to meet the insulation requirements of the battery device 200 during normal use. The melting point of the insulating member 32 is limited to be less than or equal to 400° C. so that the insulating member 32 can melt in time when thermal runaway occurs.

[0146] In some embodiments, T1 satisfies: 200°C≤T1≤250°C.

[0147] Optionally, the value of T1 may be 200°C, 210°C, 220°C, 230°C, 240°C or 250°C.

[0148] The melting point of the insulating member 32 is further limited to greater than or equal to 200° C. to further meet the insulation requirements of the battery device 200 during normal use. The melting point of the insulating member 32 is further limited to less than or equal to 250° C. to enable the insulating member 32 to melt faster when thermal runaway occurs.

[0149] In some embodiments, the battery cell 23 is a square-shell battery cell 23 .

[0150] The adapter 233 of the square-shell battery cell 23 is more easily melted by heat and is more applicable.

[0151] The embodiment of the present application further provides an electrical device, including the above-mentioned battery device 200, and the battery device 200 is used to provide electrical energy.

[0152] See also Figure 2-Figure 12The embodiment of the present application provides a battery device 200, which includes a housing 1, a battery cell assembly 2 and a connecting unit 3. The battery cell assembly 2 is located in the housing 1. The battery cell assembly 2 includes a plurality of busbars 21 and a plurality of battery cells 22 connected in series. The battery cell 22 includes at least two battery cells 23 connected in parallel through two busbars 21. The battery cell 23 includes an end cap 231, an electrode assembly 232, a transition piece 233 and an electrode terminal 234. The electrode assembly 232 and the electrode terminal 234 is electrically connected through the adapter 233, the electrode terminal 234 is insulated and arranged on the end cover 231, and the adapter 233 and the busbar 21 are respectively insulated and arranged on the end cover 231; multiple connection units 3 are arranged on at least one battery cell 23, and the two adapters 233 of the battery cell 23 are respectively insulated and arranged with connection units 3 between the end covers 231 of the battery cell 23; or, the two busbars 21 connected to the battery cell 23 are respectively insulated and arranged with connection units 3 between the end covers 231 of the battery cell 23. The connection unit 3 is configured to make the end cover 231 and the adapter 233 or the end cover 231 and the busbar 21 conductively connected when the battery cell 23 has thermal runaway. The connection unit 3 includes a connected conductive member 31 and an insulating member 32, the conductive member 31 is electrically connected to the end cover 231, and the insulating member 32 is connected to the adapter 233 or the busbar 21. The conductive member 31 includes an elastic portion 311, which is configured to be in a compressed state and store elastic potential energy before the insulating member 32 melts, and the elastic portion 311 is configured to release the elastic potential energy and extend after the insulating member 32 melts, so as to achieve conductive connection between the end cap 231 and the adapter 233 or the end cap 231 and the bus 21. The insulating member 32 includes a protective cover 321, and the conductive member 31 includes a conductive seat 313. The protective cover 321 is covered on the conductive seat 313 and surrounded by the conductive seat 313 to form a receiving cavity. The deformable portion of the conductive member 31 is electrically connected to the conductive seat 313 and is located in the receiving cavity. The conductive seat 313 is connected to the end cap 231, and the protective cover 321 is connected to the adapter 233 or the bus 21. The conductive member 31 further includes a conductive cover plate 314, which is disposed in the accommodating cavity and connected to an end of the deformable portion of the conductive member 31 away from the conductive seat 313. The conductive cover plate 314 is configured to abut against the component connected to the insulating member 32 before the insulating member 32 melts when the insulating member 32 melts. All battery cells 23 of at least one battery unit 22 are provided with a connecting unit. The battery cell 23 is a square shell battery cell 23.

[0153] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0154] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein, but these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery device, characterized in that: include: Box; A battery cell assembly is located in the box, the battery cell assembly includes a plurality of busbars and a plurality of battery cells connected in series, the battery cell includes at least two battery cells connected in parallel through two busbars, the battery cell includes an end cap, an electrode assembly, a transition piece and an electrode terminal, the electrode assembly is electrically connected to the electrode terminal through the transition piece, the electrode terminal is insulated and arranged on the end cap, and the transition piece and the busbar are respectively insulated and arranged on the end cap; A plurality of connection units are arranged on at least one of the battery cells, wherein the connection units are insulated between the two adapters of the battery cell and the end covers of the battery cell, or the connection units are insulated between the two busbars connected to the battery cell and the end covers of the battery cell, and the connection units are configured to conductively connect the end covers and the adapters or the end covers and the busbars when thermal runaway occurs in the battery cell, so as to cause the adapters or the busbars to fuse.

2. The battery device according to claim 1, characterized in that: The connecting unit includes a conductive member and an insulating member connected to each other; The conductive member is electrically connected to the end cover, and the insulating member is connected to the adapter or the current collector, or the conductive member is electrically connected to the adapter or the current collector, and the insulating member is connected to the end cover; The melting point of the insulating member is lower than that of the conductive member. When the insulating member melts, the conductive member is deformed and conductively connected to the component to which the insulating member was connected before melting.

3. The battery device according to claim 2, characterized in that: The conductive member includes an elastic portion, which is configured to be in a compressed state and store elastic potential energy before the insulating member melts, and the elastic portion is configured to release the elastic potential energy and stretch when the insulating member melts, so that the conductive member can achieve a conductive connection between the end cover and the adapter or between the end cover and the busbar.

4. The battery device according to claim 3, characterized in that: The elastic portion is a conductive structure and is used for conductive connection between the end cover and the adapter or between the end cover and the current collector.

5. The battery device according to claim 2, characterized in that: The conductive member includes a deformable portion, and the deformable portion is configured to be deformed by heat when the insulating member is melted, so as to conductively connect the end cap and the transition member or the end cap and the busbar.

6. The battery device according to claim 2, characterized in that: The insulating member includes a protective cover, and the conductive member includes a conductive seat body. The protective cover is disposed on the conductive seat body and is surrounded by the conductive seat body to form a receiving cavity. The deformable portion of the conductive member is electrically connected to the conductive seat body and is located in the receiving cavity. One of the conductive seat body and the insulating member is connected to the end cover, and the other is connected to the adapter or the busbar.

7. The battery device according to claim 6, characterized in that: The protective cover is disposed on a side of the conductive base body facing the deformable portion of the conductive member.

8. The battery device according to claim 6, characterized in that: The conductive member further comprises a conductive cover plate, which is arranged in the accommodating cavity and connected to an end of the deformable portion of the conductive member away from the conductive seat. The conductive cover plate is configured to abut against the component connected to the insulating member before melting when the insulating member melts.

9. The battery device according to claim 8, characterized in that: A plurality of conductive protrusions are disposed on a side of the conductive cover plate facing away from the conductive base body. The plurality of conductive protrusions are configured to abut against components connected to the insulating member before the insulating member is melted when the insulating member is melted.

10. The battery device according to any one of claims 1 to 9, characterized in that: All battery cells of at least one of the battery units are provided with the connecting unit.

11. The battery device according to any one of claims 2 to 9, characterized in that: The melting point of the insulating member is T1, and T1 satisfies: 200°C≤T1≤400°C.

12. The battery device according to claim 11, characterized in that: The T1 satisfies: 200°C≤T1≤250°C.

13. The battery device according to any one of claims 1 to 9, characterized in that: The battery cell is a square shell battery cell.

14. An electrical device, characterized in that: The invention comprises a battery device as claimed in any one of claims 1 to 13, wherein the battery device is used to provide electrical energy.

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