Battery device and electric device

Abstract

The embodiment of the invention provides a battery device and a power utilization device, the battery device comprises a box body and a battery monomer assembly, the battery monomer assembly is located in the box body, the battery monomer assembly comprises a plurality of battery monomers and a confluence assembly, and two adjacent battery monomers are electrically connected through the confluence assembly; wherein the confluence assembly comprises a first electric connection structure, a second electric connection structure and a fixing unit, the first electric connection structure and the second electric connection structure are spliced with each other and are respectively connected to the two single batteries, and the fixing unit is connected to the first electric connection structure and the second electric connection structure; the fixing unit is arranged to be at least partially melted when the battery monomers are in thermal runaway so as to release the fixed connection between the first electric connection structure and the second electric connection structure. The reliability of the battery device can be improved.

Description

Technical Field

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

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

[0003] Improving the reliability of battery devices is a research direction in battery technology. Summary of the Invention

[0004] This application provides a battery device and an electrical device that can improve the reliability of the battery device.

[0005] This application provides a battery device, including a housing and a battery cell assembly. The battery cell assembly is located inside the housing and includes multiple battery cells and a busbar assembly. Adjacent battery cells are electrically connected through the busbar assembly. The busbar assembly includes a first electrical connection structure, a second electrical connection structure, and a fixing unit. The first and second electrical connection structures are spliced ​​together and respectively connected to two battery cells. The fixing unit is connected to the first and second electrical connection structures and fixes the first and second electrical connection structures. The fixing unit is configured to at least partially melt in the event of thermal runaway of a battery cell, thereby releasing the fixed connection between the first and second electrical connection structures.

[0006] In the above technical solution, the battery device of this application embodiment configures the busbar assembly to include a first electrical connection structure, a second electrical connection structure, and a fixing unit. The fixing unit fixes the first and second electrical connection structures together, ensuring that the joints always abut against each other to achieve electrical connection. The fixing unit is configured to at least partially melt and lose its fixing function when a battery cell experiences thermal runaway. The top of the runaway battery cell deforms, causing the first and second electrical connection structures to separate and disconnect under the deformation of the battery cell. In this way, when thermal runaway occurs, even if the casings of the runaway battery cell overlap with those of adjacent battery cells, a circuit cannot be formed, thereby reducing the possibility of thermal runaway in adjacent battery cells and improving the reliability of the battery device.

[0007] In some embodiments, the fixing unit includes a fixing member that is at least partially surrounding or disposed at the junction of the first electrical connection structure and the second electrical connection structure and fixing the two together. The fixing member is configured to melt when the battery cell experiences thermal runaway, thereby releasing the fixing connection between the first electrical connection structure and the second electrical connection structure.

[0008] In the above technical solution, the fastener is at least partially arranged around the joint of the first electrical connection structure and the second electrical connection structure to connect the two, so there is no need to make a hole at the joint of the first electrical connection structure and the second electrical connection structure, which is convenient for manufacturing.

[0009] In some embodiments, the fastener is disposed around the junction of the first electrical connection structure and the second electrical connection structure.

[0010] In the above technical solution, the structural strength of the fastener fixing the first electrical connection structure and the second electrical connection structure is improved, thereby improving the reliability of the bus assembly.

[0011] In some embodiments, the fixing unit further includes a plurality of connectors, which respectively connect the first electrical connection structure and the second electrical connection structure to the fixing member, and the first electrical connection structure and the second electrical connection structure are fixedly connected through the connectors and the fixing member.

[0012] In the above technical solution, a connector is provided to further strengthen the fixing effect of the fixing unit on the first electrical connection structure and the second electrical connection structure, so that the first electrical connection structure and the second electrical connection structure maintain a good electrical connection and improve the reliability of the busbar assembly.

[0013] In some embodiments, the first electrical connection structure includes a protrusion, and the second electrical connection structure includes a recess adapted to the protrusion. The first electrical connection structure and the second electrical connection structure are spliced ​​together by the protrusion and the recess.

[0014] In the above technical solution, this configuration can increase the contact area between the first electrical connection structure and the second electrical connection structure, thereby improving the current carrying capacity of the busbar assembly.

[0015] In some embodiments, there are multiple protrusions and multiple recesses, with the multiple protrusions arranged along a first direction and the multiple protrusions and multiple recesses spliced ​​together one by one, wherein the first direction intersects with the arrangement direction of the first electrical connection structure to the second electrical connection structure and the thickness direction of the first electrical connection structure in pairs.

[0016] In the above technical solution, the first electrical connection structure and the second electrical connection structure can have a larger contact area, thereby improving the current carrying capacity of the busbar assembly.

[0017] In some embodiments, the protrusion includes one of a serration, a square protrusion, or an arcuate protrusion.

[0018] In the above technical solution, the first electrical connection structure and the second electrical connection structure can have a larger contact area, thereby improving the current carrying capacity of the busbar assembly.

[0019] In some embodiments, the first electrical connection structure has a first inclined surface, and the second electrical connection structure has a second inclined surface adapted to the degree of inclination and / or curvature of the first inclined surface, and the first electrical connection structure and the second electrical connection structure are spliced ​​together by the first inclined surface and the second inclined surface.

[0020] In the above technical solution, the contact area of ​​the first electrical connection structure and the second electrical connection structure can be increased, thereby improving the current carrying capacity of the busbar assembly.

[0021] In some embodiments, the first electrical connection structure has a first stepped surface, and the second electrical connection structure has a second stepped surface. The first stepped surface and the second stepped surface cooperate with each other to splice the first electrical connection structure and the second electrical connection structure together.

[0022] In the above technical solution, the contact area of ​​the first electrical connection structure and the second electrical connection structure can be increased, thereby improving the current carrying capacity of the busbar assembly.

[0023] In some embodiments, the fixing unit includes a fastener that passes sequentially through the joint of the first electrical connection structure and the joint of the second electrical connection structure and fixes them together. The fastener is configured to melt when the battery cell experiences thermal runaway, thereby releasing the fixation connection between the first electrical connection structure and the second electrical connection structure.

[0024] In the above technical solution, the fixing unit is configured to include fasteners, which lock the first electrical connection structure and the second electrical connection structure together, resulting in a high structural strength and reliable use.

[0025] In some embodiments, the bus assembly further includes an elastic element. At least one of the first electrical connection structure and the second electrical connection structure is provided with a first groove for accommodating the elastic element at the joint. The elastic element is insulated from both the first electrical connection structure and the second electrical connection structure. The elastic element is configured to store elastic potential energy in a compressed state when the first electrical connection structure and the second electrical connection structure are fixedly connected by a fixing unit; and to release the elastic potential energy when the first electrical connection structure and the second electrical connection structure are released from the fixed connection, so as to separate the first electrical connection structure and the second electrical connection structure.

[0026] In the above technical solution, by setting an elastic element, elastic potential energy is released when the first electrical connection structure and the second electrical connection structure are decoupled, thereby enabling the first electrical connection structure and the second electrical connection structure to be quickly separated, rapidly cutting off the short circuit circuit, and further improving the reliability of the battery device.

[0027] In some embodiments, the bus assembly further includes an insulating film that wraps around an elastic element to insulate the elastic element from both the first electrical connection structure and the second electrical connection structure.

[0028] In the above technical solution, an insulating film is provided to wrap the elastic element, thereby achieving insulation between the first electrical connection structure and the second electrical connection structure.

[0029] In some embodiments, the melting point T1 of the insulating film and the volumetric energy density E of the battery cell satisfy the following: when E≤390Wh / L, T1>200℃; when E>390Wh / L, T1>250℃.

[0030] In the above technical solution, a suitable insulating film can be selected according to the volumetric energy density of the battery cell, so that the insulating film can meet different usage conditions and reduce the possibility of the insulating film failing due to overheating.

[0031] In some embodiments, the bus assembly further includes a deformable member, and a second groove for accommodating the deformable member is provided at the joint of at least one of the first electrical connection structure and the second electrical connection structure. The deformable member is insulated from both the first electrical connection structure and the second electrical connection structure. The deformable member is configured to deform upon heating when the first electrical connection structure and the second electrical connection structure are released from their fixed connection, so as to separate the first electrical connection structure and the second electrical connection structure.

[0032] In the above technical solution, a deformable component is provided. When the first electrical connection structure and the second electrical connection structure are decoupled from the fixed connection, the component deforms due to heat, thereby quickly separating the first electrical connection structure and the second electrical connection structure, rapidly cutting off the short circuit circuit, and improving the reliability of the battery device.

[0033] In some embodiments, the meltable portion of the fixing unit is an insulating element.

[0034] In the above technical solution, the molten part of the fixing unit is set as an insulating part. After being heated and melted, it loses its fixing effect on the first electrical connection structure and the second electrical connection structure. Thus, under the action of the deformation of the battery cell, the first electrical connection structure and the second electrical connection structure are disconnected, reducing the possibility that the first electrical connection structure and the second electrical connection structure will be electrically connected after the fixing unit is melted, which is more reliable.

[0035] In some embodiments, the insulating element includes a plastic element or a rubber element.

[0036] In the above technical solution, the fixing unit is set as a plastic part or a rubber part. The plastic part or the rubber part can easily meet the melting point requirements and melt in time during thermal runaway, thereby losing its fixing function to the first electrical connection structure and the second electrical connection structure.

[0037] In some embodiments, the melting point of the molten portion in the fixing unit is T2, and T2 satisfies: 100℃≤T2≤300℃.

[0038] In the above technical solution, the melting point of the molten part in the fixing unit is limited to greater than or equal to 100°C to meet the conductivity function of the busbar component of the battery device under normal use; the melting point of the molten part in the fixing unit is limited to less than or equal to 300°C to meet the requirement of melting to disconnect the first electrical connection structure and the second electrical connection structure in the event of thermal runaway.

[0039] In some embodiments, T2 satisfies: 150℃≤T2≤200℃.

[0040] In the above technical solution, the melting point of the molten part in the fixed unit is further limited to greater than or equal to 150°C to meet the conductivity function of the busbar component of the larger capacity battery device under normal use; the melting point of the molten part in the fixed unit is limited to less than or equal to 200°C to melt in time in the event of thermal runaway to disconnect the first electrical connection structure and the second electrical connection structure, reduce the possibility of short circuit loop formation, and improve the reliability of the battery device.

[0041] Secondly, embodiments of this application also provide an electrical device, including the aforementioned battery device, which is used to provide electrical energy. Attached Figure Description

[0042] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0043] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0044] Figure 2 This is an exploded view of the battery device provided in some embodiments of this application;

[0045] Figure 3 A schematic diagram of a busbar assembly in a battery device provided in some embodiments of this application;

[0046] Figure 4 for Figure 3 Sectional view at AA;

[0047] Figure 5 Another schematic diagram of the busbar assembly in a battery device provided in some embodiments of this application;

[0048] Figure 6 An exploded view of a portion of the structure of a busbar assembly in a battery device provided in some embodiments of this application;

[0049] Figure 7 An exploded view of another part of the structure of the busbar assembly in a battery device provided in some embodiments of this application;

[0050] Figure 8 This is another partially exploded schematic diagram of the busbar assembly in a battery device provided in some embodiments of this application;

[0051] Figure 9 This is another partially exploded schematic diagram of the busbar assembly in a battery device provided in some embodiments of this application;

[0052] Figure 10 This is an exploded view of yet another partial structure of the busbar assembly in a battery device provided in some embodiments of this application;

[0053] Figure 11 This is another partially exploded schematic diagram of the busbar assembly in a battery device provided in some embodiments of this application;

[0054] Figure 12 A schematic diagram of a busbar assembly in a battery device provided in some embodiments of this application;

[0055] Figure 13 Another schematic diagram of the busbar assembly in a battery device provided in some embodiments of this application;

[0056] Figure 14 This is another partially exploded schematic diagram of the busbar assembly in a battery device provided in some embodiments of this application;

[0057] Figure 15 This is another partially exploded schematic diagram of the busbar assembly in a battery device provided in some embodiments of this application.

[0058] The reference numerals in the accompanying drawings for the specific embodiments are as follows:

[0059] 1. Vehicle; 2. Battery unit; 3. Controller; 4. Motor; 5. Battery cell assembly; 6. Housing; 7. Battery cell; 8. Busbar assembly;

[0060] 81. First electrical connection structure; 811. Protrusion; 812. First inclined surface; 813. First stepped surface;

[0061] 82. Second electrical connection structure; 821. Recessed portion; 822. Second inclined surface; 823. Second stepped surface;

[0062] 83. Fixing unit; 831. Fastener; 832. Fixing component; 833. Connecting component;

[0063] 84. Elastic element; 841. First groove; 842. Second groove;

[0064] 85. Deformable parts;

[0065] X, the first direction. Detailed Implementation

[0066] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0067] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application 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 description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0068] In this application, the reference to "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 in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0069] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0070] 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, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0071] In the embodiments of this application, the same reference numerals denote 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 this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0072] In this application, "multiple" means two or more (including two).

[0073] In this 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 this application are not limited thereto. The battery cell may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited thereto.

[0074] A single battery cell includes electrode components and an electrolyte. The electrode components include a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrodes. The positive electrode includes a positive current collector and a positive active material layer, which is coated on the surface of the positive current collector. The positive current collector includes a positive electrode coating area and a positive electrode tab connected to the coating area. The coating area is coated with the positive active material layer, while the tab is not. Taking a lithium-ion battery cell as an example, the positive current collector can be made of aluminum, and the positive active material layer includes the positive active material, which 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, the negative electrode active material layer being 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. The negative electrode coating area is coated with the negative electrode active material layer, while the negative electrode tab is not coated with the negative electrode active material layer. The material of the negative electrode current collector can be copper, and the negative electrode active material layer includes negative electrode active material, which can be carbon or silicon, etc. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc.

[0075] Battery systems occasionally experience thermal runaway. When one battery cell in a battery system experiences thermal runaway, adjacent cells may experience blue membrane failure and internal separator shrinkage due to temperature rise. Simultaneously, the surface of the runaway cell may bulge, causing the runaway cell's casing to overlap with that of adjacent cells. Since the busbar connecting the adjacent and runaway cells remains open, the overlap creates a short circuit through the busbar, resulting in an abnormal short circuit within the adjacent cells and ultimately causing thermal runaway in those cells.

[0076] In view of this, this application provides a battery device that comprises a busbar assembly including a first electrical connection structure, a second electrical connection structure, and a fixing unit. The fixing unit fixes the first and second electrical connection structures together, and is configured to at least partially melt in the event of thermal runaway of a single battery cell, thereby releasing the fixed connection between the first and second electrical connection structures. In this way, even if the casings of the runaway battery cell overlap with those of adjacent battery cells during thermal runaway, a circuit cannot be formed, thereby reducing the likelihood of thermal runaway in adjacent battery cells and improving the reliability of the battery device.

[0077] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells and battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0078] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0079] Figure 1 The diagram shows the structural features of a vehicle provided in some embodiments of this application.

[0080] like Figure 1 As shown, a battery device 2 is installed inside the vehicle 1. The battery device 2 can be located at the bottom, front, or rear of the vehicle 1. The battery device 2 can be used to power the vehicle 1; for example, the battery device 2 can serve as the operating power source for the vehicle 1.

[0081] The vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, for the power needs of the vehicle 1 during starting, navigation and driving.

[0082] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0083] Figure 2 This is an exploded view of the battery device provided in some embodiments of this application. Figure 3 A schematic diagram of a busbar assembly in a battery device provided in some embodiments of this application; Figure 4 for Figure 3 Sectional view at AA.

[0084] like Figures 2-4As shown, this application also provides a battery device 2, which includes a housing 6 and a battery cell assembly 5. The battery cell assembly 5 is located inside the housing 6 and includes multiple battery cells 7 and a busbar assembly 8. Adjacent battery cells 7 are electrically connected through the busbar assembly 8. The busbar assembly 8 includes a first electrical connection structure 81, a second electrical connection structure 82, and a fixing unit 83. The first electrical connection structure 81 and the second electrical connection structure 82 are spliced ​​together and respectively connected to two battery cells 7. The fixing unit 83 is connected to the first electrical connection structure 81 and the second electrical connection structure 82, and fixes the first electrical connection structure 81 and the second electrical connection structure 82. The fixing unit 83 is configured to be at least partially melted in the event of thermal runaway of the battery cell 7, so as to release the fixed connection between the first electrical connection structure 81 and the second electrical connection structure 82.

[0085] The battery cell assembly 5 in this embodiment is used to provide voltage and capacity. Multiple battery cells 7 are connected in series, parallel, or mixed via a bus assembly 8.

[0086] As an example, the battery cell assembly 5 can be a battery module, and the battery cell assembly 5 can be housed in the housing 6 by fixing the battery module in the housing 6.

[0087] As an example, the battery cell assembly 5 can also be housed in the housing 6 by directly fixing multiple battery cells 7 to the housing 6.

[0088] As an example, the housing 6 may include a first housing and a second housing. The first housing and the second housing are fastened together to form a closed space inside the housing 6 to house the battery cell assembly 5. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first housing 6 may be a top cover or a bottom plate.

[0089] As an example, the housing 6 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 the interior of the housing 6 forms an enclosed space to accommodate the battery cell assembly 5.

[0090] As an example, the box body 6 can be part of the chassis structure of the vehicle 1. For example, the top cover of the box body 6 can be at least part of the floor of the vehicle 1, or the frame of the box body 6 can be at least part of the crossbeams and longitudinal beams of the vehicle 1.

[0091] In some embodiments, battery device 2 refers to energy storage device, which includes a housing 6, with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0092] The first electrical connection structure 81 and the second electrical connection structure 82 of this application embodiment are respectively connected to two battery cells 7. Specifically, the first electrical connection structure 81 is connected to the electrode terminal of one battery cell 7, and the second electrical connection structure 82 is connected to the electrode terminal of the other battery cell 7.

[0093] The first electrical connection structure 81 and the second electrical connection structure 82 in this embodiment achieve conductive connection by splicing and abutting each other, and the fixing unit 83 further transforms the first electrical connection structure 81 and the second electrical connection structure 82 from the abutting state to a fixed connection.

[0094] The first electrical connection structure 81 and the second electrical connection structure 82 in this embodiment of the application are spliced ​​together, meaning that the first electrical connection structure 81 and the second electrical connection structure 82 are only mutually abutting and can be easily separated under the action of external force.

[0095] In this embodiment of the application, both the first electrical connection structure 81 and the second electrical connection structure 82 are battery strips, and two adjacent battery cells are electrically connected through two spliced ​​battery strips. The first electrical connection structure 81 and the second electrical connection structure 82 can be made of metallic materials, such as copper, aluminum, etc.

[0096] The fixing unit 83 in this embodiment can be a metal part, such as bismuth (Bi), tin (Sn), lead (Pb), indium (In), or their alloys. The fixing unit 83 is arranged in a circle or half circle around the splice of the first electrical connection structure 81 and the second electrical connection structure 82, fixing the first electrical connection structure 81 and the second electrical connection structure 82 in place so that they are always in a resistive state. The specific process can be casting, welding, or hot and cold rolling, etc.

[0097] The thermal runaway triggering condition in this application embodiment can be temperature or pressure, that is, the internal pressure of the battery cell is too high, causing the material inside the battery cell to rush out of the explosion-proof valve, resulting in thermal runaway.

[0098] In this embodiment, the fixing unit 83 can be completely melted or partially melted when the battery cell 7 experiences thermal runaway, but it must be able to release the fixing effect on the first electrical connection structure 81 and the second electrical connection structure 82. The top of the thermally runaway battery cell 7 will deform, and the deformation will cause the first electrical connection structure 81 and the second electrical connection structure 82 to separate, thereby releasing the electrical connection between the first electrical connection structure 81 and the second electrical connection structure 82.

[0099] The battery device 2 of this application embodiment configures the busbar assembly 8 to include a first electrical connection structure 81, a second electrical connection structure 82, and a fixing unit 83. The fixing unit 83 fixes the first electrical connection structure 81 and the second electrical connection structure 82 together, ensuring that the joint always abuts against each other to achieve electrical connection. The fixing unit 83 is configured to at least partially melt and lose its fixing function when the battery cell 7 experiences thermal runaway. The top of the runaway battery cell 7 will deform, thereby separating the first electrical connection structure 81 and the second electrical connection structure 82 under the action of the deformation of the battery cell 7, thus releasing the electrical connection. In this way, when thermal runaway occurs, even if the casings of the runaway battery cell 7 overlap with those of adjacent battery cells 7, a circuit cannot be formed, thereby reducing the possibility of thermal runaway of adjacent battery cells 7 and improving the reliability of the battery device 2.

[0100] In some embodiments, the fixing unit 83 includes a fixing member 832, which is at least partially disposed around the joint of the first electrical connection structure 81 and the second electrical connection structure 82 and fixes them together. The fixing member 832 is configured to melt when the battery cell 7 experiences thermal runaway, so as to release the fixed connection between the first electrical connection structure 81 and the second electrical connection structure 82.

[0101] The fastener 832 in this embodiment can be a welded metal layer or a cast metal layer, arranged around or semi-around the joint of the first electrical connection structure 81 and the second electrical connection structure 82 to connect the two. The fastener 832 can also be arranged around or semi-around the joint by a hot or cold rolling process. The metal used is a low-melting-point metal.

[0102] The fastener 832 in this embodiment can be a plastic part, which is arranged around or semi-around the joint of the first electrical connection structure 81 and the second electrical connection structure 82 to fix the two together. Specifically, it can be injection molded into the joint of the first electrical connection structure 81 and the second electrical connection structure 82, or it can be clamped at the joint of the first electrical connection structure 81 and the second electrical connection structure 82 by its own elasticity.

[0103] By fixing the fastener 832 at least partially around the joint of the first electrical connection structure 81 and the second electrical connection structure 82, the two are fixedly connected. This eliminates the need to drill holes at the joint of the first electrical connection structure 81 and the second electrical connection structure 82, making manufacturing easier.

[0104] In some embodiments, the fastener 832 is disposed around the junction of the first electrical connection structure 81 and the second electrical connection structure 82.

[0105] In this embodiment of the application, the fastener 832 is arranged in a ring around the splice of the first electrical connection structure 81 and the second electrical connection structure 82.

[0106] This configuration improves the structural strength of the fastener 832 in fixing the first electrical connection structure 81 and the second electrical connection structure 82, thereby improving the reliability of the bus assembly 8.

[0107] Figure 5 This is another schematic diagram of the busbar assembly in a battery device provided in some embodiments of this application.

[0108] Please see Figure 5 In some embodiments, the fixing unit 83 further includes a plurality of connectors 833, which respectively connect the first electrical connection structure 81 and the second electrical connection structure 82 to the fixing member 832. The first electrical connection structure 81 and the second electrical connection structure 82 are fixedly connected through the connectors 833 and the fixing member 832.

[0109] The connector 833 in this embodiment can be configured to melt when the battery cell 7 experiences thermal runaway, or it can be configured not to melt when the battery cell 7 experiences thermal runaway.

[0110] Optionally, the connector 833 is a plastic part and is configured to melt in the event of thermal runaway of the battery cell 7.

[0111] The connector 833 in this embodiment can be a bolt and nut or a rivet.

[0112] The connector 833 is provided to further strengthen the fixing effect of the fixing unit 83 on the first electrical connection structure 81 and the second electrical connection structure 82, so that the first electrical connection structure 81 and the second electrical connection structure 82 maintain a good electrical connection and improve the reliability of the bus assembly 8.

[0113] Figure 6 This is an exploded view of a portion of the structure of a busbar assembly in a battery device provided in some embodiments of this application.

[0114] Please see Figure 6 In some embodiments, the first electrical connection structure 81 includes a protrusion 811, and the second electrical connection structure 82 includes a recess 821 adapted to the protrusion 811. The first electrical connection structure 81 and the second electrical connection structure 82 are spliced ​​together by the protrusion 811 and the recess 821.

[0115] In this embodiment, the protrusion 811 and the recess 821 are adapted in shape and size. For example, the protrusion 811 can be an arc-shaped protrusion, a triangular pyramidal protrusion, a cuboid protrusion, or an irregular protrusion, etc., and the recess 821 is a recessed space adapted to the above-mentioned shape and size.

[0116] The number of protrusions 811 in the embodiments of this application can be one or more.

[0117] This configuration increases the contact area between the first electrical connection structure 81 and the second electrical connection structure 82, thereby improving the current-carrying capacity of the busbar assembly 8.

[0118] Figure 7 This is an exploded view of another part of the structure of the busbar assembly in a battery device provided in some embodiments of this application.

[0119] Please see Figure 7 In some embodiments, there are multiple protrusions 811 and multiple recesses 821. The multiple protrusions 811 are arranged along the first direction X, and the multiple protrusions 811 and multiple recesses 821 are spliced ​​together one by one. The first direction X intersects with the arrangement direction of the first electrical connection structure 81 to the second electrical connection structure 82 and the thickness direction of the first electrical connection structure 81.

[0120] The shapes of the plurality of protrusions 811 in the embodiments of this application may be the same or different.

[0121] Optionally, the first direction X is perpendicular to the arrangement direction of the first electrical connection structure 81 to the second electrical connection structure 82 and the thickness direction of the first electrical connection structure 81.

[0122] This configuration allows the first electrical connection structure 81 and the second electrical connection structure 82 to have a larger contact area, thereby improving the current carrying capacity of the busbar assembly 8.

[0123] Figure 8 This is another partially exploded schematic diagram of the busbar assembly in a battery device provided in some embodiments of this application.

[0124] Please see Figure 8 In some embodiments, the protrusion 811 includes one of a serration, a square protrusion, or an arcuate protrusion.

[0125] The recessed space formed by the recessed portion 821 in this embodiment of the application is adapted to the shape of the protrusion 811, corresponding to a sawtooth recessed space, a square recessed space and an arc-shaped recessed space.

[0126] This configuration allows the first electrical connection structure 81 and the second electrical connection structure 82 to have a larger contact area, thereby improving the current carrying capacity of the busbar assembly 8.

[0127] Figure 9 This is another partially exploded schematic diagram of the busbar assembly in a battery device provided in some embodiments of this application; Figure 10 This is an exploded view of yet another partial structure of the busbar assembly in a battery device provided in some embodiments of this application.

[0128] Please see Figure 9 and Figure 10In some embodiments, the first electrical connection structure 81 has a first inclined surface 812, and the second electrical connection structure 82 has a second inclined surface 822 adapted to the degree of inclination and / or curvature of the first inclined surface 812. The first electrical connection structure 81 and the second electrical connection structure 82 are spliced ​​together by the first inclined surface 812 and the second inclined surface 822.

[0129] The first inclined surface 812 in this embodiment can be a plane, a curved surface, or an irregularly shaped surface combining a plane and a curved surface. The degree of inclination in this embodiment refers to the degree of inclination of the plane, and the degree of curvature refers to the degree of curvature of the curved surface.

[0130] The first inclined surface 812 in this embodiment can be parallel to the aforementioned first direction X, such as... Figure 9 As shown, the first inclined surface 812 intersects the arrangement direction of the first electrical connection structure 81 to the second electrical connection structure 82, as well as the thickness direction of the first electrical connection structure 81; the first inclined surface 812 can also be parallel to the thickness direction of the first electrical connection structure 81, such as... Figure 10 As shown, the first inclined plane 812 intersects with the first direction X and the arrangement directions of the first electrical connection structure 81 to the second electrical connection structure 82.

[0131] Optionally, the first inclined surface 812 is a plane, parallel to the first direction X, and intersects the arrangement direction of the first electrical connection structure 81 to the second electrical connection structure 82 and the thickness direction of the first electrical connection structure 81.

[0132] This configuration increases the contact area between the first electrical connection structure 81 and the second electrical connection structure 82, thereby improving the current-carrying capacity of the busbar assembly 8.

[0133] Figure 11 This is another partially exploded schematic diagram of the busbar assembly in a battery device provided in some embodiments of this application.

[0134] Please see Figure 11 In some embodiments, the first electrical connection structure 81 has a first stepped surface 813, and the second electrical connection structure 82 has a second stepped surface 823. The first stepped surface 813 and the second stepped surface 823 cooperate with each other so that the first electrical connection structure 81 and the second electrical connection structure 82 are spliced ​​together.

[0135] The first step surface 813 and the second step surface 823 in the embodiments of this application both include at least one step.

[0136] The walking direction of the first step surface 813 in this embodiment can be along the thickness direction of the first electrical connection structure 81, or along the aforementioned first direction X.

[0137] This configuration increases the contact area between the first electrical connection structure 81 and the second electrical connection structure 82, thereby improving the current-carrying capacity of the busbar assembly 8.

[0138] Figure 12 A schematic diagram of a busbar assembly in a battery device provided in some embodiments of this application; Figure 13 This is another schematic diagram of the busbar assembly in a battery device provided in some embodiments of this application.

[0139] Please see Figure 12 and Figure 13 In some embodiments, the fixing unit 83 includes a fastener 831, which passes through the joint of the first electrical connection structure 81 and the joint of the second electrical connection structure 82 in sequence and fixes them together. The fastener 831 is configured to melt when the battery cell 7 experiences thermal runaway, so as to release the fixed connection between the first electrical connection structure 81 and the second electrical connection structure 82.

[0140] As an example, fastener 831 includes a bolt and a nut, the bolt passing sequentially through the joint of the first electrical connection structure 81 and the joint of the second electrical connection structure 82. Another example is... Figure 13 As shown, the bolt passes sequentially through the first electrical connection structure 81 and the second electrical connection structure 82 along the aforementioned first direction X, and is secured by a nut; as Figure 12 As shown, the bolt passes through the first inclined surface 812 and the second inclined surface 822 in sequence along the thickness direction of the first electrical connection structure 81, and the first electrical connection structure 81 and the second electrical connection structure 82 are secured by the nut; the bolt passes through the first stepped surface 813 and the second stepped surface 823 in sequence, and the first electrical connection structure 81 and the second electrical connection structure 82 are secured by the nut.

[0141] As an example, fastener 831 includes a rivet that passes through the joint of the first electrical connection structure 81 and the joint of the second electrical connection structure 82 and connects the two.

[0142] The fasteners in this application embodiment can be plastic parts, composite material parts with plastic as the matrix, or other materials that melt when heated.

[0143] The fixing unit 83 is configured to include fasteners, which lock the first electrical connection structure 81 and the second electrical connection structure 82 together, resulting in a high structural strength and reliable use.

[0144] Figure 14 This is another partially exploded schematic diagram of the busbar assembly in a battery device provided in some embodiments of this application.

[0145] Please see Figure 14In some embodiments, the bus assembly 8 further includes an elastic element 84. A first groove 841 for accommodating the elastic element 84 is provided at the joint of at least one of the first electrical connection structure 81 and the second electrical connection structure 82. The elastic element 84 is insulated from both the first electrical connection structure 81 and the second electrical connection structure 82. The elastic element 84 is configured to store elastic potential energy in a compressed state when the first electrical connection structure 81 and the second electrical connection structure 82 are fixedly connected by the fixing unit 83; and to release the elastic potential energy when the first electrical connection structure 81 and the second electrical connection structure 82 are released from their fixed connection, thereby separating the first electrical connection structure 81 and the second electrical connection structure 82.

[0146] The elastic element 84 in this embodiment refers to a component that has a certain elastic force, can store elastic potential energy in a compressed state, and can release elastic potential energy after the compression state is released. For example, it can be a spring or an elastic rubber component.

[0147] In this embodiment, the elastic element 84 is insulated from both the first electrical connection structure 81 and the second electrical connection structure 82. The elastic element 84 itself may be made of insulating material, such as rubber or plastic; or the main body of the elastic element 84 may be made of metal material, while the surface is coated with insulating material, thereby achieving insulation from the first electrical connection structure 81 and the second electrical connection structure 82.

[0148] Optionally, a first groove 841 is provided at the joint of the first electrical connection structure 81 and the second electrical connection structure 82.

[0149] By setting the elastic element 84, elastic potential energy is released when the first electrical connection structure 81 and the second electrical connection structure 82 are released from fixed connection, thereby enabling the first electrical connection structure 81 and the second electrical connection structure 82 to be quickly separated, and the short circuit circuit is quickly cut off, further improving the reliability of the battery device 2.

[0150] In some embodiments, the bus assembly 8 further includes an insulating film that wraps around the elastic member 84 so that the elastic member 84 is insulated from both the first electrical connection structure 81 and the second electrical connection structure 82.

[0151] The elastic element 84 in this embodiment can be a spring, and after being wrapped with an insulating film, it can be bonded to the first electrical connection structure 81 or the second electrical connection structure 82.

[0152] An insulating film is provided to wrap the elastic element 84, thereby achieving insulation from the first electrical connection structure 81 and the second electrical connection structure 82.

[0153] In some embodiments, the melting point T1 of the insulating film and the volumetric energy density E of the battery cell 7 satisfy the following: when E≤390Wh / L, T1>200℃; when E>390Wh / L, T1>250℃.

[0154] In this application embodiment, the volumetric energy density E refers to the energy stored in a unit volume of matter.

[0155] Optionally, when E≤390Wh / L, T1 can be 210℃, 220℃, 230℃, 240℃ or 250℃.

[0156] Optionally, when E > 390 Wh / L, T1 can be 260 ℃, 270 ℃, 280 ℃, 290 ℃ or 300 ℃.

[0157] With this configuration, a suitable insulating film can be selected based on the volumetric energy density of the battery cell 7, thereby enabling the insulating film to meet different usage conditions and reducing the possibility of the insulating film failing due to overheating.

[0158] Figure 15 This is another partially exploded schematic diagram of the busbar assembly in a battery device provided in some embodiments of this application.

[0159] Please see Figure 15 In some embodiments, the bus assembly 8 further includes a deformable member 85. At least one of the first electrical connection structure 81 and the second electrical connection structure 82 is provided with a second groove 842 for accommodating the deformable member 85. The deformable member 85 is insulated from both the first electrical connection structure 81 and the second electrical connection structure 82. The deformable member 85 is configured to deform when heated when the first electrical connection structure 81 and the second electrical connection structure 82 are disconnected, so as to separate the first electrical connection structure 81 and the second electrical connection structure 82.

[0160] The deformable component 85 in this embodiment can be a shape memory alloy that deforms when heated, for example, by lengthening, separating the first electrical connection structure 81 and the second electrical connection structure 82. The deformable component 85 in this embodiment can also be a thermally expanding material such as silicone or refractory fiber.

[0161] A deformable component 85 is provided, which deforms when the first electrical connection structure 81 and the second electrical connection structure 82 are disconnected due to heat, thereby quickly separating the first electrical connection structure 81 and the second electrical connection structure 82, rapidly cutting off the short circuit circuit, and improving the reliability of the battery device 2.

[0162] In some embodiments, the meltable portion of the fixing unit 83 is an insulating element.

[0163] The insulating component in this application embodiment can be plastic, or it can be other types of insulating components, such as insulating composite materials with plastic as the base, rubber, silicone, etc.

[0164] The fixing unit 83 in this embodiment can be entirely or partially insulating. The non-melting portion may or may not be insulating.

[0165] The molten part of the fixing unit 83 is made into an insulating part. After being heated and melted, it loses its fixing effect on the first electrical connection structure 81 and the second electrical connection structure 82. Thus, under the action of the deformation of the battery cell 7, the first electrical connection structure 81 and the second electrical connection structure 82 are disconnected. This reduces the possibility that the first electrical connection structure 81 and the second electrical connection structure 82 will be electrically connected after the fixing unit 83 is melted, which is more reliable.

[0166] In some embodiments, the insulating element includes a plastic element or a rubber element.

[0167] The plastic parts in the embodiments of this application can be PP (polypropylene), PET (polyethylene terephthalate), PA (polyamide) or PC (polycarbonate), or PPA (polyphthalamide) or PPS (polyphenylene sulfide).

[0168] The fixing unit 83 is made of plastic or rubber. Plastic or rubber parts can easily meet the melting point requirements and melt in time during thermal runaway, thus losing their fixing function to the first electrical connection structure 81 and the second electrical connection structure 82.

[0169] In some embodiments, the melting point of the molten portion in the fixing unit 83 is T2, and T2 satisfies: 100℃≤T2≤300℃.

[0170] Optionally, T2 can be 100℃, 120℃, 150℃, 170℃, 200℃, 220℃, 250℃, 270℃ or 300℃.

[0171] The melting point of the molten portion of the fixing unit 83 is limited to greater than or equal to 100°C to satisfy the conductivity function of the busbar assembly 8 under normal use of the battery device 2; the melting point of the molten portion of the fixing unit 83 is limited to less than or equal to 300°C to satisfy the melting in the event of thermal runaway to disconnect the first electrical connection structure 81 and the second electrical connection structure 82.

[0172] In some embodiments, T2 satisfies: 150℃≤T2≤200℃.

[0173] Optionally, T2 can be 150℃, 160℃, 170℃, 180℃, 190℃ or 200℃.

[0174] The melting point of the molten portion in the fixing unit 83 is further limited to greater than or equal to 150°C to meet the conductivity function of the busbar assembly 8 under normal use of the larger capacity battery device 2; the melting point of the molten portion in the fixing unit 83 is limited to less than or equal to 200°C so that it can melt in time in the event of thermal runaway to disconnect the first electrical connection structure 81 and the second electrical connection structure 82, reduce the possibility of short circuit circuit formation, and improve the reliability of the battery device 2.

[0175] This application embodiment also provides an electrical device, including the battery device 2 described above, which is used to provide electrical energy.

[0176] Please see Figures 2-4 This application provides a battery device 2, which includes a housing 6 and a battery cell assembly 5. The battery cell assembly 5 is located inside the housing 6 and includes multiple battery cells 7 and a busbar assembly 8. Adjacent battery cells 7 are electrically connected through the busbar assembly 8. The busbar assembly 8 includes a first electrical connection structure 81, a second electrical connection structure 82, and a fixing unit 83. The first electrical connection structure 81 and the second electrical connection structure 82 are spliced ​​together and respectively connected to two battery cells 7. The fixing unit 83 is connected to the first electrical connection structure 81 and the second electrical connection structure 82, and fixes the first electrical connection structure 81 and the second electrical connection structure 82. The fixing unit 83 is configured to at least partially melt in the event of thermal runaway of a battery cell 7, thereby releasing the fixed connection between the first electrical connection structure 81 and the second electrical connection structure 82. The melting point of the meltable portion of the fixing unit 83 is T2, which satisfies: 100℃≤T2≤300℃.

[0177] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0178] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features. However, these modifications or substitutions 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 this application.

Claims

1. A battery device, characterized in that, include: Box; A battery cell assembly is located inside the housing. The battery cell assembly includes multiple battery cells and a current-combining assembly. Two adjacent battery cells are electrically connected through the current-combining assembly. The busbar assembly includes a first electrical connection structure, a second electrical connection structure, and a fixing unit. The first electrical connection structure and the second electrical connection structure are spliced ​​together and respectively connected to two battery cells. The fixing unit is connected to the first electrical connection structure and the second electrical connection structure, and fixes the first electrical connection structure and the second electrical connection structure. The fixing unit is configured to be at least partially melted when the battery cell experiences thermal runaway, so as to release the fixed connection between the first electrical connection structure and the second electrical connection structure.

2. The battery device according to claim 1, characterized in that, The fixing unit includes a fixing member, which is at least partially disposed around the joint of the first electrical connection structure and the second electrical connection structure and fixes the two together. The fixing member is configured to melt when the battery cell experiences thermal runaway, so as to release the fixed connection between the first electrical connection structure and the second electrical connection structure.

3. The battery device according to claim 2, characterized in that, The fastener is arranged around the joint between the first electrical connection structure and the second electrical connection structure.

4. The battery device according to claim 2, characterized in that, The fixing unit further includes a plurality of connectors, which respectively connect the first electrical connection structure and the second electrical connection structure to the fixing member, and the first electrical connection structure and the second electrical connection structure are fixedly connected through the connectors and the fixing member.

5. The battery device according to claim 1, characterized in that, The first electrical connection structure includes a protrusion, and the second electrical connection structure includes a recess that is adapted to the protrusion. The first electrical connection structure and the second electrical connection structure are spliced ​​together through the protrusion and the recess.

6. The battery device according to claim 5, characterized in that, The number of protrusions and recesses is multiple. The multiple protrusions are arranged along a first direction, and the multiple protrusions and multiple recesses are spliced ​​together one by one. The first direction intersects with the arrangement direction of the first electrical connection structure to the second electrical connection structure and the thickness direction of the first electrical connection structure in pairs.

7. The battery device according to claim 5, characterized in that, The protrusion includes one of the following: a serrated protrusion, a square protrusion, or an arc-shaped protrusion.

8. The battery device according to claim 1, characterized in that, The first electrical connection structure has a first inclined surface, and the second electrical connection structure has a second inclined surface adapted to the degree of inclination and / or curvature of the first inclined surface. The first electrical connection structure and the second electrical connection structure are spliced ​​together by the first inclined surface and the second inclined surface.

9. The battery device according to claim 1, characterized in that, The first electrical connection structure has a first stepped surface, and the second electrical connection structure has a second stepped surface. The first stepped surface and the second stepped surface cooperate with each other so that the first electrical connection structure and the second electrical connection structure are spliced ​​together.

10. The battery device according to any one of claims 5-9, characterized in that, The fixing unit includes a fastener, which passes through the joint of the first electrical connection structure and the joint of the second electrical connection structure in sequence and fixes them together. The fastener is configured to melt when the battery cell experiences thermal runaway, so as to release the fixed connection between the first electrical connection structure and the second electrical connection structure.

11. The battery device according to claim 1, characterized in that, The bus assembly further includes an elastic element. A first groove for accommodating the elastic element is provided at the joint of at least one of the first electrical connection structure and the second electrical connection structure. The elastic element is insulated from both the first electrical connection structure and the second electrical connection structure. The elastic element is configured to store elastic potential energy in a compressed state when the first electrical connection structure and the second electrical connection structure are fixedly connected by the fixing unit; and to release the elastic potential energy when the first electrical connection structure and the second electrical connection structure are released from the fixed connection, so as to separate the first electrical connection structure and the second electrical connection structure.

12. The battery device according to claim 11, characterized in that, The busbar assembly further includes an insulating film that wraps around the elastic element so that the elastic element is insulated from both the first electrical connection structure and the second electrical connection structure.

13. The battery device according to claim 12, characterized in that, The melting point T1 of the insulating film and the volumetric energy density E of the battery cell satisfy the following: When E≤390Wh / L, T1>200℃; When E > 390 Wh / L, T1 > 250 ℃.

14. The battery device according to claim 1, characterized in that, The bus assembly further includes a deformable component. A second groove for accommodating the deformable component is provided at the joint of at least one of the first and second electrical connection structures. The deformable component is insulated from both the first and second electrical connection structures. The deformable component is configured to deform upon heating when the first electrical connection structure and the second electrical connection structure are disconnected, so as to separate the first electrical connection structure and the second electrical connection structure.

15. The battery device according to claim 1, characterized in that, The part of the fixing unit that can be melted is an insulating component.

16. The battery device according to claim 15, characterized in that, The insulating component may be a plastic component or a rubber component.

17. The battery device according to claim 1, characterized in that, The melting point of the molten portion in the fixed unit is T2, and T2 satisfies: 100℃≤T2≤300℃.

18. The battery device according to claim 17, characterized in that, The T2 condition is: 150℃≤T2≤200℃.

19. An electrical appliance, characterized in that, Includes the battery device as described in any one of claims 1-18, the battery device being used to provide electrical energy.

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