Heating device, battery, battery pack and electric equipment

Abstract

The embodiment of the invention provides a heating device, a battery, a battery pack and electric equipment, which can reduce the size of an existing heating device, improve the overcurrent capability of the existing heating device, directly heat a battery cell, and have the advantages of less trigger energy, high heating efficiency and obvious heating effect. The heating device comprises a heating piece, a wire and an insulating film, the heating piece is provided with an arc-shaped corner, the outer contour width of the arc-shaped corner is greater than or equal to the overall width of the heating piece, and the heating piece is embedded between a positive plate and a negative plate in the battery cell; the internal connection end of the wire is connected to the heating piece, the positive electrode connection end of the wire is led to the positive electrode end externally connected to the battery cell, and the negative electrode connection end of the wire is led to the negative electrode end externally connected to the battery cell.

Description

Technical Field

[0001] The present application relates to the technical field of battery thermal management, and in particular to a heating device, a battery, a battery pack and an electrical device. Background Art

[0002] With the rapid development of the economy, people pay more and more attention to environmental protection and energy, which has promoted the development of new energy and environmental protection technologies, making more and more new energy electric vehicles used in daily life.

[0003] For new energy electric vehicles, safety performance is one of the most important performances. As the core component of new energy electrical equipment, batteries are related to the safety of vehicles. For batteries, thermal runaway is the most common out-of-control condition that affects battery safety performance. When thermal runaway occurs in batteries and reaches a certain temperature, it will seriously cause the battery to spontaneously combust or even explode. Therefore, safety performance tests such as single-cell thermal runaway are required before the battery leaves the factory.

[0004] At present, there are many testing methods for thermal runaway of single cells. The mainstream testing scheme is to heat the battery cell by installing heating elements such as heating films inside the battery cell. The heating film usually adopts an assembly structure such as a heating component, a heat conductive layer and an assembly component to heat the inside of the battery cell over a large area, causing the temperature inside the battery cell to rise, thereby causing an internal short circuit in the battery cell and triggering thermal runaway of the battery cell.

[0005] However, the above-mentioned heating film adopts a large-area heating scheme to simulate thermal runaway, which is not only complex in structure and low in heating efficiency, but also contrary to the actual thermal runaway condition of local short-triggered battery, so the simulation results are biased. Summary of the invention

[0006] The embodiments of the present application provide a heating device, a battery, a battery pack and an electrical device, which can reduce the size of the existing heating device, improve its current carrying capacity, and directly heat the battery cells. The triggering requires less energy, less energy loss, high heating efficiency, and significant heating effect.

[0007] In a first aspect, an embodiment of the present application provides a device including: a heating element, a wire, and an insulating structure covering the outside of the heating element and the wire;

[0008] The heating element is provided with an arc-shaped corner, the outer contour width of the arc-shaped corner is greater than or equal to the width of other structures on the heating element except the arc-shaped corner, and the heating element is embedded between the positive electrode sheet and the negative electrode sheet inside the battery cell;

[0009] The inner end of the wire is connected to the heating element, the positive connection end of the wire is externally connected to the positive end of the battery cell, and the negative connection end of the wire is externally connected to the negative end of the battery cell.

[0010] In a possible implementation manner, the heating element includes at least one heating unit, and two adjacent heating units are connected via an arc-shaped corner.

[0011] In a possible implementation manner, the heating element includes a heating unit having an arc-shaped corner.

[0012] In a possible implementation manner, the heating element includes two heating units, and each of the heating units is provided with an arc-shaped corner.

[0013] In a possible implementation, the wires include two internal wires and two external wires, wherein the two internal wires are embedded in the battery cell, and the external wires include a positive external wire and a negative external wire, the internal ends of the two internal wires are connected to the heating element, and the external ends of the two internal wires are respectively connected to the internal wire connection end of the positive external wire and the internal wire connection end of the negative external wire.

[0014] In a possible implementation manner, the insulating structure includes a heating element insulating film coated on the outside of the heating element, and a wire insulating film coated on the outside of the internal wire and the external wire;

[0015] The heating element insulating film comprises an inner insulating film and an outer insulating film, wherein the inner insulating film is an insulating film resistant to electrolyte corrosion, and the outer insulating film is a high temperature resistant insulating film;

[0016] The wire insulation film is a polyimide insulation film.

[0017] In a possible implementation, the inner insulating film is a pI insulating film, and the outer insulating film is a mica paper insulating film.

[0018] In a possible implementation manner, the heating element is an integrally formed structure.

[0019] In a second aspect, an embodiment of the present application provides a battery, comprising:

[0020] Battery cells;

[0021] An insulating protective film, covering the outside of the battery cell to insulate the battery cell from the battery case;

[0022] A battery casing, used to encapsulate and fix the battery core;

[0023] A heating device is disposed between the positive and negative electrodes inside the battery cell. The heating device is electrically connected to the positive terminal and the negative terminal of the battery cell and is used to heat a preset area inside the battery cell.

[0024] In a possible implementation manner, it further includes a fixing device for fixing the heating device to the side wall of the battery core;

[0025] The fixing device includes a side panel and a side panel fixing tape. The side panel is provided with a side panel groove, and the side panel groove is used for allowing the wires of the heating device to be led out from the inner side of the side panel. The side panel fixing tape is used for fixing the wires of the heating device to the outer wall surface of the side panel.

[0026] In a possible implementation, the positive terminal of the battery housing is provided with a first positive electrode assembly and a second positive electrode assembly;

[0027] The negative electrode connection end of the wire of the heating device is used to electrically connect the negative electrode assembly of the battery housing, and the negative electrode assembly and the second positive electrode assembly are connected to an external power supply;

[0028] The positive electrode connection end of the lead wire of the heating device is used for electrically connecting to the second positive electrode assembly.

[0029] The negative electrode connection end is welded and fixed to the negative electrode assembly. The welding and fixing position of the negative electrode connection end and the negative electrode assembly is covered with a first welding portion insulating film, and the first welding portion insulating film is a polyimide insulating film.

[0030] In a possible implementation, the positive electrode connection end is welded and fixed to the second positive electrode assembly, and the welding and fixing position of the positive electrode connection end and the second positive electrode assembly is covered with a second welding portion insulating film, and the second welding portion insulating film is a polyimide insulating film.

[0031] In a possible embodiment, the second positive electrode assembly includes a positive aluminum terminal, an insulating member, a second positive conductive column and a sealing ring group, one end of the second positive conductive column is welded and fixed to a wire, the other end of the second positive conductive column is riveted and fixed to the positive aluminum terminal, and the insulating member is disposed between the second positive conductive column and the positive cover plate, and is used to insulate and fix the second positive conductive column and the positive cover plate.

[0032] In a possible implementation manner, the heating device is disposed on a short side of the battery core.

[0033] In a third aspect, an embodiment of the present application provides a battery pack, comprising a plurality of batteries, wherein the batteries are the batteries described in any one of the above claims.

[0034] In a fourth aspect, an embodiment of the present application provides an electrical device, comprising a battery as described in any one of the above items.

[0035] The heating device, battery, battery pack and electrical equipment provided by the embodiment of the present application, the heating device is arranged between the positive and negative electrodes inside the battery cell. In this way, all the energy is used to heat the inside of the battery cell, the heating efficiency is high, the energy required for thermal runaway triggering is small, and no waste is caused. In addition, it is closer to the actual working condition of local battery thermal runaway, the simulation degree is higher, and the test is more accurate. The heating element of the heating device in the present application is provided with an arc corner structure, and the width of the outer contour of the arc corner structure is set to be greater than or equal to the overall width of the heating element. By widening the arc corner position of the heating device, the size of the heating device can be set to about 5×5mm, so that the size of the heating device is smaller and the current carrying capacity is larger, which greatly improves the flow capacity and heating efficiency, reduces the energy input, and improves the heating efficiency. In addition, the wire in the present application adopts an external structure, which can be led to the positive and negative ends of the battery cell. This structure can ensure the good sealing of the internal structure of the battery, and can realize electrical extraction at the same time, effectively avoiding battery leakage, wire breakage, etc., and the packaging and fixing scheme is safer and more reliable.

[0036] In addition, the battery provided in the present application has a heating device sealed inside the battery cell, which effectively simulates and reproduces the safety accident conditions of electric vehicles caused by thermal runaway of single cells during normal driving or when stopped, and provides theoretical support and guidance for a multi-dimensional and more comprehensive understanding of battery safety performance and improving battery safety performance.

[0037] In addition, the battery pack provided in the present application includes a plurality of batteries, and the performance of the battery pack is stable and reliable.

[0038] In addition, the electrical equipment provided in the present application has the above-mentioned battery pack, so that the electrical equipment has better safety performance and lower maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0040] Figure 1 A schematic diagram of the structure of the heating device battery provided in this application;

[0041] Figure 2 A schematic diagram of the structure of the battery provided for this application;

[0042] Figure 3 A perspective view of a battery provided for this application;

[0043] Figure 4 An exploded view of the battery provided for this application;

[0044] Figure 5An enlarged assembly diagram of the positive terminal of the battery provided in this application;

[0045] Figure 6 for Figure 5 A magnified view of the middle A area;

[0046] Figure 7 and Figure 8 A partial cross-sectional view of the positive terminal of the battery provided for the present application;

[0047] Fig. 9 A schematic diagram of the structure of the second positive electrode assembly provided in this application;

[0048] Fig.10 An enlarged assembly diagram of the negative terminal of the battery provided in this application;

[0049] Fig.11 for Fig.10 Enlarged view of the B area;

[0050] Fig.12 A partial schematic diagram of the lead inside the negative terminal conductive column provided by the present application;

[0051] Fig.13 and Fig.14 A partial cross-sectional view of the negative terminal of the battery provided in the present application.

[0052] Among them, 1-battery;

[0053] 10-battery housing, 20-insulating protective film, 30-battery core, 40-heating device, 50-fixing device, 60-positive electrode separator, 70-negative electrode separator;

[0054] 101-battery housing, 102-positive electrode cover, 103-negative electrode cover, 104-first positive electrode assembly, 105-second positive electrode assembly, 106-negative electrode assembly, 401-heating element, 402-internal wire, 403-external wire, 501-side plate, 502-side plate fixing tape;

[0055] 1051-positive electrode aluminum terminal, 1052-second positive electrode conductive column, 1053-second insulating member, 1054-second sealing ring group, 1061-negative electrode ear, 1062-negative electrode insulating spacer, 1063-negative electrode inner lead, 1064-negative electrode aluminum terminal, 1065-negative electrode conductive column, 1066-negative electrode insulating assembly, 4031-positive electrode connecting end, 4032-negative electrode connecting end.

[0056] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0057] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0058] It should be noted that when a component is referred to as being "fixed on" or "disposed on" another component, it may be directly on the other component or there may also be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right", "front", "rear" and similar expressions used in the specification of this application are for illustrative purposes only and do not represent the only implementation method.

[0059] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0060] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first feature is directly in contact with the second feature, or the first feature and the second feature are in contact indirectly through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is smaller in level than the second feature.

[0061] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. 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 term "and / or" used in the specification of this application includes any and all combinations of one or more related listed items.

[0062] Considering the technical problems that the heating device 40 used in the existing battery cell 30 is large in size, small in current capacity, low in heating efficiency, and deviates from the actual working condition of the battery, the present application takes a unique approach and adopts a small-area local heat triggering scheme. This heating scheme has high heating efficiency, requires less triggering energy, and does not cause energy waste. Compared with the traditional heating device 40, the heating device 40 provided by the present application has a smaller structural size (the size can reach 3×3mm or even smaller), is closer to the working condition of local battery thermal runaway, and the simulation effect is more accurate and reliable.

[0063] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0064] like Figure 1 As shown. The heating device 40 of the present application includes: a heating element 401, a wire and an insulating structure, wherein the insulating structure is coated on the outside of the heating element 401 and the wire, so that the heating element 401 and the wire inside the insulating structure are isolated from the external environment. The heating element 401 and part of the wire are placed inside the battery cell 30, the heating element 401 is connected to the wire, and an external power supply is connected to the wire to power the heating element 401, so that the heating element 401 heats the preset position inside the battery cell 30, thereby realizing thermal triggering.

[0065] Specifically, refer to Figure 1 The heating element 401 includes a heating body, and pins are provided at both ends of the heating body. The pins and the wires are connected into a whole by laser welding. The connection area between the pins and the wires is a non-heating area. In addition, the wire is provided with a wire body, and the wire body is provided with an inner connection end, a positive connection end 4031 and a negative connection end 4032. The inner connection end is connected to the wire connection part of the heating element 401, and the positive connection end 4031 of the wire is led to the positive terminal externally connected to the battery cell 30, and the negative connection end 4032 of the wire is led to the negative terminal externally connected to the battery cell 30. In this way, it is possible to energize the heating element 401 through the wire and lead out electricity through the wire. The negative connection end 4032 is fixed to the negative electrode assembly 106 by welding, and the welding and fixing position of the negative connection end 4032 and the negative electrode assembly 106 is covered with a first welding portion insulating film, and the first welding portion insulating film can be but is not limited to a polyimide insulating film.

[0066] The main heating structure is provided with an arc corner, the inner and outer contours of the arc corner are both arc-shaped, and the outer contour width of the arc corner is greater than or equal to the width of other structures on the heating element 401 except the arc corner. In the present application, the main heating structure of the heating device 40 is provided with an arc corner, and a widened structural design is made on the outer contour width of the arc corner, and the width of the arc corner is not less than the width of other parts of the heating element 401. This structure can effectively reduce the heating size while applying a large current, and at the same time, improve the current capacity of the heating device 40. In addition, the heating device 40 is directly placed between the positive and negative electrodes inside the battery cell 30 to directly trigger the battery 1, and the heating energy is all used for internal heating of the battery 1, thereby effectively reducing the energy input, shortening the heating time, and improving the heating efficiency. Compared with the heating device 40 in the prior art, the heating device 40 of this scheme is smaller in size, has a larger current capacity, a smaller heating area, and is closer to the working condition of local battery thermal runaway. The method of leading the wires out of the battery core 30 and externally connecting to the positive and negative terminals of the battery core 30 can prevent leakage.

[0067] This application simulates the safety issues caused by the loss of control of a single cell during driving, parking, and normal charging and discharging of an electric vehicle, which helps to analyze the safety performance of the battery 1 in multiple dimensions, and provides theoretical data for the design and production of the battery 1, thereby designing a safer and more reliable battery, and providing users with more reliable safety protection. The heating device 40 in this application is suitable for traditional iron-lithium batteries and ternary batteries, as well as blade batteries, etc., and has a wide range of applications.

[0068] In a specific embodiment, the heating element 401 may include a plurality of heating monomers, and the width of the arc-shaped corner is greater than or equal to the width of other parts of the heating element 401 in the same direction. The number of heating monomers may be one, two, or more than two. The heating monomers are connected in series to form a heating main structure, and two adjacent heating monomers are connected by an arc-shaped corner. Pins are respectively provided on the two outermost heating monomers, and the pins and the wires are connected into a whole by laser welding.

[0069] The connection method between the heating cells can be but is not limited to welding or integral molding, but it should be ensured that there are no sharp corners at each part of the heating cell and between two connected heating cells, or the right angles of the connection area should be rounded to prevent the sharp right angles from piercing the internal material of the battery 1 or the insulating structure and causing a short circuit.

[0070] By adopting this solution, the number of heating cells can be set according to the size of the battery 1 to form different heating areas, meet different heating requirements, and improve the application range. It should be noted that the heating element 401 can adopt an integrated structure to ensure a better heat transfer effect.

[0071] In a preferred embodiment, the heating element 401 includes a heating unit having an arc-shaped corner. Figure 1 In the U-shaped structure shown, pins are provided at both ends of the heating element 401, and the middle of the heating element 401 is an arc-shaped corner. The U-shaped heating unit is small in size (can be 3mm), has a large cross-section, low resistance, and good current capacity.

[0072] In another preferred embodiment, the heating element 401 may include two heating units, each of which is provided with an arc-shaped corner. In this embodiment, the heating unit may adopt an M-shaped structure, which is formed by connecting two U-shaped heating units in series to form an integrated structure. Compared with the above-mentioned U-shaped structure, the M-shaped heating unit has a slightly narrower cross-section, a larger resistance, a smaller overcurrent, but a larger size, so a larger heating area can be obtained.

[0073] like Figure 1 As shown. The above-mentioned wires may include two internal wires 402 and two external wires 403, wherein the two internal wires 402 are embedded in the interior of the battery cell 30, and the external wires 403 include a positive external wire and a negative external wire, the internal ends of the two internal wires 402 are connected to the heating element 401, and the external ends of the two internal wires 402 are respectively connected to the internal wire connection end of the positive external wire and the internal wire connection end of the negative external wire, the positive connection end 4031 of the positive external wire is externally connected to the positive end of the battery cell 30, and the negative connection end 4032 of the negative external wire is externally connected to the negative end of the battery cell 30. The internal wires 402 and the external wires 403 can be large-section copper strips with a thin thickness and a wire insulation film coated on the surface. The heating element 401 and the wires can be combined by laser welding. In order to prevent the sharp right angle from piercing the insulating structure and causing a short circuit, the sharp corners of the welding matching area should be rounded.

[0074] In this embodiment, power supply to the wires and electricity extraction are achieved through two internal wires 402 and two external wires 403, and the structure is simple and easy to install.

[0075] Regarding the insulation structure in the above embodiments, in a specific implementation, the insulation structure includes a heating element insulation film and a wire insulation film, the heating element insulation film is coated on the outside of the heating element 401, and the wire insulation film is coated on the outside of the internal wire 402 and the external wire 403.

[0076] Among them, since the heating element insulating film is built into the battery cell 30, in order to improve its corrosion resistance and high temperature resistance, a double-layer insulation structure can be adopted. Specifically, the heating element insulating film includes an inner insulating film and an outer insulating film. The inner insulating film can be an insulating film resistant to electrolyte corrosion and high temperature, such as a pI insulating film (polyimide film), which can resist electrolyte corrosion and withstand high temperatures within 300°C to improve its corrosion resistance. The outer insulating film can be a high temperature resistant insulating film, such as a mica paper insulating film, which can withstand temperatures above 600°C to ensure stable performance in a high temperature environment. The wire insulating film can be, but is not limited to, a polyimide insulating film.

[0077] Regarding the insulation method of the heating device 40, the present application adopts a double-layer insulation protection structure of PI and mica paper, which has good corrosion resistance and high temperature resistance. Compared with the insulation method on the market that only uses PI insulation film, it has a better triggering effect on batteries such as iron-lithium, and is applicable to ternary, iron-lithium and other battery systems, expanding the scope of application of the battery.

[0078] The heating device 40 in the present application can directly and efficiently heat a smaller area inside the battery cell 30 to trigger thermal runaway after being powered on, and has a large overcurrent and high heating efficiency. In addition, the heating device 40 is not limited to being set at the center position inside the battery cell 30, and the heating position can be adjusted according to needs.

[0079] refer to Figures 2 to 5 . The present application also provides a battery, which mainly includes: a battery case 10, an insulating protective film 20, a battery cell 30 and a heating device 40. Among them, the insulating protective film 20 is coated on the outside of the battery cell 30 to insulate the battery cell 30 from the battery case 10. The battery case 10 is a shell structure that is closed in the circumference and end faces, and mainly includes a battery case 101, a positive electrode cover plate 102 and a negative electrode cover plate 103. The battery case 101 is a shell structure that is closed in the circumference and has through holes at both ends. One end of the battery case 101 is covered with a negative electrode cover plate 103, and the other end of the battery case 101 is covered with a positive electrode cover plate 102. The battery case 10 is used to seal and fix the battery cell 30 coated with the insulating film.

[0080] The heating device 40 is built between the positive and negative electrodes of the battery cell 30. The positive terminal and the negative terminal of the heating device 40 are electrically connected to the positive terminal and the negative terminal of the battery 1, respectively, so as to realize power supply to the heating device 40 and realize electrical extraction. Thermal runaway is triggered by heating a preset area inside the battery cell 30. For the specific structure of the heating device 40, please refer to the above.

[0081] Furthermore, in order to fix the heating device 40, a fixing device 50 may be further provided. Specifically, the fixing device 50 includes a side plate 501 and a side plate fixing tape 502. The side plate 501 is provided between the battery cell 30 and the heating device 40. A side plate groove is provided on the side plate 501. The side plate groove may be, but is not limited to, a square groove. The side plate groove allows the wires of the heating device 40 to be led out from the inner side of the side plate 501. The side plate 501 is close to the battery cell 30 to increase the strength of the battery cell 30 and prevent the battery cell 30 from moving inside the shell. After the wire passes through the side hole groove, it is wired close to the side plate 501, and the positive and negative ends of the wire are respectively connected to the positive end of the battery 1 and the negative end of the battery 1. The side plate fixing tape 502 fixes the side plate 501 and the wire together on the outer wall surface of the side plate 501.

[0082] In other words, by arranging the side plate 501 on the lead-out side of the heating device 40, the wires are led out from the inner side of the side plate 501 through the side plate grooves, which saves the space occupied by the wires while ensuring the lead-out of the wires, thereby realizing the wiring inside the battery 1 under the assembly of the battery 1 with a very high volume ratio.

[0083] In order to further save space, the heating device 40 can be fixed on the short side wall of the battery cell 30. The layout position of the heating device 40 can be set according to actual needs and is not limited herein.

[0084] Regarding the electrical connection structure between the wire and the positive and negative terminals of the battery, in a specific embodiment, a positive electrode assembly is provided at the positive terminal of the battery housing 101, and a negative electrode assembly 106 is provided at the negative terminal of the battery housing 101. The negative electrode connection end 4032 of the wire of the heating device 40 is electrically connected to the negative electrode assembly 106, and an external power supply is connected between the negative electrode assembly 106 and the second positive electrode assembly 105, so as to achieve heating of a preset area in the battery cell 30 to trigger a runaway. Alternatively, the first positive electrode assembly 104 and the second positive electrode assembly 105 are directly short-circuited through a relay to trigger thermal runaway. The positive electrode connection end 4031 of the wire of the heating device 40 is electrically connected to the positive electrode assembly, so as to realize electrical extraction of the heating device 40.

[0085] Specifically, corresponding to Figure 5 It can be seen that the positive electrode cover plate 102 is provided with a liquid injection hole, a first positive electrode assembly 104 and a second positive electrode assembly 105. After the battery is injected with liquid through the liquid injection hole, the battery is sealed by an insulating nail and a sealing cover. The first positive electrode column assembly includes a first positive electrode conductive column, a positive electrode insulating assembly and a positive electrode inner lead. One end of the positive electrode inner lead is connected to the positive electrode ear, and the other end is connected to the positive electrode conductive column to realize electrical lead-out. The positive electrode insulating assembly is arranged between the positive electrode conductive column and the positive electrode cover plate 102. The positive electrode insulating assembly mainly includes ceramics, laminates and sealing rings. The positive electrode and the battery housing 101 are insulated and the positive electrode conductive column is fixed and sealed through the positive electrode insulating assembly.

[0086] Combination Figures 6 to 9 . A second positive electrode assembly 105 is arranged between the side plate 501 on the opposite side of the injection hole and the first positive electrode conductive column, and the electrical lead-out of the heating device 40 is realized in conjunction with the wire. The second positive electrode assembly 105 includes a positive aluminum terminal 1051, a second insulating member 1053, a second positive electrode conductive column 1052 and a second sealing ring group 1054. The second insulating member 1053 and the second sealing ring group 1054 are arranged between the second positive electrode conductive column 1052 and the positive electrode cover plate 102, and are used to insulate and fix the second positive electrode conductive column 1052 and the positive electrode cover plate 102, so as to realize the insulation fixation of the second positive electrode conductive column 1052 and the positive electrode cover plate 102. One end of the second positive electrode conductive column 1052 and the wire are fixed by laser welding, so that the heating device 40 is sealed inside the battery and can be electrically connected to the outside. After welding and fixing, the welding area is coated with an insulating film, which can be but not limited to a polyimide insulating film. The other end of the second positive electrode conductive column 1052 and the positive electrode aluminum terminal 1051 are fixed by riveting.

[0087] The above structure provides a safer and more reliable packaging and fixing solution for achieving complete sealing and fixing of the heating device 40 inside the battery 1, and can also achieve electrical extraction.

[0088] like Figures 10 to 14 As shown. The negative electrode assembly 106 includes a negative electrode ear 1061 that passes through a negative electrode insulating spacer 1062 and is connected to the negative electrode connection end 4032 of the negative electrode external wire of the heating device 40, and is fixed to the negative electrode internal lead 1063 by laser welding. After welding and fixing, the welding area is coated with a polyimide insulating film or the like. The negative electrode ear 1061, the negative electrode external wire of the heating device 40, and the negative electrode internal lead 1063 are connected in sequence. The overlapping length of the negative electrode ear 1061 and the external wire 403 can be, but is not limited to, 10 mm, and the wire and the negative electrode ear 1061 are led out from the negative terminal together. The negative electrode conductive column 1065 is fixed on the negative electrode inner lead sheet 1063 on the inner side of the battery, and is combined with the negative electrode aluminum terminal 1064 on the outer side of the battery. A negative electrode insulation assembly 1066 is provided between the negative electrode inner lead sheet 1063 and the negative electrode cover plate 103, and between the negative electrode conductive column 1065 and the negative electrode cover plate 103. The negative electrode insulation assembly 1066 includes a cover plate insulation member, a sealing ring, a laminate and a ceramic ring, thereby achieving insulation between the negative electrode, the negative electrode cover plate 103 and the battery housing 101. The cover plate insulation member, the negative electrode conductive column 1065 and the negative electrode aluminum terminal 1064 together constitute a negative electrode column. A power supply is applied between the negative electrode column and the second positive electrode conductive column 1052 to energize, thereby achieving direct heating of a local area in the battery cell 30 to trigger a runaway.

[0089] Therefore, in order to cooperate with the electrical lead-out of the heating device 40, the heating device 40 is sealed as a whole inside the battery, and a second positive electrode assembly 105 is added to the positive electrode cover plate 102. One end of the lead-out wire is directly welded to the negative electrode assembly 106, and the other end of the lead-out wire is led out through the added second positive electrode assembly 105. Compared with the solution on the market in which the lead of the heating device 40 is directly led out through the open extension hole of the shell, it effectively avoids the problems of leakage and wire breakage that are easily caused by the lead-out of the wire, and the connection is safer and more reliable.

[0090] The heating device 40 proposed in this application adopts a design of locally widened arc corners, has large current capacity, high heating efficiency, and small size, which is close to the actual thermal runaway condition triggered by local internal short circuit of the battery. The heating element 401 adopts a double-layer insulation protection structure, has a higher operating temperature, and is safer and more reliable with the designed lead-out structure.

[0091] In summary, the present application realizes a complete structure in which the heating device 40 is sealed inside the battery cell 30, simulates and reproduces the safety accident conditions of electric vehicles caused by thermal runaway of single cells during normal driving or when stopped, and helps to understand the battery integrity issues in a multi-dimensional and comprehensive manner, identify weak points, and then optimize them, providing theoretical support and guidance for battery safety design, thereby improving battery safety.

[0092] In addition, the present application also provides a battery pack, including the above-mentioned battery. The present application also provides an electric device, such as an electric vehicle or a new energy vehicle, including the above-mentioned battery pack. The electric device has stable and reliable performance and high safety.

[0093] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A heating device, characterized in that: include: A heating element (401), a conducting wire, and an insulating structure covering the outside of the heating element (401) and the conducting wire; The heating element (401) is provided with an arc-shaped corner, the outer contour width of the arc-shaped corner is greater than or equal to the width of other structures on the heating element (401) except the arc-shaped corner, and the heating element (401) is embedded between the positive electrode sheet and the negative electrode sheet inside the battery cell (30); The wire, the inner end of the wire is connected to the heating element (401), the positive connection end (4031) of the wire is externally connected to the positive end of the battery cell (30), and the negative connection end (4032) of the wire is externally connected to the negative end of the battery cell (30).

2. The heating device according to claim 1, characterized in that The heating element (401) comprises at least one heating unit, and two adjacent heating units are connected via an arc-shaped corner.

3. The heating device according to claim 2, characterized in that: The heating element (401) comprises a heating unit having an arc-shaped corner.

4. The heating device according to claim 2, characterized in that: The heating element (401) comprises two heating units, each of which is provided with an arc-shaped corner.

5. The heating device according to claim 2 or 3, characterized in that: The wires include two internal wires (402) and two external wires (403), wherein the two internal wires (402) are embedded in the battery core (30), and the external wires (403) include a positive external wire and a negative external wire, the internal ends of the two internal wires (402) are both connected to the heating element (401), and the external ends of the two internal wires (402) are respectively connected to the internal wire connection end of the positive external wire and the internal wire connection end of the negative external wire.

6. The heating device according to claim 1, characterized in that: The insulating structure comprises a heating element insulating film covering the outside of the heating element (401), and a wire insulating film covering the outside of the internal wire (402) and the external wire (403); The heating element insulating film comprises an inner insulating film and an outer insulating film, wherein the inner insulating film is an insulating film resistant to electrolyte corrosion, and the outer insulating film is a high temperature resistant insulating film; The wire insulation film is a polyimide insulation film.

7. The heating device according to claim 6, characterized in that: The inner insulating film is a pI insulating film, and the outer insulating film is a mica paper insulating film.

8. The heating device according to claim 6, characterized in that The heating element (401) is an integrally formed structure.

9. A battery, characterized in that: include: Battery cell (30); An insulating protective film (20) is coated on the outside of the battery core (30) to insulate the battery core (30) from the battery casing (10); A battery casing (10) used for encapsulating and fixing the battery core (30); A heating device (40) is arranged between the positive and negative electrode sheets inside the battery cell (30), and the heating device (40) is electrically connected to the positive terminal and the negative terminal of the battery, and is used to heat a preset area inside the battery cell (30); the heating device (40) is specifically the heating device described in any one of claims 1 to 8 above.

10. The battery according to claim 9, characterized in that It also includes a fixing device (50) for fixing the heating device (40) to the side wall of the battery core (30); The fixing device (50) comprises a side plate (501) and a side plate fixing tape (502); a side plate groove is provided on the side plate (501); the side plate groove is used for allowing the wires of the heating device (40) to be led out from the inner side of the side plate (501); and the side plate fixing tape (502) is used for fixing the wires of the heating device (40) to the outer wall surface of the side plate (501).

11. The battery according to claim 9 or 10, characterized in that: The positive end of the battery housing (10) is provided with a first positive electrode assembly (104) and a second positive electrode assembly (105); The negative electrode connection end (4032) of the lead of the heating device (40) is used to electrically connect the negative electrode assembly (106) of the battery housing (10), and an external power supply is connected between the negative electrode assembly (106) and the second positive electrode assembly (105); The positive electrode connection end (4031) of the conductive wire of the heating device (40) is used for electrically connecting to the second positive electrode assembly (105).

12. The battery according to claim 11, characterized in that The negative electrode connection terminal (4032) is welded and fixed to the negative electrode assembly (106), and the welding and fixing position of the negative electrode connection terminal (4032) and the negative electrode assembly (106) is covered with a first welding portion insulating film, and the first welding portion insulating film is a polyimide insulating film.

13. The battery according to claim 11, characterized in that The positive electrode connection end (4031) is welded and fixed to the second positive electrode component (105), and the welding and fixing position of the positive electrode connection end (4031) and the second positive electrode component (105) is coated with a polyimide insulating film.

14. The battery according to claim 11, characterized in that The second positive electrode assembly (105) comprises a positive electrode aluminum terminal (1051), an insulating member, a second positive electrode conductive column (1052) and a sealing ring assembly, one end of the second positive electrode conductive column (1052) is welded and fixed to a wire, and the other end of the second positive electrode conductive column (1052) is riveted and fixed to the positive electrode aluminum terminal (1051), and the insulating member is arranged between the second positive electrode conductive column (1052) and the positive electrode cover plate (102) and is used to insulate and fix the second positive electrode conductive column (1052) and the positive electrode cover plate (102).

15. The battery according to claim 9, characterized in that The heating device (40) is arranged on the short side of the battery core (30).

16. A battery pack, characterized in that: A battery comprising any one of claims 1 to 15.

17. An electrical equipment, characterized in that: A battery pack comprising the battery pack described in claim 16 above.

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