Battery pack and electric device with same

Abstract

The utility model provides a kind of battery pack and the electric device with it, the battery pack includes: battery;Explosion-proof valve, explosion-proof valve is set on battery;High temperature resistant coating, set on battery, high temperature resistant coating covers on explosion-proof valve, the spraying area of high temperature resistant coating is greater than the area of explosion-proof valve.Through the technical scheme provided in the present application, the energy sprayed by the battery in the related art can cause the protective plate to be removed from its original position, which can directly damage the protective plate adjacent to the battery, and further cause the protective plate to be unable to protect the explosion-proof valve.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and more specifically, to a battery pack and an electrical device having the same. Background Technology

[0002] In the design of the battery pack, in order to ensure thermoelectric separation and thus improve safety, the explosion-proof valve and the battery terminals are arranged on different surfaces of the battery.

[0003] In related technologies, the battery pack contains multiple batteries, and the top cover of each battery is covered with a protective plate with heat-resistant and shock-resistant properties. This design aims to weaken the protective plate at the corresponding part of the explosion-proof valve in advance (i.e., local thinning), so that once the battery experiences abnormal temperature rise, the thinned area can be quickly and effectively destroyed to release internal pressure, while minimizing the impact of heat energy, particles, etc. generated by the runaway battery on the explosion-proof valve of the surrounding batteries.

[0004] However, the protection strategy of directly attaching the protection board has certain limitations: under extreme conditions, the energy emitted by the battery may cause the protection board to detach from its original position, allowing the ejected material to flow through the gap between the protection board and the bottom of the battery, increasing the possibility of direct damage to the protection boards of adjacent batteries. Once the protective function of the protection board is weakened, it cannot effectively isolate the high temperature attack from the runaway battery, thereby triggering thermal runaway of adjacent batteries and forming a chain reaction. Utility Model Content

[0005] This utility model provides a battery pack and an electrical device having the same, to solve the problem in the related art that the energy emitted by the battery may cause the protection board to detach from its original position, which may directly damage the protection board of the adjacent battery, and thus cause the protection board to fail to protect the explosion-proof valve.

[0006] According to one aspect of the present invention, a battery pack is provided, comprising: a battery; an explosion-proof valve disposed on the battery; and a high-temperature resistant coating disposed on the battery, the high-temperature resistant coating covering the explosion-proof valve, wherein the sprayed area of ​​the high-temperature resistant coating is larger than the area of ​​the explosion-proof valve.

[0007] According to another aspect of the present invention, an electrical device is provided, which includes a battery pack, the battery pack being the one provided above.

[0008] By applying the technical solution of this utility model, a high-temperature resistant coating is applied to the battery and then covered with the high-temperature resistant coating onto the explosion-proof valve. Since the sprayed area of ​​the high-temperature resistant coating is larger than the area of ​​the explosion-proof valve, the high-temperature resistant coating can effectively protect the explosion-proof valve. Furthermore, compared to the method of attaching a protective plate, the method of spraying the high-temperature resistant coating eliminates the possibility of the protective plate detaching from its original position. Therefore, it solves the problem in related technologies where the energy emitted by the battery may cause the protective plate to detach from its original position, potentially damaging the protective plates of adjacent batteries and rendering them unable to protect the explosion-proof valve. Attached Figure Description

[0009] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0010] Figure 1 A bottom view of the battery pack provided in an embodiment of the present invention is shown.

[0011] The above figures include the following reference numerals:

[0012] 10. Explosion-proof valve;

[0013] 20. High-temperature resistant coating;

[0014] 30. Battery film;

[0015] 40. Heat exchange plate; 41. Opening. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present utility model or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0017] like Figure 1 As shown, this embodiment of the present invention provides a battery pack, which includes a battery, an explosion-proof valve 10, and a high-temperature resistant coating 20. The explosion-proof valve 10 is disposed on the battery. The high-temperature resistant coating 20 is disposed on the battery and covers the explosion-proof valve 10, with the sprayed area of ​​the high-temperature resistant coating 20 being larger than the area of ​​the explosion-proof valve 10.

[0018] By applying the battery pack provided in this embodiment, a high-temperature resistant coating 20 is applied to the battery and then covered with the high-temperature resistant coating 20 on the explosion-proof valve 10. Since the spraying area of ​​the high-temperature resistant coating 20 is larger than the area of ​​the explosion-proof valve 10, the high-temperature resistant coating 20 can effectively protect the explosion-proof valve 10. Furthermore, compared to the method of attaching a protective plate, the method of spraying a high-temperature resistant coating eliminates the possibility of the protective plate detaching from its original position. Therefore, it solves the problem in related technologies where the energy emitted by the battery may cause the protective plate to detach from its original position, potentially damaging the protective plates of adjacent batteries and rendering the protective plates unable to protect the explosion-proof valve.

[0019] In this embodiment, the explosion-proof valve is located on the bottom surface of the battery. In other embodiments, the explosion-proof valve can be located on other surfaces of the battery, such as the top surface.

[0020] It should be noted that, Figure 1 The dotted line in the figure represents the explosion-proof valve 10. In reality, the explosion-proof valve 10 is covered by the high-temperature resistant coating 20. The explosion-proof valve 10 is shown here only for ease of understanding.

[0021] In this embodiment, the high-temperature resistant coating 20 includes a high-temperature resistant insulating coating. The high-temperature resistant coating 20 also provides insulation, improving the insulation performance of the battery pack.

[0022] In this embodiment, the high-temperature resistant coating 20 includes a high-temperature resistant foamed coating. The high-temperature resistant foamed coating can foam in a high-temperature environment, with a foaming ratio of 1 to 30 times, and has the functions of heat insulation and impact resistance, effectively preventing damage to the explosion-proof valves of other batteries.

[0023] In other embodiments, the high-temperature resistant coating 20 can be configured as a high-temperature non-foaming coating. The high-temperature non-foaming coating can also effectively protect other explosion-proof valves from rupture.

[0024] The battery is covered by a battery film 30, which serves as both protection and insulation. The high-temperature resistant coating around the explosion-proof valve provides heat insulation, effectively protecting the battery film 30 from failure.

[0025] In this embodiment, the battery film 30 is a blue film.

[0026] It should be noted that in related technologies, the explosion-proof valves have exposed blue films around their edges. Since these blue films are made of PET material, they are not heat-resistant. High-temperature substances ejected from the runaway battery can cause the exposed blue films on the bottom of other batteries to melt and fail, losing their insulating protective function. After a cell goes out of control, it will become conductive with components such as the casing. If the blue films on the bottom of unrunaway batteries fail and arcing occurs, a circuit will be formed, potentially leading to secondary thermal runaway. This application avoids the above problems by incorporating a high-temperature resistant coating 20. After the target battery goes out of control, the high-temperature resistant coating 20 effectively protects other explosion-proof valves from being breached. Simultaneously, the high-temperature resistant coating 20 around the other explosion-proof valves provides high-temperature insulation, preventing insulation failure at the bottom of the batteries.

[0027] The high-temperature resistant coating 20 includes two spraying methods: the first method is that the high-temperature resistant coating 20 can cover the battery film 30. The second method is that the high-temperature resistant coating 20 does not overlap with the battery film 30, and the edge of the high-temperature resistant coating 20 is spliced ​​with the edge of the battery film 30.

[0028] Specifically, the first spraying method has the advantages of simple structure and easy processing. However, considering that if the high-temperature resistant coating 20 is directly sprayed onto the explosion-proof valve and the blue film surface around the explosion-proof valve, the blue film has poor temperature resistance and there is concern that it may peel off under high temperature conditions, resulting in the coating not playing an effective role. Therefore, the area to be coated can be free of the blue film, i.e., the second spraying method is adopted.

[0029] Wherein, the thickness of the high-temperature resistant coating 20 is D, 0.05mm≤D≤1mm; and / or, the high-temperature resistant coating 20 is disposed on the first surface of the battery, the spraying area of ​​the high-temperature resistant coating 20 is S1, and the area of ​​the first surface is S2, 0.05≤S1 / S2≤1.

[0030] By controlling the thickness of the high-temperature resistant coating 20, sufficient protection is ensured in the event of battery thermal runaway, while avoiding increased battery pack weight and cost due to excessive coating thickness. This achieves both thermal protection requirements and maintains a lightweight battery pack with cost control.

[0031] Specifically, the thickness D of the high-temperature resistant coating 20 can be 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1 mm, and other values ​​between 0.05 mm and 1 mm.

[0032] By controlling the ratio of the sprayed area of ​​the high-temperature resistant coating 20 to the area of ​​the first surface, it is ensured that the high-temperature resistant coating 20 can provide sufficient protection in the event of battery thermal runaway, while avoiding increasing the weight and cost of the battery pack due to excessive coating area.

[0033] Specifically, S1 / S2 can be 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, and other values ​​between 0.05 and 1.

[0034] Wherein, the energy density of the battery is A, the thickness of the high-temperature resistant coating 20 is D, 0.000167≤D / A≤0.01; and / or, the battery pack also includes a housing, the battery is disposed in the housing, the high-temperature resistant coating 20 is disposed on the first surface of the battery, the distance between the first surface and the inner wall of the housing is L, and the thickness of the high-temperature resistant coating 20 is D, 0.00125≤D / L≤0.33334.

[0035] The thickness of the high-temperature resistant coating 20 is adjusted according to the battery's energy density to ensure that, in the event of battery thermal runaway, the high-temperature resistant coating 20 provides a protective effect matching the battery's energy density. The thickness of the high-temperature resistant coating 20 is also adjusted according to the distance (D / L) to ensure that, in the event of battery thermal runaway, the high-temperature resistant coating 20 provides a protective effect matching the distance (L).

[0036] Specifically, D / A can be 0.000167, 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, and other values ​​between 0.000167 and 0.01.

[0037] Specifically, D / L can be 0.00125, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.333333, 0.33334, and other values ​​between 0.00125 and 0.33334.

[0038] All surfaces of the battery are provided with a high-temperature resistant coating 20, and a terminal post is provided on the second surface of the battery. The high-temperature resistant coating 20 is positioned to avoid the terminal post; and / or, the thickness of the high-temperature resistant coating 20 gradually increases in the direction away from the center of the battery pack.

[0039] By applying a high-temperature resistant coating 20 to all surfaces of the battery, all-around thermal protection is achieved, while space is left near the terminals to ensure the battery's electrical connection performance. Furthermore, since the battery pack's deformation is larger at the center and smaller at the edges, the coating thickness can gradually increase in the direction away from the center of the battery pack.

[0040] In this embodiment, the terminal post is disposed on the top surface of the battery.

[0041] Wherein, the battery's weight loss rate is X, the thickness of the high-temperature resistant coating 20 is D, 0.3≤X / D≤14; and / or, the battery's gas generation rate is Y, the thickness of the high-temperature resistant coating 20 is D, 10≤Y / D≤2000. By adjusting the thickness of the high-temperature resistant coating 20 according to the battery's weight loss rate and gas generation rate, it is ensured that the coating can provide a protective effect matching the thermal runaway characteristics of the battery pack in the event of battery thermal runaway, while avoiding increased weight and cost of the battery pack due to excessive layer thickness. This achieves both thermal protection requirements and maintains the lightweight design and cost control of the battery pack.

[0042] Specifically, X / D can be 0.3, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, and other values ​​between 0.3 and 14.

[0043] Specifically, Y / D can be 10, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, and other values ​​between 10 and 2000.

[0044] The battery pack includes multiple explosion-proof valves 10, the number of explosion-proof valves 10 is C, the thickness of the high-temperature resistant coating 20 is D, 1≤C / D≤160; and / or, the area of ​​one explosion-proof valve 10 is S3, the thickness of the high-temperature resistant coating 20 is D, 314≤S3 / D≤402000.

[0045] By adjusting the thickness of the high-temperature resistant coating 20 according to the number and area of ​​the explosion-proof valves 10 in the battery pack, it is ensured that the coating can provide a protective effect that matches the layout of the explosion-proof valves 10 in the event of battery thermal runaway, while avoiding the impact on the heat dissipation performance and overall weight of the battery pack due to excessive coating thickness. This achieves both thermal protection requirements and maintains the heat dissipation performance and lightweight design of the battery pack.

[0046] Specifically, C / D can be 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, and other values ​​between 1 and 160.

[0047] Specifically, S3 / D can be 314, 10000, 20000, 30000, 40000, 50000, 60000, 70000, 80000, 90000, 100000, 110000, 120000, 130000, 140000, 150000, 160000, 170000, 180000, 190000, 200000, 210000, 22 0000, 230000, 240000, 250000, 260000, 270000, 280000, 290000, 300000, 310000, 320000, 330000, 340000, 350000, 360000, 370000, 380000, 390000, 400000, 402000, and other values ​​between 314 and 402000.

[0048] In this embodiment, the material of the high-temperature resistant coating 20 includes inorganic fire retardant coating, organic fire retardant coating, intumescent fire retardant coating, ceramic fire retardant coating, nano fire retardant coating, or composite fire retardant coating; and / or, at least two surfaces of the battery are provided with the high-temperature resistant coating 20, and the thickness of the high-temperature resistant coating 20 provided on the at least two surfaces is different.

[0049] Inorganic fire-retardant coatings primarily consist of inorganic materials such as silicates and phosphates, exhibiting excellent high-temperature resistance. Organic fire-retardant coatings, such as polyurethane and epoxy resins, typically require the addition of flame retardants to enhance their fire resistance. Intumescent fire-retardant coatings expand upon heating, forming a heat-insulating layer that slows the spread of fire. Ceramic fire-retardant coatings, primarily composed of ceramics, possess excellent heat insulation and fire resistance. Nano-fire-retardant coatings enhance fire resistance and mechanical strength by incorporating nanomaterials (such as alumina and zirconium oxide). Composite fire-retardant coatings combine inorganic or organic fire-retardant coatings, balancing fire resistance with ease of application.

[0050] Specifically, at least two surfaces of the battery are provided with a high-temperature resistant coating 20, and the thickness of the high-temperature resistant coating 20 on the at least two surfaces is different, which has the following advantages: 1) The high-temperature resistant coating 20 of different thicknesses can be designed according to the heat generation and transfer characteristics of different parts of the battery. For example, when the heat of the battery is concentrated in a specific area, the high-temperature resistant coating 20 in that area can be designed to be thicker to provide stronger thermal protection, while other areas can be designed to be thinner to reduce thermal resistance and weight. 2) By adjusting the thickness of the high-temperature resistant coating 20, the strength of the battery structure and the lightweight of the battery can be ensured at the same time. For parts of the battery that bear mechanical loads, such as the bottom, a thicker high-temperature resistant coating 20 can be provided to enhance protection; while for the sides or top, a thinner high-temperature resistant coating 20 can be provided to reduce weight while maintaining the necessary thermal insulation performance.

[0051] like Figure 1 As shown, in this embodiment, the battery pack also includes a heat exchange plate 40, which has an opening 41 corresponding to the explosion-proof valve 10. The sprayed area of ​​the high-temperature resistant coating 20 is larger than the area of ​​the opening 41. By increasing the coverage area of ​​the high-temperature resistant coating 20 around the opening 41 of the heat exchange plate 40, it is ensured that high-temperature substances can be effectively blocked during battery thermal runaway, preventing direct impact on the explosion-proof valve 10 of the adjacent battery. This significantly improves the safety performance of the battery pack under thermal runaway conditions and effectively reduces the risk of secondary thermal runaway.

[0052] In this embodiment, the heat exchange plate 40 is a liquid-cooled plate.

[0053] In this embodiment, the battery pack includes multiple battery rows, each battery row includes multiple batteries, each battery is equipped with an explosion-proof valve 10, and the heat exchange plate 40 has multiple openings 41, which are arranged one-to-one with the multiple explosion-proof valves 10, resulting in better protection.

[0054] In other embodiments, multiple explosion-proof valves 10 of a battery bank can be configured to correspond to the same opening 41 to simplify the structure and facilitate manufacturing. Specifically, the opening 41 can be configured as an elongated structure.

[0055] By matching the opening 41 of the heat exchange plate 40 with the corresponding setting of the battery explosion-proof valve 10, it is ensured that high-temperature substances can be effectively guided during battery thermal runaway, avoiding direct impact on the explosion-proof valve 10 of the adjacent battery. At the same time, the heat dissipation performance of the heat exchange plate 40 is guaranteed, improving the thermal protection capability of the battery pack under thermal runaway conditions, reducing the rate of thermal runaway propagation, and maintaining good heat dissipation performance.

[0056] The thickness of the heat exchange plate 40 is B, and the thickness of the high-temperature resistant coating 20 is D, where 2.5 ≤ B / D ≤ 300. By adjusting the thickness of the high-temperature resistant coating 20 according to the thickness of the heat exchange plate 40, it is ensured that the coating can provide a protective effect that matches the thickness (heat exchange capacity) of the heat exchange plate 40 in the event of battery thermal runaway.

[0057] Specifically, B / D can be 2.5, 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, and other values ​​between 2.5 and 300.

[0058] This utility model embodiment provides an electrical device including a battery pack, which is the battery pack provided above. Therefore, this electrical device can also protect the explosion-proof valve 10 using the high-temperature resistant coating 20. Furthermore, by using a sprayed high-temperature resistant coating, compared to the method of attaching a protective plate, there is no risk of the protective plate detaching from its original position. Therefore, it can solve the problem in related technologies where the energy emitted by the battery may cause the protective plate to detach from its original position, potentially damaging the protective plates of adjacent batteries and thus rendering the protective plates unable to protect the explosion-proof valve.

[0059] Electrical devices include, but are not limited to, vehicles.

[0060] The apparatus provided by the embodiments has the following beneficial effects:

[0061] 1) By applying a high-temperature resistant coating to the critical areas of the battery, the coating can effectively block the ejected high-temperature substances and conductive particles when the battery runs away, preventing these substances from flowing or rebounding to other explosion-proof valves, thereby greatly improving the overall safety of the battery system and reducing the risk of a chain reaction caused by the runaway of a single battery.

[0062] 2) The high-temperature resistant coating can cover the exposed area of ​​the blue film, and can maintain good insulation even in high-temperature environments, avoiding the risk of short circuit due to the melting and failure of the blue film, and further improving the electrical safety and stability of the system.

[0063] The battery in this application is a secondary battery, also known as a rechargeable battery or storage battery, which refers to a battery that can be used again after being discharged by recharging to activate the active materials.

[0064] Typically, a secondary battery includes electrode components, electrolyte, and an outer casing. The electrode components consist of a positive electrode, a negative electrode, and a separator. The electrode components and electrolyte are assembled inside the outer casing. During charging and discharging, active ions (such as lithium ions) move back and forth between the positive and negative electrode plates, inserting and extracting. The separator, positioned between the positive and negative electrode plates, primarily prevents short circuits while allowing active ions to pass through. The electrolyte, located between the positive and negative electrode plates, mainly serves to conduct active ions.

[0065] As an example, the preparation process of a secondary battery is as follows: the positive electrode, separator, and negative electrode are stacked in sequence, with the separator acting as a separator between the positive and negative electrodes. Then, the electrodes are wound or stacked to obtain an electrode assembly. The electrode assembly is placed in an outer packaging shell, dried, and then injected with electrolyte. After vacuum sealing, settling, formation, and shaping, a secondary battery is obtained.

[0066] A positive electrode typically includes a positive current collector and a positive electrode film layer disposed on at least one side of the positive current collector. The positive electrode film layer includes a positive electrode active material, which can be any existing publicly disclosed positive electrode active material or a positive electrode active material optimized based on existing materials.

[0067] This application does not impose any particular restrictions on the type of positive electrode active material for the positive electrode sheet. As an example, the positive electrode active materials in this application include lithium-containing transition metal oxides (e.g., LiCoO2), phosphides (e.g., LiFePO4), or lithium intercalation compounds (e.g., positive electrode materials for binary lithium batteries such as lithium cobalt oxide and lithium nickel oxide, or positive electrode materials for ternary lithium batteries such as lithium nickel cobalt manganese oxide and lithium nickel cobalt aluminum oxide).

[0068] In some embodiments, the positive electrode sheet can be prepared by dispersing the above-mentioned components for preparing the positive electrode sheet, such as positive electrode active material, conductive agent, binder and any other components, in a solvent (e.g., N-methylpyrrolidone) to form a positive electrode slurry; coating the positive electrode slurry onto the positive electrode current collector, and then obtaining the positive electrode sheet after drying, rolling, cutting and other processes.

[0069] In this application, the binder is used to improve the adhesion between positive electrode active material particles and the adhesion between the positive electrode active material and the current collector. This application does not impose any particular limitation on the type of binder for the positive electrode sheet; the binder can be any conventional choice in the battery industry. Specifically, the binder can be at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl alcohol (PVA), styrene-butadiene rubber (SBR), polyacrylonitrile (PAN), polyimide (PI), polyacrylic acid (PAA), polyacrylate, polyolefin, sodium carboxymethyl cellulose (CMC), or sodium alginate.

[0070] This application does not impose any particular restrictions on the positive electrode current collector, as long as it is conductive and will not cause adverse chemical changes in the battery, and can be made of, for example: stainless steel, aluminum, nickel, titanium, sintered carbon; or aluminum or stainless steel that has been surface treated with one of carbon, nickel, titanium, silver, etc.

[0071] The negative electrode includes a negative electrode current collector and a negative electrode active material layer disposed on at least one side of the negative electrode current collector. The negative electrode active material layer comprises a silicon-based material. This application does not specifically limit the type of silicon-based material; the silicon-based material can be a silicon-carbon material and / or a silicon-oxygen material. As an example, the silicon-based material can be one or more of silicon-carbon composite negative electrode materials, silicon suboxide negative electrode materials, modified silicon suboxide negative electrode materials, and nano-silicon materials. The negative electrode active material in the negative electrode active material layer may also optionally include one or more of artificial graphite, natural graphite, and hard carbon.

[0072] In some embodiments, the negative electrode sheet can be prepared by dispersing the components used to prepare the negative electrode sheet, such as the negative electrode active material, conductive agent, binder and any other components, in a solvent (e.g., water) to form a negative electrode slurry; coating the negative electrode slurry onto the negative electrode current collector, and then obtaining the negative electrode sheet after drying, rolling, cutting and other processes.

[0073] This application does not specifically limit the type of negative electrode conductive agent. In some embodiments, as an example, the negative electrode conductive agent can be one or more of conventional negative electrode conductive agents such as acetylene black and carbon nanotubes.

[0074] This application does not impose specific restrictions on the type of negative electrode binder. In some embodiments, as an example, the binder may be one or more of conventional negative electrode binders such as styrene-butadiene rubber latex (SBR), polyvinylidene fluoride (PVDF), polyacrylic acid (PAA), and sodium carboxymethyl cellulose (CMC). In this application, the binder is preferably PAA, SBR, and CMC, and the mass ratio of PAA, SBR, and CMC may be (34.38-74.29):(20-59.38):(5-7.14).

[0075] This application does not impose specific limitations on the type of negative electrode current collector. In some embodiments, as an example, the negative electrode current collector can be one of the conventional negative electrode current collectors such as copper foil.

[0076] The electrolyte acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. As an example, the electrolyte in this application can be any electrolyte suitable for electrochemical energy storage devices in the art. The electrolyte includes an electrolyte and a solvent; the electrolyte typically includes a lithium salt, and additives may also be added to the electrolyte.

[0077] Specifically, the lithium salt includes at least one selected from lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluorooxalate borate (LiDFOB), lithium dioxalate borate (LiBOB), lithium difluorophosphate (LiPO2F2), lithium difluorodioxalate phosphate (LiDFOP), and lithium tetrafluorooxalate phosphate (LiTFOP). The concentration of the electrolyte in the electrolyte solution can be 0.5–5 mol / L.

[0078] Specifically, the solvent includes at least one of ethylene carbonate (EC), propylene carbonate (PC), methyl ethyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), butyl carbonate (BC), fluoroethylene carbonate (FEC), methyl formate (MF), methyl acetate (MA), ethyl acetate (EA), propyl acetate (PA), methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), methyl butyrate (MB), ethyl butyrate (EB), 1,4-butyrolactone (GBL), sulfolane (SF), dimethyl sulfone (MSM), methyl ethyl sulfone (EMS), and diethyl sulfone (ESE).

[0079] In some implementations, as an example, the additive may be a conventional electrolyte additive such as fluoroethylene carbonate (FEC), chloroethylene carbonate (CEC), or vinylene carbonate (VC).

[0080] In some embodiments, the secondary battery also includes a separator. This application does not impose any particular limitation on the type of separator; any known porous separator with good chemical and mechanical stability can be selected.

[0081] In some embodiments, as an example, the diaphragm can be one of PP, PE, or PP / PF; the diaphragm can also be a structure in which a coating is formed on the surface of the base film, wherein the base film coating can be one of PP, PE, or PP / PF, and the coating can be an inorganic coating and / or an organic coating. The inorganic coating can be selected from alumina ceramic layers, osmium silicate, etc., and the organic coating can be selected from PVDF, etc.

[0082] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0083] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as exemplary only and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0084] In the description of this utility model, it should be understood that "multiple" means two or more. Directional terms such as "front, back, up, down, left, right," "horizontal, vertical, perpendicular, horizontal," and "top, bottom" indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are used solely for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this utility model. The directional terms "inner" and "outer" refer to the inner or outer contours relative to the outline of each component itself.

[0085] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0086] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this utility model.

[0087] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A battery pack, characterized in that, The battery pack includes: Battery; An explosion-proof valve (10) is disposed on the battery; A high-temperature resistant coating (20) is applied to the battery and covers the explosion-proof valve (10). The sprayed area of ​​the high-temperature resistant coating (20) is larger than the area of ​​the explosion-proof valve (10).

2. The battery pack according to claim 1, characterized in that, The high-temperature resistant coating (20) includes a high-temperature resistant insulating coating.

3. The battery pack according to claim 1, characterized in that, The high-temperature resistant coating (20) includes a high-temperature resistant foamed coating.

4. The battery pack according to claim 1, characterized in that, The battery is covered with a battery film (30) on the outside, and the high-temperature resistant coating (20) covers the battery film (30).

5. The battery pack according to claim 2, characterized in that, The battery is covered with a battery film (30) on the outside. The high-temperature resistant coating (20) does not overlap with the battery film (30), and the edge of the high-temperature resistant coating (20) is spliced ​​with the edge of the battery film (30).

6. The battery pack according to any one of claims 1 to 5, characterized in that, The thickness of the high-temperature resistant coating (20) is D, 0.05 mm ≤ D ≤ 1 mm; and / or, The high-temperature resistant coating (20) is disposed on the first surface of the battery, the spraying area of ​​the high-temperature resistant coating (20) is S1, the area of ​​the first surface is S2, and 0.05≤S1 / S2≤1.

7. The battery pack according to any one of claims 1 to 5, characterized in that, The energy density of the battery is A, the thickness of the high-temperature resistant coating (20) is D, 0.000167≤D / A≤0.01; and / or, The battery pack also includes a housing, the battery is disposed in the housing, the high-temperature resistant coating (20) is disposed on the first surface of the battery, the distance between the first surface and the inner wall of the housing is L, and the thickness of the high-temperature resistant coating (20) is D, 0.00125≤D / L≤0.33334.

8. The battery pack according to any one of claims 1 to 5, characterized in that, All surfaces of the battery are provided with the high-temperature resistant coating (20), and a terminal post is provided on the second surface of the battery, with the high-temperature resistant coating (20) positioned to avoid the terminal post; and / or, The thickness of the high-temperature resistant coating (20) gradually increases in the direction away from the center of the battery pack.

9. The battery pack according to any one of claims 1 to 5, characterized in that, The weight loss rate of the battery is X, the thickness of the high-temperature resistant coating (20) is D, 0.3≤X / D≤14; and / or, The gas production rate of the battery is Y, and the thickness of the high-temperature resistant coating (20) is D, 10≤Y / D≤2000.

10. The battery pack according to any one of claims 1 to 5, characterized in that, The battery pack includes a plurality of the explosion-proof valves (10), the number of which is C, and the thickness of the high-temperature resistant coating (20) is D, where 1 ≤ C / D ≤ 160; and / or, The area of ​​one of the explosion-proof valves (10) is S3, and the thickness of the high-temperature resistant coating (20) is D, 314≤S3 / D≤402000.

11. The battery pack according to any one of claims 1 to 5, characterized in that, The high-temperature resistant coating (20) is made of inorganic fire-retardant coatings, organic fire-retardant coatings, intumescent fire-retardant coatings, ceramic fire-retardant coatings, nano fire-retardant coatings, or composite fire-retardant coatings; and / or, The high-temperature resistant coating (20) is provided on at least two surfaces of the battery, and the thickness of the high-temperature resistant coating (20) provided on at least two surfaces is different.

12. The battery pack according to any one of claims 1 to 5, characterized in that, The battery pack also includes a heat exchange plate (40), which has an opening (41) corresponding to the explosion-proof valve (10), and the spraying area of ​​the high-temperature resistant coating (20) is larger than the area of ​​the opening (41).

13. The battery pack according to claim 12, characterized in that, The battery pack includes multiple battery columns, each battery column includes multiple batteries, each battery is provided with the explosion-proof valve (10), and the heat exchange plate (40) has multiple openings (41); The plurality of openings (41) are provided in a one-to-one correspondence with the plurality of explosion-proof valves (10); or, Multiple explosion-proof valves (10) of one of the battery banks are provided corresponding to the same opening (41).

14. The battery pack according to claim 12, characterized in that, The thickness of the heat exchange plate (40) is B, and the thickness of the high-temperature resistant coating (20) is D, 2.5≤B / D≤300.

15. An electrical appliance, characterized in that, The electrical device includes a battery pack, which is the battery pack according to any one of claims 1 to 14.

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