Battery pack, battery package, and electric device

Abstract

The utility model provides a kind of battery pack, battery pack and electric device, the battery pack includes: at least two single batteries, single battery has the first side and the second side of adjacent arrangement, the area of first side is greater than the area of second side, at least two single batteries are stacked by first side arrangement;Insulating piece, at least two single batteries are provided with insulating piece between;Wherein, in the stacking direction of single battery, the sum of the size of all insulating pieces is L1, the size of battery pack is L2, 0.02≤L1 / L2≤0.3.Through the technical scheme provided in the present application, the problem that the battery pack is affected by vibration and affects the normal use of the battery pack in the related art can be solved.

Description

Technical Field

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

[0002] In traditional battery pack designs, battery packs are typically composed of multiple individual cells arranged in a specific manner.

[0003] However, in related technologies, battery packs have significant problems when facing vibration environments. For example, during vehicle operation, the battery pack will inevitably be subjected to impacts and vibrations from the road surface, and there will be vibration effects between the two battery cells, which will affect the normal use of the battery pack. Utility Model Content

[0004] This utility model provides a battery pack, a battery module, and an electrical device to solve the problem in related technologies where vibration affects the normal use of the battery module.

[0005] According to one aspect of the present invention, a battery pack is provided, comprising: at least two individual cells, each individual cell having a first side and a second side disposed adjacent to each other, the area of ​​the first side being larger than the area of ​​the second side, the at least two individual cells being stacked together via the first side; and a spacer, wherein a spacer is disposed between the at least two individual cells; wherein, in the stacking direction of the individual cells, the sum of the dimensions of all spacers is L1, the dimension of the battery pack is L2, and 0.02≤L1 / L2≤0.3.

[0006] According to another aspect of the present invention, a battery pack is provided, the battery pack including a battery pack, the battery pack being the battery pack provided above.

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

[0008] By applying the technical solution of this utility model, and by setting an isolation component between adjacent individual cells, the problem of battery packs being affected by vibration and thus unable to function normally is effectively solved.

[0009] On the one hand, the presence of separators can absorb and disperse vibration energy in the direction of battery stacking, reducing the interaction forces between individual cells caused by vibration, thereby reducing the impact of vibration on the battery pack. Especially when the battery pack is installed in a vehicle, this isolation effect can significantly improve the stability and reliability of the battery pack under complex road conditions.

[0010] On the other hand, by optimizing the L1 / L2 size ratio, the overall size and space utilization of the battery pack are considered while ensuring sufficient vibration isolation capability. A reasonable ratio setting can avoid the reduction in energy density caused by excessive space occupied by the isolation components, thereby improving the vibration resistance performance of the battery pack without sacrificing its energy storage capacity. Attached Figure Description

[0011] 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:

[0012] Figure 1 A schematic diagram of the battery pack provided in an embodiment of the present invention is shown;

[0013] Figure 2 A schematic diagram of the battery pack provided in an embodiment of the present invention is shown;

[0014] Figure 3 A schematic diagram of the battery pack provided in an embodiment of the present invention is shown;

[0015] Figure 4 It shows Figure 1 A schematic diagram of the structure of a single cell in the diagram;

[0016] Figure 5 It shows Figure 1 A schematic diagram of the structure of the isolation component in the middle;

[0017] Figure 6 This shows a partial enlarged view of the battery pack at the separator provided in an embodiment of the present invention;

[0018] Figure 7 This is a partially enlarged view of the battery pack provided in an embodiment of the present invention at the separator, from another perspective.

[0019] The above figures include the following reference numerals:

[0020] 10. Single cell; 11. First side; 12. Second side; 13. Top surface; 14. Bottom surface; 15. Terminal post; 16. Explosion-proof valve;

[0021] 20. Isolation component; 21. Isolation surface;

[0022] 30. Battery pack;

[0023] L1, the sum of the dimensions of all separators in the stacking direction of the individual cells;

[0024] La, the dimension of a single separator in the stacking direction of the individual cells;

[0025] L2, the dimensions of the battery pack in the stacking direction of individual cells. Detailed Implementation

[0026] 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.

[0027] The battery pack includes a battery management system (BMS), a thermal management system, an electrical connection system (high-voltage / low-voltage connectors, wiring harnesses, etc.), structural components (shell, brackets, etc.), and protective components, etc., and the above components are placed in a box and sealed with a cover plate to form a complete functional unit that can directly output electrical energy.

[0028] like Figures 1 to 7 As shown, this embodiment of the present invention provides a battery pack, which includes at least two individual cells 10 and separators 20. Each individual cell 10 has a first side 11 and a second side 12 arranged adjacent to each other. The area of ​​the first side 11 is larger than the area of ​​the second side 12. The at least two individual cells 10 are stacked together via the first side 11, and a separator 20 is disposed between the at least two individual cells 10. In the stacking direction of the individual cells 10, the sum of the dimensions of all separators 20 is L1, and the dimension of the battery pack is L2, where 0.02 ≤ L1 / L2 ≤ 0.3. Furthermore, L1 and L2 have the same unit.

[0029] By using the battery pack provided in this embodiment, the problem of the battery pack being affected by vibration is effectively solved by setting an isolation member 20 between adjacent individual cells 10.

[0030] On the one hand, the presence of the separator 20 can absorb and disperse vibration energy in the direction of battery stacking, reducing the interaction force between individual cells 10 caused by vibration, thereby reducing the impact of vibration on the battery pack. Especially when the battery pack is installed in a vehicle, this isolation effect can significantly improve the stability and reliability of the battery pack under complex road conditions.

[0031] On the other hand, by optimizing the size ratio of L1 / L2, the overall size and space utilization of the battery pack are considered while ensuring sufficient vibration isolation capability. A reasonable ratio setting avoids a decrease in energy density due to excessive space occupied by the separator 20, thereby improving the vibration resistance without sacrificing the battery pack's energy storage capacity.

[0032] It should be noted that at least two individual cells 10 are provided with a separator 20, including the following two structures: the first structure is that a separator 20 is provided between two adjacent individual cells 10; the second structure is that it is sufficient to ensure that a separator 20 is provided between some of the adjacent two individual cells 10, and a separator 20 is not provided between the remaining adjacent two individual cells 10.

[0033] in, Figure 1 The size of the separator 20 in the stacking direction of the single cell 10 is La, and the sum of the sizes of the multiple separators 20 in the stacking direction of the single cell 10 is L1.

[0034] In this embodiment, the first structure is adopted, that is, an isolation element 20 is provided between each two adjacent single cells 10, which has a better isolation effect.

[0035] L1 / L2 can be 0.02, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, or other values ​​between 0.02 and 0.3.

[0036] Wherein, 20mm≤L1≤200mm; and / or, 600mm≤L2≤2500mm.

[0037] Specifically, L1 can be 20mm, 40mm, 60mm, 80mm, 100mm, 120mm, 140mm, 160mm, 180mm, 190mm, 200mm, or other values ​​between 20mm and 200mm. In this embodiment, 60mm ≤ L1 ≤ 190mm.

[0038] Specifically, L2 can be 600mm, 700mm, 800mm, 900mm, 1000mm, 1100mm, 1200mm, 1300mm, 1400mm, 1500mm, 1600mm, 1700mm, 1800mm, 1900mm, 2000mm, 2100mm, 2200mm, 2300mm, 2400mm, 2500mm, or other values ​​between 600mm and 2500mm. In this embodiment, 720mm ≤ L2 ≤ 2400mm.

[0039] In this embodiment, the surface of the separator 20 facing the first side 11 is the separator surface 21, which is planar. Technically, the planar separator surface design simplifies the battery pack assembly process and ensures the contact area and contact stability between the separator 20 and the individual battery cell 10. In principle, the planar design helps to evenly distribute the pressure of the separator 20 on the individual battery cell 10, avoiding localized stress concentration and thus improving the structural safety of the battery pack.

[0040] Therefore, the above structure improves the assembly efficiency of the battery pack, while enhancing the structural strength of the battery pack and reducing the risk of battery damage caused by vibration.

[0041] Specifically, the insulating surface 21 is parallel to the first side surface 11. This design, where the insulating surface 21 is parallel to the first side surface 11, further improves the assembly efficiency of the battery pack, enhances the structural strength of the battery pack, and reduces the risk of battery damage caused by vibration.

[0042] In some embodiments, the separator 20 includes a reinforcing plate. The introduction of the reinforcing plate enhances the structural strength of the battery pack and improves its vibration resistance to external impacts. Specifically, the reinforcing plate, through its rigid support, disperses the vibration and impact forces experienced by the individual battery cells 10, reduces direct contact between the individual battery cells 10, and thus reduces the risk of battery damage.

[0043] Therefore, by setting the separator 20 as a reinforcing plate, the structural safety of the battery pack in complex environments is ensured, and the service life of the battery pack is extended.

[0044] The reinforcing plate includes a PCM plate, a steel plate, or an epoxy fiberglass plate; and / or, the tensile stiffness of the reinforcing plate is K, where 45MPa≤K≤620MPa.

[0045] The choice of PCM board, steel plate, or epoxy fiberglass board is based on their excellent mechanical strength and thermal stability, which can effectively support the battery pack and maintain structural stability in high-temperature environments.

[0046] The range of tensile stiffness K of the reinforcing plate is set to ensure that the reinforcing plate provides sufficient support without increasing the weight of the battery pack or reducing its energy density due to excessive stiffness.

[0047] Therefore, by making the reinforcing plate include a PCM plate, a steel plate, or an epoxy fiberglass plate, and setting the tensile stiffness K of the reinforcing plate in the range of 45MPa to 620MPa, the structural strength and thermal stability of the battery pack are improved, while maintaining a high energy density.

[0048] The tensile stiffness K of the reinforcing plate can be 45MPa, 50MPa, 100MPa, 150MPa, 200MPa, 250MPa, 300MPa, 350MPa, 400MPa, 450MPa, 500MPa, 550MPa, 600MPa, 620MPa, or other values ​​between 45MPa and 620MPa.

[0049] If the reinforcing plate is a high-frequency PCM plate, the tensile stiffness K = 50 MPa; if the reinforcing plate is a flexible PCM plate, the tensile stiffness K = 150 MPa; if the reinforcing plate is an epoxy fiberglass board, the tensile stiffness K ≥ 400 MPa; if the reinforcing plate is a DC06 steel plate, the tensile stiffness K = 260 MPa; if the reinforcing plate is a DP590 steel plate, the tensile stiffness K = 590 MPa.

[0050] It should be noted that PCM board refers to PCM (Prepreg Compression Molding) board, which is a composite material semi-finished product in which resin is pre-impregnated in fiber reinforcement material.

[0051] In some embodiments, the separator 20 includes a buffer pad. The buffer pad further improves the vibration isolation effect of the battery pack and reduces direct collisions between individual battery cells 10. In principle, the buffer pad utilizes the elastic properties of its material to absorb and disperse the vibration energy experienced by the individual battery cells 10, reducing the efficiency of vibration transmission. In terms of effectiveness, the technical solution in this embodiment significantly reduces vibration damage to the battery pack during transportation and use, improving the battery pack's lifespan and safety.

[0052] The buffer pad is made of rubber, silicone, or polyurethane to adapt to the different usage environments and requirements of battery packs, while maintaining the basic vibration isolation effect of the buffer pad.

[0053] When the spacer 20 includes a buffer pad, 0.02 ≤ L1 / L2 ≤ 0.25. This is because the buffer pad has a good cushioning effect, and setting L1 / L2 within the above range can further ensure energy density.

[0054] Specifically, the L1 / L2 range setting ensures that the isolation component provides effective vibration isolation without excessively occupying battery pack space, thus maintaining a high energy density. By setting the L1 / L2 ratio, the vibration isolation effect and space utilization can be balanced, avoiding the problem of reduced overall battery pack performance due to excessive isolation.

[0055] L1 / L2 can be 0.02, 0.05, 0.1, 0.15, 0.2, 0.25, or other values ​​between 0.02 and 0.25.

[0056] In this embodiment, the elastic modulus of the buffer pad is E, where 1 MPa ≤ E ≤ 50 MPa. Setting the range of the elastic modulus E ensures that the buffer pad provides effective vibration isolation without reducing its energy absorption capacity due to an excessively high elastic modulus. By precisely controlling the elastic modulus of the buffer pad, its energy absorption and dispersion effects during vibration can be optimized, thus improving vibration isolation performance.

[0057] Specifically, the elastic modulus E of the cushioning pad can be 1 MPa, 10 MPa, 20 MPa, 30 MPa, 40 MPa, 50 MPa, and other values ​​between 1 MPa and 50 MPa.

[0058] In this embodiment, the cushioning pad is made of silicone foam, PU (polyurethane) foam, PE (polyethylene) foam, or rubber foam. Specifically, if the cushioning pad is made of silicone foam, then 1MPa ≤ E ≤ 10MPa; if the cushioning pad is made of PU foam, then 1MPa ≤ E ≤ 10MPa; if the cushioning pad is made of PE foam, then 2MPa ≤ E ≤ 50MPa; and if the cushioning pad is made of rubber foam, then 1MPa ≤ E ≤ 20MPa.

[0059] In some embodiments, the separator 20 includes a thermal insulation pad. The thermal insulation pad further improves the thermal management capabilities of the battery pack and reduces heat transfer between individual cells. Utilizing the low thermal conductivity of its material, the thermal insulation pad blocks the heat generated by the battery during charging and discharging, preventing localized overheating, significantly improving the thermal stability of the battery pack, and extending its service life.

[0060] It should be noted that the materials of the heat insulation pad include polyurethane, polyethylene, silicone foam, or aerogel, to adapt to the usage environment and requirements of different battery packs, while maintaining the basic heat insulation effect of the heat insulation pad.

[0061] The thermal conductivity of the insulation pad is N, 0.013W / (m K)≤N≤0.2W / (m K).

[0062] Specifically, the thermal conductivity N of the heat insulation pad can be 0.013 W / (m K), 0.015 W / (m K), 0.02 W / (m K), 0.05 W / (m K), 0.1 W / (m K), 0.15 W / (m K), 0.2 W / (m K), or other values ​​between 0.013 W / (m K) and 0.2 W / (m K). Setting the range of thermal conductivity N ensures that the heat insulation pad provides effective insulation without increasing the difficulty of thermal management of the battery pack due to excessively low thermal conductivity. By precisely controlling the thermal conductivity of the heat insulation pad, its insulation effect and the overall thermal management performance of the battery pack can be balanced, avoiding the problem of reduced heat dissipation capacity of the battery pack due to excessive insulation. This improves its thermal management efficiency and energy density while ensuring the thermal stability and lifespan of the battery pack.

[0063] Specifically, if the heat insulation pad is made of polyurethane, then 0.02W / (m K)≤N≤0.04W / (m K); if the heat insulation pad is made of polyethylene, then 0.03W / (m K)≤N≤0.06W / (m K); if the heat insulation pad is made of silicone foam, then 0.1W / (m K)≤N≤0.2W / (m K); and if the heat insulation pad is made of aerogel, then 0.013W / (m K)≤N≤0.02W / (m K).

[0064] In some embodiments, the separator 20 includes a heat exchange plate. The heat exchange plate improves the thermal management capability of the battery pack by effectively dispersing the heat generated by individual cells during charging and discharging by increasing the heat exchange area. The heat exchange plate, with its excellent thermal conductivity and structural design, promotes uniform heat distribution within the battery pack, avoids localized overheating, significantly improves the thermal management efficiency of the battery pack, and extends its service life.

[0065] When the separator 20 includes a heat exchange plate, 0.02 ≤ L1 / L2 ≤ 0.28. This is because the heat exchange plate has a good heat exchange effect, and the thermal impact between two adjacent individual cells is small. Setting L1 / L2 within the above range can ensure the energy density of the battery pack.

[0066] Specifically, the L1 / L2 range setting ensures that the heat exchange plate provides effective thermal management without excessively occupying battery pack space, maintaining a high energy density. By setting the L1 / L2 ratio, the thermal management effect and space utilization can be balanced, avoiding the problem of reduced overall battery pack performance due to excessive isolation. This improves the energy density and space utilization while ensuring the battery pack's thermal management efficiency and lifespan.

[0067] L1 / L2 can be 0.02, 0.05, 0.1, 0.15, 0.2, 0.25, 0.28, or other values ​​between 0.02 and 0.28.

[0068] like Figure 2 and Figure 4 As shown, the single cell 10 also has a top surface 13 and a bottom surface 14. The terminal post 15 of the single cell 10 is disposed on the top surface 13 or the bottom surface 14, and the explosion-proof valve 16 of the single cell 10 is disposed on the top surface 13 or the bottom surface 14.

[0069] The placement of the terminal post 15 and the explosion-proof valve 16 optimizes the internal layout of the battery pack, improving assembly efficiency and safety. By placing the terminal post 15 and the explosion-proof valve 16 on the top or bottom surface, direct contact between them and the separator 20 is avoided, reducing the risk of failure due to vibration or thermal expansion, improving the structural safety and reliability of the battery pack, while maintaining high energy density and space utilization.

[0070] like Figure 1 As shown, another embodiment of this utility model provides a battery pack, which includes a battery group 30, the battery group 30 being the battery group provided above. Therefore, this battery pack can also effectively solve the problem of the battery pack being affected by vibration by providing a spacer 20 between adjacent individual cells 10.

[0071] Another embodiment of this utility model provides an electrical device, which includes a battery pack, the battery pack being the one described above. Therefore, this electrical device can also effectively solve the problem of the battery pack being affected by vibration by providing an insulating member 20 between adjacent individual battery cells 10.

[0072] Electrical devices include, but are not limited to, vehicles.

[0073] The apparatus provided by the embodiments has the following beneficial effects:

[0074] 1) The isolation components can effectively absorb and disperse vibration energy in the stacking direction of individual cells, reduce vibration transmission between adjacent cells, and significantly improve the stability and reliability of the battery pack in dynamic environments, especially in scenarios with frequent vibrations such as vehicle operation.

[0075] 2) By controlling the ratio of the sum of the dimensions of all the isolation components L1 to the battery pack size L2, sufficient vibration isolation is ensured while avoiding the reduction in energy density caused by excessive space occupied by the isolation components, thus achieving an optimized balance between battery pack performance and space utilization.

[0076] 3) The separators include reinforcing plates, which enhance the structural strength of the battery pack, making it more stable in the face of external impacts. Furthermore, the use of heat insulation pads and heat exchange plates further optimizes the battery pack's thermal management, preventing overheating or undercooling and ensuring efficient operation within a suitable temperature range. The inclusion of buffer pads further improves the vibration isolation of the battery pack, reducing direct collisions between individual cells.

[0077] 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.

[0078] Typically, a secondary battery includes an electrode assembly, an electrolyte, and an outer casing. The electrode assembly consists of a positive electrode, a negative electrode, and a separator. The electrode assembly 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 electrodes, inserting and extracting. The separator, positioned between the positive and negative electrodes, primarily prevents short circuits while allowing active ions to pass through. The electrolyte, located between the positive and negative electrodes, mainly serves to conduct active ions.

[0079] 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.

[0080] 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.

[0081] 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).

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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).

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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).

[0093] 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).

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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: At least two individual cells (10) have a first side (11) and a second side (12) arranged adjacent to each other, the area of ​​the first side (11) is larger than the area of ​​the second side (12), and at least two individual cells (10) are stacked through the first side (11). The separator (20) is disposed between at least two of the individual cells (10); In the stacking direction of the individual cells (10), the sum of the dimensions of all the separators (20) is L1, the dimension of the battery pack is L2, and 0.02≤L1 / L2≤0.

3.

2. The battery pack according to claim 1, characterized in that, The surface of the isolation member (20) facing the first side (11) is the isolation surface (21), and the isolation surface (21) is a plane.

3. The battery pack according to claim 2, characterized in that, The isolation surface (21) is parallel to the first side surface (11).

4. The battery pack according to any one of claims 1 to 3, characterized in that, The isolation element (20) includes a reinforcing plate.

5. The battery pack according to claim 4, characterized in that, The reinforcing plate includes a PCM plate, a steel plate, or an epoxy fiberglass board; and / or, The tensile stiffness of the reinforcing plate is K, where 45MPa≤K≤620MPa.

6. The battery pack according to any one of claims 1 to 3, characterized in that, The isolation element (20) includes a cushioning pad.

7. The battery pack according to claim 6, characterized in that, 0.02≤L1 / L2≤0.

25.

8. The battery pack according to claim 6, characterized in that, The elastic modulus of the buffer pad is E, where 1MPa≤E≤50MPa.

9. The battery pack according to any one of claims 1 to 3, characterized in that, The isolation element (20) includes a heat insulation pad.

10. The battery pack according to claim 9, characterized in that, The thermal conductivity of the insulation pad is N, 0.013W / (mK)≤N≤0.2W / (mK).

11. The battery pack according to any one of claims 1 to 3, characterized in that, The isolation element (20) includes a heat exchange plate.

12. The battery pack according to claim 11, characterized in that, 0.02≤L1 / L2≤0.

28.

13. The battery pack according to any one of claims 1 to 3, characterized in that, The single cell (10) also has a top surface (13) and a bottom surface (14); The terminal post (15) of the single cell (10) is disposed on the top surface (13) or the bottom surface (14); The explosion-proof valve (16) of the single battery (10) is disposed on the top surface (13) or the bottom surface (14).

14. The battery pack according to any one of claims 1 to 3, characterized in that, 20mm≤L1≤200mm; And / or, 600mm≤L2≤2500mm.

15. A battery pack, characterized in that, The battery pack includes a battery pack (30), which is the battery pack according to any one of claims 1 to 14.

16. An electrical appliance, characterized in that, The electrical device includes a battery pack, which is the battery pack according to claim 15.

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