A fast-charging battery and an electric device

Abstract

The application provides a fast-charging battery and an electric device, the fast-charging battery comprises a negative electrode sheet, the negative electrode sheet comprises a negative electrode active material, the negative electrode active material contains graphite, and the charging time of the fast-charging battery is less than or equal to 15 min from 10% SOC to 80% SOC; the negative electrode active material comprises secondary particles formed by agglomeration of primary particles, the average particle size of the primary particles is d microns, the average particle size of the secondary particles is D microns, the gap area ratio of the negative electrode active material is b measured by a scanning electron microscope, and the following condition is met: 145 <= (d x D) / b <= 675. The fast-charging battery provided by the application synchronously improves the interface embedding environment and internal diffusion channel of the negative electrode material by synergistically optimizing the relationship between various microstructure parameters in the negative electrode active material, reduces the transmission resistance of lithium ions at the negative electrode interface and the bulk phase, improves the negative electrode fast-charging kinetic performance, and takes into account the high-temperature storage performance of the battery.

Description

Technical Field

[0001] This invention belongs to the field of battery technology, and relates to a fast-charging battery, and more particularly to a fast-charging battery and an electrical device. Background Technology

[0002] With the rapid development of new energy vehicles, portable electronic devices, and the energy storage industry, the market has placed higher demands on the fast-charging performance of lithium-ion batteries, and significantly shortening charging time has become an important R&D goal for the battery industry. However, the charging efficiency of current mainstream lithium-ion battery systems still has significant shortcomings. High-rate charging exacerbates battery polarization, results in insufficient fast-charging performance, and is prone to problems such as lithium plating on the negative electrode and performance degradation at high temperatures, which seriously restricts the commercial application of fast-charging batteries.

[0003] Technicians have confirmed that the bottleneck to improving the fast-charging performance of lithium-ion batteries lies on the negative electrode side. During charging, lithium ions migrate from the positive electrode to the negative electrode surface via the electrolyte, requiring two steps: interfacial charge transfer and bulk diffusion, before finally embedding into the negative electrode material. However, widely used graphite-based and other negative electrode materials generally suffer from kinetic transport barriers: firstly, the number of lithium-ion insertion / extraction channels at the interface of the negative electrode material is limited, and the number of reactive sites is insufficient, resulting in significant resistance to interfacial charge transfer and making it difficult for lithium ions to quickly complete the interfacial embedding process; secondly, the lithium-ion diffusion channels inside the negative electrode material are long and tortuous, leading to a low diffusion rate of lithium ions within the bulk phase of the material, further increasing the internal transport resistance.

[0004] The combined transport resistance of the interface and bulk phase causes a lag in the lithium-ion kinetics performance on the negative electrode side. During high-rate charging, lithium ions cannot be inserted into the negative electrode bulk phase in time, easily leading to the precipitation of lithium dendrites on the negative electrode surface. This directly limits the improvement of the charging rate and also causes problems such as irreversible capacity loss and internal short-circuit safety hazards. Traditional modification methods, such as particle nano-sizing and single-surface coating, often fail to simultaneously optimize the interface channels and bulk diffusion paths, and are often accompanied by side effects such as reduced high-temperature storage performance, failing to fundamentally improve the fast-charging kinetics performance of the negative electrode.

[0005] Therefore, how to simultaneously improve the interfacial embedding environment and internal diffusion pathway of the anode material, reduce the transport resistance of lithium ions at the anode interface and bulk phase, improve the fast charging dynamics of the anode, and at the same time take into account the high-temperature storage performance of the battery has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a fast-charging battery and power device that simultaneously improves the interface embedding environment and internal diffusion pathway of the negative electrode material, reduces the transport resistance of lithium ions at the negative electrode interface and bulk phase, improves the fast-charging dynamic performance of the negative electrode, and at the same time takes into account the high-temperature storage performance of the battery.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a fast-charging battery, including a negative electrode sheet, the negative electrode sheet including a negative electrode active material, the negative electrode active material containing graphite, and the fast-charging battery having a charging time of ≤15 min from 10% SOC to 80% SOC.

[0009] The negative electrode active material includes secondary particles formed by the agglomeration of primary particles. The average particle size of the primary particles is set to d μm, and the average particle size of the secondary particles is set to D μm. The interstitial area ratio of the negative electrode active material is determined by scanning electron microscopy to be b. Then, the following condition is satisfied: 145≤(d×D) / b≤675.

[0010] In a second aspect, the present invention provides an electrical device comprising a fast-charging battery as described in the first aspect.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] The fast-charging battery provided by this invention improves the interfacial embedding environment and internal diffusion pathway of the negative electrode material by synergistically adjusting key parameters such as the average particle size of primary and secondary particles and the proportion of gap area of ​​the negative electrode active material as determined by scanning electron microscopy. This effectively reduces the transport resistance of lithium ions at the negative electrode interface and in the bulk phase, and well balances the dynamic performance and high-temperature storage performance of the fast-charging battery. Attached Figure Description

[0013] Figure 1 This is a scanning electron microscope image of the negative electrode active material in the fast-charging battery provided in Example 1. Detailed Implementation

[0014] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0015] One embodiment of the present invention provides a fast-charging battery, including a negative electrode sheet, the negative electrode sheet including a negative electrode active material containing graphite, and the charging time of the fast-charging battery from 10% SOC to 80% SOC is ≤15 min, for example, it can be 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min or 15 min, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0016] This invention specifically limits the charging capacity range of the fast-charging battery to 10% SOC to 80% SOC because within this range, the graphite anode has sufficient lithium intercalation sites, exhibits the best kinetic performance, facilitates smooth lithium-ion intercalation, ensures the safest high-current charging, and achieves the highest efficiency—the golden range for fast charging. If the charging capacity range is too low (e.g., 0% SOC to 10% SOC), the battery voltage is low, polarization is significant, lithium intercalation is weak, and high current can easily lead to lithium metal deposition, even puncturing the separator, causing bulging, and fire, making it unsuitable for high-current fast charging. If the charging capacity range is too high (e.g., 80% SOC to 100% SOC), the graphite layer is almost completely filled with lithium, leaving very few vacancies. This causes a sharp increase in lithium intercalation resistance, and continued high-current charging will result in a large amount of lithium failing to intercalate and directly depositing, leading to a dramatic thickening of the SEI film, severe heat generation, and a precipitous degradation during cycling.

[0017] Based on this, the present invention further limits the charging time of the fast-charging battery from 10% SOC to 80% SOC to ≤15min, which well balances the four major boundaries of user energy replenishment efficiency, cell heat generation control, negative electrode lithium plating safety, and cycle life, and represents the optimal fast-charging balance point of current liquid lithium batteries.

[0018] The negative electrode active material includes secondary particles formed by the agglomeration of primary particles. The average particle size of the primary particles is set to d μm, and the average particle size of the secondary particles is set to D μm. The interstitial area ratio of the negative electrode active material is determined by scanning electron microscopy to be b. Then, the following condition is satisfied: 145≤(d×D) / b≤675. For example, it can be 145, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650 or 675, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0019] In the above parameter relationship, by reducing the product d×D of the average particle size d of primary particles and the average particle size D of secondary particles, the transport path of ions at the interface can be shortened and the lithium-ion insertion / extraction channels can be increased, thereby improving lithium-ion transport performance and enhancing kinetics. Specifically, reducing the average particle size D of secondary particles significantly shortens the migration path of lithium ions from the particle interior to the surface, reducing diffusion time and solid-phase diffusion resistance; reducing the average particle size d of primary particles increases the channels for lithium-ion insertion and extraction. The shortened transport path of lithium ions in the negative electrode particles, coupled with the increased insertion / extraction channels at the negative electrode interface, improves lithium-ion transport performance and enhances fast-charging performance. However, if d×D is too small, it will lead to an increase in the active reaction area between the electrolyte and the negative electrode material, affecting high-temperature storage performance. Therefore, further reducing the proportion b of the interstitial area of ​​the negative electrode active material as measured by scanning electron microscopy can reduce the amount of electrolyte between the secondary particles, thereby reducing side reactions between the electrolyte and the negative electrode material and improving high-temperature storage performance.

[0020] Therefore, this invention comprehensively controls the numerical range of (d×D) / b. If the parameter relationship exceeds 675, the fast charging performance deteriorates; if the parameter relationship is less than 145, the high-temperature storage performance deteriorates. By limiting 145≤(d×D) / b≤675, this invention effectively balances the dynamics of fast-charging batteries and high-temperature storage performance.

[0021] In some embodiments, the OI value of the negative electrode active material is 4.2 to 9.6, for example, it can be 4.2, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5 or 9.6, preferably 4.4 to 8.9, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0022] In this invention, the OI value of the negative electrode active material specifically refers to the ratio of the peak area of ​​the (004) crystal plane to the peak area of ​​the (110) crystal plane of graphite, which is used to characterize the degree of orientation order of graphite sheets. It can be calculated by testing the XRD pattern of graphite at 10°~90° using an X-ray diffractometer.

[0023] In some embodiments, the average particle size d μm of the primary particles is 4.5 to 7.5 μm, for example, it can be 4.5 μm, 5.0 μm, 5.5 μm, 6.0 μm, 6.5 μm, 7.0 μm or 7.5 μm, preferably 5.2 to 7.0 μm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0024] In some embodiments, the average particle size D μm of the secondary particles is 9.0~13.5 μm, for example, it can be 9.0 μm, 9.5 μm, 10.0 μm, 10.5 μm, 11.0 μm, 11.5 μm, 12.0 μm, 12.5 μm, 13.0 μm or 13.5 μm, preferably 9.2~13.0 μm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0025] In some embodiments, the gap area ratio b of the negative electrode active material is determined by scanning electron microscopy to be 15% to 28%, for example, it can be 15%, 17%, 20%, 22%, 25%, 27% or 28%, preferably 17% to 25%, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0026] In some embodiments, the charging time of the battery from 10% SOC to 80% SOC is ≤12 min, for example, it can be 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min or 12 min, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0027] In some embodiments, the sphericity of the primary particles is 0.68 to 0.92, for example, it can be 0.68, 0.7, 0.72, 0.74, 0.76, 0.78, 0.8, 0.82, 0.84, 0.86, 0.88, 0.9 or 0.92, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0028] In this invention, the sphericity is defined as the ratio of the surface area of ​​a sphere with the same volume as the primary particle to the actual surface area of ​​the primary particle. It is used to characterize the regularity of the shape of the primary particle. The sphericity of a perfect sphere is 1, while the sphericity of particles of other shapes is less than 1.

[0029] This invention limits the sphericity of primary particles to the range of 0.68 to 0.92, which optimizes the negative electrode particle packing structure and ion transport channels, while also considering electrode compaction performance, lithium-ion conductivity, and interface stability. Specifically, the moderate morphology of the primary particles results in a reasonable distribution of packing pores, ensuring smooth electrolyte wetting within the electrode and providing continuous channels for lithium-ion migration, thus adapting to high-current fast charging.

[0030] In some embodiments, the major axis of the primary particle is 4.6 to 7.8 μm, for example, it can be 4.6 μm, 5.0 μm, 5.5 μm, 6.0 μm, 6.5 μm, 7.0 μm, 7.5 μm or 7.8 μm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0031] In some embodiments, the minor axis of the primary particle is 3.5 to 6.9 μm, for example, it can be 3.5 μm, 4.0 μm, 4.5 μm, 5.0 μm, 5.5 μm, 6.0 μm, 6.5 μm or 6.9 μm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0032] In some embodiments, the negative electrode active material further includes individual particles discrete between primary and secondary particles.

[0033] In some embodiments, the volume percentage of the single particle in the negative electrode material is 10% to 40%, for example, it can be 10%, 15%, 20%, 25%, 30%, 35% or 40%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0034] This invention limits the volume ratio of single particles in the negative electrode material to within the range of 10% to 40%, which can precisely control the overall particle size distribution, pore structure and ion transport network of the negative electrode active material, and optimize the comprehensive performance of the electrode by coordinating primary and secondary particles, thereby balancing fast charging capability and interface stability.

[0035] In some embodiments, the secondary particles account for ≥60% of the volume of the negative electrode material, for example, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 100%, but are not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0036] In some embodiments, the total volume percentage of the single particles and secondary particles in the negative electrode material is 75% to 99%, for example, it can be 75%, 80%, 85%, 90%, 95% or 99%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0037] In some embodiments, the negative electrode sheet further includes a current collector. The average particle size of the particles of the negative electrode active material near the current collector is set as M1, and the average particle size of the particles of the negative electrode active material away from the current collector is set as M2. Then, the following condition is satisfied: M1 > M2.

[0038] For example, this invention uses half the thickness of the negative electrode active material as a dividing line to divide the negative electrode active material into upper and lower layers, and limits the average particle size of the lower layer particles (i.e., near the current collector) to be greater than the average particle size of the upper layer particles (i.e., away from the current collector). This is because the larger particle size of the lower layer particles allows for more interparticle gaps and large pores, more thorough electrolyte wetting, and smoother conduction channels for lithium ions to migrate from the current collector to the upper layer of the electrode, thereby significantly reducing the overall liquid phase mass transfer resistance, adapting to high-rate fast charging such as 4C, and reducing polarization under high current. At the same time, the lower layer has more pores and sufficient electrolyte storage, while the upper layer has more reaction sites for small particles. During charging, the lithium insertion rate is gradient matched from bottom to top, which can effectively prevent the rapid saturation of lithium on the surface and the precipitation of lithium dendrites, thereby improving the safety of fast charging.

[0039] In some embodiments, the compaction density of the negative electrode sheet is 1.45~1.70 g / cm³. 3 For example, it could be 1.45 g / cm³ 3 1.50 g / cm 3 1.51 g / cm3 1.53 g / cm 3 1.55 g / cm 3 1.57 g / cm 3 1.59 g / cm 3 1.60 g / cm 3 1.61 g / cm 3 1.63 g / cm 3 1.65 g / cm 3 1.67 g / cm 3 1.69 g / cm 3 Or 1.70 g / cm 3 However, this does not apply to all values ​​listed; other unlisted values ​​within the same range also apply.

[0040] In some embodiments, the pore volume percentage of the negative electrode active material with a pore size of 0.5 μm or larger is 10% to 25%, for example, it can be 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24% or 25%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0041] In this invention, the pore volume ratio with a pore size of 0.5 μm or larger can be measured by nitrogen adsorption-desorption test (BET).

[0042] In some embodiments, the fast-charging battery further includes a positive electrode sheet comprising a positive electrode material containing lithium iron phosphate. The charging time of the fast-charging battery from 10% SOC to 80% SOC is 12-14 minutes, for example, 12 minutes, 12.2 minutes, 12.4 minutes, 12.6 minutes, 12.8 minutes, 13 minutes, 13.2 minutes, 13.4 minutes, 13.6 minutes, 13.8 minutes, or 14 minutes. The corresponding fast-charging battery satisfies: 350 ≤ (d×D) / b ≤ 500, for example, 350, 360, 380, 400, 420, 440, 460, 480, or 500, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0043] In some embodiments, the fast-charging battery further includes a positive electrode sheet comprising a positive electrode material containing a ternary material. The nickel content in the ternary material is 60 wt% to 80 wt%, for example, 60 wt%, 62 wt%, 64 wt%, 66 wt%, 68 wt%, 70 wt%, 72 wt%, 74 wt%, 76 wt%, 78 wt%, or 80 wt%. The charging time of the fast-charging battery from 10% SOC to 80% SOC is ≤13 min, for example, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, or 13 min. The corresponding fast-charging battery satisfies: 240 ≤ (d×D) / b ≤ 400, for example, 240, 260, 280, 300, 320, 340, 360, 380, or 400, but is not limited to the listed values; other unlisted values ​​within this range also apply.

[0044] In some embodiments, the fast-charging battery is prepared using the following method:

[0045] (1) Preparation of positive electrode sheet: Mix positive electrode active material and additives, add solvent to obtain positive electrode slurry; coat the positive electrode slurry on at least one side of the positive electrode current collector, dry, roll and cut to obtain positive electrode sheet.

[0046] Specifically, the additives include at least one of conductive agents, dispersants, or binders.

[0047] The amount of positive electrode active material, conductive agent, binder, dispersant and solvent can be selected according to the needs in this field. For example, the mass ratio of positive electrode active material, conductive agent, dispersant and binder is (93-98.2):(0.5-3.1):(0.1-1.8):(1.2-3.5).

[0048] Specifically, the positive electrode active material is a nickel-cobalt ternary material or lithium iron phosphate, wherein the general chemical formula of the nickel-cobalt ternary material can be represented as: Li a Ni b Co c M1 d M2 e O f R g, wherein 0.75≤a≤1.2, 0<b<1, 0<c<1, 0<d<1, b+c+d=1, 0≤e≤0.2, 1≤f≤2.5, 0≤g≤1, f+g≤3; M1 may be Mn and / or Al, M2 is selected from at least one of B, Zr, Ti, Si, Mo, La, Ce, Te, Nb, Ta, Si, Al, W, Sr, V, Y, Mg, Co or Li, the content of M2 in the nickel-cobalt ternary material is 100-10000 ppm; R includes but is not limited to at least one of N, F, S or Cl.

[0049] Specifically, lithium iron phosphate is a positive electrode active material with an olivine-type crystal structure, and has the advantages of low cost, high safety, etc. Its general chemical formula can be expressed as: LiFe 1-x M x PO y Q z , wherein x≤0.1, 3.85≤y≤4, 0≤z≤0.05; M is a doping element, including but not limited to at least one of Mn, Ni, Co, Cr, Cu, Bi or Sb, the content of M in lithium iron phosphate is 500-5000 ppm.

[0050] For a positive electrode sheet using a nickel-cobalt ternary material as the positive electrode active material, the areal density after rolling is 200~280 g / m 2 and the compaction density is 3.2~3.6 g / cm 3 ; for a positive electrode sheet using lithium iron phosphate as the positive electrode active material, the areal density after rolling is 300~580 g / m 2 and the compaction density is 2.2~2.8 g / cm 3 .

[0051] In the above positive electrode sheet, the conductive agent is selected from at least one of superconducting carbon (SP), acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene or carbon nanofibers.

[0052] In the above positive electrode sheet, the binder is selected from at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer or fluorine-containing acrylate resin.

[0053] In the above positive electrode sheet, the dispersant is selected from at least one of acrylics, acrylates, polyether esters, phosphate esters, small molecule alcohol amines, polyurethanes, modified styrene / maleic anhydrides, hydrogenated nitrile butadiene rubber (HNBR), polyvinylpyrrolidone (PVP) or polyethylene glycol (PEG). A dispersant is used when the positive electrode active material is selected from lithium iron phosphate and / or lithium manganese iron phosphate.

[0054] Specifically, the positive electrode current collector can be a composite current collector or a metal foil. For example, carbon-coated aluminum foil can be used as the current collector, with the aluminum foil thickness being 12 μm and the carbon coating layer thickness being 2 μm.

[0055] Specifically, the composite current collector includes a middle polymer layer and metal layers disposed on both sides of the polymer layer; wherein, the polymer layer includes polymer materials, including at least one of polyamide (PA), polyterephthalate, polyimide (PI), polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), aramid, acrylonitrile-butadiene-styrene copolymer (ABS), polybutylene terephthalate (PET), poly(p-phenylene terephthalamide) (PPTA), polypropylene (PPE), polyoxymethylene (POM), epoxy resin, phenolic resin, polytetrafluoroethylene (PTEE), polyvinylidene fluoride (PVDF), silicone rubber, polycarbonate (PC), polyvinyl alcohol (PVA), polyethylene glycol (PEG), cellulose, starch, protein, its derivatives, its crosslinks or copolymers; the metal layer includes at least one of aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver or silver alloy.

[0056] (2) Preparation of negative electrode sheet: Mix negative electrode active material, conductive agent, dispersant and other raw materials, add solvent to obtain negative electrode slurry; coat the negative electrode slurry on at least one side of the negative electrode current collector, dry, roll and cut to obtain negative electrode sheet.

[0057] Specifically, the mass ratio of the negative electrode active material, conductive agent, and dispersant adopts a conventional ratio in the art. For example, the mass ratio of the negative electrode active material, conductive agent, and dispersant is (95.5-98.95):(0.5-2):(0.05-0.3).

[0058] In the aforementioned negative electrode sheet, the negative electrode active material is selected from graphite, and is divided into natural graphite and artificial graphite. The raw materials for preparing the artificial graphite include petroleum coke and / or needle coke.

[0059] In the aforementioned negative electrode sheet, the negative electrode active material further contains a binder, which is selected from at least one of asphalt, styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, waterborne acrylic resin, polyvinyl alcohol (PVA), sodium alginate (SA), or sodium carboxymethyl cellulose (CMC); the waterborne acrylic resin may be at least one of polyacrylic acid (PAA), polymethacrylic acid (PMAA), sodium polyacrylate (PAAS), or polyacrylamide (PAM).

[0060] For example, the preparation method of the negative electrode active material includes: drying petroleum coke and / or needle coke raw materials, adjusting the pulverizing pressure (0.6~1.0 MPa) using an air jet mill, and adjusting the classifying wheel speed (800~2200 rpm) using an air classifier to prepare primary graphite particles (4.5~7.5 μm) with a target particle size; then adding asphalt binder (5~12 wt%) in proportion and mixing evenly at high temperature, followed by agglomeration and maturation under an inert atmosphere and at 500~600 ℃ by adjusting the binder dosage and the constant temperature granulation time (2~5 h), and obtaining secondary graphite particles (9.0~13.5 μm) with controllable morphology, particle size, and internal gaps after cooling and sieving, and finally performing high-temperature graphitization and carbon coating on the graphite particles to obtain the negative electrode active material.

[0061] In the aforementioned negative electrode sheet, the conductive agent is selected from at least one of superconducting carbon (SP), conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, or carbon nanofibers.

[0062] In the above-mentioned negative electrode sheet, the dispersant is selected from at least one of acrylic acid, acrylate, polyether ester, phosphate ester, small molecule alkanolamine, polyurethane, modified styrene / maleic anhydride, hydrogenated nitrile butadiene rubber (HNBR), polyvinylpyrrolidone (PVP) or polyethylene glycol (PEG).

[0063] In the aforementioned negative electrode sheet, the negative electrode current collector is selected from metal foil or composite current collector.

[0064] Specifically, the metal foil can be copper or a copper alloy.

[0065] Specifically, the composite current collector includes a middle polymer layer and metal layers disposed on both sides of the polymer layer; wherein, the polymer layer includes polymer materials, including at least one of polyamide (PA), polyterephthalate, polyimide (PI), polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), aramid, acrylonitrile-butadiene-styrene copolymer (ABS), polybutylene terephthalate (PET), poly(p-phenylene terephthalamide) (PPTA), polypropylene (PPE), polyoxymethylene (POM), epoxy resin, phenolic resin, polytetrafluoroethylene (PTEE), polyvinylidene fluoride (PVDF), silicone rubber, polycarbonate (PC), polyvinyl alcohol (PVA), polyethylene glycol (PEG), cellulose, starch, protein, its derivatives, its crosslinks or copolymers; the metal layer includes at least one of aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver or silver alloy.

[0066] (3) Electrolyte preparation: Mix organic solvents, then dissolve the dried lithium salt in the mixed organic solvents, and then add additives to obtain the electrolyte.

[0067] As previously mentioned, the lithium salt concentration of the electrolyte is 0.5~2.5 mol / L, and the lithium salt includes at least one of lithium bis(fluorosulfonyl)imide (LiFSI), lithium hexafluorophosphate (LiPF6), lithium difluorooxalate borate (LiDFOB), lithium tetrafluoroborate (LiBF4), or lithium bis(trifluoromethanesulfonyl)imide (LiTFSI).

[0068] Specifically, the additive may be at least one of fluoroethylene carbonate (FEC), vinylene carbonate (VC), or ethylene disulfide (BiDTD).

[0069] Specifically, the organic solvent may be at least one of the following: cyclic carbonates (fluoroethylene carbonate (FEC), propylene carbonate (PC), ethylene carbonate (EC)), chain carbonates (dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC), methyl propyl carbonate (MPC), methyl butyl carbonate (BMC)), and chain carboxylic acid esters (methyl formate, ethyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl acrylate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate).

[0070] (4) Separator: It is placed between the positive electrode and the negative electrode to separate the positive electrode and the negative electrode and prevent the positive electrode and the negative electrode from short-circuiting.

[0071] The material of the diaphragm is selected from at least one of glass fiber, nonwoven fabric, polyethylene (PE), polypropylene (PP) or polyvinylidene fluoride.

[0072] Specifically, a coating may also be provided on the surface of the diaphragm. The coating may be an inorganic coating and / or an organic coating. The inorganic coating material includes at least one of alumina, silicon oxide, titanium oxide, magnesium oxide, zirconium oxide or boehmite. The organic coating includes at least one of aramid coating or polyvinylidene fluoride (PVDF) coating.

[0073] (5) The above positive electrode sheet, separator and negative electrode sheet are wound in sequence to obtain a bare cell; the bare cell is placed in a cylindrical shell, dried, injected with electrolyte, and then packaged, left to stand and formed to obtain a fast-charging battery.

[0074] One embodiment of the present invention also provides an electrical device, the electrical device comprising the fast-charging battery described in any of the above embodiments.

[0075] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0076] Examples 1-12

[0077] This set of embodiments provides a fast-charging battery, including a positive electrode, a separator, a negative electrode, and an electrolyte. The negative electrode includes a negative electrode active material containing graphite. The negative electrode active material includes secondary particles formed by the aggregation of primary particles and single particles dispersed between the primary and secondary particles (see the scanning electron microscope image of the negative electrode active material obtained in Example 1). Figure 1 The average particle size d μm of the primary particles, the average particle size D μm of the secondary particles, the interstitial area ratio b of the negative electrode active material as determined by scanning electron microscopy, and the relationship between the above three parameters are detailed in Table 1 below.

[0078] Table 1

[0079]

[0080] In addition, in each embodiment, the OI value of the negative electrode active material, the long axis A μm, the short axis C μm and the sphericity ψ of the primary particles, the volume ratio φ1 of the single particle in the negative electrode material and the volume ratio φ2 of the secondary particles in the negative electrode material are detailed in Table 2 below.

[0081] Table 2

[0082]

[0083] Furthermore, the negative electrode active material is divided into upper and lower layers with half the thickness of the negative electrode active material as the dividing line. The average particle size M1 of the lower layer particles (i.e., near the current collector), the average particle size M2 of the upper layer particles (i.e., far from the current collector), and the pore volume ratio φ3% of the negative electrode active material with a pore size of 0.5 μm or larger are detailed in Table 3 below.

[0084] Table 3

[0085]

[0086] Specifically, the fast-charging batteries provided in each embodiment are manufactured using the following method:

[0087] (1) Preparation of positive electrode: The nickel-cobalt-manganese ternary material LiNi 0.8 Co 0.1 Mn 0.1O2, conductive agent acetylene black, dispersant CMC, and binder PVDF are mixed evenly at a mass ratio of 85:10:1:4. N-methylpyrrolidone is added, and the mixture is stirred under vacuum until the system is homogeneous, yielding a positive electrode slurry with a solid content of 75 wt%. The positive electrode slurry is then coated onto both sides of an aluminum foil, dried, rolled, and slit to obtain a compacted density of 3.5 g / cm³. 3 The positive electrode plate.

[0088] (2) Preparation of negative electrode sheet: After drying the petroleum coke raw material, the grinding pressure is adjusted by an air jet mill and the speed of the classifying wheel is adjusted by an air jet classifier to prepare primary graphite particles with the target particle size; then, asphalt binder is added in proportion and mixed evenly at high temperature. Subsequently, under nitrogen atmosphere and 550℃ conditions, agglomeration and maturation are completed by adjusting the binder dosage and constant temperature granulation time. After cooling and sieving, secondary graphite particles with controllable morphology, particle size and internal gap are obtained. Finally, the graphite particles are subjected to high temperature graphitization and carbon coating. The process involves coating to obtain the negative electrode active material (process parameters for each step are detailed in Table 4); the obtained negative electrode active material, conductive agent SWCNT, and dispersant CMC are mixed evenly at a mass ratio of 98.8:1:0.2, and deionized water is added to obtain the negative electrode slurry (solid content of the slurry is shown in Table 4); a double-layer coating method is used, the lower slurry is first coated on the surface of the copper foil, dried at high temperature, and then the upper slurry is coated on the surface of the lower active material. After drying, rolling, and slitting, the negative electrode sheet is obtained (compacted density is shown in Table 4).

[0089] Table 4

[0090]

[0091] In the table above, the combined effects of crushing pressure and classifying wheel speed on the average particle size d μm of primary graphite particles decrease with increasing crushing pressure or classifying wheel speed. The combined effects of binder dosage and granulation time on the average particle size D μm of secondary graphite particles increase with increasing binder dosage or granulation time. The combined effects of slurry solid content and compaction density on the interstitial area ratio b of the negative electrode active material as determined by scanning electron microscopy decrease with increasing slurry solid content or compaction density.

[0092] (3) Electrolyte preparation: EC, EMC and DEC are mixed evenly in a volume ratio of 1:1:1, and dry LiFSI and LiPF6 (mass ratio of 1:1) are added to prepare an electrolyte with a lithium salt concentration of 1 mol / L. Then FEC is added and its content in the electrolyte is controlled to be 5 wt%.

[0093] (4) PP film is selected as the separator.

[0094] (5) The above positive electrode sheet, separator and negative electrode sheet are wound in sequence to obtain a bare cell; the bare cell is placed in a cylindrical shell, dried, injected with electrolyte, and then packaged, left to stand and formed to obtain a fast-charging battery.

[0095] Comparative Examples 1-2

[0096] This comparative group provides a fast-charging battery, including a positive electrode, a separator, a negative electrode, and an electrolyte. The negative electrode includes a negative electrode active material containing graphite. The negative electrode active material includes secondary particles formed by the agglomeration of primary particles and single particles dispersed between the primary and secondary particles. The average particle size d μm of the primary particles, the average particle size D μm of the secondary particles, the interstitial area ratio b of the negative electrode active material measured by scanning electron microscopy, and the relationship between the above three parameters are detailed in Table 5 below.

[0097] Table 5

[0098]

[0099] In addition, the OI value of the negative electrode active material, the long axis A μm, the short axis C μm and the sphericity ψ of the primary particles, the volume ratio φ1 of the single particle in the negative electrode material and the volume ratio φ2 of the secondary particles in the negative electrode material are detailed in Table 6 below.

[0100] Table 6

[0101]

[0102] Furthermore, the negative electrode active material is divided into upper and lower layers with half the thickness of the negative electrode active material as the dividing line. The average particle size M1 of the lower layer particles (i.e., near the current collector), the average particle size M2 of the upper layer particles (i.e., far from the current collector), and the pore volume ratio φ3% of the negative electrode active material with a pore size of 0.5 μm or larger are detailed in Table 7 below.

[0103] Table 7

[0104]

[0105] Specifically, the fast-charging batteries provided in each comparative example were manufactured using the following method:

[0106] (1) Preparation of positive electrode: The nickel-cobalt-manganese ternary material LiNi 0.8 Co 0.1 Mn 0.1O2, conductive agent acetylene black, dispersant CMC, and binder PVDF are mixed evenly at a mass ratio of 85:10:1:4. N-methylpyrrolidone is added, and the mixture is stirred under vacuum until the system is homogeneous, yielding a positive electrode slurry with a solid content of 75 wt%. The positive electrode slurry is then coated onto both sides of an aluminum foil, dried, rolled, and slit to obtain a compacted density of 3.5 g / cm³. 3 The positive electrode plate.

[0107] (2) Preparation of negative electrode sheet: After drying the petroleum coke raw material, the grinding pressure is adjusted by an air jet mill and the speed of the classifying wheel is adjusted by an air jet classifier to prepare primary graphite particles with the target particle size; then, asphalt binder is added in proportion and mixed evenly at high temperature. Subsequently, under nitrogen atmosphere and 550℃ conditions, agglomeration and maturation are completed by adjusting the binder dosage and constant temperature granulation time. After cooling and sieving, secondary graphite particles with controllable morphology, particle size and internal gap are obtained. Finally, the graphite particles are subjected to high temperature graphitization and carbon coating. The process involves coating to obtain the negative electrode active material (process parameters for each step are detailed in Table 8); the obtained negative electrode active material, conductive agent SWCNT, and dispersant CMC are mixed evenly at a mass ratio of 98.8:1:0.2, and deionized water is added to obtain the negative electrode slurry (solid content of the slurry is shown in Table 8); a double-layer coating method is used, first coating the lower slurry onto the surface of the copper foil, drying it at high temperature, and then coating the upper slurry onto the surface of the lower active material, drying, rolling, and slitting to obtain the negative electrode sheet (compacted density is shown in Table 8).

[0108] Table 8

[0109]

[0110] (3) Electrolyte preparation: EC, EMC and DEC are mixed evenly in a volume ratio of 1:1:1, and dry LiFSI and LiPF6 (mass ratio of 1:1) are added to prepare an electrolyte with a lithium salt concentration of 1 mol / L. Then FEC is added and its content in the electrolyte is controlled to be 5 wt%.

[0111] (4) PP film is selected as the separator.

[0112] (5) The above positive electrode sheet, separator and negative electrode sheet are wound in sequence to obtain a bare cell; the bare cell is placed in a cylindrical shell, dried, injected with electrolyte, and then packaged, left to stand and formed to obtain a fast-charging battery.

[0113] In Tables 1-8, the parameters were tested using the following methods:

[0114] (a) Average particle size d μm of primary particles: After discharging the battery at 0.33C to the lower limit cutoff voltage of 2.5V, the cell was disassembled, the negative electrode sheet was removed and the negative electrode active material was peeled off. The obtained sample was cold-mounted and polished. The secondary particles were cut open and the cross-sectional morphology was photographed by scanning electron microscope to clearly distinguish the internal primary particles. A sufficient number of complete primary particles were selected, and the cross-sectional area occupied by a single primary particle was obtained by dividing the cross-sectional area occupied by all particles by the total number of particles. The diameter of the equivalent area circle was calculated as the average particle size d μm of the primary particles.

[0115] (b) Average particle size D μm of secondary particles: After discharging the battery at 0.33C to the lower limit cutoff voltage of 2.5V, the cell was disassembled, the negative electrode sheet was removed and the negative electrode active material was peeled off. The obtained sample was cold-mounted and polished. The cross-sectional morphology was photographed by scanning electron microscope to clearly distinguish the internal secondary particles. A sufficient number of complete secondary particles were selected, and the cross-sectional area occupied by a single secondary particle was obtained by dividing the cross-sectional area occupied by all particles by the total number of particles. The diameter of the equivalent area circle was calculated as the average particle size D μm of the secondary particles.

[0116] (c) Scanning electron microscopy (SEM) determination of the gap area ratio of the negative electrode active material: After discharging the battery at 0.33C to the lower limit cutoff voltage of 2.5V, the cell is disassembled, the negative electrode sheet is removed and the negative electrode active material is peeled off, the sample is placed in the SEM sample chamber, and observation is started after vacuuming; the magnification is fixed at 800x, which can clearly distinguish secondary particles and particle gaps. The brightness and contrast are required to be moderate, the boundaries between particles and gaps are clear, there is no overexposure and no large area of ​​shadow. At least 5 images with different fields of view are taken for each sample, and at least 3 parallel samples are taken for each group of experiments; the graphite particles (bright area) and particle gaps (dark area) are distinguished by image grayscale segmentation. The pixel area of ​​the two types of regions is counted by ImageJ image software, and the ratio of the dark area to the total area is calculated, which gives the gap area ratio of the negative electrode active material.

[0117] (d) OI value of negative electrode active material: After discharging the battery at 0.33C to the lower limit cutoff voltage of 2.5V, the cell was disassembled, the negative electrode sheet was removed and the graphite material was peeled off. The XRD pattern of graphite at 10-90° was tested using an X-ray diffractometer. The pattern was fitted and the peak area ratio of the (004) crystal plane and the (110) crystal plane was calculated, i.e., OI value = I(004) / I(110), where I is the diffraction peak area.

[0118] (e) Major axis A μm, minor axis C μm, and sphericity ψ of primary particles: After discharging the battery at 0.33C to the lower cutoff voltage of 2.5V, the cell was disassembled, the negative electrode sheet was removed, and the negative electrode active material was peeled off. The resulting sample was cold-mounted, polished, and the secondary particles were cut open. The cross-sectional morphology was photographed using a scanning electron microscope. A sufficient number of primary particles were selected, and the major and minor axis dimensions were measured and the average values ​​were calculated. Then, the sphericity ψ = C / ((A μm) was calculated based on the major axis A μm and the minor axis C μm.2 +AC) / 2) 1 / 2 .

[0119] (f) Volume percentage of single particles and secondary particles in negative electrode material φ1% and φ2%: After discharging the battery to the lower limit cutoff voltage of 2.5V at 0.33C, the cell was disassembled, the negative electrode sheet was removed and the negative electrode material was peeled off. The obtained sample was cold-mounted and polished. The morphology image was taken by electron microscope to distinguish the two types of particles. The area percentage was calculated by using ImageJ image software and the volume percentage was equivalently converted.

[0120] (g) Average particle size M1 and M2 of lower and upper particles: After discharging the battery at 0.33C to the lower limit cutoff voltage of 2.5V, the cell was disassembled, the negative electrode sheet was removed and the negative electrode active material was peeled off. The obtained sample was cold-mounted and polished. The cross-sectional morphology was photographed by scanning electron microscope. The lower and upper particles were clearly distinguished by taking half the thickness of the negative electrode active material as the dividing line. A sufficient number of complete particles were selected, and the cross-sectional area occupied by a single particle was obtained by dividing the cross-sectional area occupied by particles in different regions by the total number of particles. The diameter of the equivalent area circle was calculated as the average particle size of the lower and upper particles.

[0121] (h) Compacted density of negative electrode sheet: Multiple samples were randomly cut from the graphite negative electrode sheet after roll pressing, avoiding defective areas, using a standard cutter. The average thickness h1 of the sample was measured at multiple points using a thickness gauge with an accuracy of 0.001 mm. The mass m1 of the sample was then weighed using an analytical balance with a precision of 0.001 mm. The compacted density was calculated using the formula: compacted density = (m1-m2) / (S1×(h1-h2)). The average value of the parallel sample data was taken as the final result after the parallel sample data were qualified.

[0122] Performance testing:

[0123] (1) Fast charging performance: Using copper wire as the reference electrode, after normalization and capacitance, the battery was discharged to 2.8V at 0.33C. Then, lithium was plated on the three-electrode copper wire at a rate of 0.01C for 10 hours on the positive side. After lithium plating, the following fast charging test steps were performed: The battery was charged to 4.4V at a constant current of 0.33C, and then charged to ≤0.05C at a constant voltage; then discharged to 2.8V at 0.33C. The above steps were repeated 3 times, and the capacity discharged in the third cycle was taken as the battery discharge capacity; after standing for 10 minutes, it was discharged to 2.8V at 1C, and after standing for 10 minutes, it was charged to 10% at 0.33C. SOC; then charge at 4C to 4.4V, record time t0, then charge at 0.4C in descending order, i.e., charge at 3.6C, 3.2C, 2.8C, 2.4C, 2.0C, 1.6C, 1.2C, 0.8C, and 0.4C. The cutoff condition for each charge is charging to 4.4V; record time t1, and calculate t1-t0 to get the fast charging time.

[0124] (2) High-temperature storage performance: The battery was discharged at a constant current of 0.33C to 2.8V, then charged at a constant current of 0.33C to 4.4V, and then charged at a constant voltage to 0.05C before the charging was stopped. The battery was then discharged at a constant current of 0.33C to 2.8V. This process was repeated three times to obtain the third discharge capacity Q3, which was taken as the fixed capacity. The battery was then charged at a constant current of 0.33C to 4.4V, and then charged at a constant voltage to 0.05C before the charging was stopped. At this point, the battery was at 100% SOC. The battery continues to be stored in this state for the next step; after storing the battery at 60℃ and 100% SOC for 15, 30, 60 and 90 days respectively, it is discharged at a constant current of 0.33C to 2.8V, then charged at a constant current of 0.33C to 4.4V, charged at a constant voltage to 0.05C to stop charging, and discharged at a constant current of 0.33C to 2.8V. The above steps are repeated for a total of 3 charge and discharge cycles to obtain the third discharge capacity Q4. The high temperature storage capacity recovery rate is calculated as Q4 / Q3×100%.

[0125] The fast charging performance and high-temperature storage performance test results of the batteries obtained in Examples 1-12 and Comparative Examples 1-2 are shown in Table 9 below.

[0126] Table 9

[0127]

[0128] As shown in the table above, for the fast-charging batteries prepared in Examples 1 to 12, since they meet the limiting condition of 145≤(d×D) / b≤675, their charging time from 10% SOC to 80% SOC is ≤15 min, and the high-temperature storage capacity recovery rate at different placement times at 60℃ is maintained at a high level. It can be seen that their fast-charging performance and high-temperature storage performance have been synergistically optimized.

[0129] Compared to Examples 1-12, the fast-charging battery prepared in Comparative Example 1, due to its (d×D) / b=122<145, ultimately resulted in a significant decrease in its high-temperature storage capacity recovery rate at different storage times at 60°C, i.e., a significant decrease in high-temperature storage performance.

[0130] Compared to Examples 1-12, the fast-charging battery prepared in Comparative Example 2, due to its (d×D) / b=834>675, ultimately resulted in a charging time of 20 minutes from 10% SOC to 80% SOC, which is a significant reduction in fast-charging performance.

[0131] Therefore, the fast-charging battery provided by the present invention improves the interfacial embedding environment and internal diffusion pathway of the negative electrode material by synergistically adjusting key parameters such as the average particle size of primary and secondary particles and the proportion of gap area of ​​the negative electrode active material as determined by scanning electron microscopy. This effectively reduces the transport resistance of lithium ions at the negative electrode interface and in the bulk phase, and well balances the dynamic performance and high-temperature storage performance of the fast-charging battery.

[0132] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A fast-charging battery, comprising a negative electrode sheet, said negative electrode sheet comprising a negative electrode active material, said negative electrode active material containing graphite, characterized in that, The charging time for the fast-charging battery from 10% SOC to 80% SOC is ≤15 min; The negative electrode active material includes secondary particles formed by the agglomeration of primary particles. The average particle size of the primary particles is set to d μm, and the average particle size of the secondary particles is set to D μm. The interstitial area ratio of the negative electrode active material is determined by scanning electron microscopy to be b. Then, the following condition is satisfied: 145≤(d×D) / b≤675.

2. The fast-charging battery according to claim 1, characterized in that, The OI value of the negative electrode active material is 4.2~9.

6.

3. The fast-charging battery according to claim 2, characterized in that, The OI value of the negative electrode active material is 4.4~8.

9.

4. The fast-charging battery according to claim 1, characterized in that, The average particle size d μm of the primary particles is 4.5~7.5 μm.

5. The fast-charging battery according to claim 4, characterized in that, The average particle size d μm of the primary particles is 5.2~7.0 μm.

6. The fast-charging battery according to claim 1, characterized in that, The average particle size D μm of the secondary particles is 9.0~13.5 μm.

7. The fast-charging battery according to claim 6, characterized in that, The average particle size D μm of the secondary particles is 9.2~13.0 μm.

8. The fast-charging battery according to claim 1, characterized in that, Scanning electron microscopy determined that the interstitial area ratio b of the negative electrode active material was 15%~28%.

9. The fast-charging battery according to claim 8, characterized in that, Scanning electron microscopy determined that the interstitial area ratio b of the negative electrode active material was 17%~25%.

10. The fast-charging battery according to claim 1, characterized in that, The charging time for the battery from 10% SOC to 80% SOC is ≤12 min.

11. The fast-charging battery according to claim 1, characterized in that, The sphericity of the primary particles is 0.68~0.

92.

12. The fast-charging battery according to claim 11, characterized in that, The major axis of the primary particles is 4.6~7.8 μm.

13. The fast-charging battery according to claim 11 or 12, characterized in that, The minor axis of the primary particles is 3.5~6.9 μm.

14. The fast-charging battery according to claim 1, characterized in that, The negative electrode active material also includes single particles discrete between primary and secondary particles.

15. The fast-charging battery according to claim 14, characterized in that, The volume percentage of the single particle in the negative electrode material is 10% to 40%.

16. The fast-charging battery according to claim 14, characterized in that, The secondary particles account for ≥60% of the volume of the negative electrode material.

17. The fast-charging battery according to claim 15 or 16, characterized in that, The total volume percentage of the single and secondary particles in the anode material is 75% to 99%.

18. The fast-charging battery according to claim 1, characterized in that, The negative electrode sheet also includes a current collector. The average particle size of the particles of the negative electrode active material near the current collector is set as M1, and the average particle size of the particles of the negative electrode active material away from the current collector is set as M2. Then, the following condition is satisfied: M1 > M2.

19. The fast-charging battery according to claim 1, characterized in that, The compaction density of the negative electrode sheet is 1.45~1.70 g / cm³. 3 .

20. The fast-charging battery according to claim 1, characterized in that, The pore volume of the negative electrode active material with a pore size of 0.5 μm or larger accounts for 10% to 25%.

21. The fast-charging battery according to claim 1, characterized in that, The fast-charging battery also includes a positive electrode sheet, which includes a positive electrode material containing lithium iron phosphate. The charging time of the fast-charging battery from 10% SOC to 80% SOC is 12-14 minutes.

22. The fast-charging battery according to claim 21, characterized in that, The fast-charging battery satisfies the following condition: 350≤(d×D) / b≤500.

23. The fast-charging battery according to claim 1, characterized in that, The fast-charging battery also includes a positive electrode sheet, which includes a positive electrode material containing a ternary material. The nickel content in the ternary material is 60 wt% to 80 wt%, and the charging time of the fast-charging battery from 10% SOC to 80% SOC is ≤13 min.

24. The fast-charging battery according to claim 23, characterized in that, The fast-charging battery satisfies the following condition: 240≤(d×D) / b≤400.

25. An electrical appliance, characterized in that, The electrical device includes a fast-charging battery as described in any one of claims 1 to 24.

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