809results about "Cobalt compounds" patented technology

In order to solve the problems that an existing positive electrode material is unstable in structure and low in energy density, the invention provides a positive electrode material and a preparation method thereof, a positive electrode plate and a battery, the positive electrode material comprises lithium cobalt oxide of a layered structure, the chemical formula of the lithium cobalt oxide is Li < 1-alpha-beta > Na < alpha > (Mg < gamma > Ti < delta > Co < 1-gamma-delta >) O2, alpha is smaller than or equal to 0.005, and beta is 0.02-0.05; gamma is equal to 0.002 to 0.004, delta is equal to 0.001 to 0.003, and gamma + delta is equal to 0.003 to 0.006.

To provide a positive electrode active material with high capacity and good cycle characteristics.SOLUTION: A positive electrode active material exhibits minimal change in crystal structure between the charged and discharged states. For example, a positive electrode active material that has a layered rock-salt crystal structure in the discharged state and a pseudo-spinel crystal structure in the charged state at a high voltage of about 4.6 V exhibits less change in crystal structure and volume between charge and discharge than known positive electrode active materials. When this pseudo-spinel crystal structure is present, diffraction peaks appear at 2θ=19.30±0.20° and 2θ=45.55±0.10° when analyzed by XRD.SELECTED DRAWING: Figure 1

The invention relates to the technical field of batteries, in particular to a composite positive electrode material, a preparation method thereof and a battery. The composite positive electrode material comprises a positive electrode substrate, a fast ion conductor layer and a halide layer, the positive electrode substrate comprises a doped lithium cobalt oxide material; the fast ion conductor layer is positioned on the surface of the positive electrode substrate and comprises an oxide of a metal element Q with a spinel phase; the halide layer is located on the surface of the fast ion conductor layer and comprises element lithium, metal element M and halogen X. Through coordination and cooperation of the matrix material, the fast ion conductor layer and the halide layer, the structural stability and the surface morphology of the material can be effectively improved, the defects of the material are overcome, and the composite positive electrode material has excellent conductivity and has excellent cycling stability and rate capability at high temperature and / or high voltage, so that the battery has high safety performance.

The invention relates to the technical field of lithium ion batteries, in particular to a high-voltage lithium cobalt oxide positive electrode material and a preparation method thereof. According to the technical scheme, the chemical composition of the positive electrode material is at least two elements selected from Al, Mg, Ti and Zr. Through triple strategies of multi-element synergistic doping, core-shell structure design and surface defect regulation and control, breakthrough improvement of the performance of the high-voltage lithium cobalt oxide positive electrode material is achieved, and especially through the synergistic effect of a specific element combination Al + Mg + Ti and the coupling effect of the gradient-distributed F element and the nanometer defect structure, the performance of the high-voltage lithium cobalt oxide positive electrode material is improved. The structure phase change and the interface side reaction in the high-pressure circulation process are effectively inhibited, and the cycle life and the thermal stability of the material are remarkably improved.

The invention discloses a method for regenerating and preparing high-voltage lithium cobalt oxide by using an invalid lithium cobalt oxide material, and belongs to the technical field of battery recovery. The method comprises the following steps: S1, carrying out ball milling and mixing on failed lithium cobalt oxide powder and a sodium source, and then carrying out solid-phase sintering to obtain a P2 type sodium cobalt oxide and lithium cobalt oxide material; s2, the P2 type sodium cobaltate and lithium cobaltate material is placed in a lithium-containing solution for a hydrothermal reaction, a regenerated O2-O3 cotype lithium cobaltate material is obtained, the regenerated O2-O3 cotype lithium cobaltate material has the advantages of being good in cycling stability, high in rate capability, high in low-temperature performance and the like under the high voltage of 4.6 V, and the performance of the regenerated O2-O3 cotype lithium cobaltate material is superior to that of a commercial lithium cobaltate material.

The invention provides a polycrystalline ultrahigh-nickel ternary positive electrode material and a preparation method thereof, a lithium ion battery and electric equipment, and relates to the field of lithium ion batteries. The polycrystalline ultrahigh-nickel ternary positive electrode material comprises an inner core, a first coating layer and a second coating layer, the chemical general formula of the inner core is LiNiXMyM 'ZO2; m comprises at least two of Co, Mn and Al, and M'comprises at least two of Zr, Sr, Y, Sb, Al, W, Ta, Mg, Ca, Ti, Mo and Nb; the first coating layer comprises a lithium-M ''multi-element oxidation compound, and M'' comprises at least two of Sb, Al, Co, Ti, W and P; the second cladding layer includes a lithium-M ''oxidation complex, and M'' includes one or more of B, Al, W, and Ti. The polycrystalline ultrahigh-nickel ternary positive electrode material has excellent high-temperature storage performance and capacity.

The invention provides a method for strengthening recovery of a waste lithium iron phosphate material by using waste lithium cobalt oxide as an oxidizing agent. The method comprises the following steps: discharging and disassembling waste lithium iron phosphate and lithium cobalt oxide batteries to obtain positive plates; dissolving aluminum foil in the positive plate in a sodium hydroxide alkaline leaching solution to obtain lithium iron phosphate and lithium cobalt oxide positive electrode powder; the method comprises the following steps: leaching lithium iron phosphate positive electrode powder by adopting a deep-eutectic solvent, and meanwhile, realizing an enhanced leaching process by taking lithium cobalt oxide positive electrode powder as an oxidizing agent; and carrying out coordination separation and photo-reduction separation on the completely leached solution to realize selective recovery of cobalt, iron, phosphorus and lithium. According to the method, the oxidation-reduction capacity of the material is fully utilized to strengthen the leaching process, efficient recovery of valuable elements in the waste positive electrode material is achieved, and additional addition of an oxidizing agent and a reducing agent is avoided. The method can achieve the purposes of synergistic enhanced leaching and selective separation of the waste lithium cobalt oxide material and the waste lithium iron phosphate material, and is low in cost, high in recovery rate and wide in industrial application prospect.

The invention discloses a regeneration method of a positive electrode active material, a regenerated positive electrode active material and a battery, and belongs to the technical field of regeneration of positive electrode active materials. The method comprises the following steps: mixing a positive electrode active material and a lithium salt, heating and preserving heat to obtain eutectic molten salt in a molten state, and inducing the eutectic molten salt to generate a cavitation effect. The molten lithium salt in the eutectic molten salt can supplement lithium ions lost by the positive electrode active material and repair and regenerate the positive electrode active material, the eutectic molten salt in the molten state is a carrier of the cavitation effect, the cavitation effect can further promote repair and regeneration of the positive electrode active material in the eutectic molten salt, and the two are combined to generate a synergistic effect; the regeneration of the retired lithium ion positive electrode active material is improved in situ in one step, so that the regenerated positive electrode active material with relatively high capacity retention ratio can be obtained, and the remanufacturing requirement of a vehicle-specification-grade power battery is met.

The invention belongs to the technical field of air power supplies, and relates to modification treatment of an oxide, in particular to a cerium oxide doped transition metal oxide and a preparation method thereof, an air cathode and an air power supply. The preparation method comprises the following steps: dissolving cerium salt, cobalt salt and manganese salt in water, uniformly mixing to obtain a mixed solution, adjusting the pH value of the mixed solution to 9-11, and carrying out a sedimentation reaction to obtain a sediment; and drying the precipitate, and calcining in an air atmosphere at 300 + / -10 DEG C for 2-4 hours to obtain the cerium oxide doped transition metal oxide. The cerium oxide doped transition metal oxide is cerium doped cobalt manganese oxide with a spinel structure, and the doping amount of cerium is 20 + / -1wt%. The cerium oxide doped transition metal oxide provided by the invention is applied to an air cathode as a catalyst, and has good stability and high catalytic activity. The performance of an air power supply containing the oxide is remarkably improved. The method for preparing the oxide provided by the invention is simple and easy to operate, and is suitable for large-scale production.

The invention relates to the field of negative electrode materials, in particular to a carbon nanotube enhanced negative electrode material and a preparation method thereof. The carbon nanotube enhanced negative electrode material comprises the following substances in parts by weight: an artificial graphite inner core, a carbon nanotube coating layer and an asphalt coating layer which are sequentially coated from inside to outside, and the carbon nanotube coating layer further comprises magnetic modified particles, the asphalt coating layer comprises the following substances in parts by weight: 25-35 parts of biochar particles; 65 to 70 parts of asphalt particles; and 0.1-0.5 part of a dispersant. According to the application, a continuous conductive network can be constructed through the carbon nanotube coating layer, the electron transmission efficiency is improved, and meanwhile, the asphalt coating layer is compounded through the biochar particles and the asphalt. The synergistic effect of the three-layer structure can repair the surface defects of the artificial graphite, reduce the side reaction of the electrolyte and inhibit the volume expansion in the charge-discharge process, so that the cycling stability and conductivity of the negative electrode material are comprehensively improved.

To provide a method for producing a positive electrode active material for a lithium secondary battery, the positive electrode active material being capable of imparting excellent high-temperature storage characteristics and reducing impedance, when used as a positive electrode active material of a lithium secondary battery.SOLUTION: A method for producing a positive electrode active material for a lithium secondary battery includes: a first mixing step of mixing a lithium compound, a cobalt compound and an aluminum compound and obtaining a first mixture; a first calcination step of calcining the first mixture and obtaining, as a first calcined product, aluminum-containing lithium cobalt composite oxide particles which are such that aluminum is present in a solid solution at least inside the particles; and a second mixing step of dry mixing the first calcined product obtained in the first calcination step and MgF2 and AlF3 which are inorganic fluoride particles and obtaining, as a second mixture, a positive electrode active material.SELECTED DRAWING: Figure 1

The invention belongs to the technical field of lithium ion batteries, and particularly discloses a composite coated high-voltage lithium cobalt oxide positive electrode material as well as a preparation method and application thereof. The positive electrode material comprises an inner core, and a first coating layer and a second coating layer which sequentially coat the inner core from inside to outside; the inner core is a doped lithium cobalt oxide matrix, the chemical formula is Li1 + xCo1-yM1yM2zO2, x is more than or equal to 0 and less than or equal to 0.1, y is more than or equal to 0.001 and less than or equal to 0.05, z is more than or equal to 0.001 and less than or equal to 0.05, M1 is selected from at least one of Al, Ni and Fe, and M2 is selected from at least one of Mg, Al, Zr, Zn, Ni, Fe, Sr, Mo, Ta and W; the chemical formula of the first coating layer is La1-mNmCoO3-n.Co3O4, m is greater than 0 and less than 1, n is greater than 0 and less than 3, and N is selected from one or two of Ca, Mg, Fe, Zn, Ba and Zr; and the second coating layer is cobalt oxide of YOF and Y. The core problems of bulk phase structure degradation, serious interface side reaction, interface impedance increase and the like under high voltage can be cooperatively solved.

The invention discloses an electromagnetic wave absorbing material CoFe2O4 / ZnO-RGO with a ternary heterostructure as well as a preparation method and application of the electromagnetic wave absorbing material CoFe2O4 / ZnO-RGO, and belongs to the technical field of electromagnetic wave absorption. According to the material, a novel heterostructure with a multi-scale interface and a three-dimensional conductive network is constructed by compounding magnetic loss type CoFe2O4, dielectric loss type ZnO nanorods and resistance loss type RGO. Wherein the ZnO nanorod not only serves as a dielectric loss body, but also effectively enhances the structural anisotropy and the interface polarization effect of the material, and cooperates with the magnetic loss of CoFe2O4 and the resistance loss of RGO to jointly optimize impedance matching and improve the electromagnetic attenuation capability, so that the material shows excellent wave-absorbing performance under various thickness and even ultrathin conditions. The material source is wide, the cost is low, the preparation process is green, simple and convenient, the material is suitable for large-scale production, and an effective material solution is provided for electromagnetic wave absorption application in the national defense and civil fields.

To provide a novel positive electrode active material, a positive electrode, and a lithium ion secondary battery.SOLUTION: A lithium ion secondary battery includes a positive electrode, a negative electrode, and an electrolyte. The positive electrode includes a positive electrode active material including a complex oxide containing lithium and cobalt. The positive electrode active material contains barium, magnesium, and aluminum in a surface layer part. In the analysis of the surface layer part, it is preferable to include a region where a first point at which the concentration of barium is the maximum and a second point at which the concentration of magnesium is the maximum exist on a surface side of the positive electrode active material relative to a third point at which the concentration of aluminum is the maximum.SELECTED DRAWING: Figure 3

The invention provides a lithium cobalt oxide composite material and a preparation method thereof, a positive plate and a lithium ion battery. The lithium cobalt oxide composite material comprises first lithium cobalt oxide composite particles and second lithium cobalt oxide composite particles; the first lithium cobalt oxide composite particles comprise first lithium cobalt oxide and a lithium-rich positive electrode material coating the surface of the first lithium cobalt oxide; the second lithium cobalt oxide composite particles comprise second lithium cobalt oxide and a lithium-rich positive electrode material coated on the surface of the second lithium cobalt oxide; the D50 particle size of the first lithium cobalt oxide composite particles is larger than that of the second lithium cobalt oxide composite particles. The lithium-rich positive electrode material is arranged on the surface of the lithium cobalt oxide material, so that the first coulombic efficiency, the specific discharge capacity and the energy density of the battery are improved; and the first lithium cobalt oxide composite particles and the second lithium cobalt oxide composite particles with different particle sizes are selected for grading, so that the first charge-discharge capacity and the cycling stability of the material are improved, and the requirements of a high-performance lithium ion battery using a silicon-carbon negative electrode are met.

The invention relates to the technical field of fuel cell new materials and new energy, in particular to an A-site high-entropy perovskite cathode material and a preparation method thereof. According to the technical scheme, the material comprises the following raw materials: Pr (NO3) 3.6 H2O, La (NO3) 3.6 H2O, Co (NO3) 2.6 H2O, CaCO3, BaCO3, SrCO3 and citric acid. The molar ratio of the praseodymium ions to the lanthanum ions to the cobalt ions to the calcium ions to the barium ions to the strontium ions to the citric acid is 1: (1-2). According to the invention, the A site of the perovskite material is doped with a plurality of elements, a rapid quenching preparation process is combined, the oxygen vacancy concentration and the proton conduction path can be optimized, the ORR activity and the conductivity can be improved, and excellent electrochemical performance and thermal stability can be shown through the synergistic effect of the plurality of elements and structural regulation and control, so that the performance of the cell can be improved.

The invention relates to an A-site high-entropy double perovskite anode material and a preparation method and application thereof. The chemical general formula of the anode material is (Ln < 1 > < 0.2 > Ln < 2 > < 0.2 > Ln < 3 > < 0.2 > Ln < 4 > < 0.2 > Ln < 5 > < 0.2 >) A 'B2O5 + delta (wherein delta is greater than or equal to 0 and less than or equal to 1). Wherein Ln1 to Ln5 are five different lanthanide rare earth elements and jointly occupy the A site, and the A site elements are any five of Sm, Pr, Nd, La, Gd, Eu, Er, Dy, Te, Yb, Y and Sc; the A'site is composed of any two elements of Ba, Sr and Ca; and the B site is Co. According to the invention, the double perovskite structure can be effectively stabilized, the number of catalytic active sites of an OER reaction is increased, the TEC of a cathode is effectively reduced, the electro-catalysis ORR reaction activity is increased, the performance of hydrogen production by electrolysis of water of a single cell is improved, and the output stability of the cell is effectively enhanced.

The invention belongs to the technical field of inorganic nano materials and electro-catalysis, and particularly relates to a cobalt-based spinel oxide nano material as well as a preparation method and application thereof. The cobalt-based spinel oxide nano material comprises a conductive substrate and cobalt-based spinel oxide grown on the surface of the conductive substrate, the molecular formula of the cobalt-based spinel oxide is MxCo1-xO4, and M is transition metal or P-region metal and is selected from one or more of titanium, vanadium, chromium, manganese, iron, nickel, aluminum, cerium and neodymium. Multiple metal elements are doped into a cobaltosic oxide lattice, and the intrinsic structure of spinel is not changed by metal doping. Multiple metal elements are highly uniformly dispersed in the material, so that active sites are comprehensively regulated and controlled, the material shows excellent thermodynamic and chemical stability under harsh conditions of high temperature, large current, concentrated alkali and the like, is suitable for various electrolysis modes, has no metal dissolution risk in long-term operation, can effectively avoid the problems of membrane poisoning and membrane degradation, and has good application prospects. Wide application prospects are shown.

The invention provides a positive electrode material and a preparation method thereof, a battery monomer, a battery device and a power utilization device. The positive electrode material comprises a sodium transition metal oxide and a silicate material located on the surface of the sodium transition metal oxide, the positive electrode material has the following chemical formula: NaxMyNzO2 / (aNa2O.nSiO2-XrOt.SiO2) b, M comprises one or more of Fe, In, Co, Mn, Ni and Cr, N comprises one or more of Cu, Li, Ti, Zr, K, Sb, Nb, Mg, Ca, Mo, Zn, W, Bi, Sr, Sn, Ga and Al, and X comprises one or more of Na, Li, K, Mg, Ca, Zn, Al, Cr, Sr, Sn and Sb; 0.58 < = x < = 1.05, 0 < y < = 1, 0 < = z < = 1, 0 < y + z < = 1, 1 / 3 < = r / t < = 2, 1 < = n / a, and 0 < b < = 0.2. The positive electrode material provided by the invention can improve the rate capability and the processability of the battery monomer.

The invention discloses a high-entropy sulfur selenide and preparation and application thereof, the high-entropy sulfur selenide is a Co9S8 compound doped with cations and anions, the doped cations are Fe, Ni, Mo and V, the doped anions are Se, each doped cation and anion are uniformly doped in Co9S8 crystal lattices, the molar ratio of Fe to Co to Ni to Mo to V is (8-11): 10: (8-11): (8-11): (8-11), and the molar ratio of S to Se is (5-15): 1. The invention provides application of the high-entropy sulfur selenide as a lithium ion battery negative electrode active material, and provides a lithium ion battery. According to the high-entropy sulfur selenide disclosed by the invention, the lithium ion battery can have excellent long cycle stability, high specific capacity and high-rate charge-discharge performance.

The invention discloses a high-entropy perovskite hydroxide, a preparation method thereof and application of the high-entropy perovskite hydroxide in electro-catalysis of nitrate to synthesize ammonia, and belongs to the technical field of high-entropy perovskite hydroxides. The high-entropy perovskite hydroxide is ASn (OH) 6, and A is one or more of Zn, Mn, Co, Ni and Cu. The high-entropy perovskite hydroxide electrocatalyst which is simple in synthesis method, stable in structure and easy in raw material obtaining is obtained, the electrocatalyst can be applied to electrocatalysis of nitrate to synthesize ammonia, the highest NH3 Faraday efficiency is 98.16%, and the yield is 5.12 mg h <-1 > mgcat <-1 >. And a foundation is laid for developing other high-entropy perovskite compounds as electrocatalysts for electrocatalytic synthesis of nitrate.

A positive electrode active material for secondary batteries includes a lithium metal composite oxide having a crystal structure that can be attributed to the space group Fm-3m. The lithium metal composite oxide contains at least Li, Mn, Ti, and M. The M is a positive element different from Li, Mn, and Ti. The crystallite size of the lithium metal composite oxide is in a range of 1 nm to 100 nm, or in an X-ray diffraction (XRD) profile using CuKα radiation of the lithium metal composite oxide, the half-value width of a diffraction peak attributed to the (200) plane is in a range of 0.1° to 1.8°, based on 2θ.

The invention relates to a manganese-directionally-doped CoS2 / MoS2 heterostructure composite material and preparation and application thereof.In the manganese-directionally-doped CoS2 / MoS2 heterostructure composite material, manganese ions are directionally doped on cobalt sites and are not uniformly distributed in a whole heterojunction system, so that the electronic conductivity of CoS2 and the utilization rate of active sites are improved; and meanwhile, the damage to the MoS2 lattice structure is avoided, so that the interface charge transmission capability and the cycling stability of the heterojunction are enhanced. In addition, the electrode material does not need to use a binder or a conductive agent, can be directly applied to various electrochemical energy storage devices such as supercapacitors and the like, and has a good application prospect.

The application relates to the technical field of chemical product preparation, in particular to a cobalt hydroxide preparation device and a preparation process thereof. The cobalt hydroxide preparation device comprises a reaction kettle provided with a manhole, the manhole is provided with a manhole cover, the manhole cover comprises a lower seat and a fixing assembly, a support is hinged to the lower seat, a connecting seat is arranged on the support, an upper cover is arranged on the connecting seat, the upper cover is used for controlling the opening and closing of the manhole, a sealing ring is arranged between the lower seat and the upper cover, the fixing assembly is used for fixing the lower seat and the upper cover, the upper cover can rotate around a second axis, the direction of the gravity of the connecting seat and the upper cover and the second axis are coplanar, when the manhole is opened through the upper cover, the lower end surface of the upper cover and the upper end surface of the lower seat are kept parallel in a short time, and then the damage of the sealing ring caused by uneven stress is avoided, the connecting seat can rotate around a first axis, the first axis and the second axis are perpendicular, the upper cover has the freedom of two rotating directions, and the damage of the sealing ring is reduced.

The invention belongs to the technical field of electrode materials, and particularly relates to a MnCo2O4 / ZnCo2O4 nano composite material as well as a preparation method and application thereof. The preparation method comprises the following steps: taking soluble manganese salt and soluble cobalt salt as raw materials, taking foamed nickel as a carrier, carrying out hydrothermal reaction in an alkaline environment to obtain MnCo-LDH / NF, then immersing the MnCo-LDH / NF in a precursor solution composed of the soluble cobalt salt, soluble zinc salt and 2-methylimidazole, carrying out coordination reaction to obtain MnCo-LDH ZIF-67 / ZIF-8, and finally carrying out heat treatment to obtain the MnCo2O4 / ZnCo2O4 nano composite material. In the MnCo2O4 / ZnCo2O4 nano composite material obtained by the method disclosed by the invention, MnCo2O4 with a nanorod structure and ZnCo2O4 with a dodecahedron structure form a heterojunction, so that the defect of poor conductivity of MnCo2O4 is overcome.

The application belongs to the technical field of inorganic nanometer material preparation, and particularly relates to a hollow manganese dioxide / cobalt manganate loaded nitrogen-doped carbon hybrid material and a preparation method thereof. The steps of the application are as follows: S1, dispersing manganese source material in N,N-dimethylformamide to form a uniform solution; S2, adding an organic ligand to the solution obtained in step S1 and continuously stirring to obtain a mixed solution, and then transferring the mixed solution to a reaction kettle for a solvothermal reaction; S3, sequentially washing and drying the product obtained through the solvothermal reaction, and then grinding the product and a cobalt salt to form a mixture powder; and S4, performing a high-temperature pyrolysis reaction on the mixture powder, and obtaining the hollow manganese dioxide / cobalt manganate loaded nitrogen-doped carbon hybrid material rich in mesopores and macropores after the reaction stops. The application has a large specific surface area and a multi-pore structure, slows down the migration and aggregation of metal particles and the loss of pyrolysis intermediates in the heat treatment process, and improves the electrochemical activity and stability of the transition metal / nitrogen-doped carbon electrocatalyst.

The invention provides a low-cost lithium cobalt oxide positive electrode material and a preparation method and application thereof.The preparation method comprises the steps that firstly, a cobalt source, a lithium source and a sodium source with Dv50 being 3-5 microns are subjected to dry mixing treatment, and a mixed material is obtained; secondly, the mixed material is subjected to high-temperature sintering treatment, and a sintered material is obtained; and finally, crushing and sieving the sintered material to obtain the low-cost lithium cobalt oxide positive electrode material with Dv50 of 16-21 [mu] m. According to the preparation method provided by the invention, a traditional large-particle cobalt source is replaced with a small-particle cobalt source, a sodium source is introduced as a functional additive, and a simple process of'dry mixing-high-temperature sintering-crushing and sieving 'is matched, so that the use amount of a lithium source does not need to be additionally increased in the preparation process, and the sintering temperature does not need to be increased; the cost is controlled in the whole process from raw material selection to process execution, so that the precursor purchase cost, the additional consumption cost of the lithium source and the high-temperature sintering energy consumption expenditure are remarkably reduced, and the multi-dimensional cost advantage is formed.

The application discloses a kind of composite coated lithium transition metal oxide materials and preparation method and application thereof, belong to battery material technical field.The composite coated lithium transition metal oxide material includes lithium transition metal oxide material and the composite of coating on the surface of lithium transition metal oxide material;The chemical formula of lithium transition metal oxide material is Li a M 1‑b M′ b O2, the chemical formula of composite is ABC3;When B and M have same element, the chemical state of same element in composite is different from the chemical state in lithium transition metal oxide material.The composite coated lithium transition metal oxide material has lower impedance, better ion conduction, lower gas production, better cycle performance and safety performance at high voltage, which is beneficial to improve the electrochemical performance of lithium ion battery.

To provide a cathode active material with a large charge / discharge capacity, or to provide a cathode active material with a high charge / discharge voltage, or to provide a secondary battery with little deterioration, or to provide a highly safe power storage device, or to provide a novel secondary battery.SOLUTION: A cathode active material containing cobalt, oxygen, and fluorine, with cobalt-fluorine bonds at the surface or near grain boundaries. The fluorine bonds cause at least some of the cobalt to become high-spin (paramagnetic) Co2+. Therefore, in ESR analysis, the spin concentration at 113K is greater than the spin concentration at 300K by 1.1×10-5 spins / g or more.SELECTED DRAWING: Figure 1

The invention discloses a low-temperature solid-phase synthesis cobalt blue pigment preparation method, which comprises: (1) placing a cobalt source, an aluminum source and an inert template dispersant in a planetary ball mill, carrying out ball milling, and drying to obtain nanometer composite precursor powder; (2) adding a mixture of a lithium source and a boron source into the nano composite precursor obtained in the step (1), putting the mixture into a mortar, and mechanically mixing to obtain a mixed material; and (3) putting the mixed material obtained in the step (2) into a muffle furnace, melting and calcining, cooling to room temperature along with the furnace, grinding, washing with hot water, and drying to obtain cobalt blue pigment powder. According to the method, the synthesis temperature is low, particle coarsening and sintering caused by high temperature are avoided, the energy consumption is low, the process is green, and the obtained cobalt blue pigment is pure in chromaticity, large in specific surface area and excellent in thermal stability.