6937results about "Nickel compounds" patented technology

The invention provides an in-situ modified lithium-rich manganese-based precursor and a preparation method and application thereof.The preparation method comprises the following steps that a nickel-cobalt-manganese mixed metal salt solution, a precipitator solution and a complexing agent solution are introduced into a base solution for a first coprecipitation reaction, and after the first coprecipitation reaction is finished, feeding is stopped; and introducing a doped nickel-cobalt-manganese mixed metal salt solution, a precipitant solution, a complexing agent solution and a carbon source solution into a system after the first coprecipitation reaction is finished, and carrying out a second coprecipitation reaction to obtain the in-situ modified lithium-rich manganese-based precursor. According to the preparation method, doping elements and a carbon source are introduced when the lithium-rich manganese-based precursor is prepared through the coprecipitation reaction, in-situ uniform construction of oxygen vacancies and a carbon coating layer on the surface of the material is synchronously achieved, the in-situ modified lithium-rich manganese-based precursor is obtained, the treatment step of subsequent secondary coating can be reduced, the production cost can be reduced, and the method is suitable for industrial production. The technological process is shortened.

The invention belongs to the technical field of energy storage materials, and particularly relates to a high-entropy oxide Fe0. 2Co0. 2Ni0. 2Cu0. 2Zn0. 2O and an ultrafast synthesis method and application thereof. According to the preparation method, ferroferric oxide, cobalt oxide, nickel oxide, copper oxide and zinc oxide with equal molar ratio are adopted as direct synthesis raw materials, toxic gases such as chlorine and nitrogen dioxide generated in the synthesis process of a metal salt precursor are avoided, and the uniformly distributed single-phase high-entropy oxide is synthesized in an ultrafast manner within 10 seconds by using a Joule heating technology; the synthesized high-entropy oxide is used as a lithium ion battery negative electrode material, and shows more excellent electrochemical performance and cycling stability compared with other high-entropy oxides prepared from transition metals with different proportions; in the preparation process, extra additives are not needed, operation is easy, the synthesis speed is high, the yield is high, element distribution is uniform, and the method has the advantages of being low in cost, high in efficiency and free of pollution and has the industrialization prospect.

The invention provides a ternary precursor and a preparation method thereof, a positive electrode material and a preparation process thereof, and a battery. The ternary precursor comprises an inner core, and a transition layer and a shell which are sequentially coated outside the inner core, the nickel content of the inner core is gt; the nickel content of the transition layer is gt; and the nickel content of the shell. The inner core in the ternary precursor has the highest nickel content, so that the capacity of the positive electrode material prepared from the ternary precursor is ensured; the nickel contents of the inner core, the transition layer and the shell are changed in a gradient manner, so that the thermal stability of the ternary precursor is improved; the shell reduces the interface side reaction between the positive electrode material prepared from the ternary precursor and an electrolyte; the transition layer can be used as a buffer layer between the inner core and the shell, so that the ternary precursor and the structural stability are improved. Therefore, the battery containing the positive electrode material prepared from the ternary precursor has excellent capacity and cycling stability at normal temperature and high temperature.

The invention provides a coated modified high-nickel ternary positive electrode material, a preparation method and a lithium ion battery, the coated modified high-nickel ternary positive electrode material comprises a high-nickel ternary matrix and a coating layer containing an oxide solid electrolyte, the coating layer is coated outside the high-nickel ternary matrix and accounts for 1%-3% of the mass of the high-nickel ternary matrix; the oxide solid electrolyte comprises Li < 3x > La < 2 / 3-x > TiO < 3 > (0 lt; x < = 0.16), Li < 7 > La < 3 > Zr < 2 > O < 12 >, Li < 1 + y > Al < y > Ti < 2-y > (PO < 4 >) < 3 > (0 lt; y < = 0.5); the ionic conductivity of the oxide solid electrolyte is greater than or equal to 1 * 10 <-4 > S / cm. The selected oxide solid electrolyte has high ionic conductivity and electronic insulativity, a rapid lithium ion transmission channel can be provided, interface side reaction can be inhibited, the rate capability and the cycling stability of the material can be remarkably improved, and when the oxide solid electrolyte forms a coating layer, the coating layer is not prone to deformation, and the service life of the material is prolonged. The interface bonding strength with a high-nickel ternary matrix can be improved through chemical bonding, the interface impedance can be remarkably reduced, and the dynamic performance of the material is improved.

The invention discloses a nickel-containing etching wastewater treatment process, which belongs to the technical field of environmental protection, and comprises a raw water regulating tank, a pH pre-regulating tank, a heterogeneous catalytic oxidation tower, a neutralization coagulation tank, an inclined tube sedimentation tank and a clean water tank which are connected in sequence. According to the process, under the neutral condition, a catalyst loaded with cobalt manganese oxide is used for activating sodium hydrogen persulfate, high-activity sulfate free radicals are generated, a Ni-EDTA complex structure is fractured in a targeted mode, free nickel ions are released in situ, organic ligands are synchronously mineralized, and the adding amount of sodium hydrogen persulfate is dynamically adjusted through a clean water pool closed-loop control system; and high-purity nickel hydroxide precipitate is generated through alkaline precipitation and coagulation, so that efficient solid-liquid separation is realized. The treatment process disclosed by the invention is compact in flow and stable in operation, effectively solves the problems of difficult complex breaking, low nickel removal efficiency, high sludge toxicity, difficult resource recovery and the like when the EDTA complex nickel wastewater is treated by a traditional method, realizes closed-loop recovery of nickel resources, and has the remarkable advantages of low cost, high efficiency and environmental friendliness.

The invention provides a high-stability lithium-rich manganese-based positive electrode material and a preparation method thereof, and relates to the technical field of lithium-rich manganese-based positive electrode materials, and the method comprises three steps of preparation of a homogeneous precursor, solid-state mechanical fusion doping and coating, and high-temperature sintering; a lithium-rich manganese-based precursor is prepared by adopting a homogeneous coprecipitation process, uniform distribution of metal ions is ensured, then an aluminum source, a zirconium source and a fluorine source are introduced as doping agents, phosphate and a titanate coating agent are combined, doping and coating integrated treatment is realized through mechanical ball milling, and the lithium-rich manganese-based composite material is obtained. And finally, mixing with a lithium source in an argon atmosphere, and carrying out high-temperature sintering of temperature programming and staged heat preservation to form a stable composite coating layer in situ. Therefore, manganese ion migration is effectively inhibited through lattice doping, a layered structure is prevented from being converted into spinel or rock salt phase, meanwhile, a nanoscale ion / electron transmission channel is constructed, interface impedance is reduced, and the charging and discharging efficiency under high voltage is improved.

A modified nickel-based positive electrode material comprises a nickel-based positive electrode material matrix and a doping element doped in the nickel-based positive electrode material matrix, the electronegativity of the doping element is higher than that of lithium and transition metal elements in the nickel-based positive electrode material matrix, and the porosity of the material is 10%-20%. The preparation method comprises the following steps: mixing and sintering a positive electrode material precursor, a lithium source and a doping agent to obtain a sintered product; washing and drying the sintered product to obtain a washed product; and mixing the washed product with a coating agent, and sintering to obtain the modified nickel-based positive electrode material. The invention also discloses a lithium ion battery. In the modified nickel-based positive electrode material, a part of doped elements enter a lattice body of a nickel-based positive electrode material matrix, the electronegativity of the doped elements is larger than that of lithium and transition metal elements, the doped elements have higher covalence, higher bond strength and higher oxidation potential, lattice oxygen in the structure is stabilized, precipitation of the lattice oxygen is reduced, and therefore the structural stability of the material is improved.

The invention relates to the technical field of batteries, and discloses a preparation method of a lithium nickel manganese oxide positive electrode active material, a battery monomer, a battery device and a power utilization device. The battery monomer comprises a positive pole piece, the positive pole piece comprises a positive pole film layer, the positive pole film layer comprises a lithium nickel manganese oxide positive pole active material, in an XRD diffraction pattern of the lithium nickel manganese oxide positive pole active material, the full width at half maximum of a characteristic diffraction peak of a (111) crystal face is 0.1-0.2 degree, the full width at half maximum of a characteristic diffraction peak of a (311) crystal face is 0.1-0.2 degree, and the full width at half maximum of a characteristic diffraction peak of a (311) crystal face is 0.1-0.2 degree. And (400) the full width at half maximum of the characteristic diffraction peak of the crystal face is 0.1-0.2 degree. According to the battery monomer provided by the embodiment of the invention, lattice defects of the positive electrode active material are few, capacity fading can be delayed in the cycle process, and the cycle performance of the lithium ion battery can be remarkably improved.

The present invention relates to a positive electrode material including a plurality of single particle-based positive electrode active material particles, wherein the single particle-based positive electrode active material particle includes 1 to 30 primary particles, the product of an arithmetic mean value of the circularities of the primary particles and an arithmetic mean value of the convexities of the primary particles, which are measured from the segmentation image partitioned for each primary particle unit obtained by image-processing a scanning electron microscope (SEM) image of the positive electrode material, is at least 0.60, the circularity is defined by Equation 1 below, the convexity is defined by Equation 2 below, and the single particle-based positive electrode active material includes a lithium nickel-based oxide having a composition represented by Formula 1 below: Circularity=4πA / P2 wherein, in Equation 1 above, A is the area of each primary particle measured from the segmentation image, and P is the circumference of each primary particle measured from the segmentation image, Convexity=Pc / Pr wherein, in Equation 2 above, Pr is the actual circumference of each primary particle measured from the segmentation image, and Pc is the circumference of a virtual figure obtained by connecting the outermost points of each primary particle measured from the segmentation image, and         [Formula 1]     Lia[NixCoyM1zM21-x-y-z]O2 wherein, in Formula 1 above, M1 includes Mn, Al, or a combination thereof, M2 includes at least one selected from the group consisting of B, Ba, Ce, Cr, F, Mg, Al, V, Ti, Fe, Zr, Zn, Si, Y, Nb, Ga, Sn, Mo, W, P, and Sr, 1.0≤a≤1.3, 0.5≤x<1.0, 0<y<0.5, and 0<z<0.5.

A ternary polycrystalline positive electrode material is a secondary ball formed by agglomerating primary particles, the secondary ball is equally divided into four parts in the direction from the center to the surface of the secondary ball, the four parts are an inner core layer, a first middle layer, a second middle layer and a shell layer, and the section of the ternary polycrystalline positive electrode material is observed through a scanning electron microscope. The porosity is sequentially reduced from inside to outside. The preparation method comprises the following steps: mixing a positive electrode material precursor, a lithium source and a Li-containing polyanion compound, and sintering at a high temperature to obtain a primary sintered matrix; and washing and drying the primary sintering substrate, mixing the primary sintering substrate with a coating agent, and sintering to obtain the ternary polycrystalline positive electrode material. The invention also discloses a lithium ion battery. The porosity of the section of the positive electrode material is sequentially reduced from inside to outside, so that the positive electrode material can be in more sufficient contact with an electrolyte, more diffusion paths are formed, the transmission obstruction of lithium ions is reduced, and the transmission rate of the lithium ions is effectively improved, so that the discharge performance of the positive electrode material is improved, and the cycle performance of the material is improved.

A method of synthesis of single crystal nickel-rich cathode materials can include preparing a precursor solution by dissolving lithium nitrate, nickel nitrate, manganese nitrate, and cobalt nitrate in water, aerosolizing the solution of a) in a stream of air using an ultrasonic sprayer, preheating the resulting droplets, premixing the droplets with methane, decomposing the droplets by passing through a co-flow burner, depositing solid particles on a filter, and calcinating the solid particles in a furnace in oxygen to produce a single crystal cathode material.

The present invention relates to a positive electrode material comprising a plurality of single-particle-based positive electrode active material particles, each of which includes 1 to 30 primary particles, wherein the arithmetic average value of tortuosity of the primary particles as measured from a segmentation image divided for each primary particle unit, obtained by image processing of a scanning electron microscope (SEM) image of the positive electrode material, is 0.92 or greater, and the tortuosity is a value defined by equation (1). Equation (1): Tortuosity =Pc / Pr, where Pr is the real length of the perimeter of each primary particle measured in the segmentation image, and Pc is the length of the perimeter of a conceptual figure obtained by connecting outermost points of each primary particle measured in the segmentation image.

The invention discloses a carbon-loaded high-entropy oxide and a preparation method thereof, the carbon-loaded high-entropy oxide is of a core-shell structure formed by coating carbon with a high-entropy oxide, and the high-entropy oxide comprises at least five metal elements of chromium, manganese, iron, cobalt, nickel and copper. The carbon-loaded high-entropy oxide has the advantages of low density, high dielectric loss and excellent wave-absorbing performance, and is expected to be widely applied to electromagnetic absorption and elimination in the fields of electronics, communication civil affairs and aerospace military.

The invention discloses a high-stability layered oxide sodium-ion battery positive electrode material and a preparation method thereof.The high-stability layered oxide sodium-ion battery positive electrode material comprises a layered oxide matrix and a surface coating layer, a sodium source, a nickel source, a manganese source, a lithium source and a magnesium source are mixed according to the stoichiometric ratio, a pre-sintered product is heated to 850-950 DEG C at the speed of 0.5-2 DEG C / min to be calcined, and the high-stability layered oxide sodium-ion battery positive electrode material is obtained. The calcined product, lithium phosphate and aluminum nitrate are subjected to ball milling and mixing in a citric acid solution with the pH value of 3-5 according to the mass ratio of 1: (0.005-0.03): (0.002-0.02), and the capacity retention ratio of the battery is larger than or equal to 88% after 500 times of circulation under the voltage range of 2.0-4.0 V and the multiplying power of 0.5 C. The comprehensive protection from the bulk phase to the interface is realized by triple doping and gradient coating, and the cycle life is prolonged by two times. Interlayer spacing expansion and coating layer ion conduction cooperate to reduce polarization, and the applicable temperature range is widened to-30 DEG C to 60 DEG C. Seed crystal induction and segmented sintering ensure batch consistency, and the method is suitable for large-scale production. Cheap Fe / Mn is adopted to replace part of Ni, and the material cost is reduced by 40% compared with similar products.

A layered oxide positive electrode material and a preparation method therefor, a positive electrode composition, a sodium-ion secondary battery and the use. The layered oxide positive electrode material has the following general formula: NaaNibCucMndTieMfOg, wherein M is a doping element, a=0.75-0.95, b=0.33-0.45, c=0.03-0.15, d=0.20-0.45, e=0.05-0.20, f=0-0.1, and g=1.80-2.20. In an XRD pattern of the layered oxide positive electrode material, the peak intensity ratio I(101) / I(003)=0.02-0.15, the peak intensity ratio I(101) / I(012)=0.35-0.47, and the peak intensity ratio I(101) / I(006)=0.08-0.57.

The invention discloses a P2-phase sodium ion positive electrode material with a superlattice ordered structure and a preparation method of the P2-phase sodium ion positive electrode material. The chemical formula of the P2-phase sodium ion positive electrode material is Na < x > M < 1-a-b > A B O < 2 >, wherein M is a transition metal element Mn or / and Ni; a doping sites are transition metal vacancies, and / or doped metal elements Mg and / or doped metal elements Li; the doping site of B is doped with a transition metal element Fe or doped with a transition metal element Cu or doped with a transition metal element Zn; 0.8 < = x < = 0.9, 0.25 < = a, 0.04 < = b < = 0.09. According to the P2 type material with the superlattice ordered structure, the layered structure stability and the sodium ion transmission efficiency of the material can be remarkably improved, so that the problems of poor structure stability and low ion diffusion rate of a traditional sodium ion positive electrode material are effectively solved; the P2 type material with the superlattice ordered structure can be suitable for preparing a sodium ion battery system with high energy density.

The invention relates to the technical field of lithium ion batteries, in particular to a composite lithium-rich manganese-based positive electrode material and a preparation method and application thereof. The composite lithium-rich manganese-based positive electrode material is of a three-layer structure and sequentially comprises a lithium-rich manganese-based oxide positive electrode material matrix, a first coating layer and a second coating layer from inside to outside, the first coating layer is a mixture of halide solid electrolyte and lithium-containing oxide; and the second coating layer is an oxide solid electrolyte. The conductivity of a contact interface with a positive electrode material can be improved, the resistance is reduced, the moisture absorption degradation of halide is inhibited, the packaging difficulty is reduced, and the cycle performance of the halide-added solid electrolyte after moisture absorption is improved.

The invention relates to a lightweight porous nickel ferrite composite electromagnetic absorbing material and a preparation method thereof, and belongs to the field of electromagnetic wave absorbing materials, and the lightweight porous nickel ferrite composite electromagnetic absorbing material is a porous electromagnetic absorbing material prepared by high-temperature annealing of a mixture containing ferric salt, nickel salt, an acetic acid solution and chitosan. The lightweight and porous nickel ferrite composite electromagnetic absorbing material has both lightweight and electromagnetic absorbing properties.

The invention belongs to the technical field of lithium batteries, and particularly relates to a lithium-rich manganese-based positive electrode material and a preparation method and application thereof. The preparation method comprises the following steps: mixing a metal salt solution, a precipitator and a complexing agent, and carrying out coprecipitation reaction on an obtained coprecipitation reaction precursor solution to obtain a lithium-rich manganese-based precursor; the metal salt solution comprises a manganese element, a cobalt element and a nickel element; and mixing the lithium-rich manganese-based precursor, a lithium source, an auxiliary agent and a dispersing agent, and calcining to obtain the lithium-rich manganese-based positive electrode material, the auxiliary agent comprises a nitrogen source or a nitrogen source and a carbon source. The first discharge specific capacity, the rate capability and the cycling stability of the lithium-rich manganese-based positive electrode material can be improved, and the problems of capacity fading, discharge voltage drop and dynamic delay in an electrochemical reaction process are solved.

Improved electrocatalysts for promoting a hydrogen evolution reaction (HER) or an oxygen evolution reaction (OER) from alkaline fresh water and seawater are disclosed. By incorporating metals, such as tungsten and rare earth elements, into the nickel molybdenum nitride framework, Ni1-xMoxN, the disclosed electrocatalysts demonstrate improved catalytic activity and stability compared to the original Ni&Ni0.2Mo0.8N catalysts, particularly under high-current alkaline conditions, in water electrolysis for hydrogen and oxygen production.

The invention provides a lithium-rich manganese-based positive electrode material, a preparation method thereof and a lithium ion battery, and relates to the field of lithium ion batteries. Comprising a base body, a first coating layer and a second coating layer, the chemical general formula of the matrix is LiaNixCoyMnzMwO (1 + a-b) Rb, M comprises one or more of Al, Mg, Mn, Zr, Ti, W, Nb, Ta, Te, Na, La and Sr, R comprises one or more of Cl, N and S, 1.2 < = a < = 1.4, 0 < = b < = 0.1, 0.25 < = x < = 0.4, 0 < = y < = 0.1, 0.6 < = z < = 0.75, 01t, and 0 < = y < = 0.1. W < = 0.02, and x + y + z + w = 1; the first coating layer comprises spinel phase and / or spinel-like phase lithium manganese oxide; the second coating layer includes a Y-containing compound. And the cycling stability and the ionic conductivity of the lithium-rich manganese-based positive electrode material can be effectively improved.

The present invention provides a cathode material, a preparation method thereof and an application. The chemical formula of the cathode material is xLi2MnO3·(1−x−y)LiNi a T M(1‑a) O2·yLiMn b A (1‑b) PO4, wherein 0 < x < 1, 0 < y < 1, 0 ≤ a ≤ 1, 0.5 ≤ b ≤ 1, T M and A each independently include a metal element; the cathode material can form a continuous phase transition, has a supercrystalline domain structure and a stable layered structure, can stabilize lattice oxygen, reduce voltage drop, and thus can significantly improve the cycling performance of the battery at high voltages.

The present invention relates to a cathode material comprising a plurality of discrete-particle-based cathode active material particles. Each of the discrete-particle-based cathode active material particles comprises 1 to 30 primary particles, the ratio of the arithmetic average value of the circularities of the primary particles to the average aspect ratio of the primary particles, which is measured from a segmentation image segmented by primary particle unit and obtained through processing of a scanning electron microscope (SEM) image of the cathode active material, is 0.45 or more, the circularity is defined by the relation 1, and the discrete-particle-based cathode active material comprises a lithium nickel-based oxide having the composition represented by [chemical formula 1]. [Relation 1] Circularity = 4πA / P2 In relation 1, A is the area of each primary particle measured in the segmentation image, and P is the circumferential length of each primary particle measured in the segmentation image. [Chemical formula 1] Lia[NixCoyM1zM21-x-y-z]O2 In chemical formula 1, M1 includes Mn, Al or a combination thereof, M2 includes at least one selected from the group consisting of B, Ba, Ce, Cr, F, Mg, Al, V, Ti, Fe, Zr, Zn, Si, Y, Nb, Ga, Sn, Mo, W, P and Sr, 1,0≤a≤1.3, 0.5≤x<1.0, 0<y<0.5 and 0<z<0.5.

The invention discloses a manganese-rich precursor, a positive electrode material and a preparation method of the positive electrode material, and relates to the technical field of lithium ion batteries. The invention provides the manganese-rich precursor which does not need to add a complexing agent and is provided with the seed crystal layer and the shell layer, the manganese-rich precursor prepared by the method is low in production cost, safe, environment-friendly and high in sphericity degree, and can effectively improve the distribution uniformity of lithium ions and reduce the residual lithium amount in the charging and discharging process of a sintered positive electrode material; meanwhile, the material is not easy to break during rolling and charge-discharge cycles, the structural integrity of the particles is improved, the particle breaking condition is reduced, and the material cycle performance is improved.

Clean version of Abstract A catalyst and anode for hydrogen production by electrolysis as well as a preparation method, activation method and use thereof are provided. The anode for hydrogen production by electrolysis includes a catalyst which is nickel iron barium hydrotalcite with a nano hexagonal sheet structure and a thickness of 100-200 nm. The catalyst can be prepared by a one-step solvothermal reaction method. Alkaline-earth metal ions are evenly doped in the nickel iron barium hydrotalcite and are in atomic level dispersion, so that the anode for hydrogen production by electrolysis based on the catalyst, when being applied to a process for hydrogen production by electrolysis of an aqueous solution containing chlorine ions, not only can maintain good catalytic performance, but also has greatly improved chlorine ion corrosion resistance, leading to significant improvement of working stability and service life.

The invention discloses a preparation method of a composite lithium-rich and lithium-supplement additive, which comprises the following steps: taking lithium ferrite as a core, preparing NiO (at) lithium salt by adopting an ALD atomic deposition method, fully and uniformly mixing carbon-coated lithium ferrite and the NiO (at) lithium salt, and sintering to prepare the composite lithium-rich and lithium-supplement additive. According to the invention, the advantages of high lithium supplement capacity of lithium ferrite, less gas production of lithium nickelate and good environmental adaptability are fully exerted, and the lithium supplement agent with high capacity and good stability is obtained; the nanometer nickel protoxide is in full contact with a lithium salt coating layer prepared by an ALD method, subsequent sintering is facilitated, preparation can be performed at a lower temperature, cost reduction is facilitated, meanwhile, the nickel protoxide and the peripheral lithium salt coating layer are subjected to a solid solution reaction, and residual lithium on the surface of lithium ferrite of a nuclear body can be obtained. The'two-channel lithium acquisition mode 'can reduce the overall residual alkali amount of the material, and is beneficial to improving the processing performance of subsequent battery slurry.

The invention provides a positive electrode active material and a preparation method thereof, a positive electrode and a solid-state battery, and particularly relates to the technical field of solid-state batteries. The positive electrode active material has a core-shell structure, and the core-shell structure comprises a core layer and a coating layer coating the core layer; the core layer is made of a lithium-rich manganese-based material; and the coating layer is made of a fast ion conductor and a halide solid electrolyte. The fast ion conductor in the coating layer of the positive electrode active material can improve the ionic conductivity of the surface layer of the positive electrode active material, promote rapid migration of lithium ions and assist in improving the initial coulombic efficiency. Meanwhile, the coating layer improves the chemical stability of the positive electrode active material, effectively inhibits the interface side reaction between the positive electrode body and the sulfide electrolyte, and relieves the structural degradation in the cycle process. The coating layer can also be used as a buffer layer to inhibit stress generated by volume shrinkage and expansion in charge and discharge cycles, maintain good contact of an electrode interface, and realize improvement of the electrochemical performance of the material.

The invention discloses an alkaline electrolyzed water diaphragm based on nickel oxyhydroxide and a preparation method and application of the alkaline electrolyzed water diaphragm, and relates to the technical field of composite diaphragms.The alkaline electrolyzed water diaphragm is prepared through a phase inversion method, and nanometer nickel oxyhydroxide NiOOH particles are selected as inorganic nanometer filler; the mass percent of the nickel oxyhydroxide in the membrane casting solution is 15-30%. A strong chemical bond formed by nickel ions and hydroxyl in the hydroxyl nickel oxide crystal endows the material with excellent structural stability, and the material shows excellent solubility resistance, hydrolysis resistance and structural collapse resistance in a strong alkaline electrolysis environment and can tolerate high-concentration OH <-> erosion for a long time; meanwhile, the intrinsic high-oxidation-resistance characteristic is achieved.

The present invention relates to the field of lithium-ion batteries, and more specifically, to a positive electrode material, a preparation method thereof, a positive electrode, and a battery. The present invention provides a positive electrode material comprising a lithium-rich core and a conductive layer coated on the surface of the lithium-rich core; at least one of the core and the conductive layer is doped with at least one of the elements P and B. The positive electrode material provided by the present invention, having a conductive layer doped with at least one of the elements P and B, can stabilize the material structure and improve the material's rate capability and cycling stability.

The present invention provides a single-crystal lithium-rich manganese-based positive electrode precursor and its preparation method and application. The single-crystal lithium-rich manganese-based positive electrode precursor comprises secondary particles formed by primary particles and satisfies the following relationship: 1.2μm≤D50≤1.8μm, 0.5μm≤D R <6.0μm, 0.5g / cm 3 ≤α≤0.8g / cm 3 , 30m 2 / g≤β≤50m 2 / g, 22≤α·β≤28, 20nm≤N≤45nm, 5≤M / N≤10, wherein D50 is the median particle size of the secondary particles, D R is the particle size of the secondary particles, α is the tap density of the secondary particles, β is the specific surface area of ​​the secondary particles, N is the average thickness of the primary particles, and M is the average length of the primary particles. The median particle size of the secondary particles of the single-crystal-like lithium-rich manganese-based positive electrode precursor provided by the present invention is no more than 1.8 μm, which is significantly lower than the reported particle size of (quasi) single-crystal lithium-rich positive electrode precursors. The precursor can be made into a submicron-level single-crystal-like lithium-rich manganese-based positive electrode material with excellent dispersibility.