45results about How to "Reduce surface residual alkali" patented technology

The invention relates to the technical field of lithium ion batteries. In order to solve the problems of poor compatibility and poor cycle performance, rate performance, processability, and safety ofexisting high nickel ternary materials and electrolytes, the invention provides a high nickel ternary positive electrode material applied to a lithium secondary battery and a preparation method thereof. The high nickel ternary positive electrode material applied to the lithium secondary battery comprises a base material and a composite coating layer outside the base material. The chemical formulaof the base material is Li1.02Ni1-x-yCoxMnyMZO2. M is selected from the group consisting of Al, Mg, Ti, and Si. (1-x-y), x, y, and z are the molar ratios of Ni, Co, Mn, and M respectively. (1-x-y) isgreater than or equal to 0.6 and less than 1. x is greater than 0 and less than 0.4. y is greater than 0 and less than 0.4. z is greater than 0 and less than or equal to 0.02. According to the invention, the high nickel ternary positive electrode material applied to the lithium secondary battery has the advantages of low surface alkalinity, good processability, excellent electrochemical performance, high safety, and good compatibility with electrolytes; and the battery made of the material has the advantages of significantly improved cycle life and excellent electrochemical performance.

The invention relates to the technical field of lithium ion batteries, and discloses a positive electrode material, a preparation method thereof and a lithium ion battery. The positive electrode material comprises a high-nickel cobalt-free multi-element positive electrode material intermediate and a cobalt-containing compound coating the outer surface of the high-nickel cobalt-free multi-element positive electrode material intermediate, and the total mole number of nickel and manganese in the high-nickel cobalt-free multi-element positive electrode material intermediate is taken as a reference, the content of the cobalt-containing compound in terms of cobalt element is 0.5-5 mol%. The positive electrode material is stable in structure, high in energy density, good in rate capability, high in capacity retention ratio, simple in preparation method and low in cost.

The invention relates to a lithium cobaltate-coated high-nickel ternary positive electrode material and a preparation method thereof. The preparation method comprises the following steps of: mixing a high-nickel ternary precursor, nano cobaltosic oxide, and a lithium source, and calcining the mixture at 750-820 degrees centigrade to obtain the lithium cobaltate-coated high-nickel ternary positive electrode material, wherein the mass ratio of the nano cobaltosic oxide to the high-nickel ternary precursor is 0.05 to 0.2:1. The surface of the high-nickel ternary positive electrode material is uniformly coated with a layer of lithium cobaltate material, thereby protecting the reticular structure of the high-nickel ternary positive electrode material, reducing the nickel-lithium ion mixing, improving the electronic conduction, the cycle performance and the rate performance of the material, additionally avoiding direct contact between the surface of high-nickel ternary positive electrode material and the air, reducing the water absorption of the material and the formation of surface lithium hydroxide and lithium carbonate, reducing residual alkali on the surface of the material, and optimizing the processing properties of the material.

The invention provides a preparation method of a ternary cathode material precursor. The preparation method comprises the following steps: (1) co-precipitation: using pure water to prepare a mixed metal ion solution of soluble nickel salts, manganese salts, and cobalt salts, mixing the mixed metal ion solution with an alkali metal hydroxide solution and an ammonium salt solution; after precipitation, separating solids and liquid, and blowing the solids to obtain a first nickel-manganese-cobalt hydroxide material; and (2) primary drying: drying the first nickel-manganese-cobalt hydroxide material obtained in the step (1) in vacuum to obtain the primarily dried ternary cathode material precursor. The ternary cathode material precursor prepared by the provided preparation method has the following physical and chemical indexes: the particle distribution span is not more than 1.2; D50 is 9 to 12 [mu]m; and the tap density is not less than 2.40 g/cm3. The preparation method has the advantages that the operation is simple, the particle distribution of prepared ternary cathode material precursor is uniform, the tap density is high, impurities can be removed easily, and the method is practical.

The invention discloses a preparation method of a layered lithium-rich sosoloid cathode material. In the preparation method, the excess lithium source is sintered, then the sintered lithium source is washed by water, and then the processed intermediate is subjected to surface modification so as to obtain the cathode material. Through the technical scheme mentioned above, the mixed arrangement of Li+ and Ni2+ in the cathode material is effectively reduced, at the same time, the alkali residues on the cathode material surface are reduced, and the stability of the cathode material is improved. The cathode material prepared by the provided preparation method has the characteristics of good high temperature cycling performance, good storage performance, good rate capability, simple and easy preparation process, and low cost.

The invention provides a Mg-doped nickel-cobalt-aluminum ternary cathode material and a preparation method and application thereof. The Mg-doped nickel-cobalt-aluminum ternary cathode material has thechemical formula of (LiaNi1-x-yCoxAly)1-bMgbO2, with y>0, 1-x-y>0, 1</=a</=1.1, and 0<b</=0.01. The preparation method comprises: sintering a ternary cathode material precursor Ni1-x-yCoxAly(OH)2+y;adding a lithium source and a doping material into the sintering resultant, and carrying out sintering; performing tertiary sintering to obtain the target product. The Mg-doped nickel-cobalt-aluminumternary cathode material prepared herein has good cycle performance. The preparation method having the triple sintering steps has simple technicality and controllable process and facilitates industrial large-scale production.

A preparation method of a modified high-nickel positive electrode material comprises the following steps: uniformly mixing a high-nickel positive electrode material precursor, an additive and a lithium source, carrying out primary sintering in an oxygen atmosphere, crushing, and sieving to obtain a primary sintered high-nickel positive electrode material; washing the primary sintered high-nickel positive electrode material with water, and drying to obtain a washed and dried primary sintered high-nickel positive electrode material; performing primary surface treatment on the washed and dried primary sintered high-nickel positive electrode material to obtain a primary surface treated high-nickel positive electrode material; and uniformly mixing the modifier with the primary surface treatmenthigh-nickel positive electrode material, and then carrying out secondary surface treatment to obtain the modified high-nickel positive electrode material. The residual alkali amount on the surface ofthe material and the specific surface area of a final product are reduced, so that the impedance on the surface of the material is obviously reduced, the gas production phenomenon of the battery is obviously relieved, the structural stability and the cycling stability of the material are improved, the processability of the positive electrode material in the preparation process can be improved, the preparation condition is easy to control, and mass production can be realized.

The invention discloses a high-nickel ternary positive electrode material, and a preparation method and application thereof. The preparation method of the high-nickel ternary positive electrode material comprises the steps of primary sintering, water washing, drying, coating, secondary sintering, sieving, demagnetizing and packaging, wherein water washing, drying, coating, sieving, demagnetizing and packaging are completed in a drying room, a moisture content of the drying room is smaller than or equal to 10 ppm, and a carbon dioxide content of the drying room is smaller than or equal to 10 ppm. The control of H2O and CO2 in the air is added in the production process, and the steps of water washing, drying, coating, sieving, demagnetizing and packaging are all completed in the drying room,so the contact between the produced high-nickel ternary positive electrode material and H2O and CO2 is avoided; and after residual lithium is reduced after the high-nickel ternary positive electrodematerial is washed with water, reaction with carbon dioxide rarely occurs, so the residual lithium is ensured not to increase, and thus, the content of residual alkali on the surface of the high-nickel ternary positive electrode material is reduced, the surface residual alkali content is kept to be less than or equal to 0.12%, the processability and safety of the material are improved, and the high-nickel ternary positive electrode material can be widely applied to preparation of electrode materials of lithium ion batteries.

The invention discloses a ternary positive electrode composite material and a preparation method and application thereof. The composite material comprises a ternary positive electrode material core and a shell coating the surface of the core, and the shell comprises a first coating material and a second coating material; the first coating is of a three-dimensional nano-network layered structure and comprises a conductive polymer/graphene/carbon nanotube compound, a hydrogen-containing lithium titanium oxide compound and FeF3(H2O)0.33, the hydrogen-containing lithium titanium oxide compound andthe FeF3 (H2O) 0.33 are dispersed on the surface of the compound in situ, and the second coating material is a carbonization product of polyvinyl alcohol. The lithium ion battery prepared from the ternary positive electrode composite material has relatively high ionic conductivity and electronic conductivity, and has the outstanding advantages of high specific discharge capacity, high initial coulombic efficiency, high cycling stability and the like.

The invention provides a lithium battery positive electrode material containing a fluorine-containing alkyl compound additive and/or a weak acid additive. The fluorine-containing alkyl compound additive has a very high chemical stability and maintains a good surface activity in a solvent. A small amount of the fluorine-containing alkyl compound additive is added to a positive electrode material inorder to reduce the surface tension of a solvent-based system, so the wetting property, the dispersing property, the leveling property and other surface properties of the positive electrode materialare enhanced, the diffusion of lithium is facilitated, and the rate performance is improved. The addition of the weak acid additive can reduce the amount of residual alkalis on the surface of the positive electrode material. Additionally, the fluorine-containing alkyl compound additive has hydrophobic properties, so the waterproof property of the positive electrode material is improved, the requirements for the humidity of the storage and use environment of the positive electrode material are reduced, and the cost is saved.

The invention provides a doped nickel-cobalt-aluminum ternary lithium-ion battery positive electrode material as well as a preparation method and application. A chemical formula of the material is asfollows: (LiaNi1-x-yCoxAly)1-bMbO2, wherein x is greater than 0 and y is greater than 0; the 1-x-y is greater than 0; the a is greater than or equal to 1 and less than or equal to 1.1; the b is greater than 0 and less than or equal to 0.01. A preparation method of the material comprises the following steps: firstly, sintering a ternary positive electrode material precursor Ni1-x-yCoxAly(OH)2+y; then adding a sintered product into a lithium source and a doping material and sintering; finally, carrying out third-time sintering to obtain a target product. The doped nickel-cobalt-aluminum ternarylithium-ion battery positive electrode material synthesized by the preparation method provided by the invention has good circulating performance. The preparation method provided by the invention comprises three times of sintering steps and has the advantages of simple technology, controllable process and easiness for industrialized mass production.

The invention relates to the field of positive electrode materials, and provides a high-nickel positive electrode material, a preparation method thereof, and a lithium ion secondary battery. The high-nickel positive electrode material comprises secondary particles, wherein the secondary particles comprise a plurality of primary particles, the primary particles comprise an active substance, the general chemical formula of the active substance is LibNixCoyMzNwO2, 0.95 <=b <=1.05, 0.8 <=x < 1, 0<y+z<=0.2, x+y+z=1, 0.0001<=w<=0.003, M is selected from at least one of Mn and Al, and N is a metal; acoating layer which comprises a first coating layer and a second coating layer, wherein the first coating layer is formed on the surface of the primary particle, the second coating layer is formed onthe surface of the secondary particle, and each of the first coating layer and the second coating layer contains a phosphoric acid compound. According to the high-nickel positive electrode material,the preparation method thereof and the lithium ion secondary battery, the cost is low, large-scale production can be realized, and the rate capability and the cycling stability of the lithium batterycan be effectively improved.

The invention discloses a preparation method of a low moisture absorption and low gas production lithium titanate anode material. The method includes the steps of: preparing a titanium source and a lithium salt into a lithium titanate precursor by hydrothermal process, performing cooling, then conducting cleaning, and then subjecting the lithium titanate precursor to high temperature calcinationstreatment to obtain lithium titanate powder; dissolving lithium titanate powder in deionized water to form a lithium titanate solution, then adding a PVP (polyvinylpyrrolidone) water solution, and conducting mixing and heating to carry out coating reaction on lithium titanate and PVP in a liquid phase; and performing vacuum drying on the reactant so as to obtain a PVP coated lithium titanate material. The lithium titanate powder material prepared by hydrothermal process lowers the pH value of lithium titanate from the raw material end, thereby weakens the material water absorption, and can effectively inhibits gas production. Then PVP is employed to perform surface film coating on lithium titanate, thus lowering the lithium titanate surface residue and weakening the catalytic effect of Ti<4+> on an electrolyte solution, and preventing the electrolyte solution from being reduced and decomposed on the lithium titanate surface to produce gas.

The invention relates to a positive electrode slurry and an application thereof, the positive electrode slurry comprises a high-nickel positive electrode material and an additive, and the additive comprises at least one of LiPF6, boric acid, oxalic acid, citric acid, tartaric acid, tetraethyl silicate, LiPO2F2 and HPF6; the additive can react with residual alkali on the surface of a high-nickel positive electrode material to reduce the alkalinity of positive electrode slurry and improve the stability and processability of the positive electrode slurry, so that the gas production of a battery prepared from the additive in the use process is reduced, the safety of the battery is improved, the application of the waterless high-nickel positive electrode material is facilitated, and the cost ofthe battery is reduced; meanwhile, the preparation process of the positive electrode slurry is simple to operate, and industrialization is easy to realize.

The invention provides an Al-doping nickel-cobalt-aluminum ternary lithium ion battery positive electrode material as well as a preparation method and a purpose thereof. The material has a chemical formula of (LiaNi1-x-yCoxAly)1-bAlbO2, wherein the x is greater than 0; the y is greater than 0; 1-x-y is greater than 0; the a is greater than or equal to 1 but smaller than or equal to 1.1; the b is greater than 0 but smaller than or equal to 0.01. According to the preparation method of the material, firstly, a three-ingredient positive electrode material precursor Ni1-x-yCoxAly(OH)2+y is sintered; then, a lithium source and doping materials are added into the obtained materials after the sintering; sintering is performed; finally, the third time sintering is performed; target products are obtained. The doping nickel-cobalt-aluminum ternary lithium ion battery positive electrode material synthesized by the preparation method has excellent circulation performance. The preparation method comprises three times sintering steps; the process is simple; the process is controllable; the industrial mass production is easy.

The invention discloses a high-nickel multi-element positive electrode material as well as a preparation method and application thereof. The preparation method comprises the steps that: a nickel-cobalt-manganese precursor solution added with a metal dopant is obtained, and the precursor solution is condensed to obtain precursor particles; the precursor particles are in contact with sprayed lithium source powder, aggregated secondary particles are obtained through crystallization, and the secondary particles and a surface coating additive are mixed, and the mixture is sintered, and the high-nickel multi-element positive electrode material is prepared. According to the preparation method, the synthesis of the precursor and the sintering of the secondary particles are completed in the same equipment, so that the cost is reduced, the influence of external environment on the surface property of the high-nickel material is avoided, the obtained high-nickel multi-element positive electrode material has excellent cycle performance and good structural stability, and the problem of high-temperature gas production is solved.