51results about How to "Reduce residual alkali content" patented technology

The invention discloses a method for reducing the content of residual alkaline in nickel cobalt manganese acid lithium. According to the method, LiH2PO4 serving as an alkaline treatment agent is used for removing alkaline components such as LiOH, Li2CO3 and LiHCO3 retained in a nickel cobalt manganese acid lithium positive electrode material, so that the structure of the positive electrode material cannot be damaged; furthermore, the circulating performance and the compaction density of the positive electrode material can be improved, and the performance of the battery can be improved; meanwhile, the method is simple and feasible and is suitable for industrial production.

The invention discloses a method for preparing a graphene modified high-nickel series positive electrode material through a spray drying process and the positive electrode material prepared by the same. The method includes following steps: 1), well mixing high-nickel precursor with lithium carbonate or lithium hydroxide according to a certain molar ratio, calcining in an oxygen atmosphere roller way kiln, and smashing to obtain a high-nickel primary smashed material; 2), adding a dispersant, a binder and graphene into a solvent, and stirring and dispersing well to form graphene electroconductive paste with certain solid content, wherein the graphene electroconductive paste is a uniform emulsion in dispersion state; 3), stirring and mixing an oxygen-containing compound source with the high-nickel primary smashed material, adding the graphene electroconductive paste, stirring to obtain graphene mixed paste; 4), utilizing a spray dryer for drying, calcining in the oxygen roller way kiln,smashing, and screening to obtain a final graphene modified high-nickel product. The graphene modified high-nickel positive electrode material produced by adopting the method has the advantages of lowresidual alkali and excellent rate performance and circulating performance and is suitable for industrial production.

The invention discloses a preparation method of a coated ternary nickel-cobalt-manganese lithium oxide positive electrode material. The preparation method comprises the following steps of (1) preparing a ternary nickel-cobalt-manganese lithium precursor; (2) preparing an oxide-coated ternary nickel-cobalt-manganese lithium precursor; and (3) preparing an ion conductor oxide-coated ternary nickel-cobalt-manganese lithium positive electrode material. By the preparation method of the positive electrode material, a lithium ion is easy to de-intercalate from a surface layer of the material, and thehigh-temperature circulation performance of the material is improved; a coating layer does not react with an electrolyte, interface side reaction caused by contact of the main body material and the electrolyte is reduced, and the safety of the material is improved; the processing performance of a pole plate during the uniform coating process is improved, and the high-temperature circulation performance of the material after being assembled into a battery is improved; and the prepared positive electrode material does not need to be subjected to a roasting process for two times, the energy consumption is reduced, and the cost is reduced.

The invention discloses a preparation method of a graphene modified high-nickel-series anode material. The preparation method of the graphene modified high-nickel-series anode material comprises the following steps: 1) uniformly mixing a high-nickel precursor with lithium carbonate or lithium hydroxide according to a certain molar ratio, and calcining and pulverizing the mixture in a roller kiln at an oxygen atmosphere to obtain a high-nickel primary pulverized material; 2) adding a dispersing agent, an adhesive and graphene in a solvent, and uniformly stirring and dispersing to form grapheneconductive slurry with a certain solid content, wherein the graphene conductive slurry is uniform emulsion in a dispersing state, and sedimentation and layering do not exist; 3) stirring the grapheneconductive slurry and the high-nickel primary pulverized material for a certain time according to a certain ratio, standing, filtering and drying; and 4) calcining and pulverizing the dried material in the roller kiln at a mixed gas atmosphere to obtain the final graphene modified high-nickel product. The graphene modified high-nickel anode material produced by the method has the characteristics of uniform wrapping, excellent rate capability and high-temperature cycle performance and stable process, and is suitable for industrial production.

The embodiment of the invention relates to a method for reducing the content of residual alkali on the surface of a high-nickel positive electrode material of a lithium ion battery. The method comprises the following steps: adding a certain amount of acid or a derivative of the acid into a certain amount of non-aqueous inactive hydrogen organic solvent at a stirring speed of 1m/s to 10m/s at normal temperature, and stirring until the acid or the derivative of the acid is completely dissolved, so as to obtain a washing solution for reducing residual alkali on the surface of the high-nickel positive electrode material of the lithium ion battery; wherein the mass ratio of the to-be-treated high-nickel positive electrode material to the non-aqueous non-active hydrogen organic solvent is 1:0.5-1:4; wherein the molar concentration of the acid or the derivative of the acid in the washing liquid is 0.5-1.5 times of the molar weight of the residual alkali on the surface of the to-be-treated high-nickel positive electrode material; adding a to-be-treated high-nickel positive electrode material into the washing liquid while stirring at a linear speed of 1m/s to 10m/s, and stirring for 1 to 120 minutes; and centrifuging to remove the solvent, vacuumizing, heating and drying at 20-80 DEG C to obtain the treated high-nickel positive electrode material.

The invention relates to a lithium-ion battery composite positive electrode material and a preparation method thereof. The composite electrode material comprises a base material, and a first coating layer and a second coating layer which sequentially coat the surface of the base material. The lithium-ion battery composite positive electrode material and the preparation method thereof provided by the invention are simple in process, easy for industrial production, low in residual alkali and excellent in cycle and safety performance.

The invention provides a method for reducing the residual alkali content of a high-nickel material, which comprises the following steps of: mixing a high-nickel ternary positive electrode material precursor, a lithium salt and an additive, and carrying out gradient sintering to obtain a low-residual-alkali high-nickel ternary monofired product, wherein the additive is a weak acid salt. According to the method, a gradient sintering mode is adopted, a low-temperature platform is arranged, a weak acid salt additive is molten in the low-temperature platform, and residual alkali such as LiOH and Li2CO3 on the surface of the high-nickel ternary material is consumed through the molten weak acid salt additive.

The purpose of the invention is to present a lithium ion battery cathode material and a preparation method thereof and a lithium ion battery. The cathode material includes a cathode active material, lithium phosphate arranged on at least part of the outer surface of the cathode active material, and a coating layer coating the exposed outer surfaces of the cathode active material and the lithium phosphate and including a conductive polymer. Thus, the residual alkali content on the surface of the cathode active material is low, and the rate performance stability and cyclic capacity retention rate of the cathode material can be improved. The lithium phosphate and the conductive polymer enable the cathode material to have ion-electron conductivity (double conduction), and further improve the rate performance stability and cyclic capacity retention rate of the cathode material. The coating layer can reduce or prevent the side reaction between the cathode active material and the electrolyteand improve the service life of the cathode material.

The invention discloses a preparation method of a low residual alkali Li(NiCoAl)O2 cathode material. The preparation method comprises following steps: 1, a nickel cobalt aluminium hydroxide precursoris mixed with a lithium source, and an obtained mixture is subjected to pre-sintering; 2, a product obtained in step 1 is smashed, and is subjected to sencondary sintering so as to obtain a matrix material; 3, the matrix material is smashed, an alkali treatment agent is added, and a third time of sintering is carried out after mixed so as to obtain the low residual alkali Li(NiCoAl)O2 cathode material. The pre-sintering is carried out at 300 to 700 DEG C, preferably at 400 to 650 DEG C, and more preferably at 400 to 600 DEG C, such as 500 DEG C; the secondary sintering is carried out at 600 to900 DEG C, preferably at 700 to 800 DEG C, and more preferably at 750 DEG C; and the third time of sintering is carried out at 600 to 900 DEG C, preferably at 700 to 800 DEG C, and more preferably at750 DEG C; the alkali treatment agent is one or a mixture of a plurality of ingredients selected from nanometer aluminium phosphate, nanometer alumina, nanometer aluminium hydroxide, nanometer cobaltous phosphate, nanometer cobalt oxide, and nanometer cobaltous hydroxide.

A preparing method of a nickel cobalt lithium aluminate cathode material is disclosed. Aluminum and lithium elements are introduced in one step in a wet material mixing process and evenly cover a nickel cobalt compound intermediate, thus avoiding the process difficulty that nickel, cobalt and lithium elements are difficult in uniform deposition in a precursor preparing process. The method is easy in industrial production. A production process of the method is free of pollution and low in energy consumption.

The invention relates to the field of a lithium ion battery electrode material, and discloses metal element-doped lithium iron phosphate-coated lithium nickel-cobalt manganate and a preparation methodthereof. The preparation method comprises the steps of performing thermal treatment on the lithium nickel-cobalt manganate and a mixture of an M element-doped lithium iron phosphate precursor mixed liquid comprising a lithium source, a doped metal M source, an iron source and a phosphorus source; performing solid-liquid separation on a product obtained after thermal treatment, and drying to obtain a solid phase, wherein a solvent in the M element-doped lithium iron phosphate precursor mixed liquid comprising the lithium source, the doped metal M source, the iron source and the phosphorus source is used as an organic solvent. The organic solvent is used as a reaction liquid, the problem of serious water absorption of a lithium nickel-cobalt manganate ternary material, particularly a high-nickel ternary material is effectively solved, so that the metal element-doped lithium iron phosphate-coated lithium nickel-cobalt manganate having favorable electrochemical performance is prepared.

The invention discloses a high-tap-density high-nickel positive electrode material and a preparation method thereof. The high-nickel positive electrode material is formed by grading two or more high-nickel base materials with different median particle sizes D50. The preparation method of the high-tap-density high-nickel positive electrode material comprises the steps of 1, preparing high-nickel base materials with different particle sizes; and 2, mixing the high-nickel base materials with different particle sizes. According to the invention, the high-tap-density high-nickel positive electrodematerial is prepared by adopting a grading method of particles with large and small particle sizes, the prepared high-nickel positive electrode material has relatively high tap density and relativelylow residual alkali content, a lithium ion battery prepared from the positive electrode material has excellent electrochemical performance, and the preparation method is simple, efficient, low in cost, environmentally friendly and suitable for large-scale industrial production.

The invention relates to a coated positive electrode material and a preparation method and application thereof. The preparation method comprises the steps: adding a coated metal source into a complexing solution, performing mixing and heating to obtain gel, adding a positive electrode material into the gel, and performing mixing and calcining to obtain the coated positive electrode material, wherein the coated metal source comprises a cobalt source, a manganese source and an aluminum source. According to the preparation method, the sol-gel method is adopted, residual alkali on the surface of the positive electrode material can be effectively reduced, a coating layer of the obtained coated positive electrode material has electronic conductivity, the contact area of the positive electrode material and electrolyte can be effectively reduced, side reactions are reduced, and the electrochemical performance of the positive electrode material is improved.

The invention belongs to the technical field of lithium ion battery positive electrode material preparation, and particularly relates to an ultrahigh nickel single crystal positive electrode material and a preparation method thereof. According to the invention, an ultrahigh nickel positive electrode material precursor (nickel-cobalt-manganese-aluminum hydroxide) is used as a matrix raw material, the precursor is fully crushed by using the acting force of high rotating speed and high pressure, and a lithium source and strontium carbonate are added during the period, so that the lithium source and the precursor are promoted to be mutually dissolved and then crystallized and co-grown at a relatively low temperature, the lithium-nickel mixing is reduced, and finally, calcining is performed to obtain the single-crystal-like material. The monocrystal-like material provided by the invention is uniform in size and high in particle strength, and the cycling stability of the material is enhanced. The technical problems that due to the fact that the nickel content in the ultrahigh nickel material is high, nickel in generated mono-like crystals is severely separated out due to high-temperature calcination, the later battery capacity fades, the residual alkali content is high and the like in the preparation process of the ultrahigh nickel mono-like materials are solved.