Method for washing positive electrode material precursor

Abstract

The invention provides a method for washing a positive electrode material precursor. The method comprises the following steps: putting a positive electrode material precursor containing impurity ionsinto a washing device, and treating to obtain a positive electrode material precursor slurry of which the impurity ion concentration meets the requirement, wherein the washing device comprises a cathode chamber, a mixture chamber and an anode chamber which are sequentially separated by a cation selective permeable membrane and an anion selective permeable membrane; the cation selective permeable membrane is selected from a sulfamide polypyrrole and polyether-ether-ketone permeable membrane or a sulfamide polypyrrole permeable membrane; and the anion selective permeable membrane is selected from a polyethersulfone permeable membrane. When the precursor is washed by adopting the method, the morphology and components of the precursor are not influenced, and meanwhile, impurities Na<+> and SO4<2-> of the precursor can be reduced to be 100 ppm or less, so that the excellent electrochemical performances of the precursor after the material is sintered in the later period are ensured; and according to the method, a large amount of water is saved, meanwhile, byproducts Na<+> and SO4<2-> can be recycled respectively, and the production cost of the material is reduced by washing with the method.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a washing method for a positive electrode material precursor. Background technique [0002] As a secondary battery, lithium-ion batteries have been maturely commercialized in the field of small power batteries such as 3C electronic products, mobile power supplies, electric tools, and electric bicycles. The positive electrode materials used mainly include lithium iron phosphate, lithium manganese oxide, and lithium cobalt oxide. And ternary materials, lithium-rich manganese-based cathode materials, etc. With the change of the global energy pattern, suitable high specific energy (>250Wh / g nickel-cobalt-manganese ternary materials and lithium-rich manganese-based cathode materials have attracted widespread attention from researchers, and are expected to be commercialized as cathode materials for next-generation power batteries , such as hybrid electric ...

AI Technical Summary

Problems solved by technology

However, subject to the strict production conditions of the process, there is a high content of sodium sulfate impurities in the precursor synthesis process, which seriously affects the performance of the positive electrode material. The traditional method uses water washing, but a large amount of water is wasted in the washing process, which also brings The cost of wastewater treatment is high, which directly affects the production cost of precursors and thus affects the production cost of positive electrode materials

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