Lithium cobalt phosphate preparing method

Abstract

A lithium cobalt phosphate preparing method is disclosed. The method includes dissolving cobalt powder into phosphoric acid, and then performing fine filtration to obtain a cobalt solution; preparinglithium carbonate into slurry, then feeding CO2 to allow the lithium carbonate slurry to be completely clarified to obtain a lithium solution; adding the cobalt solution and the lithium solution intoa base solution that is a polyethylene glycol solution under stirring to complete material addition, and reacting the mixture; spray-drying reacted materials to obtain a spray-dried material; adding the spray-dried material into a roller furnace, feeding nitrogen, subjecting the material to a temperature rising segment, a temperature maintaining segment and a cooling segment in order, then coolinga product and discharging the product to obtain a calcined material; conveying the calcined material through a pipeline to an jet mill; after air flow crushing, performing electromagnetic iron removing and then sieving, and packaging an obtained product in vacuum. The method can achieve co-precipitation of lithium, phosphate radicals and cobalt, the polyethylene glycol is adopted as a dispersantand a carbon source, and carbon covered type lithium cobalt phosphate with uniform particle distribution can be prepared and has high capacity and high compaction density.

Description

technical field [0001] The invention relates to a method for preparing lithium cobalt phosphate, which belongs to the technical field of new energy lithium battery materials. Background technique [0002] The working voltage of lithium cobalt phosphate material can reach 4.8V, and the capacity can reach 170mAh / g. It has the same crystal structure as lithium iron phosphate, and they are all ordered olivine structures. They belong to the orthorhombic crystal system, the space group is Pmnb, and the unit cell The parameters are a=0.5922nm, b=1.0202nm, c=0.4699nm. In the crystal, O atoms are hexagonally close-packed, P atoms occupy tetrahedral gaps, and Li atoms and Co atoms occupy octahedral gaps. Octahedral CoO with edge sharing 6 Pass PO in the same direction as the C axis 4 The tetrahedra are linked into chains. Since the crystal structure is stabilized by the Co-O-P bonds, the Li + During the extraction process, the crystal rearrangement is very small and the crystal s...

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Problems solved by technology

However, due to the low crystallinity of the material, subsequent heat treatment is required to improve the performance of the material

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