The invention relates to a
nickel-doped and carbon / silica-coated synergistically modified
cobalt lithium fluorophosphates
cathode material and a preparation method thereof. The preparation method comprises the following steps: (1) respectively adding a
lithium source, a
cobalt source, a
fluorine source and a
nickel source compound into deionized water in a certain stoichiometric ratio, stirring, adding a certain amount of a
phosphate source compound into the solution, further stirring, transferring into a
high pressure reaction kettle, airtightly heating, reacting, then naturally cooling, taking out, and
drying, so that a precursor is obtained; (2) mixing the obtained precursor and a
carbon source compound,
grinding, and calcining for two stages in
inert atmosphere, so that a carbon-coatednickel-doped Li2Co1-xNixPO4F / C material is obtained; and (3) weighing a certain amount of silica, putting into a breaker, adding deionized water, carrying out ultrasonic treatment, then adding the Li2Co1-xNixPO4F / C material, stirring,
drying, and
grinding, so that the Li2Co1-xNixPO4F / C+SiO2 target material is obtained. The
prepared material is uniform in particles and good in
crystallinity and has relatively high specific capacity and good cycle performance; and meanwhile, the synthetic process is simple and easy, and the production cost is low.