The invention relates to a method for preparing alkaline
cobalt carbonate under hyper-gravity hydrothermal condition. The method comprises the following specific steps of: adding a certain amount of
cobalt salt into deionized water to obtain a
metal salt solution with the concentration between 0.1 mol / L and 2 mol / L; dissolving a corresponding chemical
reagent which can produce CO3<2-> at the
reaction temperature between 50 DEG C and 250 DEG C; adding a certain amount of
organic solvent which has higher density in comparison with water and is insoluble in water or a water-soluble high molecular compound with density higher than that of water into the prepared solution, wherein the volume ratio of the
organic solvent or the water-soluble high molecular compound to an
aqueous solution is 1:1-1:100; filling the
mixed solution into a reaction kettle, sealing, fixing the reaction kettle on a fixing bracket in a
hearth and undergoing a
hydrothermal reaction at certain temperature in the presence of hyper-gravity, wherein the
reaction temperature is between 50 DEG C and 250 DEG C, the reaction time is between 0.1 hour and 5 hours, and relative
centrifugal force is between 500 / g and 10,000 / g; and filtering, cleaning repeatedly and
drying in vacuum to obtain a needed material. By adopting the method, a substrate-free alkaline
cobalt carbonate membrane can be directly prepared; and equipment is simple, the reaction is easy to control, and industrialization is easy to realize.