PROCESS FOR PRODUCTION OF POSITIVE ELECTRODE MATERIAL FOR SECONDARY BATTERIES, AND POSITIVE ELECTRODE MATERIAL FOR SECONDARY BATTERIES

摘要

Disclosed is a process for producing a positive electrode material for secondary batteries, which can produce a positive electrode material comprising an olivine-type phosphoric acid composite compound and having improved electrical conductivity and reliability in a simple manner. A molten material comprising 5 to 40% of A2O (wherein A represents at least one element selected from the group consisting of Li and Na), 40 to 70% of MO (wherein M represents at least one element selected from the group consisting of Fe, Mn, Co and Ni) and 15 to 40% of P2O5 [wherein all of the contents are expressed in terms of oxide contents (unit: mol%)] is solidified by cooling. The solidified material is milled while mixing with at least one material selected from the group consisting of an organic compound and a carbon powder, the resulting product is heated to cause the precipitation of crystals containing olivine-type AMPO4 and the binding of at least one material selected from the group consisting of the organic compound, the carbon powder and reaction products thereof to the surfaces of the crystals. The melting step and the heating step are carried out under inert conditions or reductive conditions.