METHOD FOR RECYCLING WASTE LITHIUM-ION SECONDARY BATTERIES AND RECYCLED LITHIUM IRON PHOSPHATE POWDER OBTAINED THEREFROM

A method for recycling a waste lithium-ion secondary battery includes (a) loading an object to be heat-treated into a heat-treatment furnace, the object being at least a part of a waste lithium-ion secondary battery in which lithium iron phosphate powder is a positive electrode material, and including the positive electrode material, (b) increasing the temperature inside the heat-treatment furnace to a range of 200° C. to 400° C., (c) maintaining the increased temperature to heat treat the object to be heat-treated, and (d) discharging first powder produced after the completion of the heat treatment, wherein the first powder includes recycled lithium iron phosphate powder.