▎ 摘　　要

NOVELTY - Preparing secondary modified lithium manganese iron phosphate comprises (1) grinding lithium iron manganese phosphate anode material, (2) heating and coating lithium manganese iron phosphate particles with a mixed gas for chemical reaction, where the mixed gas includes 40-60% methane, 20-30% ethylene and 10-30% acetylene, generating graphene, carbon black, and graphite by chemical reaction are growing and coating on lithium manganese iron phosphate particles to obtain primary modified lithium manganese iron phosphate, and (3) carrying out carbon coating to primary modified lithium manganese iron phosphate to obtain secondary modified lithium manganese iron phosphate, and carbon coating is physical coating. USE - The method is useful for preparing secondary modified lithium manganese iron phosphate. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: a secondary modified battery positive sheet of lithium manganese iron phosphate; and a battery. DESCRIPTION OF DRAWING(S) - The drawing shows a flow chart illustrating the method for preparing secondary modified lithium manganese iron phosphate (Drawing includes non-English language text).