Synthesis and Electrochemical Properties of Lithium-Ion Battery Cathode Materials Based on LiFePOsub class='a-plus-plus'4sub–LiMnsub class='a-plus-plus'2subOsub class='a-plus-plus'4sub and LiFePOsub class='a-plus-plus'4sub–LiNisub class='a-plus-plus'0.82subCosub class='a-plus-plus'0.18subOsub class='a-plus-plus'2/s