Green and efficient synthesis of micro-nano LiMn0.8Fe0.2PO4/C composite with high-rate performance for Li-ion battery

A green strategy is designed for synthesizing LiMn0.8Fe0.2PO4/C composites bases on mechano-chemical liquid-phase activation technique. The micro-nano spherical precursor is prepared by the effective redox reaction between MnO2 and H2O2 in H3PO4 aqueous solution with subsequent addition FeC2O4•2H2O and Li2CO3, which is followed by spray drying. The dense LiMn0.8Fe0.2PO4/C microspheres are formed from conformal carbon coating connected with primary nano-sized particles, which provides rapid electron and ion transport pathways during the electrode reaction. The obtained LiMn0.8Fe0.2PO4/C cathode exhibits reduced electrochemical polarization with high voltage platform and high discharge capacity of 159 mAh g −1 at 0.1 C. Even at high rate of 10 C, the composite shows an impressing discharge capacity of 130 mAh g −1 with obviously stable plateau. Besides, uniformly conductive carbon network distributed all over the primary nano-sized particles effectively inhibits the occurrence of interfacial side reactions during electrode cycling, and the electrode exhibits good cycling stability with capacity retention rate of 95% after 500 cycles at 1 C. This work provides a scalable route to fabricate high energy density LiMn0.8Fe0.2PO4/C cathode with excellent rate performance for Li-ion battery.