Preparation of Enhanced-Performance LiMn0.6 Fe0.4 PO4 /C Cathode Material for Lithium-Ion Batteries by using a Divalent Transition-Metal Phosphate as an Intermediate

Abstract The olivine‐structured LiMn 0.6 Fe 0.4 PO 4 /C composite is an alternative cathode material for lithium‐ion batteries with excellent high‐rate capability and cycle stability. A facile synthesis is achieved by applying a divalent transition metal phosphate as intermediate, spray drying, and annealing. A phosphate hydrate with a low degree of crystallinity is coprecipitated and characterized by XRD and SEM. SEM and TEM investigations show that the LiMn 0.6 Fe 0.4 PO 4 /C particles are porous microspheres with a diameter of 2–5 μm, and that the primary nanoparticles are wrapped by a 4–6 nm‐thick carbon layer. Compared with LiFePO 4 /C and LiMnPO 4 /C, the LiMn 0.6 Fe 0.4 PO 4 /C microspheres exhibit higher energy density and enhanced discharge capacities of 156, 147, and 133 mAh g −1 at 0.1, 1 and 10 C, respectively, as well as excellent cycle performance at high rates.