Capacity and charge-transport enhancement of LFP/RGO by doping with a-MnO2 in a microwave-assisted synthesis

Abstract

Manganese-doped lithium iron phosphate (LFMP), coated with reduced graphene oxide (RGO), has been prepared by a microwave-assisted solvothermal technique. The un-doped lithium iron phosphate material with RGO (i.e., LFP/RGO) gave a rod-like morphology (> 200 nm in length), while the LFMP/RGO gave a sponge-like spherical morphology (≥ 100 nm diameter). This dramatic change in morphology upon doping with Mn from α-MnO2 resulted in improved coin cell performance in terms of capacity, coulombic efficiency and charge-transfer properties. The increased performance can be attributed to improved particle size and higher surface area owing to the partial substitution of Mn ions for Fe ions. LiFe0.8Mn0.2PO4 synthesised using microwaves provides a quicker method of synthesis while providing a cathode material with a promising capacity.