Electrochemical studies of novel olivine-layered (LiFePO4-Li2MnO3) dual composite as an alternative cathode material for lithium-ion batteries

Abstract

In the present work, olivine-layered composites, i.e., LiFePO4-Li2MnO3, are successfully synthesized in the form of a single monolithic electrode and layer arrangement. X-ray diffraction (XRD) patterns revealed that the prepared compositions exhibit the peaks correspond to the layered m-Li2MnO3 (C2/m space group) and orthorhombic LiFePO4 with Pnma space group. Microstructural investigations indicate that all the samples possess nearly same morphology with a combination of smaller as well as bigger grains. CV results demonstrate that all the prepared samples possess anodic peak around 3.6 and 4.7 V along with a broad cathodic peak around 3.2 V which is due to intercalation of Li-ion at 16c octahedral sites of the spinel structure formed by MnO2. Among all the compositions, layer arrangement of LiFePO4 and Li2MnO3, i.e. LFP/LMO layered arrangement, shows the best cycling and rate performances. LFP/LMO exhibits a discharge capacity of 178 ± 5 mA h/g at a current density 10 mA/g and holds 98% of the capacity up to 100 charge/discharge cycles measured at 20 mA/g. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.