Synthesis and electrochemical investigation of novel phosphite based layered cathodes for Li-ion batteries

Abstract

Li-ion batteries (LIBs) are considered to be the best available energy storage device in the market to power electric vehicles (EVs) and stationary energy storage in grids for the efficient utilization of renewable energy sources. In this work, a novel family of phosphite containing framework materials have been synthesized and investigated as cathode materials for Li-ion batteries. The oxalatophosphite frameworks, A₂[(VO)₂(HPO₃)₂(C₂O₄)]; A = Li, Na and K were prepared by hydrothermal treatment followed by dehydration. These cathodes possess a layered structure which can host the Li ions in the interlayer space. Electrochemical investigation of these materials using galvanostatic cycling, cyclic voltammetry and electrochemical impedance spectroscopy reveal highly reversible Li intercalation at ∼3.8 V. Improved capacity was observed for the graphene composite compared to the pristine sample.