Improved Li- storage performance of heat-treated InFeCoO4 spinel prepared by glycine assisted chemical route

Herein, we show the synthesis of high-capacity anode, InFeCoO4 spinel for lithium ion batteries (LIBs), by facile glycine-assisted chemical approach. The structure and morphology are evaluated by X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS) and scanning electron microscopy (SEM) techniques, respectively. The pure phase formation of spinel InFeCoO4 is confirmed from XRD pattern, whereas the oxidation state of Co in 2+ is determined from XAS analysis. Electrochemical performance of InFeCoO4 in the half-cell configuration is evaluated by galvanostatic and cyclic voltammetry (CV) in the voltage window of 0.005–3.0 V vs. Li. When cycled at 60 mA g−1, it shows a high first cycle reversible capacity of 750 (±10) mA h g−1. However, slow capacity degradation is noticed upon cycling and reached 285 (±10) mA h g−1 after 40 cycles. An improved Li-storage performance is noticed under similar cycling condition, when the electrode is heat-treated. It shows first cycle reversible capacity of 880 (±10) mA h g−1 and reached 535 (±10) mA h g−1 after 40 cycles. The coulombic efficiency is >98 % during cycling. The improved Li-storage performance is possibly due to the distribution of PVDF (binder) in the active materials as well as better electrical contact after heat treatment.