Development of structural stability and the electrochemical performances of ‘La’ substituted spinel LiMn 2O 4 cathode materials for rechargeable lithium-ion batteries

Abstract

The LiLa x Mn 2 − x O 4 ( x = 0.00 to 0.10) cathode materials for rechargeable lithium ion batteries were synthesized by simple sol–gel technique using aqueous solutions of metal nitrates and succinic acid as the chelating agent. The gel precursors of metal succinates were dried in vacuum oven for 10 h at 110 °C. After drying, the gel precursors were ground and heated at 900 °C. The structural characterization was carried out by X-ray powder diffraction and Laser Raman spectroscopy. The sample exhibited a well-defined spinel structure and the lattice parameter was linearly increased with the increasing lanthanum contents in LiLa x Mn 2 − x O 4. Surface morphology of the synthesized materials was determined by Scanning electron microscope and it was found that the cathode materials consisted of highly-ordered single crystalline particles with cubic spinel structure. Electrochemical properties were characterized by the assembled test cells using Galvanstatic charge/discharge studies which were carried out at a current rate 0.1C and Cyclic voltammetry was carried out in the potential range of 2.75 to 4.5 V at a scan rate 0.1 mVs − 1 . Among them, lanthanum doped spinel LiLa 0.05Mn 1.95O 4 has improved the structural stability, high reversible capacity and excellent electrochemical performance of rechargeable lithium batteries.