Li‐insertion into sol‐gel Na0.44MnO2 cathode material for higher structure and electrochemical performance of batteries

Abstract

AbstractStability of electrolyte with higher electrochemical and structural performance is a key aspect for achieving greater longevity of cycle life of battery. In this article, we investigated the electrochemical performance of sol‐gel Na0.44MnO2 (SG‐NMO) as cathode material in lithium batteries within nonaqueous lithium electrolyte. The SG‐NMO was prepared by the two‐step of the sol‐gel method: a transparent gel was obtained by a stirring of precursors (Na2CO3, Mn(CH3COOH)2 and acid citric) at 80°C; then gel was calcinated at 400°C for 6 hours and 800°C for 9 hours in air. The structure and morphology were characterized by X‐ray diffraction, SEM, and Raman spectroscopy. The XRD pattern exhibited a high crystallization of orthorhombic phase and SEM images showed the well‐crystalline grains in submicrometric scale. Following charge‐discharge profile and ex‐situ XRDs result, SG‐NMO showed 0.22 ion Na+‐extraction at the end of first cycle and a reversible Li‐migration from second cycle without a phase transition. The specific capacity at rate C/10 was about 180 mAh/g with a capacity retention of 95% upon 50 cycles. Moreover, a good electrochemical performance in rate capability (from C to 3C) indicated a highly kinetic Li‐transportation.