층간구조를 가지는 LixMn1-yMyO2 (M=전이금속) 양극활물질의 전기화학적 특성 연구

Abstract

Lithiated transition metal oxides LiMO2 (M = Co, Ni, Mn) have been extensively studied as cathode materials for rechargeable lithium ion batteries. The layered LiMnO2 are promising candidates as cathodes material because of their high theoretical capacity (285 mAh/g), low cost, abundance and nontoxic. Unfortunately, solid-state reaction at high temperature to prepare layered LiMnO2 has been unsuccessful since the nonlayered structure such as spinel LiMn2O4, orthorhombic LiMnO2, or rock salt Li2MnO3. In this work, a sol-gel method was employed to prepare transition metal doped LixMn1-yMyO2 powders using glycolic acid as a chelating agent. The structural and electrochemical properties of the prepared materials were investigated using various analytical techniques and correlated to explain the electrochemical activity of the materials. This materials shows that the initial capacity is over 180 mAh/g with excellent cyclability in the 2.4-4.5 V range. The transition metal doped layered structure is very effective to increase the cycle performance of LixMn1-yMyO2 layered.