공침법을 통한 Li[Ni0.8Co0.1Mn0.1]O2, Li[Ni0.8Co0.2]O2 합성 및 전기화학적 특성

초록

Sony researchers, who successfully commercialized lithium ion batteries, were the first to develop LiCoO2 as a positive electrode material. Since then, a tremendous number of studies have been carried out all over the world to find the best material, optimize electrochemical properties, and understand the fundamental process involved in intercalation reactions. LiNiO2 is a promising positive electrode due to its advantages over LiCoO2. LiNiO2 is less expensive, less toxic, and has a higher capacity than LiCoO2. However, it has several problems, such as a difficult synthesis, low thermal stability, and poor cycle life in the charged state. To overcome these problems, several cations have been substituted for Ni. Co doping on LiNiO2 not only improves the layered characteristics of LiNiO2, but it also increases thermal stability in the charged state. It has been reported that Co reduces cation mixing and improves structural stability. However, Li[Ni1?yCoy]O2 has been found to exhibit low thermal stability and increased impedance during cycling, particularly at high temperatures. In this study, the synthesis and electrochemical properties of spherical Li[Ni0.8Co0.2?xMnx]O2 (x=0, 0.1) are reported. The effects of substitution of Mn3+ for Co3+ in Li[Ni0.8Co0.2]O2 on structure, electrochemical properties, and thermal stability are discussed.