A comparative studies on Li(Ni0.8Co0.15Al0.05)O2 and ZrO2-coated Li(Ni0.8Co0.15Al0.05)O2 cathode materials during cycling using Synchrotron based In Situ X-Ray Diffraction Technique

Abstract

LiNiO2 has been studied extensively as an alternative cathode materials for commercially used LiCoO2. LiNiO2 has higher specific capacity than LiCoO2 and an advantage of lower cost over LiCoO2. However, it suffers from poor cycling reversibility and thermal instability, which led to a problem of practical uses. Many researchers have made various efforts to improve the cycle performance and stability of the nickel based cathode materials. Among those, doping and surface modification are useful ways to improve the electrochemical performances. Among different variants of LiNiO2, Co and Al doped Li(Ni0.8Co0.15Al0.05)O2 shown to have performances over other variants. Moreover, appropriate surface modification will further improve it thermal stability and cycling performances. In this study, synchrotron based in situ XRD technique was used to study the structure change of ZrO2-coated Li(Ni0.8Co0.15Al0.05)O2 and uncoated Li(Ni0.8Co0.15Al0.05)O2. The structural information collected during charging/discharging provides valuable information related to its electrochemical performances.