Temperature dependent local structure of LiCoO2 nanoparticles determined by Co K-edge X-ray absorption fine structure

Abstract

Temperature dependent Co K-edge extended X-ray absorption fine structure is used to investigate local disorder in LiCoO2 nanoparticles. We find that the nanostructuring has direct influence on the bondlength characteristics. The results reveal a substantial decrease in the force constant of Co–O bonds (the Co–O bonds becoming more flexible), while that for the Co–Co bonds showing hardly any change (or increases slightly) in LiCoO2 nanoparticles with respect to the bulk. Therefore, both random disorder and Co–O bondlength flexibility should be the factors to limit the battery characteristics of the LiCoO2 nanoparticles.