Effect of coatings on the green electrode processing and cycling behaviour of LiCoPO4

Abstract

Several approaches involving carbon and VOx coatings of LiCoPO4 to enable aqueous electrode processing are reported in this manuscript along with detailed physico-chemical and electrochemical investigations. It is shown that the choice of the carbon source has a severe impact not only on the purity, particle size and morphology of LiCoPO4, but also on its electrochemical performance. Although carbon coating improves the conductivity of LiCoPO4 and protects the particles' surface from direct contact with the electrolyte, it also leads to capacity fading upon cycling at high potentials. Reducing the carbon amount leads to an initially reduced capacity, but it significantly improves the stability upon cycling. Finally, the application of an additional VOx coating was also investigated.