Anode properties of calcite-type MBO 3 (M:V, Fe)

Abstract

V(III) was substituted in place of Fe(III) in the calcite FeBO 3 matrix to reduce the charge/discharge voltage and increase the theoretical capacity. The mean charge/discharge voltage of the calcite VBO 3 was 1 V lower than that of FeBO 3, and the reversible capacity was 420 mAh/g. To investigate the characteristics of borate anodes, the X-ray Rietveld, XPS and XAFS profiles were measured. To further improve the anode performance of VBO 3, a carbon coating using a naphthalene-based isotropic pitch with a low-temperature softening point was applied.