Improvement of cycle capability of VS4 by addition of phosphorus element

Abstract

Vanadium tetrasulfide (VS4) have been attracting attention as the promising positive electrode material for next generation batteries because of its high theoretical capacity (1196 mAh g-1). In this study, a typical element (i.e., Phosphorus) was introduced into VS4for an attempt to improve the electrochemical cycle performance of VS4. The prepared PxVSy showed significant increase in cycle capability; e.g., ca. 70% after 50 cycles for P0.4VS5.0 sample cell, being much higher than that of pristine VS4cell (ca. 10 %). The PDF (pair distribution function) analyses indicated that the structural reversibility of VS4for Li insertion/extraction reactions was improved by the phosphorus addition.