Comparative study of Li(Li1/3Ti5/3)O-4 and Li(Ni1/2-xLi2x/3Tix/3)Ti3/2O4 (x=1/3) anodes for Li rechargeable batteries

Abstract

A solid solution of spinel (2/3)Li(Li1/3Ti5/3)O-4-(1/3)Li(Ni1/2Ti3/2)O-4 was prepared, and its structural/electrochemical properties were compared with Li(Li1/3Ti5/3)O-4 to identify the effect of doping to the structural invariance of Li(Li1/3Ti5/3)O-4. The solid solution retained the zero strain characteristic of Li(Li1/3Ti5/3)O-4 during discharge/charge with an excellent cycle stability, while the rate capability was notably improved. However, a reversible broadening of the XRD peak was observed at the end of discharge, indicating some structural changes. XANES measurements showed that the oxidation state of Ti was +4 and that of Ni was +2 in the solid solution. (C) 2009 Elsevier Ltd. All rights reserved.