High Capacity Li[Li0.2Mn0.54Ni0.13Co0.13]O2-VO2(B) Composite Cathodes with Controlled Irreversible Capacity Loss for Lithium-Ion Batteries

To reduce the huge first-cycle irreversible capacity loss of the high capacity layered oxide cathode Li[Li0.2Mn0.54Ni0.13Co0.13]O-2, the lithium-free insertion host VO2(B) has been mechanically mixed with the layered oxide and characterized. The first-cycle irreversible capacity loss decreases from 88 mAh/g with increasing VO2(B) content and vanishes completely at similar to 23 wt % VO2(B), as the lithium-free VO2(B) inserts the lithium ions that could not be inserted back into the layered oxide lattice after the first charge. The composite cathode with 20 wt % VO2(B) shows the best electrochemical performance in terms of coulombic efficiency, cyclability, and rate capability. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3515900] All rights reserved.