Considerable capacity increase of high-nickel lithium-rich cathode materials by effectively reducing oxygen loss and activating Mn4+/3+ redox couples via Mo doping

Abstract

Li- and Mn-rich layered oxides can deliver high reversible capacity but suffer from severe voltage decay, which seriously impedes their commercial applications. However, high-nickel Li-rich layered oxides could normally present stable discharge voltage but tend to deliver low reversible capacity. In this work, high-nickel Li-rich layered oxides are doped by Mo via a facile sol-gel route to realize both high reversible capacity and minor voltage decay simultaneously. The superior performance could be ascribed to the reduced size of primary particles, the enhanced stability of lattice oxygen and more Mn4+/3+ redox couples effectively activated during the electrochemical reactions which are realized via Mo doping. The present study offers a new strategy to achieve high-performance high-nickel Li-rich layered oxides with both the stable discharge potential and high reversible capacity by modifying their morphologies, structures and chemistries via the introduction of proper alien elements which are believed to be the potential cathode candidates for next generation lithium-ion batteries.