Long-Term Cycle Stability Enabled by the Incorporation of Ni into Li2MnO3 Phase in the Mn-Based Li-Rich Layered Materials

Abstract

Co-free Mn-based Li-rich layered materials have been attracting a lot of attention due to their high capacity via the additional oxygen redox reaction and their low cost. However, their poor capacity retention and voltage fade upon cycling remains a problem for practical applications. Herein, we report on long-term cyclability of a Co-free Mn-based Li-rich layered material with superior voltage retention for 490 cycles. The developed one-step solid-state reaction, which comprises a thorough mixing and a heating process at high temperature followed by a quenching process, can increase substantially the amount of Ni incorporated into the Li2MnO3 phase, and thereby the resulting material has a robust layered structure caused by the increase in the cation disordering, and a facile electron transfer for the oxygen redox reaction leading to the remarkably improved oxygen redox reversibility for long-term cycles. The findings will provide a new strategy for achieving high performance for long-term cycles in Li-rich layered materials.