Activation of a Li-rich Solid-Solution Layered Li[Ni0.18Li0.20Co0.03Mn0.58]O2 Cathode and Retention of High Capacities via an Electrochemical Pretreatment with a Low Discharge Voltage Limit

Abstract The magnitude and cycle stability of the charge–discharge capacities of a Li-rich solid-solution layered cathode material, Li[Ni0.18Li0.20Co0.03Mn0.58]O2, were examined over large voltage windows of 1.2–4.4 V (vs. Li/Li+). Discharging to below 1.5 V activated the cathode material and enabled it to reach larger charge–discharge capacities of over 300 mA h g−1. Moreover, to retain a high capacity of over 300 mA h g−1, our original electrochemical precycling treatment (stepwise control of the discharge voltage limit) was applied, resulting in improved stability of the charge–discharge capacity of over 300 mA h g−1 for at least 35 cycles.