Addressing voltage hysteresis in Li-rich cathode materials via gas-solid interface modification.

Li-rich layered materials have attracted much attention for their large capacity (>250 mA h g -1 ) stemming from anion redox at high voltage. However, inherent problems, such as capacity decay and voltage decay/hysteresis during cycling, hinder their commercial progress. In this work, an oxygen vacancy-accompanied spinel interface layer is constructed by gas-solid reaction via NiCO 3 treatment at 650 °C, which reduces the asymmetry of anion redox and improves structural stability. Therefore, a 1 mol% NiCO 3 -modified sample powerfully reduces the voltage hysteresis (∼0.23 V) in the first cycle, simultaneously exhibiting an excellent discharge capacity of 275 mA h g -1 at 0.1 C with a capacity retention of 90% for 200 cycles at 1 C.