Synthesis of NaNi0.5Mn0.5O2 cathode materials for sodium-ion batteries via spray pyrolysis method

Abstract

Because of the rich sodium reserves in nature, low cost, and high initial sodium content, O3-NaNi0.5Mn0.5O2 material stands out from other cathode materials. However, O3-NaNi0.5Mn0.5O2 shows poor kinetics and undergoes serious irreversible phase transitions, resulting in structural collapse and deteriorated cyclic performance. Herein, NaNi0.5Mn0.5O2 material with distinguished cyclic and rate performance was prepared via spray pyrolysis combined with a high-temperature solid-phase sintering method, which can deliver a specific capacity of 98.4 mAh g−1 at 1 C between 2.0 and 4.0 V. After 100 cycles, it shows outstanding capacity retention of 89.1 %. Moreover, it can recover 70.4 % of the capacity of 0.1 C even at a high rate of 10 C. This newly proposed synthesis method provides an alternative method to prepare superior electrode materials for sodium-ion batteries.