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

Because of the rich sodium reserves in nature, low cost, and high initial sodium content, O3-NaNi _0.5Mn _0.5O ₂ material stands out from other cathode materials. However, O3-NaNi _0.5Mn _0.5O ₂ shows poor kinetics and undergoes serious irreversible phase transitions, resulting in structural collapse and deteriorated cyclic performance. Herein, NaNi _0.5Mn _0.5O ₂ 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.