Al‐substituted stable‐layered P2‐Na _{0 . 6} Li _{0 . 15} Al _{0 . 15} Mn _{0 . 7} O ₂ cathode for sodium ion batteries

Abstract

P2-type Mn-based layered oxides have been considered as one of the most commercial potential cathodes for the sodium-ion batteries (SIBs) owing to the low cost, low toxicity, and abundant compositions. However, the P2-type cathode still possesses a lot of drawbacks, such as the unfavorable phase transition and poor-rate performance during the desosidation/sodiation process. Herein, we developed P2-Na0.6Li0.15Al0.15Mn0.7O2 as a promising sodium cathode with a stable performance. The batteries with this new cathode deliver 184.9 mAh/g initial reversible capacity at 0.2 C and exhibit preferable rate properties. By investigating multiple characterizations, the Al-substituted P2-Na0.6Li0.15Al0.15Mn0.7O2 is found to be absent of phase transition in the first cycle process from the ex-situ XRD characterization results. In addition, the surface charge transfer reactions have been also investigated. This work may shed substantial light on developing high-rate capability and stable Mn-based cathode materials for practical SIBs.