One-Step Sintering Coating toward Air-Stable O3-Type Layered Oxide Cathodes for Sodium-Ion Batteries
Yibo Pan, Xing Zhou, Deda Peng, Run Liu, Yongyuan Zhou, Jin Han, Tiefeng Liu, Ya You
Abstract
Layered oxides are one of the most promising cathode materials for sodium-ion batteries due to their high theoretical capacity, high voltage platform, and low manufacturing cost. However, the poor air stability severely limits the practical application of the O3-type layered oxide. In this study, a simple one-step sintering coating method is explored to construct a uniform and dense heavy metal oxide (Sb 2 O 3 ) coating layer on Na(Ni 1/3 Fe 1/3 Mn 1/3 )O 2 (NFM333), and the coating layer effectively improved the air stability of NFM333 by mitigating the contact of H 2 O and CO 2 in the air. Consequently, NFM333–0.5 wt % Sb 2 O 3 obtains a specific capacity of 92.1 mAh g –1 with a capacity retention of 84.6% after 200 cycles at 1C after exposure in air with 60% humidity for 2 days, while NFM333 without a coating layer has a specific capacity of just 85.4 mAh g –1 with a capacity retention of 65.3% after 200 cycles at 1C after the same exposure handling. This study presents a facile coating method to improve the air stability of O3-type NFM33, which provides insights for the development of air-stable NFM333.