Reviving Sodium Tunnel Oxide Cathodes Based on Structural Modulation and Sodium Compensation Strategy Toward Practical Sodium‐Ion Cylindrical Battery

• DOI: 10.1002/adma.202407994
• Publication Date: 2024-09-02T09:39:36Z
• Authors: Hanxiao Liu; Lingyi Kong; Hongrui Wang; Jiayang Li; Jingqiang Wang; Yanfang Zhu; Hongwei Li; Zhuangchun Jian; Xinbei Jia; Yu Su; Shilin Zhang; Jianfeng Mao; Shuangqiang Chen; Yang Liu; Shulei Chou; Yao Xiao
• Keywords: Sodium oxide; Sodium-ion battery; Prussian blue

Abstract As a typical tunnel oxide, Na 0.44 MnO 2 features excellent electrochemical performance and outstanding structural stability, making it promising cathode for sodium‐ion batteries (SIBs). However, suffers from undesirable challenges such as surface residual alkali, multiple voltage plateaus, low initial charge specific capacity. Herein, an internal external synergistic modulation strategy is adopted by replacing part of the Mn with Ti to optimize bulk phase construct Ti‐containing epitaxial stabilization layer, resulting in reduced + transport kinetics improved water/air stability. Specifically, 0.85 0.15 O using water‐soluble carboxymethyl cellulose binder can realize capacity retention rate 94.30% after 1,000 cycles at 2C, stability further verified kilogram large‐up applications. In addition, taking advantage rich content Prussian blue analog (PBA), PBA‐Na 1‐x x composites are designed compensate insufficient oxide matched hard carbon achieve preparation coin full cell 18650 cylindrical battery satisfactory performance. This work enables application oxides SIBs first time promotes commercialization SIBs.