Multiple Strategies to Build High-Performance Spherical Na-Ion Layered Oxide Cathodes.

Li, Xiangnan; Tang, Xinyu; Zhang, Mengdan; Ge, Ming; Liu, Xiaojian; Cui, Yuantao; Xu, Yiwei; Zhang, Huishuang et al. · Nano Lett · 2024

basic_science · Level V

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Abstract

The development prospect of layered transition metal oxides in sodium-ion batteries is excellent, but there are some problems, such as poor cycle stability and a complex phase transition. The spherical NaNi<sub>0.25</sub>Fe<sub>0.15</sub>Mn<sub>0.3</sub>Ti<sub>0.1</sub>Sn<sub>0.05</sub>Co<sub>0.05</sub>Li<sub>0.1</sub>O<sub>2</sub> (SP-HEO) has been developed to address the challenges faced by O3-type layered oxide in sodium-ion batteries. The SP-HEO material is synthesized by piling and high entropy. The multiple strategies combine to enhance the electrochemical performance and air stability. The SP-HEO demonstrated a specific discharge capacity of 150.1 mA h g<sup>-1</sup> at 0.1 C and 100.4 mA h g<sup>-1</sup> at 7 C. Ex situ XRD analysis confirmed that the SP-HEO effectively retards complex phase transitions. This study not only introduces a high-entropy design for high tap density spherical storage materials but also dispels industry concerns regarding the performance of sodium ion layered oxide cathode materials.