Xue Haitao, Lian Zhiyue, Liu Yanjiao, Liu Yunying, Liu Qi, Qiu Hengrui, Zhang Yongqiang, He Wenxiu
School of Chemistry and Chemical Engineering, Inner Mongolia University of Science & Technology, Baotou, Inner Mongolia, 014010, China.
Beijing Key Laboratory of Environment Science and Engineering, School of Material Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China.
Small Methods. 2025 Jul 26:e01022. doi: 10.1002/smtd.202501022.
Fe/Mn-based P2-type layered oxides are promising cathodes for sodium-ion batteries (SIBs), yet suffer from poor cycling stability due to Jahn-Teller distortion of Mn and irreversible P2-Z phase transitions. In this study, a multi-element doping strategy involving Cu, Mg, and La is employed to construct a structurally stable P2/O3 composite, NaFeMnCuMgLaO (FMCML), via a sol-gel method and high-temperature calcination. The synergistic doping suppresses Mn redox activity, mitigates lattice distortion, and enhances Na diffusion kinetics. Notably, La incorporation induces LaO octahedral formation, which refines particle size and boosts crystallinity. As a result, FMCML exhibits outstanding rate performance and long-term durability, with capacity retentions of 99.11%, 87.21%, and 74.92% after 100, 300, and 1600 cycles at 200, 1000, and 2000 mA·g, respectively. The dual-phase structure promotes structural reversibility, suppresses Na/vacancy ordering, and enhances ambient air stability. This work offers a practical approach to designing robust layered oxide cathodes through rational phase and composition engineering, paving the way for next-generation high-performance SIBs.
铁/锰基P2型层状氧化物是很有前景的钠离子电池（SIBs）正极材料，但由于锰的 Jahn-Teller 畸变和不可逆的P2-Z相变，其循环稳定性较差。在本研究中，采用了一种涉及铜、镁和镧的多元素掺杂策略，通过溶胶-凝胶法和高温煅烧构建了一种结构稳定的P2/O3复合材料NaFeMnCuMgLaO（FMCML）。协同掺杂抑制了锰的氧化还原活性，减轻了晶格畸变，并增强了钠扩散动力学。值得注意的是，镧的掺入诱导了LaO八面体的形成，细化了颗粒尺寸并提高了结晶度。结果，FMCML表现出出色的倍率性能和长期耐久性，在200、1000和2000 mA·g下循环100、300和1600次后，容量保持率分别为99.11%、87.21%和74.92%。双相结构促进了结构可逆性，抑制了钠/空位有序化，并增强了在环境空气中的稳定性。这项工作为通过合理的相和成分工程设计坚固的层状氧化物正极提供了一种实用方法，为下一代高性能钠离子电池铺平了道路。
