Wang Xian-Zuo, Zuo Yuting, Qin Yuanbin, Zhu Xu, Xu Shao-Wen, Guo Yu-Jie, Yan Tianran, Zhang Liang, Gao Zhibin, Yu Lianzheng, Liu Mengting, Yin Ya-Xia, Cheng Yonghong, Wang Peng-Fei, Guo Yu-Guo
Center of Nanomaterials for Renewable Energy, State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, P. R. China.
State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, P. R. China.
Adv Mater. 2024 Jun;36(24):e2312300. doi: 10.1002/adma.202312300. Epub 2024 Apr 9.
O3-type layered transition metal cathodes are promising energy storage materials due to their sufficient sodium reservoir. However, sluggish sodium ions kinetics and large voltage hysteresis, which are generally associated with Na diffusion properties and electrochemical phase transition reversibility, drastically minimize energy density, reduce energy efficiency, and hinder further commercialization of sodium-ion batteries (SIBs). Here, this work proposes a high-entropy tailoring strategy through manipulating the electronic local environment within transition metal slabs to circumvent these issues. Experimental analysis combined with theoretical calculations verify that high-entropy metal ion mixing contributes to the improved reversibility of redox reaction and O3-P3-O3 phase transition behaviors as well as the enhanced Na diffusivity. Consequently, the designed O3-NaNiFeCoMnTiCuO material with high-entropy characteristic could display a negligible voltage hysteresis (<0.09 V), impressive rate capability (98.6 mAh g at 10 C) and long-term cycling stability (79.4% capacity retention over 2000 cycles at 5 C). This work provides insightful guidance in mitigating the voltage hysteresis and facilitating Na diffusion of layered oxide cathode materials to realize high-rate and high-energy SIBs.
O3型层状过渡金属阴极因其充足的钠储存能力而成为很有前景的储能材料。然而，通常与钠扩散特性和电化学相变可逆性相关的缓慢的钠离子动力学和较大的电压滞后，极大地降低了能量密度，降低了能量效率，并阻碍了钠离子电池（SIB）的进一步商业化。在此，这项工作提出了一种高熵剪裁策略，通过操纵过渡金属板内的电子局部环境来规避这些问题。实验分析与理论计算相结合证实，高熵金属离子混合有助于提高氧化还原反应的可逆性和O3-P3-O3相变行为以及增强的钠扩散率。因此，设计的具有高熵特性的O3-NaNiFeCoMnTiCuO材料可显示出可忽略不计的电压滞后（<0.09 V）、令人印象深刻的倍率性能（10 C时为98.6 mAh g）和长期循环稳定性（5 C下2000次循环后容量保持率为79.4%）。这项工作为减轻层状氧化物阴极材料的电压滞后和促进钠扩散以实现高倍率和高能量的钠离子电池提供了有见地的指导。
