Wang Ke, Wu Dongxu, Wei Yong, Zhong Linfeng, Wu Chuanqiang, Song Li, Ge Binghui
Information Materials and Intelligent Sensing Laboratory of Anhui Province, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China.
National Synchrotron Radiation Lab, University of Science and Technology of China, Hefei, Anhui 230029, China.
ACS Nano. 2025 Sep 9;19(35):31457-31466. doi: 10.1021/acsnano.5c07211. Epub 2025 Aug 28.
High-entropy oxides represent a burgeoning class of anode materials for lithium-ion batteries. They reduce the mutual repulsion among constituent elements, enhance structural stability, and effectively mitigate volume changes-induced structural collapse and capacity decay during charge-discharge cycles. However, the complex elemental composition of high-entropy oxides complicate their lithium storage mechanism, particularly the evolution of structural stability during cycling, which requires further elucidation. In this work, the spinel-type (ZnMnFeCoNi)O high-entropy oxide was synthesized via the solvothermal method. Transmission electron microscopy reveals that it exhibits an uniform mesoporous microsphere morphology. As an anode material for lithium-ion batteries, it exhibits excellent electrochemical properties, maintaining a reversible capacity of 757.8 mAh g after 1000 cycles at 1000 mA g. In situ transmission electron microscopy clearly indicates that it undergoes only minor volume changes during lithiation and delithiation, with no evidence of structural collapse or cracking. Furthermore, detailed analysis through multiple consecutive charge-discharge cycles elucidate the conversion reaction mechanism of (ZnMnFeCoNi)O high-entropy oxide, involving transformations from high-entropy oxide to metal monomers and back to high-entropy oxide phases. Therefore, optimizing the spinel-type structure of the high-entropy oxide anode material is of great significance for the development of lithium-ion batteries.
高熵氧化物是一类新兴的锂离子电池负极材料。它们减少了组成元素之间的相互排斥，增强了结构稳定性，并有效减轻了充放电循环过程中体积变化引起的结构坍塌和容量衰减。然而，高熵氧化物复杂的元素组成使其锂存储机制变得复杂，尤其是循环过程中结构稳定性的演变，这需要进一步阐明。在这项工作中，通过溶剂热法合成了尖晶石型(ZnMnFeCoNi)O高熵氧化物。透射电子显微镜显示其呈现出均匀的介孔微球形态。作为锂离子电池的负极材料，它表现出优异的电化学性能，在1000 mA g的电流密度下循环1000次后，可逆容量保持在757.8 mAh g。原位透射电子显微镜清楚地表明，在锂化和脱锂过程中它仅发生微小的体积变化，没有结构坍塌或开裂的迹象。此外，通过多个连续充放电循环的详细分析阐明了(ZnMnFeCoNi)O高熵氧化物的转化反应机制，包括从高熵氧化物到金属单体再回到高熵氧化物相的转变。因此，优化高熵氧化物负极材料的尖晶石型结构对锂离子电池的发展具有重要意义。
