Tuning single-phase medium-entropy oxides derived from nanoporous NiCuCoMn alloy as a highly stable anode for Li-ion batteries  

作　　者：Zhen-Yang Yu Qi Sun Hao Li Zhi-Jun Qiao Wei-Jie Li Shu-Lei Chou Zhi-Jia Zhang Yong Jiang 

机构地区：[1]School of Mechanical Engineering,Tiangong University,Tianjin,300387,China [2]State Key Laboratory for Powder Metallurgy,Central South University,Changsha,410083,China [3]School of Material Science and Engineering,Tiangong University,Tianjin,300387,China [4]School of Electronic and Information Engineering,Institute of Quantum Materials and Devices,Tiangong University,Tianjin,300387,China

出　　处：《Rare Metals》2023年第9期2982-2992,共11页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (Nos. 52271011, 52102291 and 51701142)。

摘　　要：Incorporating four cations into a single-phase oxide is beneficial for maintaining structural stability during Li+insertion/desertion because of the produced entropy-dominated phase stabilization effects. However,medium-entropy oxides exhibit inherently poor electron and ion conductivity. As such, in this work, a single-phase medium-entropy oxide of Ni_(x)Cu_(y)CozMn_(1-x-y-z)O(named as NCCM@oxides(H_(2))) is prepared by modified-NiCuCoMn alloy through the epitaxial-growing-based self-combustion and hydrogen reduction. During hydrogen reduction, some Cu ions are reduced to elemental Cu(defined as Cu^(0)),which is distributed among the metal oxides, while generating extensive oxygen vacancies around Cu. The synergetic effect between nanoporous metal-core oxide-shell structure and enriched oxygen/Cu^(0) vacancies greatly enhances the electronic/ionic conductivity. In addition, the lattice of single-phase quaternary metal oxides has the configuration entropy stability, which enables the rock-salt structure to remain stable during repeated conversion reactions. Benefiting from the above-mentioned merits, the anodeforLi-ionbatterieswithentropy-stabled NCCM@oxides(H_(2)) composite shows a high specific capacity of 699 mAh·g^(-1) at 0.1 A·g^(-1) and ultra-stable cycling stability, which maintains 618 and 489 mAh·g^(-1) at 0.1 and 1.0 A·g^(-1) after 200 cycles, respectively. This is the first use of this novel and simple strategy for modifying medium-entropy oxides, which paves the way for the development of high-entropy oxides as high-performance electrodes.

关 键 词：NiCuCoMn alloy Medium-entropy oxides Li-ion batteries Ultrahigh stability Mechanism 

分 类 号：TM912[电气工程—电力电子与电力传动] TB383.1[一般工业技术—材料科学与工程]