Yu Lianzheng, Xing Xuan-Xuan, Zhang Si-Yuan, Zhang Xiaoyan, Han Xiaogang, Wang Peng-Fei, Xu Sailong
State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
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, China.
ACS Appl Mater Interfaces. 2021 Jul 21;13(28):32948-32956. doi: 10.1021/acsami.1c06576. Epub 2021 Jul 9.
O3-type sodium-layered oxides (such as antimony-based O3 structures) have been suggested as one of the most fascinating cathode materials for sodium-ion batteries (SIBs). Honeycomb-ordered antimony-based O3 structures, however, unsatisfactorily exhibit complex phase transitions and sluggish Na kinetics during cycling. Herein, we prepared a completely cationic-disordered O3-type NaNiSbO compound by composition regulation for SIBs. Surprisingly, the measured redox potentials for typical O3-P3 phase transition are located at 3.4 V. Operando X-ray diffraction confirms a reversible phase transition process from the O3 to P3 structure accompanied with a very small volume change (1.0%) upon sodium extraction and insertion. The low activation barrier energy of 400 meV and the fast Na migration of 10 cm·s are further obtained by first-principles calculations and galvanostatic intermittent titration technique, respectively. As a result, the O3-NaNiSbO cathode displays a reversible capacity of 106 mA h g at 0.1C (12 mA g), smooth charge-discharge curves, and a high average working voltage of 3.5 V during battery cycling. The results highlight the importance of searching for a new O3-type structure with cation-disordering and high working voltage for realizing high energy SIBs.
O3型钠层状氧化物（如锑基O3结构）被认为是钠离子电池（SIBs）中最具吸引力的阴极材料之一。然而，蜂窝状有序的锑基O3结构在循环过程中表现出复杂的相变和缓慢的钠动力学，不尽人意。在此，我们通过成分调控制备了一种用于SIBs的完全阳离子无序的O3型NaNiSbO化合物。令人惊讶的是，典型O3-P3相变的测量氧化还原电位位于3.4 V。原位X射线衍射证实了从O3到P3结构的可逆相变过程，在钠脱嵌时伴随着非常小的体积变化（1.0%）。通过第一性原理计算和恒电流间歇滴定技术分别进一步获得了400 meV的低活化势垒能量和10 cm·s的快速钠迁移率。结果，O3-NaNiSbO阴极在0.1C（12 mA g）下显示出106 mA h g的可逆容量、平滑的充放电曲线以及电池循环期间3.5 V的高平均工作电压。这些结果突出了寻找具有阳离子无序和高工作电压的新型O3型结构对于实现高能量SIBs的重要性。
