Ilmenite Nanotubes for High Stability and High Rate Sodium-Ion Battery Anodes

作者：Litao Yu, Jun Liu, Jun Liu, Xijun Xu, Liguo Zhang, Renzong Hu, Jiangwen Liu, Jiangwen Liu, Liuzhang Ouyang, Lichun Yang, Min Zhu · 发表于：ACS Nano · 年份：2017 · DOI：10.1021/acsnano.7b02136 · 被引用次数：122 · 研究领域：Advancements in Battery Materials、Advanced Battery Materials and Technologies、Extraction and Separation Processes

To solve the problem of large volume change and low electronic conductivity of earth-abundant ilmenite used in rechargeable Na-ion batteries (SIBs), an anode of tiny ilmenite FeTiO 3 nanoparticle embedded carbon nanotubes (FTO⊂CNTs) has been successfully proposed. By introducing a TiO 2 shell on metal–organic framework (Fe-MOF) nanorods by sol–gel deposition and subsequent solid-state annealing treatment of these core–shell Fe-MOF@TiO 2, such well-defined FTO⊂CNTs are obtained. The achieved FTO⊂CNT electrode has several distinct advantages including a hollow interior in the hybrid nanostructure, fully encapsulated ultrasmall electroactive units, flexible conductive carbon matrix, and stable solid electrolyte interface (SEI) of FTO in cycles. FTO⊂CNT electrodes present an excellent cycle stability (358.8 mA h g –1 after 200 cycles at 100 mA g –1 ) and remarkable rate capability (201.8 mA h g –1 at 5000 mA g –1 ) with a high Coulombic efficiency of approximately 99%. In addition, combined with the typical Na 3 V 2 (PO 4 ) 3 cathode to constitute full SIBs, the assembled FTO⊂CNT//Na 3 V 2 (PO 4 ) 3 batteries are also demonstrated with superior rate capability and a long cycle life.