Advanced Materials ( IF 19.791 ) Pub Date : 2018-01-03 , DOI: 10.1002/adma.201704337 Jiangfeng Ni, Shidong Fu, Yifei Yuan, Lu Ma, Yu Jiang, Liang Li, Jun Lu
Sodium-ion batteries (SIBs) offer a promise of a scalable, low-cost, and environmentally benign means of renewable energy storage. However, the low capacity and poor rate capability of anode materials present an unavoidable challenge. In this work, it is demonstrated that surface phosphorylated TiO2 nanotube arrays grown on Ti substrate can be efficient anode materials for SIBs. Fabrication of the phosphorylated nanoarray film is based on the electrochemical anodization of Ti metal in NH4F solution and subsequent phosphorylation using sodium hypophosphite. The phosphorylated TiO2 nanotube arrays afford a reversible capacity of 334 mA h g−1 at 67 mA g−1, a superior rate capability of 147 mA h g−1 at 3350 mA g−1, and a stable cycle performance up to 1000 cycles. In situ X-ray diffraction and transmission electron microscopy reveal the near-zero strain response and robust mechanical behavior of the TiO2 host upon (de)sodiation, suggesting its excellent structural stability in the Na+ storage application.
TiO2 nanotube arrays on Ti substrate functionalized by surface phosphorylation are directly adapted as efficient anodes for sodium-ion batteries. Benefiting from synergy of unique nanotube structure, 3D array architecture, and high surface reactivity, the TiO2 arrays afford a high reversible capacity of 334 mA h g−1 and a superior rate capability of 147 mA h g−1 at 3350 mA g−1.