Single‐Crystalline TiO<sub>2</sub>(B) Nanobelts with Unusual Large Exposed {100} Facets and Enhanced Li‐Storage Capacity
Qiang Wang, Lei Shen, Tong Xue, Gao Cheng, Cheng Zhi Huang, Hong Jin Fan, Yuan Ping Feng
Abstract
Abstract The {100} facet of single‐crystalline TiO 2 (B) is an ideal platform for inserting Li ions, but it is hard to be obtained due to its high surface energy. Here, the single‐crystalline TiO 2 (B) nanobelts from H 2 Ti 3 O 7 with nearly 70% {100} facets exposed are synthesized, which significantly enhances Li‐storage capacity. The first‐principle calculations demonstrate an ab in‐plane 2D diffusion through the exposed {100} facets. As a consequence, the nanobelts can significantly accommodate Li ions in LiTiO 2 formula with specific capacity up to 335 mAh g −1 , which is in good agreement with the electrochemical characterizations. Coating with conductive and protective poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate), the cut‐off discharge voltage is as low as 0.5 V, leading to a capacity of 160.7 mAh g −1 after 1500 cycles with a retention rate of 66% at 1C. This work provides a practical strategy to increase the Li‐ion capacity and cycle stability by tailoring the crystal orientation and nanostructures.