Three‐Layer Structured SnO<sub>2</sub>@C@TiO<sub>2</sub> Hollow Spheres for High‐Performance Sodium Storage
Yu Tian, Ping Hu, Ting Zhu, Zhenhui Liu, Guangwu Hu, Congcong Cai, Zelang Jian, Liang Zhou, Liqiang Mai
Abstract
The unsatisfactory conductivity and large volume variation severely handicap the application of SnO 2 in sodium‐ion batteries (SIBs). Herein, we design unique three‐layer structured SnO 2 @C@TiO 2 hollow spheres to tackle the above‐mentioned issues. The hollow cavity affords empty space to accommodate the volume variation of SnO 2 , while the C and TiO 2 protecting shells strengthen the structural integrity and enhances the electrical conductivity. As a result, the three‐layer structured SnO 2 @C@TiO 2 hollow spheres demonstrate enhanced Na storage performances. The SnO 2 @C@TiO 2 manifests a reversible capacity two times to that of pristine SnO 2 hollow spheres. In addition, Ex situ XRD reveals highly reversible alloying and conversion reactions in SnO 2 @C@TiO 2 hollow spheres. This study suggests the introduction of a hollow cavity and robust protecting shells is a promising strategy for constructing SIB anode materials.