Three‐Layer Structured SnO2@C@TiO2 Hollow Spheres for High‐Performance Sodium Storage

• Published in: Energy & environmental materials (Hoboken, N.J.) Vol. 4; no. 3; pp. 428 - 433
• Main Authors: Tian, Yu, Hu, Ping, Zhu, Ting, Liu, Zhenhui, Hu, Guangwu, Cai, Congcong, Jian, Zelang, Zhou, Liang, Mai, Liqiang
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.07.2021
• Subjects: Anodes; Anodic protection; Electrical conductivity; Electrical resistivity; Electrode materials; hollow sphere; protecting shell; Rechargeable batteries; Shells; SnO2; Sodium; Sodium-ion batteries; sodium‐ion battery; Structural integrity; Tin dioxide; Titanium dioxide
• ISSN: 2575-0356; 2575-0356
• DOI: 10.1002/eem2.12117

The unsatisfactory conductivity and large volume variation severely handicap the application of SnO2 in sodium‐ion batteries (SIBs). Herein, we design unique three‐layer structured SnO2@C@TiO2 hollow spheres to tackle the above‐mentioned issues. The hollow cavity affords empty space to accommodate the volume variation of SnO2, while the C and TiO2 protecting shells strengthen the structural integrity and enhances the electrical conductivity. As a result, the three‐layer structured SnO2@C@TiO2 hollow spheres demonstrate enhanced Na storage performances. The SnO2@C@TiO2 manifests a reversible capacity two times to that of pristine SnO2 hollow spheres. In addition, Ex situ XRD reveals highly reversible alloying and conversion reactions in SnO2@C@TiO2 hollow spheres. This study suggests the introduction of a hollow cavity and robust protecting shells is a promising strategy for constructing SIB anode materials. Unique three‐layer structured SnO2@C@TiO2 hollow spheres are designed to tackle the low electrical conductivity and large volume expansion issues of SnO2. The as‐designed SnO2@C@TiO2 hollow spheres demonstrate improved Na storage performances.