J. Mater. Sci. Technol. ›› 2022, Vol. 107: 64-69.DOI: 10.1016/j.jmst.2021.08.035

• Research Article • Previous Articles     Next Articles

Interlayer gap widened TiS2 for highly efficient sodium-ion storage

Chengcheng Huang, Yiwen Liu, Runtian Zheng, Zhengwei Yang, Zhonghao Miao, Junwei Zhang, Xinhao Cai, Haoxiang Yu, Liyuan Zhang, Jie Shu*()   

  1. School of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, China
  • Received:2021-06-08 Revised:2021-06-08 Accepted:2021-06-08 Published:2022-04-30 Online:2022-04-28
  • Contact: Jie Shu
  • About author:* E-mail address: shujie@nbu.edu.cn (J. Shu).
    First author contact:1These authors contributed equally to this work.

Abstract:

As an alternative for lithium-ion batteries (LIBs), sodium-ion batteries (SIBs) have lately received tremendous interest due to their abundant reserves as well as low cost. Nevertheless, the lack of suitable anode materials severely hinders the application of sodium-ion batteries. TiS2 is elected as a representative material owing to its unique layered structure. But it always suffers from capacity fade due to poor electrochemical kinetics and structural stability. In this work, we fabricate a pre-potassiated TiS2 as a host material for sodium storage by an electrochemical pre-potassiation strategy. The intercalation/extraction mechanism, structural changes and reaction kinetics are completely investigated to reveal the outstanding electrochemical property of pre-potassiated TiS2 electrode. It turns out that the large interlayer space of pre-potassiated TiS2 is conducive to the diffusion of sodium ions, inducing the reduction of entropic barrier for the electrochemical reactions. In addition, the pre-potassiated host structure is still firmly maintained upon repeated cycles. Therefore, the pre-potassiated TiS2 presents superior rate capability (165.9 mA h g-1 at 1 C and 132.1 mA h g -1 at 20 C) and long-term cycling stability (85.3% capacity retention at 5 C after 500 cycles) for SIBs. This research provides an avenue to construct long-life sodium energy storage systems based on pre-potassiated TiS2.

Key words: Pre-potassiation, TiS2, Expanded interlayer gap, Anode material, Sodium-ion batteries