Design of SiO x/TiO2@C hierarchical structure for efficient lithium storage

Junhui Zou; Shuai Yuan; Ying Huang; Xianping Du; Chen Chen; Jiaming Wang

doi:10.1088/1361-6528/acee83

Design of SiO _x/TiO₂@C hierarchical structure for efficient lithium storage

Nanotechnology. 2023 Aug 25;34(45). doi: 10.1088/1361-6528/acee83.

Authors

Junhui Zou¹, Shuai Yuan¹, Ying Huang¹, Xianping Du¹, Chen Chen¹, Jiaming Wang¹

Affiliation

¹ MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an 710072, People's Republic of China.

PMID: 37557095
DOI: 10.1088/1361-6528/acee83

Abstract

The large volume expansion effect and unstable solid electrolyte interface films of SiO_x-based anode materials have hindered their commercial development. It has been shown that composite doping is a general strategy to solve critical problems. In this study, TiO₂-doped core-shell SiO_x/TiO₂@C composites were created using the sol-gel method. On the one hand, the uniformly dispersed TiO₂nanoparticles can alleviate the volume expansion of the SiO_xactive material during the lithiation process. On the other hand, they can react with Li⁺to form Li_xTiO₂, thereby increasing the ion diffusion rate in the composite material. The outer carbon shell acts as a protective layer that not only alleviates the volume expansion of the composite, but also improve the electron migration rate of the composite. The prepared SiO_x/TiO₂@C composite has a reversible capacity of 828.2 mA h g^-1(0.2 A g^-1100 cycles). After 500 cycles, it still maintains a reversible capacity of 500 mA h g^-1even at a high current density of 2 A g^-1. These findings suggest that SiO_x/TiO₂@C composites have a bright future in applications.

Keywords: SiO x -based anode materials; anatase-phase TiO2; electrochemical characteristic; lithium-ion batteries.