Si-induced insertion of Li into SiC to form Li-rich SiC twin crystal--颗粒学报PARTICUOLOGY

Zhang, D., Zhang, C., Lu, F., Jiang, H., & Wei, F. (2023). Si-induced insertion of Li into SiC to form Li-rich SiC twin crystal. Particuology, 74, 56-63. https://doi.org/10.1016/j.partic.2022.05.009

Si-induced insertion of Li into SiC to form Li-rich SiC twin crystal

Di Zhang, Chenxi Zhang ^*, Feng Lu, Hairong Jiang, Fei Wei ^*

Received 13 April 2022, Revised 13 May 2022, Accepted 13 May 2022, Available online 28 May 2022, Version of Record 13 June 2022.

10.1016/j.partic.2022.05.009

Volume 74, March 2023, Pages 56-63

Received 13 April 2022, Revised 13 May 2022, Accepted 13 May 2022, Available online 28 May 2022, Version of Record 13 June 2022.

E-mail: cxzhang@tsinghua.edu.cn; wf-dce@tsinghua.edu.cn

Highlights

• Li has a discernible effect on the core-shell structured Si@SiC.

• Li easily inserts into the (111) plane of SiC in the presence of Si.

• A well-organized Li-rich SiC twin crystal is formed.

• This Li-rich SiC twin crystal can be a promising candidate for application in high-capacity Li-ion batteries cathode.

• Si-induced Li insertion contributes to the changes in the surface species and structure of pristine SiC.

Abstract

The energy density of Li-ion batteries is closely related to the capacity and average voltage of cathode materials. Unfortunately, current cathode materials either have low capacity or voltage, which limits the development of high-energy-density Li-ion batteries. This has given challenge to many attempts to develop new cathode materials with high capacity and voltage. In this study, we find that Li easily inserts into the (111) plane of SiC in the presence of Si, and a well-organized Li-rich SiC twin crystal is formed. Ultraviolet–visible diffuse reflectance spectra and electrochemical test results suggest that this Li-rich SiC twin crystal possesses the band gap energy of 3.5 eV and charging capacity of 1979 mAh/g at the current density of 200 mA/g, making it a promising candidate for the cathode material in high-capacity Li-ion batteries. X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy results reveal that Si-induced Li insertion contributes to the changes in the surface species and structure of pristine SiC. These findings suggest that the Li-rich SiC twin crystal raises new possibilities for the development of high-capacity cathode materials and merits further investigation to expand its application scope.

Graphical abstract

Keywords

Si; Li insertion; SiC; Li-rich twin crystal; Cathode; Li-ion batterie

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