Chemical Coupled PEDOT:PSS/Si Electrode: Suppressed Electrolyte Consumption Enables Long-Term Stability

Xuejiao Liu; Zhixin Xu; Asma Iqbal; Ming Chen; Nazakat Ali; CheeTongJohn Low; Rongrong Qi; Jiantao Zai; Xuefeng Qian

doi:10.1007/s40820-020-00564-5

Chemical Coupled PEDOT:PSS/Si Electrode: Suppressed Electrolyte Consumption Enables Long-Term Stability

Nanomicro Lett. 2021 Jan 8;13(1):54. doi: 10.1007/s40820-020-00564-5.

Authors

Xuejiao Liu¹, Zhixin Xu¹, Asma Iqbal¹, Ming Chen¹, Nazakat Ali¹, CheeTongJohn Low², Rongrong Qi³, Jiantao Zai⁴, Xuefeng Qian⁵

Affiliations

¹ School of Chemistry and Chemical Engineering and State Key Laboratory of Metal Matrix Composites, Shanghai Electrochemical Energy Devices Research Center, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China.
² Warwick Electrochemical Engineering Group, Energy Innovation Centre, WMG, University of Warwick, Coventry, CV4 7AL, UK.
³ School of Chemistry and Chemical Engineering and State Key Laboratory of Metal Matrix Composites, Shanghai Electrochemical Energy Devices Research Center, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China. rrqi@sjtu.edu.cn.
⁴ School of Chemistry and Chemical Engineering and State Key Laboratory of Metal Matrix Composites, Shanghai Electrochemical Energy Devices Research Center, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China. zaijiantao@sjtu.edu.cn.
⁵ School of Chemistry and Chemical Engineering and State Key Laboratory of Metal Matrix Composites, Shanghai Electrochemical Energy Devices Research Center, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China. xfqian@sjtu.edu.cn.

Abstract

Huge volume changes of Si during lithiation/delithiation lead to regeneration of solid-electrolyte interphase (SEI) and consume electrolyte. In this article, γ-glycidoxypropyl trimethoxysilane (GOPS) was incorporated in Si/PEDOT:PSS electrodes to construct a flexible and conductive artificial SEI, effectively suppressing the consumption of electrolyte. The optimized electrode can maintain 1000 mAh g^-1 for nearly 800 cycles under limited electrolyte compared with 40 cycles of the electrodes without GOPS. Also, the optimized electrode exhibits excellent rate capability. The use of GOPS greatly improves the interface compatibility between Si and PEDOT:PSS. XPS Ar⁺ etching depth analysis proved that the addition of GOPS is conducive to forming a more stable SEI. A full battery assembled with NCM 523 cathode delivers a high energy density of 520 Wh kg^-1, offering good stability.

Keywords: Conductive binder; Cross-link; Lithium-ion batteries; PEDOT:PSS; Stable SEI; XPS depth analysis.