Influence of Additives on the Electrochemical and Interfacial Properties of SiOx-Based Anode Materials for Lithium-Sulfur Batteries

Swamickan Sathya; N Angulakshmi; Jou-Hyeon Ahn; M Kathiresan; A Manuel Stephan

doi:10.1021/acs.langmuir.1c02342

Influence of Additives on the Electrochemical and Interfacial Properties of SiO_x-Based Anode Materials for Lithium-Sulfur Batteries

Langmuir. 2022 Mar 1;38(8):2423-2434. doi: 10.1021/acs.langmuir.1c02342. Epub 2022 Feb 15.

Authors

Swamickan Sathya^{1

2}, N Angulakshmi³, Jou-Hyeon Ahn³, M Kathiresan^{1

2}, A Manuel Stephan^{1

2}

Affiliations

¹ CSIR-Central Electrochemical Research Institute, Karaikudi 630 003, India.
² Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
³ Department of Materials Engineering and Convergence Technology, Gyeongsang National University, 501 Jinju-daero, Jinju 52828, South Korea.

PMID: 35167306
DOI: 10.1021/acs.langmuir.1c02342

Abstract

The influence of electrolyte additives on the electrochemical and interfacial properties of SiO_x-based anodes for lithium-sulfur batteries (Li-S) was systematically investigated. Four different electrolyte additives, namely, lithium nitrate, vinylene carbonate (VC), vinyl ethylene carbonate, and fluoroethylene carbonate (FEC), were added to the bare electrolyte comprising 1 M LiTFSI in tetraethylene glycol dimethyl ether/1,3 dioxolane in a ratio of 1:1 (v/v). The self-extinguishing time (SET) of the liquid electrolytes was measured. The 2032-type half-cells composed of Li/SiO_x/Si/C were assembled, and their charge -discharge studies were analyzed at the 0.1 C-rate. Upon cycling, the electrode materials were subjected to surface morphology and differential scanning calorimetry analyses. The interfacial properties of SiO_x-based electrodes were investigated by electrochemical impedance spectroscopy, Fourier transform infrared, and X-ray photoelectron spectroscopy studies. Among the electrolytes examined, FEC-added electrolytes offered the lowest SET and interfacial resistance values. The superior charge-discharge properties of FEC-added electrolytes were attributed to the formation of a stable solid electrolyte interface layer on the electrode surface. The surface chemistry studies revealed the formation of Li₂CO₃ and ROCO₂Li peaks on the electrode surface.