Characterizing Solid Electrolyte Interphase on Sn Anode in Lithium Ion Battery

Daniel M Seo,Brett L Lucht,David R Heskett,Joseph C Woicik,Benjamin T Young,Cao Cuong Nguyen

doi:10.1149/2.0121513jes

Abstract

Tin (Sn) nanoparticle electrodes have been prepared and battery cycling performance has been investigated with 1.2 M LiPF6 in ethylene carbonate (EC) / diethyl carbonate (DEC) electrolyte (1:1, w/w) with and without added vinylene carbonate (VC) or fluoroethylene carbonate (FEC). Incorporation of either VC or FEC improves the capacity retention of Sn nanoparticle electrodes although incorporation of VC also results in a significant increase in cell impedance. The best electrochemical performance was observed with electrolyte containing 10% of added FEC. In order to develop a better understanding of the role of the electrolyte in capacity retention and solid electrolyte interface (SEI) structure, ex-situ surface analysis has been performed on cycled electrodes with infrared (IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and Hard XPS (HAXPES). The ex-situ analysis reveals a correlation between electrochemical performance, electrolyte composition, and SEI structure.

Highlights

In order to develop a better understanding of the role of the electrolyte in solid electrolyte interface (SEI) formation and stability, the Sn nanoparticle electrodes were extracted from cells and ex-situ surface analysis with infrared with attenuated total reflectance (IR-ATR), X-ray photoelectron spectroscopy (XPS) and Hard XPS (HAXPES) was conducted
The first cycle efficiencies for cells cycled with added fluoroethylene carbonate (FEC) or vinylene carbonate (VC) are slightly lower than the standard electrolyte due to the reduction of FEC or VC to form a protective SEI on the tin electrodes
The SEI for cells cycled with electrolyte containing FEC has a similar evolution to the SEI for the cells cycled with the standard electrolyte, the evolution results in significantly less capacity fade and related electrolyte decomposition (Table I).[27]

Summary

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Characterizing Solid Electrolyte Interphase on Sn Anode in Lithium Ion Battery. This article is available at DigitalCommons@URI: https://digitalcommons.uri.edu/chm_facpubs/125

JES FOCUS ISSUE ON ELECTROCHEMICAL INTERFACES IN ENERGY STORAGE SYSTEMS

Results and Discussion

Conclusions