Fluorinated Acetic Anhydrides as Electrolyte Additives to Improve Cycling Performance of the Lithium Metal Anode

Satu Kristiina Heiskanen,Brett L Lucht

doi:10.1149/1945-7111/aba079

Satu Kristiina Heiskanen, Brett L Lucht

Open Access

https://doi.org/10.1149/1945-7111/aba079

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Abstract

The investigation of novel fluorinated electrolyte additives for lithium metal anodes has been conducted. Two acetic anhydride derivatives, difluoroacetic anhydride (DFAA) and trifluoroacetic anhydride (TFAA), were investigated in electrolytes composed of LiPF6 in ethylene carbonate (EC) and ethyl methyl carbonate (EMC). The addition of either DFAA or TFAA results in a significant improvement in capacity retention and reversibility of lithium plating. Ex situ surface analysis (XPS, IR-ATR) suggests that incorporation of either TFAA or DFAA results in a lithium carboxylate rich SEI which in turn inhibits SEI degradation resulting in superior cycling performance.

Highlights

To cite this article: Satu Kristiina Heiskanen and Brett L
We investigate two fluorinated acetic anhydride derivatives, difluoroacetic anhydride (DFAA) and trifluoroacetic anhydride (TFAA) as electrolyte additives
This investigation reveals that both TFAA and DFAA improve the reversibility of lithium plating in carbonate electrolyte, and ex situ surface analysis of the plated lithium metal electrodes by X-ray Photoelectron Spectroscopy (XPS) and infra-red with attenuated total reflectance (IR-ATR) suggesting that the additives increase the stability of the solid electrolyte interphase (SEI) to the electrolyte solvents

Summary

Introduction

To cite this article: Satu Kristiina Heiskanen and Brett L. Fluorinated Acetic Anhydrides as Electrolyte Additives to Improve Cycling Performance of the Lithium Metal Anode The performance of several electrolyte formulations containing DFAA and TFAA has been investigated electrochemically in Cu∣∣LiFePO4 cells and by ex situ surface analysis of the plated lithium metal.

Results

Conclusion