TY - JOUR AU - Emma J Hopkins AU - Sarah Frisco AU - Ryan T Pekarek AU - Caleb Stetson AU - Zoey Huey AU - Steven Harvey AU - Xiang Li AU - Baris Key AU - Chen Fang AU - Gao Liu AU - Guang Yang AU - Glenn Teeter AU - Nathan R Neale AU - Gabriel M Veith AB -

We demonstrate that the addition of CO2 to a standard 1.0 M LiPF6 3:7 wt% ethylene carbonate:ethyl methyl carbonate electrolyte results in the formation of a thinner insoluble solid electrolyte interphase (SEI) that is dominated by the presence of LiF. In contrast, cells without CO2 result in a thicker insoluble SEI layer containing more organic constituents. The CO2 is incorporated in the dimethyl carbonate soluble part of the SEI composed primarily of polymeric poly(ethylene oxide) (PEO) on the surface of a thin inorganic layer. This combination of properties from CO2 addition provides an improved cycling performance through the reduction of irreversible side reactions, leading to higher coulombic efficiency. The results indicate that CO2 incorporates into the SEI and plays a role similar to additives like fluorinated ethylene carbonate and vinylene carbonate with respect to polymeric components.

BT - Journal of The Electrochemical Society DA - 01/2021 DO - 10.1149/1945-7111/abec66 IS - 3 LA - eng N2 -

We demonstrate that the addition of CO2 to a standard 1.0 M LiPF6 3:7 wt% ethylene carbonate:ethyl methyl carbonate electrolyte results in the formation of a thinner insoluble solid electrolyte interphase (SEI) that is dominated by the presence of LiF. In contrast, cells without CO2 result in a thicker insoluble SEI layer containing more organic constituents. The CO2 is incorporated in the dimethyl carbonate soluble part of the SEI composed primarily of polymeric poly(ethylene oxide) (PEO) on the surface of a thin inorganic layer. This combination of properties from CO2 addition provides an improved cycling performance through the reduction of irreversible side reactions, leading to higher coulombic efficiency. The results indicate that CO2 incorporates into the SEI and plays a role similar to additives like fluorinated ethylene carbonate and vinylene carbonate with respect to polymeric components.

PY - 2021 EP - 030534 ST - J. Electrochem. Soc. T2 - Journal of The Electrochemical Society TI - Examining CO2 as an Additive for Solid Electrolyte Interphase Formation on Silicon Anodes VL - 168 SN - 0013-4651 ER -