Low-temperature electrolytes based on linear carboxylic ester co-solvents for SiO /graphite composite anodes

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Silicon-based anodes offer high energy density for lithium-ion batteries.
• Low-temperature electrolyte performance remains a critical challenge for silicon anodes.

Purpose of the Study:

• To investigate the impact of ethyl propionate (EP) as a co-solvent on silicon-based anode performance.
• To evaluate the electrochemical behavior of EP-containing electrolytes at low temperatures.

Main Methods:

• Electrolyte formulation with ethyl propionate (EP) co-solvent.
• Electrochemical testing of SiO/graphite (SiOC) composite anodes at various temperatures.
• Analysis of full cell performance (SiOC‖LiCoO2) under low-temperature cycling.

Main Results:

• EP-containing electrolytes significantly improve anode performance at -50 °C.
• SiOC anodes show 680.31 mA h g⁻¹ capacity at -50 °C and 97.02% retention after 100 cycles at 25 °C.
• Full cells demonstrate superior cycling stability at -20 °C with EP.

Conclusions:

• Ethyl propionate (EP) effectively enhances silicon-based anode stability and performance, especially at low temperatures.
• EP likely promotes a stable solid electrolyte interphase with improved ion transport.
• This research offers a promising electrolyte strategy for advanced lithium-ion batteries.