Constructing stable solid electrolyte interfaces and facilitating Li transport via an electrolyte additive for...

Area of Science:

• Electrochemistry
• Materials Science
• Battery Technology

Background:

• The development of stable solid electrolyte interphase (SEI) and cathode electrolyte interphase (CEI) layers is crucial for advanced battery performance.
• Electrolyte additives play a key role in modifying interphase formation and improving battery longevity.

Purpose of the Study:

• To investigate the efficacy of N-methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA) as a novel electrolyte additive for lithium-ion batteries.
• To evaluate the impact of MSTFA on the stability and performance of lithium metal and lithium iron phosphate (LiFePO4) battery cells.

Main Methods:

• Electrochemical testing of Li‖Li and LiFePO4‖Li cells with electrolytes containing MSTFA.
• Analysis of the formation and stability of the SEI/CEI layers.

Main Results:

• MSTFA was observed to integrate into the solvation structure, promoting the formation of a stable SEI/CEI.
• Li‖Li cells demonstrated stable cycling for 400 cycles with the MSTFA-containing electrolyte.
• LiFePO4‖Li cells exhibited excellent capacity retention of 93.6% after 500 cycles at a high rate of 5C.

Conclusions:

• MSTFA is a promising electrolyte additive for enhancing the cycle life and stability of lithium-based batteries.
• The formation of a robust SEI/CEI layer by MSTFA contributes significantly to improved battery performance.