Bi-affinity Electrolyte Optimizing High-Voltage Lithium-Rich Manganese Oxide Battery via Interface Modulation...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• High-voltage lithium-rich manganese oxide (LRMO) cathodes face challenges in practical application due to electrolyte decomposition and transition metal ion dissolution.
• These issues limit the cycle life and performance of LRMO-based batteries.

Purpose of the Study:

• To develop a bi-affinity electrolyte formulation to enhance the stability and performance of LRMO cathodes.
• To investigate the synergistic effects of ethyl vinyl sulfone (EVS) and fluoroethylene carbonate (FEC) as electrolyte additives.

Main Methods:

• Formulation of a bi-affinity electrolyte using ethyl vinyl sulfone (EVS) and fluoroethylene carbonate (FEC) as additives.
• Investigation of interface modulation strategies to form robust interphase layers on the electrode.
• Analysis of the composition and properties of the cathode electrolyte interphase (CEI).

Main Results:

• The synergistic use of EVS and FEC created robust interphase layers, featuring a dominant -SO2- component and LiF assistance.
• This modified interphase promoted interface transport kinetics and effectively suppressed transition metal ion dissolution.
• The optimized electrolyte significantly inhibited lithium dendrite growth, enabling a 4.8V LRMO/Li cell to retain 97% capacity after 300 cycles at 1C.

Conclusions:

• The bi-affinity electrolyte formulation with EVS and FEC additives is a promising strategy for stabilizing high-voltage LRMO cathodes.
• This approach enhances electrochemical performance, cycle life, and safety by preventing electrolyte decomposition and lithium dendrite formation.
• The study demonstrates a viable pathway for the practical implementation of advanced LRMO-based battery technologies.