Bifunctional Electrolyte Additive Enabling Simultaneous Interphase Formation on Both Electrodes in High-Energy...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Next-generation Lithium-ion batteries (LIBs) require stable electrode interphases for improved performance.
• Electrolyte additives offer a direct strategy for facilitating effective interphase formation.

Purpose of the Study:

• To introduce and evaluate a novel bifunctional electrolyte additive for LIBs.
• To investigate the simultaneous formation of solid electrolyte interphase (SEI) and cathode electrolyte interphase (CEI).

Main Methods:

• Synthesis and incorporation of a bifunctional additive combining vinylene carbonate (VC) and thiophene motifs.
• Electrochemical performance testing in NMC811||AG + 20% SiO_x pouch cells.
• Advanced characterization using XPS, SEM, and operando SHINERS to confirm interphase formation.

Main Results:

• The additive successfully formed both VC-assisted SEI and polythiophene-based CEI in situ.
• Significant improvements in overall battery performance were observed compared to baseline electrolytes.
• Dual interphase stabilization was confirmed through multiple advanced characterization techniques.

Conclusions:

• A new design strategy for multifunctional electrolyte additives was demonstrated.
• Simultaneous stabilization of both electrodes via dual interphase formation enhances LIB performance and lifetime.
• This approach presents a promising pathway for advancing LIB technology.