Revealing the Dynamic Evolution of Electrolyte Configuration on the Cathode-Electrolyte Interface by Visualizing (De)...

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Electrolyte engineering is key for enhancing lithium-ion battery performance, particularly at high voltages.
• Current strategies often overlook the dynamic interface between cathode and electrolyte, crucial for cathode electrolyte interphase (CEI) formation.

Purpose of the Study:

• To investigate the anti-synergy effect between Li+-solvation and interfacial electric fields at the cathode-electrolyte interface.
• To understand how this effect influences the dynamic evolution of electrolyte solvation and CEI construction.

Main Methods:

• Visualization of dynamic electrolyte solvation configuration at the cathode-electrolyte interface.
• Analysis of interfacial Li+-solvation concentration under varying electrochemical conditions.
• Modification of electrochemical protocols and electrolyte formulations.

Main Results:

• An anti-synergy effect was identified, where Li+-solvation promotes a concentrated interface while the electric field induces a diluted interface.
• This dynamic influences the formation of anion-derived vs. solvent-derived CEI.
• Regulating the 'inflection voltage' prolonged the concentrated interface lifetime and improved CEI functionality.

Conclusions:

• The study reveals a critical interplay between solvation and electric fields governing CEI formation.
• Optimizing electrolyte and electrochemical protocols can mitigate anti-synergy effects, enhancing battery performance.
• This provides a new avenue for designing advanced electrolytes for high-performance lithium-ion batteries.