Designing Advanced Electrolytes for High-Voltage High-Capacity Disordered Rocksalt Cathodes.

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• Lithium (Li)-excess transition metal oxides with cation-disordered rock salt (DRX) structures offer potential for low-cost, high-energy-density Li batteries.
• Current Li-ion battery electrolytes lack the high-voltage stability required for advanced DRX cathodes.
• Electrolyte solvation structure critically impacts battery performance and stability.

Purpose of the Study:

• To investigate the structure-property relationships of electrolytes with varying solvent-to-diluent ratios.
• To develop advanced electrolytes with enhanced high-voltage stability for DRX cathodes.
• To guide the design of novel electrolytes for next-generation Li batteries.

Main Methods:

• Systematic investigation using theoretical calculations.
• Experimental testing and analysis of electrolyte properties.
• Correlation of solvation structure with electrochemical performance.

Main Results:

• Developed electrolytes with unique solvation structures exhibiting high voltage stability.
• Demonstrated enhanced formation of stable electrode/electrolyte interphases.
• Achieved improved specific capacity and cycle life in Li||Li_1.094Mn_0.676Ti_0.228O₂ (LMTO) DRX cells using optimized electrolytes compared to conventional ones.

Conclusions:

• Understanding electrolyte solvation structure is key to designing high-performance electrolytes for high-voltage DRX cathodes.
• Optimized controlled-solvation electrolytes significantly improve the stability and cycling life of Li||LMTO cells.
• This work provides a foundation for developing advanced electrolytes crucial for emerging high-voltage cathode technologies.