Si─O Molecular Engineering Enhances Cathode-Anode Interface Stability for High-Loading and High-Voltage Layered...

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Nickel-rich layered cathodes and lithium metal anodes are key for next-generation high-energy-density batteries.
• Unstable electrode-electrolyte interfaces cause degradation and failure, especially at high voltages and loadings.

Purpose of the Study:

• To develop an electrolyte stabilizer for improving the interfacial stability of nickel-rich cathode/lithium metal batteries.
• To overcome high-voltage limitations and enhance cycle life in these advanced battery systems.

Main Methods:

• Synthesized a fluorosilane-coupled electrolyte stabilizer: 1H, 1H, 2H, 2H-perfluorooctyltrimethoxysilane (PFOTMS).
• Investigated the adsorption energy of PFOTMS with LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) cathode.
• Analyzed the interfacial layer formed and its effect on battery performance.

Main Results:

• PFOTMS exhibits higher adsorption energy with the NCM811 cathode than conventional solvents.
• An interfacial layer rich in F and Si─O species effectively stabilizes the cathode structure and suppresses transition metal migration.
• Li||NCM811 batteries retained 80.8% capacity after 600 cycles at 4.7 V; Li||LiCoO₂ cells with high mass loading retained 92.79% after 500 cycles at 4.4 V.

Conclusions:

• The fluorosilane stabilizer effectively mitigates interfacial instability in high-voltage nickel-rich cathode/lithium metal batteries.
• This approach enhances Li⁺ conduction, promotes uniform Li deposition, and suppresses detrimental side reactions.
• The developed interfacial stabilization strategy overcomes critical limitations for practical high-energy battery applications.