Nucleophilic Oxygen-Engineering Dual-Gradient Cathode-Electrolyte-Interphase for High-Voltage Lithium-Rich Manganese...

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• High-voltage stability of lithium-rich manganese-based layered oxide (LRMO) cathodes is limited by the cathode electrolyte interphase (CEI), electrolyte oxidative stability, and transition metal dissolution.
• Achieving stable operation at voltages near 4.8 V is crucial for advanced lithium-ion batteries.

Purpose of the Study:

• To develop a molecular engineering strategy using nucleophilic oxygen-functionalized additives to improve the high-voltage stability of LRMO cathodes.
• To construct a dual-gradient inorganic CEI that modulates interfacial redox reactions and suppresses Mn dissolution.

Main Methods:

• Design and synthesis of nucleophilic oxygen-functionalized additives.
• Characterization of the CEI structure and composition.
• Electrochemical testing of LRMO cathodes with engineered additives at high voltages.

Main Results:

• The engineered CEI exhibits a robust, zipper-like dual-gradient architecture (inner lithium borates, outer lithium phosphates).
• The CEI promotes fast Li+ transport and enhances interfacial kinetics.
• LRMO cathodes demonstrate 80% capacity retention after 580 cycles at 4.8 V, with mitigated oxidative degradation and suppressed Mn dissolution.

Conclusions:

• Nucleophilic oxygen-mediated interfacial engineering effectively stabilizes LRMO cathodes for durable high-voltage operation.
• The dual-gradient CEI is key to enhancing electrochemical performance and cycle life.
• This approach offers a promising strategy for developing next-generation high-energy-density batteries.