Charging Voltage-Dependent Interphase Stabilization Enabling Wide-Temperature High-Voltage Li/LiCoO₂ Battery.

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Designing stable electrolytes for high-voltage lithium metal batteries (LMBs) is challenging due to extreme temperature and voltage requirements.
• Existing strategies often focus on solvation structure, limiting performance in harsh conditions.

Purpose of the Study:

• To present a charging voltage-driven interfacial stabilization strategy for robust interphase construction in LMBs.
• To improve the performance and durability of LMBs under high voltage and wide temperature ranges.

Main Methods:

• Constructed a robust interphase using a thin organic layer over a LiF/borate-rich matrix.
• Utilized a charging voltage-driven approach to passivate lithium metal and cathode surfaces.
• Tested Li/LiCoO2 cells under various conditions: high voltage, elevated temperature (60 °C), room temperature, and extreme cold (-40 °C).

Main Results:

• Achieved 88% capacity retention over 900 cycles at 4.5 V (0.5 C).
• Maintained 83% capacity after 300 cycles at 60 °C (3 C, 3-4.6 V).
• Demonstrated 72% capacity retention after 200 cycles at room temperature (1 C, 3-4.7 V) and 92% at -40 °C (4.6 V).

Conclusions:

• The developed strategy effectively passivates interfaces, enhancing LMB stability and cycle life.
• Tuning charging voltage for interphase engineering offers a promising alternative to solely regulating solvation structure.
• This approach advances the development of high-voltage LMBs for extreme environmental conditions.