Constructing Highly Li⁺ Conductive Electrode Electrolyte Interphases for 4.6 V Li||LiCoO₂ Batteries via Electrolyte...

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• High voltage operation is key to boosting energy density in Li||LiCoO2 batteries.
• Instability of electrode-electrolyte interphases, including Li dendrite growth and LiCoO2 structural degradation, limits high-voltage performance in carbonate electrolytes.

Purpose of the Study:

• To develop a strategy for constructing stable interphases for high-voltage Li||LiCoO2 batteries.
• To enhance the stability and energy density of Li||LiCoO2 batteries operating at 4.6V.

Main Methods:

• Utilized 4-nitrophthalic anhydride as an electrolyte additive.
• Formed a LiNxOy-contained cathode electrolyte interphase (CEI) and a LiF-rich solid electrolyte interphase (SEI) on the Li anode.

Main Results:

• Achieved stable operation of Li||LiCoO2 batteries at 4.6V.
• Demonstrated a high initial specific capacity of 216.9 mAh g-1.
• Maintained a capacity retention of 167.1 mAh g-1 after 200 cycles at 0.3 C.

Conclusions:

• The electrolyte additive strategy effectively enhances the stability of high-voltage Li||LiCoO2 batteries.
• The formation of protective LiNxOy-contained CEI and LiF-rich SEI is crucial for stable high-voltage performance.
• This work presents a viable approach for the practical application of high-voltage Li||LiCoO2 batteries.