Self-Formation CoO Nanodots Catalyst in Co(TFSI)₂ -Modified Electrolyte for High Efficient Li-O₂ Batteries

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Lithium-oxygen (Li-O2) batteries face challenges like sluggish kinetics and high overpotentials.
• Cathode passivation by insulating lithium peroxide (Li2O2) hinders performance.

Purpose of the Study:

• To develop a novel nanodot (ND)-modified electrolyte for improved Li-O2 battery performance.
• To address cathode passivation and enhance reaction kinetics.

Main Methods:

• Employing cobalt bis(trifluoromethylsulfonyl)imide (Co(TFSI)2) as an electrolyte additive.
• Formation of dispersed cobalt oxide (CoO) nanodots (NDs) through reaction with discharge intermediates and products.
• Investigating the catalytic effect of CoO NDs on Li2O2 formation and decomposition.

Main Results:

• Co(TFSI)2 additive generates well-dispersed CoO NDs with high catalytic activity and good wettability.
• CoO NDs facilitate Li2O2 decomposition at lower overpotentials during recharge.
• Li-O2 cells with Co(TFSI)2 achieved 200 cycles at 200 mA g-1 with superior reversibility.

Conclusions:

• The CoO NDs effectively catalyze Li-O2 reactions, improving cycle life and reversibility.
• This approach offers a new strategy for developing highly dispersed nanodot catalysts for Li-O2 batteries.
• Broadens the scope of electrolyte additives for advanced energy storage solutions.