Engineering and construction of multi-functional Janus separator for high-stability Li-CO₂ battery

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Lithium-carbon dioxide (Li-CO2) batteries offer high theoretical energy density for electricity generation from CO2.
• Key challenges include lithium dendrite formation and rapid cathode passivation, hindering battery development.

Purpose of the Study:

• To develop a novel Janus separator with dual functionalities for advanced Li-CO2 batteries.
• To address lithium dendrite growth and cathode passivation issues.

Main Methods:

• Fabrication of a Janus separator using in-situ growth and hydrothermal techniques.
• Incorporation of Prussian blue (PB) nanocubes on the anode side for ion transport control.
• Utilizing a Prussian blue and reduced graphene oxide (PB-rGO) composite on the cathode side as a cathode extender.

Main Results:

• The Janus separator effectively inhibited lithium dendrite proliferation in Li||Li symmetrical batteries, achieving over 1700 hours of stable cycling.
• The PB-rGO cathode extension facilitated the decomposition of discharge products, providing a self-cleaning effect.
• Li-CO2 batteries with the Janus separator demonstrated a high discharge capacity of 12100 mAh g-1 and a cycle life of 3144 hours.

Conclusions:

• The developed Janus separator significantly enhances the stability and performance of Li-CO2 batteries.
• Dual functionalities of the separator address critical challenges in dendrite inhibition and cathode passivation.
• This advancement paves the way for more efficient and durable energy storage solutions using CO2.