Converting CO₂ into functionally valuable materials: a hybrid polymer electrolyte for high-performance lithium metal...

Area of Science:

• Materials Science
• Electrochemistry
• Sustainable Chemistry

Background:

• Upcycling carbon dioxide (CO2) into battery components offers a path toward carbon-neutral energy storage.
• Existing CO2-derived polymers often require harsh synthesis conditions and exhibit limited electrochemical integration.
• Developing efficient and stable electrolytes is crucial for advancing next-generation battery technologies.

Purpose of the Study:

• To develop a novel hybrid polymer electrolyte using CO2 as a feedstock under ambient conditions.
• To enhance the electrochemical performance and stability of lithium metal batteries through a composite electrolyte design.
• To demonstrate a sustainable carbon utilization strategy for energy storage applications.

Main Methods:

• Synthesis of a CO2-derived polyurethane (PCO2) under ambient conditions (room temperature, 1 atm).
• Construction of a composite electrolyte (GPCO2-2) by integrating PCO2 with a polymer matrix and a deep eutectic solvent.
• In situ densification and interfacial reconstruction to achieve mechanical integrity and electrochemical stability.
• Investigation of ion transport mechanisms and solid-electrolyte interphase formation.

Main Results:

• The GPCO2-2 electrolyte exhibits excellent Li+ dissociation and migration due to abundant coordination sites and a competitive coordination mechanism.
• Stable cycling of lithium metal for over 2500 hours was achieved.
• Li/GPCO2-2/NCM811 batteries demonstrated 500 stable cycles at 0.5 C (4.3 V) and 100 stable cycles at 0.2 C (4.7 V).
• Flexible pouch cells retained 71.1% capacity after 100 cycles.
• Enhanced safety features were observed, including stable current and lower temperature rise during overcharge tests.

Conclusions:

• The developed hybrid polymer electrolyte from upcycled CO2 offers a promising route for sustainable and high-performance energy storage.
• The unique composite structure and ion transport properties lead to superior electrochemical stability and cycling life.
• This work highlights the potential of ambient-condition CO2 utilization for advanced battery materials and enhanced safety.