Covalent netting restrains dissolution enabling stable high-loading and high-rate iron difluoride cathodes

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Metal fluoride conversion cathodes offer potential for low-cost, high-energy lithium-ion batteries.
• Active material dissolution leads to capacity fade and limits commercialization of these promising battery systems.

Purpose of the Study:

• To develop a covalent netting strategy to prevent active material dissolution in metal fluoride conversion cathodes.
• To enhance the stability, capacity, and rate capability of these battery systems.

Main Methods:

• A polydopamine-derived carbon-mediated covalent binding approach was employed.
• A pyrolyzed bacterial cellulose netting structure was utilized to create fast ion and electron transport pathways.
• The strategy focused on forming a robust blocking layer to suppress material leaching.

Main Results:

• The covalent netting strategy effectively inhibited active material dissolution.
• High capacity, high rate, and long-lasting stability were achieved at practical loading levels.
• A stable performance was demonstrated without relying on electrolyte engineering.

Conclusions:

• The covalent netting strategy successfully stabilizes metal difluorides, addressing a key challenge for their commercialization.
• This approach provides a viable solution for developing higher-level, lower-cost batteries.
• The findings offer a pathway for stabilizing other dissolving electrode materials in energy storage devices.