Robust battery interphases from dilute fluorinated cations.

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Controlling the solid electrolyte interphase (SEI) is critical for efficient battery cycling and longevity.
• High-energy batteries often rely on fluorinated species in electrolytes, increasing cost and environmental concerns.

Purpose of the Study:

• To develop a cost-effective and environmentally friendly approach for robust SEI formation in batteries.
• To enable stable cycling of high-energy, lithium-metal full cells using minimal additive fractions.

Main Methods:

• Utilizing very low concentrations (∼0.1 wt%) of readily reducible fluorinated cations in the electrolyte.
• Employing electrostatic attraction to concentrate these cations at the anode surface for SEI formation.

Main Results:

• Formation of a robust, fluorine-rich SEI layer on the anode.
• Achieved dendrite-free deposition of dense lithium and stable cycling of Li-metal full cells with high-voltage cathodes.

Conclusions:

• The proposed method offers a general strategy for targeted delivery of chemical species to battery anodes via electrostatic attraction.
• This approach significantly reduces the reliance on high fractions of fluorinated additives, lowering environmental footprint and cost.