Designing Polymeric Interphases for Stable Lithium Metal Deposition

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Reactive metals like lithium electrodeposit with irregular morphologies on planar substrates.
• Interphase properties such as composition, mechanics, and ion transport critically regulate these morphologies.

Purpose of the Study:

• To investigate the effect of fluorinated thermoset polymer coatings on lithium deposition morphology.
• To understand how polymer interphase properties influence lithium electrodeposit morphology.

Main Methods:

• Experimental investigation of lithium deposition with polymer coatings.
• Theoretical linear stability analysis of electrodeposition.
• Tuning polymer chemistry to modify interphase properties (elasticity, diffusivity).

Main Results:

• An interplay between elasticity and diffusivity determines optimal interphase thickness for stable lithium deposition.
• Higher interfacial energy enhances elastic stresses, preventing out-of-plane lithium deposition.
• Polymer interphase design can effectively stabilize metal anodes.

Conclusions:

• Fluorinated polymer interphases offer a strategy to control lithium electrodeposition morphology.
• Understanding the relationship between interphase mechanics, ion transport, and interfacial energy is key to designing stable metal anodes.
• This work provides guidelines for developing advanced polymer interphases for rechargeable batteries.