Reshaping Lithium Plating/Stripping Behavior via Bifunctional Polymer Electrolyte for Room-Temperature Solid Li Metal...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Rechargeable lithium metal batteries face challenges with dendrite growth, primarily due to liquid electrolytes.
• Solid polymer electrolytes are sought for their potential to enhance safety and performance but struggle to balance ionic conductivity and mechanical strength.

Purpose of the Study:

• To develop a bifunctional solid polymer electrolyte that combines high ionic conductivity with robust mechanical strength.
• To address the limitations of current electrolytes in enabling stable, high-energy lithium metal batteries.

Main Methods:

• Fabrication of an interpenetrating polymer network (ipn-PEA) electrolyte via photopolymerization.
• Incorporation of ion-conductive poly(ethylene oxide) and branched acrylate components.
• Characterization of mechanical properties (12 GPa) and ionic conductivity (0.22 mS cm⁻¹).

Main Results:

• The ipn-PEA electrolyte demonstrated high mechanical strength and excellent room-temperature ionic conductivity.
• Uniform lithium plating and stripping were significantly promoted by the electrolyte.
• Assembled Li metal full cells (4.5 V vs Li⁺/Li) showed effective operation at 5 C and stable cycling at 1 C.

Conclusions:

• The bifunctional ipn-PEA electrolyte offers a promising solution for dendrite-free lithium metal plating.
• Its facile fabrication and dual properties pave the way for practical, room-temperature solid-state lithium metal batteries.