Anchoring Side Chains to Carbonate Groups for Reviving Stable Polycarbonate-Based Solid-State Lithium Metal Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Polycarbonate-based electrolytes offer wider electrochemical windows and higher ionic conductivity for solid-state lithium metal batteries (LMBs).
• A major challenge is the interfacial degradation of polycarbonates due to side reactions with lithium metal anodes.
• This degradation limits the long-term stability and performance of LMBs.

Purpose of the Study:

• To suppress interfacial degradation in polycarbonate-based electrolytes for solid-state LMBs.
• To enhance the stability and cycling performance of lithium metal batteries.
• To demonstrate a novel strategy for improving solid-state battery electrolytes.

Main Methods:

• Designed a polycarbonate-based electrolyte with in situ anchored side chains to form a restricted conformation.
• Utilized the restricted conformation to shield degradable ester bonds within the polycarbonate structure.
• Investigated the electrolyte's performance in Li/Li cells and LiNi0.8Co0.1Mn0.1O2/Li pouch cells.

Main Results:

• The protected polycarbonate electrolyte demonstrated stable cycling of Li/Li cells for over 1000 hours at 0.5 mA cm⁻².
• The strategy effectively suppressed interfacial contact and degradation between the electrolyte and lithium metal anode.
• Assembled LiNi0.8Co0.1Mn0.1O2/Li pouch cells showed significant improvements in cycling performance.

Conclusions:

• Constructing restricted conformations via anchored side chains is a viable strategy for highly stable polycarbonate-based solid-state LMBs.
• This approach effectively mitigates interfacial degradation, paving the way for more robust lithium metal battery technology.
• The findings offer a promising direction for developing advanced solid-state battery electrolytes.