Unprecedented Impact of Main Chain on Comb Polymer Electrolytes Performances

Comb-like polymers are one of the most auspicious candidates for building fully amorphous and highly conductive solid polymer electrolytes (SPEs), which are essential components to develop high-performance solid-state rechargeable lithium metal batteries (RLMBs). Herein, two kinds of comb-like polymers containing either polymethacrylate or polyacrylate as main chains are comparatively investigated, aiming to illustrate the role of polymer backbones on the basic properties of SPEs. The comb-like SPEs are fully amorphous, and exhibit significantly higher ionic conductivities at room temperature over traditional poly(ethylene oxide) (PEO)-based ones (close to 10(-4) S cm(-1)). In particular, the polymethacrylate-based SPEs show significantly improved interfacial stability against lithium metal electrode compared with the polyacrylate-based ones, due to the elimination of electrochemically labile C-H moiety at the alpha position of the carbonyl group (C=O) in the polyacrylate structure. The present work provides not only a new family of SPEs consisting of lithium bis(fluorosulfonyl)imide (LiFSI) and poly(methoxy-polyethylene glycol methacrylate) (i.e., LiFSI/P(CH3-MPEGMA)), with high ionic conductivities at room temperature but also insights into developing lithium-metal-friendly SPE for safe RLMBs.

Automated summary

Comb-like polymers are promising candidates for highly conductive solid polymer electrolytes, and this study compares two different comb-like polymers. The polymethacrylate-based electrolytes exhibit better interfacial stability compared to polyacrylate-based ones.