Single-Ion Polymer-in-Salt Electrolytes Enabling Percolating Ionic Nanoaggregates for Ambient-Temperature Solid-State...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Solid polymer electrolytes (SPEs) are critical for high-performance solid-state batteries, requiring high ion conduction and interfacial stability.
• Tuning solvation structures in SPEs improves interfacial stability but often compromises ionic conductivity.

Purpose of the Study:

• To develop a novel single-ion polymer-in-salt (SIP-in-salt) electrolyte that achieves both high ionic conductivity and enhanced interfacial stability.
• To investigate the formation and properties of nanometric percolating ionic aggregates (p-AGGs) in SIP-in-salt electrolytes.

Main Methods:

• Synthesis of a single-ion polymer-in-salt electrolyte with an ionic polymer backbone.
• Characterization of the electrolyte's ionic conductivity and interfacial properties.
• Analysis of the structure and ion transport mechanisms within the electrolyte, focusing on p-AGGs.

Main Results:

• The SIP-in-salt electrolyte forms homogeneous, interconnected nanometric percolating ionic aggregates (p-AGGs) at high salt concentrations.
• p-AGGs exhibit enhanced Li+-anion dissociation and facilitate continuous Li+ transport pathways.
• A 100-fold improvement in Li+ conductivity was achieved compared to traditional polymer-in-salt electrolytes, enabling battery operation at 25 °C.

Conclusions:

• The developed SIP-in-salt electrolyte offers a promising strategy for advancing SPEs by optimizing ionic solvation structures.
• This approach paves the way for next-generation high-performance solid-state batteries operating at lower temperatures.