Polyzwitterion-SiO₂ Double-Network Polymer Electrolyte with High Strength and High Ionic Conductivity

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Developing high-performance polymer electrolytes (PEs) requires balancing high strength and ionic conductivity, a significant challenge in energy storage.
• Existing polymer electrolytes often struggle to meet the demands for robust mechanical properties and efficient ion transport simultaneously.

Purpose of the Study:

• To design and synthesize a novel double-network polymer electrolyte (PE) with enhanced mechanical strength and ionic conductivity.
• To investigate the structure-property relationships governing the performance of the new PE for solid-state energy storage applications.

Main Methods:

• A double-network PE was fabricated using a nonhydrolytic sol-gel reaction of tetraethyl orthosilicate and in situ polymerization of zwitterions.
• Mechanical properties (strength, stretchability), ionic conductivity, electrochemical window, and interfacial compatibility with Li metal were characterized.

Main Results:

• The synthesized PE exhibited high strength (0.75 MPa) and stretchability (560%) attributed to synergistic inorganic and polymer networks.
• A maximum ionic conductivity of 0.44 mS cm⁻¹ at 30 °C was achieved due to dynamic ion channels.
• The electrolyte demonstrated a high electrochemical window (>5 V) and excellent compatibility with Li metal electrodes.

Conclusions:

• The developed double-network polymer electrolyte successfully overcomes the trade-off between mechanical strength and ionic conductivity.
• This material offers a promising platform for high-performance, safe solid-state energy storage devices.
• The study provides valuable insights into designing advanced polymer electrolytes via dual-network strategies.