Lithium Salt-Induced In Situ Polymerizations Enable Double Network Polymer Electrolytes

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Structural design enhances polymer electrolytes (PEs) for lithium-ion batteries.
• Complex synthesis and non-electrolyte components hinder PE development.

Purpose of the Study:

• To develop a facile method for fabricating a double network polymer electrolyte (DN-PE).
• To improve the mechanical and electrochemical properties of PEs for practical battery applications.

Main Methods:

• Fabrication of DN-PE via lithium salt-accelerated thiol-Michael addition and radical polymerization.
• In situ formation of a cross-linked double network structure at room temperature and 80°C.
• Utilizing lithium salt as both accelerator and catalyst to avoid side reactions.

Main Results:

• DN-PE demonstrates significantly improved mechanical strength and interfacial compatibility compared to single network PEs.
• Stable cycling of a symmetric Li|DN-PE|Li cell for over 1000 hours at 0.05 mA cm⁻².
• A Li|DN-PE|LiFePO₄ cell achieved a high discharge capacity (150.3 mAh g⁻¹ at 0.1 C) and 99% coulombic efficiency.

Conclusions:

• The developed DN-PE offers a promising alternative to conventional polymer electrolytes.
• The facile synthesis and enhanced properties of DN-PE pave the way for advanced lithium-ion batteries.