Zwitterion-Modulated Quasi-Solid-State Polymer Electrolyte with Janus Interface toward Low-Temperature Lithium Metal...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Polymer-based lithium batteries offer high energy density but struggle with low-temperature performance due to interfacial issues and slow ion transport in solid electrolytes.
• Instability at the lithium anode-electrolyte interface and inefficient lithium-ion (Li+) transport hinder the practical application of solid-state lithium batteries.

Purpose of the Study:

• To engineer a unique Janus interface for PVDF-based polymer electrolytes to overcome low-temperature performance limitations in lithium batteries.
• To enhance interfacial stability and accelerate Li+ transport for improved solid-state lithium battery performance.

Main Methods:

• Constructed a Janus interface between a lithium anode and PVDF polymer electrolyte using oriented zwitterion assembly under an electric field.
• Investigated the electrochemical and mechanical properties of the modified polymer electrolyte and its performance in full cells.

Main Results:

• The Janus interface effectively reduced Li+ desolvation energy and suppressed side reactions at the anode.
• Achieved high ionic conductivity (0.66 mS cm⁻¹ at RT), an elevated Li+ transference number (0.61), and excellent mechanical properties (8.2 MPa strength, 520% elongation).
• Demonstrated outstanding cycling stability (83.6% capacity retention over 1000 cycles at 5C) and remarkable low-temperature performance (86.3% retention over 700 cycles at -10°C).

Conclusions:

• The developed Janus interface significantly enhances the performance of quasi-solid-state polymer electrolytes for lithium metal batteries.
• The strategy provides a promising pathway for developing high-performance, stable, and safe solid-state lithium batteries with improved low-temperature capabilities.