A Mechanically Robust In-Situ Solidified Polymer Electrolyte for SiO_x-Based Anodes Toward High-Energy Lithium...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Silicon suboxide (SiO_x) offers higher theoretical capacity than graphite for advanced lithium batteries.
• Significant volume changes and rapid capacity decay of SiO_x anodes hinder practical application.
• Stabilizing SiO_x anodes is crucial for developing higher-energy-density batteries.

Purpose of the Study:

• To develop a novel polymer electrolyte for stabilizing SiO_x anodes.
• To address the challenges of volume expansion and capacity decay in SiO_x-based lithium batteries.
• To enhance the cycling and rate performance of lithium batteries utilizing SiO_x anodes.

Main Methods:

• In-situ polymerization of a novel monomer (bicyclic phosphate ester and urethane motifs) with methyl methacrylate.
• Creation of a polymer electrolyte (PPM-PE) with a dragonfly wing-inspired microstructure.
• Fabrication and testing of button and soft package batteries with SiO_x anodes and PPM-PE.

Main Results:

• The developed PPM-PE exhibits excellent mechanical properties due to micro-phase separation, mimicking dragonfly wings.
• PPM-PE effectively buffers electrode volume expansion and stabilizes the solid electrolyte interface.
• Batteries with PPM-PE showed significantly improved cycling and rate performance compared to those with liquid electrolytes.
• Electrolyte decomposition was notably reduced with the use of PPM-PE.

Conclusions:

• A dragonfly wing microstructure-inspired polymer electrolyte (PPM-PE) effectively enhances the performance of SiO_x anodes.
• The unique microstructure and mechanical properties of PPM-PE mitigate key challenges in SiO_x battery technology.
• This design approach facilitates the practical implementation of high-energy lithium batteries with SiO_x anodes.