Gel Polymer Electrolyte Enables Low-Temperature and High-Rate Lithium-Ion Batteries via Bionic Interface Design

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Traditional ethylene carbonate (EC)-based electrolytes limit silicon-carbon (Si-C) anode performance in fast-charging and low-temperature conditions.
• Sluggish Li+ migration kinetics and unstable solid electrolyte interphase (SEI) are key challenges.
• Developing advanced electrolytes is crucial for next-generation energy storage.

Purpose of the Study:

• To design a stable SEI with a 3D desolvation interface for Si-C anodes.
• To accelerate Li+ desolvation and migration at the interface and within the SEI.
• To enhance the performance of Si-C anodes under demanding conditions.

Main Methods:

• In situ ring-opening polymerization of 1,3-dioxolane (DOL) to create poly(1,3-dioxolane) (PDOL).
• Theoretical simulations and experimental validation of the GPE structure and properties.
• Fabrication and testing of Si-C anodes with the novel GPE in pouch full cells.

Main Results:

• The PDOL-based GPE exhibits a 3D desolvation area, improving Li+ desolvation and yielding high ionic conductivity (5.73 mS cm-1).
• An anion-derived stable SEI is formed, enhancing Li+ transport.
• Si-C anodes demonstrate excellent rate performance at room temperature and -40 °C.
• Pouch full cells achieve 97.42 mAh g-1 after 500 cycles at 5 C/5 C.

Conclusions:

• The innovatively designed 3D desolvation interface and SEI represent significant breakthroughs.
• This approach overcomes limitations of EC-based electrolytes for Si-C anodes.
• The developed GPE is promising for developing high-performance fast-charging and low-temperature batteries.