Improving the Conductivity of Solid Polymer Electrolyte by Grain Reforming

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Polyethylene oxide (PEO)-based solid polymer electrolytes (SPEs) show promise for all-solid-state lithium-ion batteries.
• Low ionic conductivity in PEO-based SPEs, linked to crystallinity and grain boundaries, limits their application.

Purpose of the Study:

• To investigate a press-rolling method for reducing crystallinity in PEO-based SPEs.
• To evaluate the impact of this method on the electrochemical performance of solid-state lithium-ion batteries.

Main Methods:

• A simple and effective press-rolling technique was applied to PEO-based SPEs.
• Fabrication of LiFePO₄/SPE/Li all-solid-state lithium-ion batteries using the modified SPE.

Main Results:

• The press-rolling method significantly reduced SPE crystallinity.
• The modified SPE exhibited doubled ionic conductivity and reduced activation energy compared to conventionally cast SPEs.
• The LiFePO₄/SPE/Li battery demonstrated a superior rechargeable specific capacity of 162.6 mAh g^-1 at 0.2 C with a low voltage gap and reduced capacity decay.

Conclusions:

• Press-rolling is an effective grain reforming method for PEO-based SPEs.
• This technique enhances ionic conductivity and electrochemical performance in solid-state lithium-ion batteries.
• The study presents a promising approach for developing advanced solid polymer electrolytes.