Foldable nano-Li₂MnO₃ integrated composite polymer solid electrolyte for all-solid-state Li metal batteries with...

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• All-solid-state lithium-ion batteries (ASSLBs) are crucial for next-generation energy storage.
• Developing safe and high-performance solid electrolytes is a key challenge.
• Poly (ethylene oxide) (PEO) based electrolytes offer flexibility but often require optimization for conductivity.

Purpose of the Study:

• To develop a low-cost, foldable composite polymer solid electrolyte (CPSE) for ASSLBs.
• To enhance ionic conductivity and safety through nano-Li2MnO3 integration.
• To evaluate the electrochemical performance and mechanical properties of the developed CPSE.

Main Methods:

• A simple solid-phase method was used to synthesize nano-Li2MnO3 integrated PEO-based CPSE.
• Density functional theory (DFT) calculations were employed to understand ion transport mechanisms.
• Electrochemical performance was tested in lithium metal batteries and pouch cells with various cathode materials.

Main Results:

• The CPSE exhibited high ionic conductivity (5.1 × 10^-4 S cm^-1 at 60°C) and a high lithium-ion transference number (0.5).
• The electrolyte demonstrated excellent thermal stability and improved battery safety.
• Lithium metal batteries assembled with CPSE showed stable cycling over 200 cycles at 0.5C with a specific capacity of 125 mAh g^-1.
• The CPSE was compatible with three different cathode materials and enabled foldable pouch cells with good mechanical properties.

Conclusions:

• The developed nano-Li2MnO3/PEO CPSE offers a promising low-cost, safe, and high-performance solid electrolyte for ASSLBs.
• Its excellent electrochemical and mechanical properties suggest broad commercial application potential.
• The integration of nano-Li2MnO3 effectively facilitates lithium-ion transport within the PEO matrix.