Robust and Adhesive Laminar Solid Electrolyte with Homogenous and Fast Li-Ion Conduction for High-Performance...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Composite solid electrolytes (CSEs) are crucial for high-performance all-solid-state lithium metal batteries (ASSLMBs).
• A key challenge in CSE development is balancing mechanical strength with electrode adhesion for stable Li-ion flux.
• Existing CSEs often struggle to overcome the trade-off between modulus and adhesion.

Purpose of the Study:

• To propose a novel strategy for constructing laminar solid electrolytes (LSE-HFC) that integrates mechanical robustness with efficient Li-ion conduction.
• To address the limitations of current CSEs by intercalating ionic conductors into a robust coordination laminar framework.
• To demonstrate the effectiveness of this approach in enhancing the performance of ASSLMBs.

Main Methods:

• Fabrication of a 9 µm-thick laminar solid electrolyte with metal-organic framework nanosheets as building blocks.
• Intercalation of poly(ethylene oxide)/succinonitrile into the coordination laminar framework to create the LSE-HFC.
• Characterization of Li-ion transfer mechanism, ionic conductivity, and Li-ion transference number.
• Evaluation of mechanical properties (puncture resistance, adhesion) and electrochemical performance in LiFePO4/Li and LiNi0.6Mn0.2Co0.2O2/Li cells.

Main Results:

• The LSE-HFC exhibits homogeneous and fast Li-ion conduction with low migration energy barriers.
• Achieved high ionic conductivity of 5.62 × 10⁻⁴ S cm⁻¹ and a Li-ion transference number of 0.78 at 25 °C.
• Demonstrated outstanding mechanical strength and enhanced adhesion to electrodes, leading to uniform Li plating/stripping.
• The LSE-HFC enabled high-energy-density ASSLMBs with excellent cycling stability.

Conclusions:

• The developed LSE-HFC strategy effectively overcomes the trade-off between mechanical modulus and adhesion in CSEs.
• This approach facilitates homogeneous Li-ion flux and enhances the overall performance of ASSLMBs.
• The LSE-HFC shows significant promise for the development of next-generation high-performance and safe solid-state batteries.