Elastomeric Electrolyte for High Capacity and Long-Cycle-Life Solid-State Lithium Metal Battery

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Solid-state electrolytes are crucial for lithium metal batteries, requiring high ionic conductivity and compatibility with battery components.
• Existing electrolytes often face challenges with interfacial stability and performance at room temperature.

Purpose of the Study:

• To develop a solid-state polymer electrolyte (SSPE) with enhanced ionic conductivity and electrochemical stability.
• To investigate the structural properties influencing ion transport and interfacial behavior.
• To evaluate the performance of the SSPE in lithium metal battery applications.

Main Methods:

• Preparation of SSPE using two-roll milling and interface wetting techniques.
• Characterization of ionic conductivity, electrochemical stability, and interfacial properties.
• Advanced structural analysis using synchrotron radiation Fourier-transform infrared microscopy and X-ray scattering techniques.
• Electrochemical testing of Li||SSPE||LFP coin cells at room temperature.

Main Results:

• The SSPE achieved a high room temperature ionic conductivity of 4.6×10^-4 S cm^-1.
• Demonstrated excellent electrochemical oxidation stability up to 5.08 V and improved interface stability.
• Li||SSPE||LFP coin cells showed high capacity (161.5 mAh g^-1 at 0.1 C) and long cycle life (50% capacity retention after 2000 cycles).
• Good rate capability was observed, with performance maintained up to 5 C.

Conclusions:

• The developed SSPE meets critical electrochemical and mechanical requirements for practical lithium metal batteries.
• Continuous ion conductive paths formed within the electrolyte contribute to its high performance.
• This study presents a promising solid-state electrolyte for advancing lithium metal battery technology.