Stable Lithium Deposition Generated from Ceramic-Cross-Linked Gel Polymer Electrolytes for Lithium Anode

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Lithium metal batteries (LMBs) offer high energy density but face challenges with lithium dendrite growth and electrolyte instability.
• Developing stable and efficient electrolytes is crucial for advancing LMB technology.

Purpose of the Study:

• To develop a composite gel electrolyte with enhanced mechanical strength and ionic conductivity for LMBs.
• To investigate the effect of ceramic cross-linkers on the properties and performance of poly(ethylene oxide)-based gel electrolytes.

Main Methods:

• Fabrication of nanocomposite gel electrolytes using poly(ethylene oxide) (PEO) and silica cross-linkers.
• Electrochemical characterization including electrochemical window, rate capability, and cycling performance tests.
• Analysis of lithium ion transport, interfacial resistance, and lithium metal surface morphology using SEM.

Main Results:

• The composite gel electrolyte demonstrated superior resistance to lithium dendrite growth compared to pristine gel electrolytes.
• Enhanced compatibility with liquid electrolytes, a wider electrochemical window (up to 5.0 V), and improved rate and cycling performance were observed.
• Increased lithium transference number to 0.5, reduced polarization and interfacial resistance, and suppressed electrolyte decomposition and lithium corrosion were achieved.
• A uniform passivation layer formed on the lithium metal surface with 20% silica cross-linker, leading to 97% Coulombic efficiency after 100 cycles.

Conclusions:

• The developed ceramic cross-linked PEO-based gel electrolyte functions as a high-performance lithium-ionic conductor and reliable separator for lithium metal batteries.
• This composite gel electrolyte offers a promising solution for improving the safety and cycle life of next-generation lithium metal batteries.