Low Melting Temperature Gallium-Indium Liquid Metal Anode for Solid-State Li-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Solid-state lithium-ion batteries offer improved safety and energy density over liquid electrolyte systems.
• Key challenges include poor cycling and rate performance due to inadequate interfacial contact between solid electrolyte and electrodes.
• Addressing these interfacial issues is crucial for advancing solid-state battery technology.

Purpose of the Study:

• To investigate the use of a gallium-indium (Ga-In) liquid metal as an anode in solid-state lithium-ion batteries.
• To evaluate the performance and stability of a solid-state battery employing Ga-In liquid metal anode with Li6PS5Cl solid electrolyte.
• To understand the role of the liquid metal anode in improving interfacial properties and overall battery performance.

Main Methods:

• Fabrication of a solid-state Li-ion battery using Li6PS5Cl solid electrolyte and a Ga-In liquid metal anode.
• Electrochemical testing including cycling performance and rate capability measurements at room temperature.
• In situ X-ray diffraction (XRD) and ex situ scanning electron microscopy (SEM) for material characterization.
• Comparative analysis of stack pressure during cycling against a solid tin anode.

Main Results:

• The Ga-In liquid metal anode demonstrated excellent initial capacity (389 mAh g-1) and sustained 88% capacity after 30 cycles at 0.05 C.
• Significant capacity retention of 66% was achieved after 500 cycles at 0.5 C.
• The liquid metal anode exhibited superior cycling stability and rate capacity compared to solid tin anodes.
• In situ/ex situ analyses confirmed indium's role in maintaining the alloy's liquid state and facilitating stable interfaces.

Conclusions:

• The integration of a Ga-In liquid metal anode significantly enhances the cycling stability and rate performance of solid-state Li-ion batteries.
• The self-healing and fluid properties of the liquid metal alloy ensure robust interfacial contact with the solid electrolyte, mitigating performance degradation.
• The Ga-In liquid metal anode effectively buffers pressure changes during cycling, contributing to improved battery longevity.
• This approach presents a promising strategy for overcoming interfacial challenges and advancing the development of high-performance solid-state batteries.