Syndiotactic Polystyrene-Based Ionogel Membranes for High Temperature Electrochemical Applications

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Current lithium-ion batteries face safety risks like thermal runaway due to volatile liquid electrolytes.
• High-temperature applications, such as in hybrid vehicles, require batteries with enhanced thermal stability and safe operation.
• Syndiotactic polystyrene (sPS) offers thermal stability, while ionic liquids (ILs) provide low volatility.

Purpose of the Study:

• To develop and evaluate ionogel membranes for high-temperature lithium-ion battery applications.
• To improve the thermal stability and safety of lithium-ion batteries.
• To enhance battery performance at elevated temperatures.

Main Methods:

• Fabrication of ionogel membranes using syndiotactic polystyrene (sPS) gels and ionic liquids (ILs).
• Assembly and testing of lithium metal/graphite half-cells with ionogel membranes and conventional Celgard-3501 membranes.
• Performance evaluation at room temperature and elevated temperatures (100 °C).

Main Results:

• Ionogel membranes enable continuous operation of lithium-ion cells at 100 °C without failure.
• Cells with ionogel membranes exhibit improved charge-discharge capacity compared to those with Celgard-3501.
• High ionic conductivity and electrolyte retention are attributed to the high porosity of sPS gels and IL wetting.

Conclusions:

• Ionogel membranes represent a promising advancement for high-temperature lithium-ion battery technology.
• The combination of sPS and ILs significantly enhances battery safety and operational stability at elevated temperatures.
• These ionogel membranes offer a viable solution for demanding applications requiring reliable battery performance under thermal stress.