Scalable self-assembly interfacial engineering for high-temperature dielectric energy storage.

Area of Science:

• Materials Science
• Polymer Science
• Electrical Engineering

Background:

• High-temperature polymer dielectrics are crucial for energy storage in demanding environments.
• Existing polymers with conjugated structures for thermal stability suffer from reduced bandgaps and charge injection issues.
• Developing robust dielectric materials for high-temperature applications remains a significant challenge.

Purpose of the Study:

• To develop a novel coating for enhancing the dielectric properties of polyimide (PI) films at elevated temperatures.
• To investigate the mechanism by which the coating modifies charge transport and electrical conduction in PI films.
• To improve the energy storage performance of flexible polymer dielectrics for harsh condition electrification.

Main Methods:

• Fabrication of a self-assembled polyvinyl alcohol (PVA)/montmorillonite (MMT) coating on polyimide (PI) films.
• Utilizing anisotropic conductivity of 2D nanolayers in the coating to impede charge carriers.
• Conducting high-field pre-breakdown conduction measurements and space-charge profiling to analyze conduction mechanisms.
• Evaluating the performance of coated PI films at 150°C, focusing on electrical conduction, discharge efficiency, and energy density.

Main Results:

• The PVA/MMT coating effectively impedes charge carrier injection into the PI film.
• The coating induces a transition in conduction mode from bulk-limited hopping to Schottky-injection limited conduction.
• Electrical conduction in PI films is suppressed by approximately 10 times.
• Discharge efficiency is improved by 7 times, and energy density by 2.7 times at 150°C.
• The flow-induced fabrication method is facile and scalable.

Conclusions:

• The self-assembled PVA/MMT coating significantly enhances the high-temperature performance of polyimide dielectrics.
• The coating effectively suppresses electrical conduction and improves energy storage capabilities.
• This technology offers promising applications for harsh condition electrification, particularly in energy storage devices.
• The facile and scalable fabrication method supports potential commercialization.