Scalable Polyimide-Poly(Amic Acid) Copolymer Based Nanocomposites for High-Temperature Capacitive Energy Storage

Area of Science:

• Materials Science
• Polymer Science
• Nanotechnology

Background:

• Next-generation electric power systems require high-performance dielectric capacitors capable of operating at high temperatures (≈150°C).
• Existing polymer-based capacitors often lack the necessary energy density, efficiency, scalability, and cost-effectiveness for demanding applications like hybrid electric vehicles.
• There is a critical need for advanced dielectric materials that can meet these stringent operational requirements.

Purpose of the Study:

• To design and synthesize novel polymer nanocomposites for high-temperature dielectric capacitors.
• To evaluate the energy density, efficiency, and stability of these nanocomposites under realistic operating conditions.
• To provide a scalable and low-cost strategy for developing advanced polymer-based capacitors.

Main Methods:

• Synthesis of polyimide-poly(amic acid) copolymer nanocomposites incorporating a small quantity of boron nitride nanosheets.
• Characterization of the dielectric properties and energy storage performance of the nanocomposites.
• Testing under high electric fields (200 MV m⁻¹) and elevated temperatures (150°C), including charge-discharge cycling and high-temperature endurance tests.

Main Results:

• Achieved a high energy density of 1.38 J cm⁻³ and efficiency >96% at 150°C and 200 MV m⁻¹.
• Demonstrated a 2.5-fold increase in energy density compared to biaxially oriented polypropylene at room temperature.
• Exhibited no degradation in energy density or efficiency after 20,000 cycles and 35 days of high-temperature testing.

Conclusions:

• The developed boron nitride nanosheet-reinforced polyimide nanocomposites offer exceptional high-temperature dielectric performance.
• This research presents an effective and economical approach for creating advanced polymer capacitors for demanding applications.
• The materials show significant potential for use in next-generation electric power systems and electric vehicles.