Trap-Anchored Crosslinked Polyetherimide Networks for Extreme-Temperature Energy Storage

Area of Science:

• Materials Science
• Polymer Chemistry
• Electrical Engineering

Background:

• Polyetherimide (PEI) is a promising high-temperature dielectric material.
• High temperatures cause conductive loss and thermal runaway, limiting PEI's use in capacitive energy storage.
• A novel approach is needed to enhance PEI's high-temperature dielectric properties.

Purpose of the Study:

• To design a dual-functional molecular strategy for high-temperature dielectric materials.
• To improve the capacitive energy storage performance of polyetherimide at elevated temperatures.
• To suppress leakage current and Joule heating in dielectrics under extreme conditions.

Main Methods:

• Synthesized a 3D crosslinked network of polyetherimide incorporating electron-deficient boroxine rings (B-PEI).
• Utilized experimental and computational analyses to investigate the material's properties.
• Evaluated breakdown strength, discharge energy density, and efficiency at high temperatures (150°C and 200°C).

Main Results:

• Boroxine rings act as deep traps, restricting charge carrier mobility.
• Topological constraints reduce free volume and increase the energy barrier for breakdown.
• The optimized B-PEI4 film showed exceptional breakdown strengths (682.2 MV m⁻¹ at 150°C, 586.2 MV m⁻¹ at 200°C).
• Achieved a discharge energy density of 6.78 J cm⁻³ with 79.3% efficiency at 200°C.

Conclusions:

• The 'source-control' paradigm effectively enhances intrinsic high-temperature dielectrics.
• B-PEI offers superior performance compared to other polymer dielectrics at high temperatures.
• This advancement facilitates next-generation electronic and power systems requiring stable high-temperature dielectrics.