Design of Polymer Nanodielectrics for Capacitive Energy Storage

Area of Science:

• Materials Science
• Polymer Science
• Electrical Engineering

Background:

• Polymer nanodielectrics are crucial for capacitive energy storage, demanding high permittivity and breakdown strength for high energy density.
• Existing strategies often involve trade-offs, where increasing permittivity can decrease breakdown strength and elevate energy loss.

Purpose of the Study:

• To identify optimal filler compositions and morphologies in polymer nanodielectrics that enhance both permittivity and breakdown strength without increasing energy loss.
• To develop a design framework for optimizing competing dielectric properties in nanodielectrics.

Main Methods:

• Utilized physics-based, multiscale 3D dielectric property simulations.
• Employed mixed-variable machine learning and Bayesian optimization to explore the design parameter space.
• Integrated first-principles calculations for interface trap densities and continuum modeling for permittivity and loss.

Main Results:

• Identified a parameter space for functionalized fillers of modest aspect ratio that simultaneously increases permittivity and breakdown strength.
• Demonstrated a method to limit increases in energy loss through careful tuning of filler properties and microstructure.
• Developed a design framework based on microstructural and interface property tuning.

Conclusions:

• A novel approach to designing polymer nanodielectrics for enhanced energy storage was proposed.
• The study provides a pathway to simultaneously optimize critical dielectric properties, overcoming traditional material design limitations.
• Mixed-variable global sensitivity analysis revealed insights into the interplay of microstructural and interface variables for nanodielectric design.