Ultrahigh energy storage density in epitaxial AlN/ScN superlattices

TL;DR

This paper predicts that epitaxial AlN/ScN superlattices can achieve extremely high energy storage density of up to 200 J/cm³ with perfect efficiency, based on first-principles calculations and a phenomenological model.

Contribution

It introduces a novel design of AlN/ScN superlattices with ultrahigh energy density for energy storage applications, supported by theoretical modeling.

Findings

Achieves up to 200 J/cm³ energy density

Ideal efficiency of 100%

Optimal energy density near a ferroelectric phase transition

Abstract

Dielectric and antiferroelectric materials are particularly promising for high-power energy-storage applications. However, relatively low energy density greatly hinders their usage in storage technologies. Here, we report first-principles-based calculations predicting that epitaxial and initially non-polar AlN/ScN superlattices can achieve an ultrahigh energy density of up to 200 J/cm$^{\textrm{3}}$, accompanied by an ideal efficiency of 100%. We also show that high energy density requires the system being neither too close nor too far from a ferroelectric phase transition under zero electric field. A phenomenological model is further proposed to rationalize such striking features.