Chirality‐Induced Twisted Supramolecular Assembly Unlocks Ultrahigh Energy Density at Elevated Temperatures

Abstract

ABSTRACT To meet the demands of high‐power‐density electronics, high‐temperature‐resistant polymer dielectrics are essential for ensuring reliable operation. Although doping with molecular semiconductors effectively improves the high‐temperature performance of polymer dielectrics, the semiconductors often exist in an isolated, discontinuous distribution. Beyond the inherent issues of poor dispersion and interfacial incompatibility, this morphology may also form conductive pathways under excessive doping, resulting in severe degradation of dielectric properties. Herein, we incorporated chiral molecules e.g., (13bR)‐5,6‐dihydro‐5‐(trans‐4‐propylcyclohexyl)‐4H‐dinaphtho[2,1‐f:1’,2’‐h][1,5]dioxonin (R5011) and its chiral enantiomer (S5011) into polyethersulfone (PES) to construct supramolecular chiral co‐assembly structure. Through π – π stacking interactions, the chiral molecules give rise to an amplified and emergent chiral expression at the macroscopic polymer chain level. The local twisted structure formed by chiral amplification leads to an enlarged torsional angle between the sulfone‐flanking phenyl rings and constructs carrier traps, thereby significantly enhancing the breakdown strength. Ultimately, the co‐assembly PES achieved high energy densities of 8.73 J cm −3 (150°C) with efficiency of 90% and maximum discharge energy density of 10.08 J cm −3 at 150°C. Furthermore, stacked film capacitors based on the PES composite films demonstrated excellent high‐temperature capacitance stability at 150°C. This work demonstrates a novel approach to designing advanced polymer dielectrics through supramolecular interactions.