Scalable Hybrid Films of Polyimide‐Animated Quantum Dots for High‐Temperature Capacitive Energy Storage Utilizing Quantum Confinement Effect

Abstract The miniaturization trend of future electrical and electronic systems tender higher demands for high‐temperature resistant dielectric capacitors. The exponential increase in leakage current of dielectric polymers under high temperatures and strong electric fields is a pivotal bottleneck constraining the application of capacitors. Herein, a design is described where various animated quantum dots (A‐QDs), serving as crosslinkers, are introduced into the polyimide (PI) matrix to regulate the excitation and transport of carriers. Using fluorescence lifetime imaging (FLIM) and Kelvin probe force microscopy (KPFM), it is demonstrated that the intrinsic quantum confinement effect of quantum dots (QDs) significantly enhances carrier immobilization. Moreover, the dynamic stability of the covalently bonded network at elevated temperatures has proven to be effective in reducing dielectric loss, while enhancing the electrical insulation properties of the hybrid films. Therefore, at 200 °C, the optimal hybrid film exhibits an exceptional discharged energy density of 5.8 J cm −3 with an efficiency exceeding 90%, surpassing the performance observed in the majority of other polymer nanocomposites. Collectively, these characteristics highlight the promising potential of incorporating A‐QDs as crosslinked points within the polymer matrix, thereby enhancing the applicability of dielectric polymers for high‐temperature applications.