Quantum-Confinement-Driven Advancements of Energy Storage Density in Dielectric Polymers: TiO2 Nanowires Decorated with Ultra-Small Metal Nanoparticles

초록

Introducing high dielectric constant (high-k) ceramic fillers into dielectric polymers is a widely adopted strategy for improving the energy storage density of nanocomposites. However, the mismatch in electrical properties between ceramic fillers and polymer matrix often results in reduced dielectric breakdown strength and increased dielectric loss. This study addresses these challenges by utilizing TiO2 nanowires (NWs) decorated with ultra-small palladium (Pd) or gold (Au) nanoparticles, leveraging the quantum-confinement effect of nanometals to enhance energy storage performance. The decorated TiO2 NWs exhibit a core-satellite structure, where the nanometal particles mitigate the interfacial polarization between the ceramic fillers and the polymer matrix, reducing dielectric loss and increasing breakdown strength. Compared to pristine P(VDF-HFP) polymer, the composite with 6 vol% TiO2@PDA@Pd NWs demonstrated a 535% improvement in discharge energy density. This significant enhancement arises from the synergistic effects of the quantum-confinement properties of the metal nanoparticles and the optimized interface between the fillers and the polymer matrix.

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