High Performance Energy Storage Materials Based on Rochelle Salt Micro-Doped Composite Films

Polymer dielectric materials are widely applied in next-generation capacitive energy storage systems due to their low dielectric loss, ease of processing, and excellent chemical stability. However, their generally low dielectric constant and limited charge regulation capability constrain further improvement in energy density. In this study, a flexible nanocomposite dielectric film with enhanced dielectric and energy storage properties was developed by introducing trace amounts of Rochelle salt (RS) into polypropylene (PP) through melt blending. The strong polarization and charge trapping effects of RS significantly suppressed carrier migration, reducing leakage current by 38.19 % and improving breakdown strength at various temperatures. Experimental results showed that the energy density of the composite film increased by approximately 25 % and 28 % at 25° C and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$85^{\circ} \mathrm{C}$</tex> compared with unmodified PP, demonstrating excellent thermal stability. This approach provides a new strategy for designing highperformance dielectric materials with promising potential for next-generation electrostatic energy storage systems.