Interfacial Approach toward Benzene-Bridged Polypyrrole Film–Based Micro-Supercapacitors with Ultrahigh Volumetric Power Density

2D soft nanomaterials are an emerging research field due to their versatile chemical structures, easily tunable properties, and broad application potential. In this study, a benzene-bridged polypyrrole film with a large area, up to a few square centimeters, is synthesized through an interfacial polymerization approach. As-prepared semiconductive films exhibit a bandgap of ≈2 eV and a carrier mobility of ≈1.5 cm² V⁻¹ s⁻¹, inferred from time-resolved terahertz spectroscopy. The samples are employed to fabricate in-plane micro-supercapacitors (MSCs) by laser scribing and exhibit an ultrahigh areal capacitance of 0.95 mF cm⁻², using 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF₄]) as an electrolyte. Importantly, the maximum energy and power densities of the developed MSCs reach values up to 50.7 mWh cm⁻³ and 9.6 kW cm⁻³, respectively; the performance surpassing most of the 2D material-based MSCs is reported to date.