Abstract
In an ionic liquid electrolyte, namely 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI-BF4), a compact and dense polypyrrole film was formed on a nano-porous Ta pellet anode (average pore diameter: 250 nm, specific surface area: 4,000 cm2 g−1, and specific capacitance: 50,000 µFV g−1) under a pulse anodization. In the EMI-BF4 electrolyte, polypyrrole film was uniformly deposited at a pellet surface (thickness: 240 nm) and a nano-porous domain (thickness: 240 nm). However, in a conventional aqueous electrolyte (0.1 M sodium dodecylbenzenesulfonate aqueous solution), deposition thickness was different at the pellet surface (3000 nm) and at the nano-porous domain (230 nm). The resistivity of polypyrrole film formed in the EMI-BF4 was found as low as 2×10−2 Ω/□.
