Layered conductive polymer-inorganic anion network for high-performance ultra-loading capacitive electrodes

Abstract

Conducting layered capacitive materials that utilize interlayer space to store charges usually exhibit higher areal and volumetric capacitive performance than porous carbons as a result of the bulk storage mechanism. Here, an organic-inorganic hybrid conducting layered material is designed through a ‘bottom-up’ strategy, and is synthesized facilely using a ‘one-pot’ approach. This material consists of periodically stacked nanosheets with a large lamellar period of 11.81 Å. It is postulated that each nanosheet is composed of parallel oriented fully oxidized polyaniline (pernigraniline) molecular chains that are crosslinked by monomeric/oligomeric protonated tungstate molecules, both of which are self-organized through multiple side-chain hydrogen bonds. The binder-free high-loading electrodes made from this material can deliver high volumetric and areal capacitance in neutral electrolyte, along with moderate gravimetric capacitance. As exemplified, a 40 mg cm−2 binder-free electrode achieves an areal capacitance of 4.62 F cm−2 and a volumetric capacitance of 219.4 F cm−3 at 1 mA cm−2.