Efficient high active mass paper-based energy-storage devices containing free-standing additive-less polypyrrole-nanocellulose electrodes

Free-standing and additive-free paper electrodes containing up to 90 wt% polypyrrole (PPy), and with PPy mass loadings up to 20 mg cm(-2), are made from PPy@nanocellulose and interconnecting PPy nanofibres for high-performance paper-based energy storage devices exhibiting close to theoretical energy densities and cell capacitances of about 1 F cm(-2) at a current density of 270 mA cm(-2).