High-Energy-Storage Capacitor

A method was created for electroless deposition of conformal ultrathin (<20 nm) metal oxides on the high-surface-area walls of commercial carbon nanofoam papers, typically 0.1–0.3 mm thick. The resulting ultrathin metal oxides rapidly take up and release electrons and ions, thereby storing energy at 300–600 Farads per gram of oxide, while the carbon nanofoam paper serves as a three-dimensional current collector and defines a pre-selected porous electrode architecture.