Combination of porous silica monolith and gold thin films for electrode material of supercapacitor

Autor: Christophe Kinowski, H. El Hamzaoui, A. Boe, Nathalie Rolland, D Branzea, A Pastre, Remy Bernard, Odile Cristini-Robbe, K. Raulin
Rok vydání: 2015
Předmět:
Zdroj: Materials Research Express. 2:125001
ISSN: 2053-1591
Popis: An all-solid electrical double layer supercapacitor was prepared, starting from a porous silica matrix coated with a gold thin-film. The metallization of the silica xerogel was performed by an original wet chemical process, based on the controlled growth of gold nanoparticles on two opposite faces of the silica monolith as a seed layer, followed by an electroless deposition of a continuous gold thin film. The thickness of the metallic thin film was assessed to be 700 nm. The silica plays two major roles: (1) it is used as a porous matrix for the gold electrode, creating a large specific surface area, and (2) it acts as a separator (non-metallized part of the silica). The silica monolith was soaked in a polyvinyl alcohol and phosphoric acid mixture which is used as polymer electrolyte. Capacitance effect was demonstrated by cyclic voltammetry experiments. The specific capacitance was found to be equal to 0.95 mF cm− 2 (9.5 F g−1). No major degradation occurs within more than 3000 cycles.
Databáze: OpenAIRE