New Generation Ultracapacitor

Australian and South African researchers have designed and produced an ultracapacitor containing gold instead of the carbon used previously. Gold-based devices can store up to six times the energy of a standard capacitor.

The research program by Professor Michael Cortie of the University of Technology, Sydney, Australia, and Dr. Elma van der Lingen from Mintek in Johannesburg, has improved existing designs, which are subject to significant operational problems, including a ‘modest’ capability for energy storage and operational inefficiencies due to internal heat generation.

This is the first time that an ultracapacitor based on gold has been made anywhere in the world. The researchers first used an intermetallic compound of gold and aluminum, known as purple glory. Subsequently they removed the aluminum, leaving a sponge of pure gold.

“Gold seems rather an improbable choice compared to carbon,” Professor Cortie said. “But it turns out the electric power that can be efficiently drawn from a carbon-based ultracap is limited by the high internal resistance of such devices. Gold by contrast is a truly excellent electrical conductor. Additionally, carbon-based ultracaps are not cheap, so including a fraction of a gram of gold in an ultra-cap is only slightly more expensive.”