The Silicon Air Battery

Most of us would be more familiar with silicon being used for computer chips and solar panels – now the substance looks set to become a vital component in the next generation of batteries.

Technion – Israel Institute of Technology scientists are developing a silicon-air battery that can supply electricity for thousands of hours of continual use without needing to be replaced – and a rechargeable version is already on the drawing board.

The silicon-air batteries would be cheap to produce, lightweight, could be stored indefinitely and have a high tolerance for both humid and extremely dry conditions. The batteries would also be more earth-friendly; not relying on toxic metals.

Unlike traditional and current deep cycle batteries, the silicon-air battery has no internal anode – it substitutes this with oxygen that comes from the atmosphere through a membrane.

According to lead researcher Yair Ein-Eli, within a decade it may be possible to build rechargeable electric car batteries made from silicon. What’s good enough for a car may likely also be good enough for off-grid renewable energy systems.

Another battery based on similar technology is the lithium – air battery; also currently under development. While lithium is a relatively rare resource, silicon is in abundance. In the Earth’s crust, silicon is the second most abundant element after oxygen, making up 25.7% of the crust by mass.

This application isn’t the only new potential of silicon in our energy future. In 2008, W. Earl Bardsley from the Department of Earth and Ocean Sciences, University of Waikato in New Zealand published a vision of a sustainable global silicon energy economy as a potential alternative to the hydrogen economy.

Bardsley’s vision is based on large-scale and carbon-neutral silicon fuel production from major smelters in North Africa and elsewhere, supplied by desert silica sand and electricity from extensive solar generating systems.