Created from oxygen and silicon (the second most plentiful element in the earth’s crust), such batteries would be lightweight, have an unlimited shelf life, and have a high tolerance for both humid and extremely dry conditions. Potential uses include medical applications (for example, powering diabetic pumps or hearing aids), sensors, and microelectronics structured from silicon.

‘Silicon-air batteries will be used like the ones already in use today,’ says lead researcher, Professor Yair Ein-Eli of the Department of Materials Engineering. ‘But by using silicon – a safe, non-toxic, stable and more common material – we can create very lightweight batteries with infinite shelf life and high energy capacity.’

Silicon-air batteries would provide significant savings in cost and weight, because they lack the built-in cathode of conventional batteries. The cathode in silicon-air (and metal-air) batteries is the oxygen that comes from the atmosphere through the membrane. Ein-Eli estimates that in three to four years, silicon-air batteries can be made more powerful, as well as rechargeable.

The silicon-air battery research by Professor Ein-Eli was financed by the Bi-National Research Foundation (BSF). Also involved in the research were Dr David Starosvetsky and graduate student Gil Cohen from the Technion, Professor Digby Macdonald from Pennsylvania State University, and Professor Rika Hagiwara of Kyoto University in Japan.

The findings are published in the October 2009 issue of Electrochemistry Communications.