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Researchers claim lithium-ion battery breakthrough

Tom Espiner ZDNet UK

Published: 02 Nov 2009 16:49 GMT

Academics have developed a silicon gel that could make batteries used in phones and laptops 10 times more efficient.

Stefan Koller, a researcher at the Graz University of Technology (TU Graz) in Austria, told ZDNet UK on Monday that the gel was designed for use with lithium-ion batteries.

"With the silicon gel it's possible to store 10 times more [power] per weight than graphite," said Koller. "It has much better cycling efficiency and capacity retention."

Koller said that to produce the gel his team had taken a hydrated silicon compound, irradiated it with ultraviolet light, and heated it to form an amorphous silicon gel.

However, the problem with using silicon gel as a substrate is that it expands and contracts by up to 300 percent during uptake and transfer of lithium ions. Koller said his team had overcome this by using graphite as a buffer material.

The project was partly funded by the EU as part of Project NanoPoliBat, a scheme to use nanomaterials to develop polymer microbatteries, and by battery maker Varta.

The TU Graz researchers and industry partner Varta have applied to patent the method, said Koller, but have no plans to try to commercialise the findings themselves.

Koller's next stage of research is to produce a cathode material suitable for use with the silicon gel, said the researcher.

Academics and the technology and automotive industries are striving to improve battery life, due to increasing demand from consumers for more efficient cars and mobile devices. For example, researchers from the University of St Andrews are developing an air-based battery that replaces a lithium cobalt oxide electrode with a porous carbon electrode, allowing lithium ions in the battery to react with oxygen molecules in the surrounding air.