© Glen Wallace
© Glen Wallace

UK scientists develop ‘ultimate’ battery demonstrator

Researchers at the University of Cambridge, UK, have successfully showed how many of the problems hindering the development of the so-called ‘ultimate’ battery could be overcome.

Lithium-oxygen batteries have been hailed the ‘ultimate’ batteries due to their theoretical energy density, which is ten times that of a lithium-ion battery. Such a high energy density would enable an electric car with a battery that is one-fifth the cost and one-fifth the weight of those currently on the market to drive from London to Edinburgh, UK, on a single charge.

However, like many other next-generation batteries, a number of practical challenges stand in the way of lithium-air batteries becoming a viable alternative to gasoline.

But Cambridge scientists have now developed a working laboratory demonstrator of a lithium-oxygen battery which has very high energy density, is more than 90% efficient, and, to date, can be recharged more than 2,000 times.

The researchers’ demonstrator relies on a highly porous, ‘fluffy’ carbon electrode made from graphene and additives that alter the chemical reactions at work in the battery, making it more stable and more efficient.

“We haven’t solved all the problems inherent to this chemistry, but our results do show routes forward towards a practical device,” said Professor Clare Grey of Cambridge’s Department of Chemistry, the study’s senior author, cautioning that a practical lithium-oxygen battery still remains at least a decade away.

This study, which has been published in the journal Science, has received support from the US Department of Energy, the Engineering and Physical Sciences Research Council, Johnson Matthey and the EU via the Marie Curie Actions, as well as the Graphene Flagship.

The technology has been patented and is being commercialised through Cambridge Enterprise, the university’s commercialisation arm.