Platinum and gold alloy nanoparticles can significantly improve the efficiency of rechargeable lithium-air batteries, according to new research.

A study published in the Journal of the American Chemical Society claimed that the catalyst returned 77 per cent of energy used to charge the batteries as electricity when discharged.

This represents an improvement from the previous record of 70 per cent and could lead to the required 85 to 90 per cent level required to commercialise the batteries.

The research was conducted by MIT mechanical engineering professors Yang Shao-Horn and Hubert Gasteiger, in collaboration with mechanical engineering and biological engineering professor Kimberly Hamad-Schifferli.

Professor Shao-Horn explained that although platinum initially returned poor results for catalysing lithium and oxygen in the batteries, the new research shows that it helps to free oxygen from lithium oxide during charging.

"Everyone knew that platinum was inactive for discharging the battery, but we showed that platinum was one of the best catalysts for charging," he told Technology Review.

The expert added that the white metal works "synergistically" with gold, despite the latter also originally being considered unsuitable because it is inert.

Platinum group metals are typically used in catalytic converters in modern automobile engines.

Source:

Record Efficiency for Lithium-Air Batteries (09/06/10)

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