Thursday, 9 October 2008

Assessing the potential of nanoscopic meadows in driving electric cars

A report has highlighted that nanoscale meadows of grass and flowers could hold the key to increasing the amount of energy that can be stored in ultracapacitors, devices tipped to replace batteries in high-demand applications like electric cars.

The approach adopoted by Hao Zhang at the Research Institute of Chemical Defence in Beijing, China, and colleagues at Peking University is as follows: It is being said that this purpose can be served by creating nanoscale meadows of fuzzy flowers of manganese oxide (MnO), a material with a much greater capacity for ions than activated carbon.

The usually resistant MnO can be charged up to attract the ions it can store so well, and consequently the nano-meadow performs 10 times better than MnO alone. The nanomeadow's complex structure is resistant to the mechanical degradation that reduces the performance of ultracapacitors over time. The energy capacity of the new device drops by just three percent after 20,000 charge and discharge cycles, better than other high-capacity designs.

According to, Mike Barnes at the University of Manchester, UK, says this is an interesting approach to improving ultracapacitor performance. But he points out that that a design ready for market needs to be even more resistant to physical degradation. In vehicles, ultracapacitors are charged during braking, which might happen about 60 times per hour in urban situations.

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