Which battery is the best for electric vehicles?

The answer might be - a capacitor!

In a recent IEA-workshop, a good survey of the status of battery development was delivered. The Li-ion batteries are almost ready to be used in plug-in hybrid vehicles, but there is a further development needed to get batteries to the energy-density required for "standard-size" electrical vehicle.

The idea of using capacitors instead of batteries is not a new one. In the late 90s, Nissan tested it in a hybrid truck concept. It is a tempting idea since capacitors charge faster and last longer, if not for the fact that the capacitor basically needs a huge electrode-surface to be able to hold a reasonable capacity. So, some time ago, there were claims that the surface problem could be solved by the application of nano-technology.

Another development now seems to be underway. This time, it is said to be a combination of battery and capacitor using bariumtitanate to boost the capacity. In this case, it is more like a rumour of the sort we often see in technical magazines.

It would, however, be more surprising if there were not some substance to the matter and would be a hopeful sign indeed if only we could take a shortcut from electricity to transportation and avoid the laborious chemical part in between.