Original URL: http://www.theregister.co.uk/2009/05/19/basf_sion_power/

BASF to develop 350-mile e-car 'super battery'

Lithium-sulphur to rain on lithium-ion from great height

By Alun Taylor

Posted in Science, 19th May 2009 11:38 GMT

Leccy Tech German firm BASF and US company Sion Power have agreed to co-develop a battery technology with the potential to deliver five times the capacity of a conventional lithium-ion battery of the same size.

The battery is based on lithium-sulphur chemistry, which Sion’s been tinkering with for some time. Now it's time to take the technology and put it to practical use.

Enter BASF, and a partnership designed to “accelerate the commercialisation of Sion Power’s proprietary lithium-sulphur battery technology... for the electric vehicle market”.

Should we care? Yes, because Li-S batteries are said to have a very high specific energy density, roughly 2600Wh/kg. They're also said to perform better than lithium-ion batteries at low temperatures, and are made from cheaper and less toxic raw materials.

There are catches. Cycle life has always been one of the traditional problems with Li-S batteries. A 2600Wh/kg battery is a great idea on paper – but not if it will only take a charge 150 or 200 times before giving up the ghost.

This is BASF's role: to help address the lifespan problem while Sion continues working on upping the battery’s energy density.

Even a 500Wh/kg Li-S battery with a Li-ion life cycle would provide more than twice the energy density of existing EV batteries. This would open up the possibility of e-cars chugging for 350 miles, or further, on a single charge.

When it'll happen is anyone's guess - no further details about the project’s timescale have been released. ®