New Air Battery to Provide 10X the Energy?

Scientists at St. Andrews are developing an air fueled battery that already provides 3X the energy density of a lithium cobalt oxide cell. They are aiming for 10X the energy sometime in the next 4 to 5 years.

Improved capacity is thanks to the addition of a component that uses oxygen drawn from the air during discharge, replacing one chemical constituent used in rechargeable batteries today. Not having to carry the chemicals around in the battery offers more energy for the same size battery. Reducing the size and weight of batteries with the necessary charge capacity has been a long-running battle for developers of electric cars.

The STAIR (St Andrews Air) cell should be cheaper than today’s rechargeables too. The new component is made of porous carbon, which is far less expensive than the lithium cobalt oxide it replaces.

This four-year research project, which reaches its halfway mark in July, builds on the discovery at the university that the carbon component’s interaction with air can be repeated, creating a cycle of charge and discharge. Subsequent work has more than tripled the capacity to store charge in the STAIR cell. _ImpactLab

Air has proven to be a useful reactant for many human purposes. Zinc-air and aluminium-air fuel cells use a similar chemical trick as the air-carbon batteries. Of course all combustion engines that operate in Earth's atmosphere utilise air as a reactant. New hybrid rocket engines are an attempt to save on rocket fuel by using air as a reactant on the upward passage through the atmosphere. And so on.

Now if they could only devise battery that consumed CO2 from the air in the charge cycle. But that might not be as good as you think -- most plants evolved in a much denser CO2 atmosphere. They are already starving for CO2 as it is. And don't get me started on how chronically hungry the oceans are for more CO2. The oceans simply cannot get enough -- like most terrestrial plants.