Researchers at the University of St Andrews in Scotland have shown prototypes of a battery with the lithium cobalt oxide electrode replaced by porous carbon. The researchers suggest the battery could provide up to ten times the energy capacity of designs currently available and could enable uninterrupted electrical output from renewable energy sources such as wind and solar.
Half way through the four year project, which also involves scientists at the universities of Strathclyde (Scotland) and Newcastle (England) and is sponsored by the Engineering and Physical Sciences Research Council (EPSRC), the researchers say they have achieved a battery lasting eight times longer than a lithium cobalt oxide battery.
Principal investigator on the project, Professor Peter Bruce of the University of St Andrews, said the capacity improvement is provided by an additional component that uses oxygen drawn from the air during discharge. This replaces a chemical constituent used in regular rechargeable batteries. The oxygen is drawn in through a battery surface exposed to air and reacts in the pores of the carbon to discharge the battery.
Initial prototypes achieved a capacity to weight ratio of 1,000 mA-hours per gram of carbon (mAh/g), while recent devices have reached up to 4,000 mAh/g. This amounts to an eight-fold increase compared to standard cobalt oxide batteries used in mobile phones.
The STAIR (St Andrews Air) battery should also be cheaper than today's rechargeables, the researchers suggest. It will likely be at least five years before the STAIR cell is commercially available, and initially it will be targeted at applications such as mobile phones and MP3 players.
Informative articles
Password forgotten?
)
