IBM has invented a lithium-air battery technology that makes it possible to drive electric vehicles (EVs) for 500 miles (804 km) per charge.
Lithium-air battery technology is not new, but it does have the potential to achieve unusually high energy densities that rival that of all rechargeable batteries in use today. The reason why batteries with higher energy densities enable EVs to drive further is simply because they are lighter (they have a better gravimetric energy density).
Lighter batteries weigh down the vehicle less, so it requires less energy to drive a given distance. This translates into more energy being available for driving. Each kWh (kilowatt-hour) of energy takes you further.
A greater gravimetric energy density can also mean that fewer batteries can be used to achieve the usual < 100-mile range, and this could be used to save money on the batteries instead (depending on their cost). Fewer batteries are, obviously, cheaper.
Typical lithium-ion batteries such as the lithium cobalt and lithium-iron phosphate batteries in use today are not able to store nearly as much energy per kg of their mass because of a lower energy density, and, as a result of this, EVs powered by them often have a driving range of less than 100 miles (160 km) per charge. They are, however, more practical than lithium-air batteries that have a reliability issue due to chemical instability.
Lithium-air batteries use carbon in their positive electrode (unlike typical li-ion batteries that use metal oxides, such as lithium cobalt oxide), and that carbon reacts with oxygen in the air to generate electricity. As I say sometimes, in other posts: Batteries do not store electricity, they generate it.
IBM’s Lithium-Ion Battery Technology
IBM decided to start work on these batteries somewhat recently due to their great potential and discovered that the oxygen in the air is not only reacting with the carbon electrode mentioned, but also with the battery’s electrolyte.
So, physicist Winfried Wilcke and his colleague Alessandro Curioni at IBM’s Zurich research labs in Switzerland used the Blue Gene supercomputer to simulate extremely detailed models of the reactions using alternative electrolytes until they finally found a more suitable one, which is confidential.
Winfried Wilcke said: “We now have one which looks very promising.”
The hope is to have a full-scale battery prototype operation by 2013 and commercial batteries around 2020.