Could Lithium-air batteries make oil obsolete?

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Sooner than it takes to build a nuclear power station, lithium-air batteries could be helping wind and solar to make coal, oil and nuclear obsolete, say Cambridge scientists. Five times lighter and five times cheaper than current lithium batteries, Li-air would open the way to our 100% renewable future.

Sooner than it takes to build a nuclear power station, lithium-air batteries could be helping wind and solar to make coal, oil and nuclear obsolete, say Cambridge scientists. Five times lighter and five times cheaper than current lithium batteries, Li-air would open the way to our 100% renewable future.

Scientists have developed a working laboratory demonstrator of a lithium-oxygen battery which has very high energy density, is more than 90% efficient over its discharge-recharge cycle, and can be recharged more than 2,000 times.

Lithium-oxygen, or lithium-air, batteries have been touted as the 'ultimate' battery due to their theoretical energy density, which is ten times that of a lithium-ion battery.

Such a high energy density would be comparable to that of gasoline - and would enable an electric car with a battery that is a fifth the cost and a fifth the weight of those currently on the market to drive 400 miles on a single charge - from London to Edinburgh, or from Boston to Washington DC.

Although the energy density remains lower than for oil, the electrical energy is used far more efficiently with very low losses. Typical cars and trucks today waste 75% of fuel energy in heat. Also there is no need for the heavy engines and transmission systems required in oil-powered vehicles.

In fact the Li-air batteries could even be light enough to propel aircraft - weaning the world off one of the most intractable uses of fossil energy as aviation fuel.

This is the first time that any battery technology has even come close to challenging the energy density of petroleum fuels, and therefore represents a major tipping point in the world's energy choices in coming decades.

However, as is the case with other next-generation batteries, there are several practical challenges that need to be addressed before lithium-air batteries become a viable alternative to gasoline.

Now researchers from the University of Cambridge have shown how some of these obstacles may be overcome, and developed a lab-based demonstrator of a lithium-air battery which has higher capacity, increased energy efficiency and improved stability over previous attempts.

Continue reading at ENN affiliate, The Ecologist.

Lithium capsule image via Shutterstock.