Batteries are a hugely important technology. Modern life would be impossible without them. But many engineers find them disappointing and feel that they could be better still. Produce the right battery at the right price, these engineers think, and you could make the internal-combustion engine redundant and usher in a world in which free fuel, in the form of wind and solar energy, was the norm.
It is, however, a revolution that people have been awaiting a long time. And the longer they wait, the more the doubters wonder if it will ever happen. The Joint Centre for Energy Storage Research (JCESR), at which Dr Pupek and his colleagues work, hopes to prove the doubters wrong. It has drawn together the best brains in energy research from America’s national laboratories and universities, along with a group of interested companies. It has money, too. It has just received a grant of $120m from the country’s Department of Energy. The aim, snappily expressed, is to make batteries five times more powerful and five times cheaper in five years.
Think positive
Most batteries, from the ancient, lumbering lead-acid monsters used
to start cars, to the sleek, tiny lithium cells that power everything
from e-book readers to watches, have three essential components: two
electrodes (an anode and a cathode) and a medium called an electrolyte
that allows positively charged ions to move between the electrodes,
balancing the flow of negatively charged electrons that form the
battery’s useful current. The skill of creating new types of battery is
to tinker with the materials of these three components in ways that
make things better and cheaper. Dr Pupek’s white powders are among
those materials.To discover more of them, Argonne will make use of a rapidly growing encyclopedia of substances created by Gerbrand Ceder of the Massachusetts Institute of Technology. Dr Ceder runs the Materials Project, which aims to be the “Google of material properties”. It allows researchers to speed up the way they search for things with specific properties. Argonne will use the Materials Project as a reference library in its search for better electrodes, and also hopes to add to it.
The first test of any combination of substances that comes out of the Materials Project, or anywhere else, will be to beat the most successful electricity-storage device to emerge over the past 20 years: the lithium-ion battery. Such batteries are now ubiquitous. Most famously, they power many of the electric and hybrid-electric cars that are starting to appear on the roads. More infamously, they have a tendency to overheat and burn. Two recent fires on board Boeing’s new 787 Dreamliners may have been caused by such batteries or their control systems. Improving on lithium-ion would be a feather in the cap of any laboratory.
George Crabtree, JCESR’s newly appointed director, thinks such improvements will be needed soon. He reckons that most of the gains in performance to be had from lithium-ion batteries have already been achieved, making the batteries ripe for replacement. Jeff Chamberlain, his deputy, is more bullish about the existing technology. He says it may still be possible to double the amount of energy a lithium-ion battery of given weight can store, and also reduce its cost by 30-40%.
This illustrates the uncertainty about whether lithium-ion technology, if pushed to its limits, can make electric vehicles truly competitive with those run by internal-combustion engines, let alone better. McKinsey, a business consultancy, reckons that lithium-ion batteries might be competitive by 2020 but, as the chart below shows, there is still a lot of work to do. Moreover, pretenders to lithium-ion’s throne are already emerging.
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