Inventors race to breathe extra life into batteries
May 17, 2012
WHEN Noam Kedem was strolling around the Consumer Electronics Show in Las Vegas in January, he was struck by the fact that business seemed to slow down every afternoon. And it wasn’t because of the usual post-lunch blahs.
With attendees using bigger and more powerful mobile phones, “you couldn’t talk to anyone after 3 p.m. because their smartphone batteries had all died,” said Kedem, vice president of marketing at Leyden Energy, a battery technology firm based in Fremont, California. “Everyone was running from charger to charger.”
From iPhones and laptops to electric vehicles, much of our plugged-in lifestyle seems tied to finding a suitable wall outlet. Yet consumer frustration has only grown as each new device drains batteries ever more quickly. Perhaps it’s not surprising, then, that the phrase “ihatebatterylow” has become a big hit on Facebook and Twitter.
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Driven by this consumer frustration as well as by a recent jolt of federal funding for improved batteries, university labs, small start-ups and corporate research divisions are all trying to make breakthroughs that will give us more room to roam away from our alternating-current tethers.
Though most of these designs haven’t hit the consumer market yet, the past few years have seen a surge of new configurations and chemistry that may solve some of our low-battery woes, said Esther Takeuchi, a professor of advanced power systems at the State University of New York at Buffalo. “With the combination of new materials, new design concepts, and new production and manufacturing methodologies, I believe we will get there,” she said.
Takeuchi said the current gold standard for batteries is lithium-ion, which was commercialised more than 20 years ago and is now commonly found in computers, camcorders and mobile phones.
Some researchers are trying to pack more power into existing lithium-ion cells; others are looking to incorporate such elements as sulphur, zinc, magnesium and even air into new types of batteries.
But while the race is on to make this quantum leap, some observers caution that improvements will take longer than the big jumps in memory and speed that have occurred in the computer industry roughly every 18 months.
“If you want to talk about a tenfold improvement, it might be a while,” said John Gartner, senior research analyst at Pike Research in Boulder, Colo. “But we are going to see consistent improvements across the board.”
Batteries work by converting a chemical reaction into electrical energy. Electrons form a circuit by flowing from one electrode – a positively charged cathode – to another one – a negatively charged anode – through an electrolyte, which can be either liquid or solid. The voltage difference between the two electrodes produces an electrical current. Italian physicist Alessandro Volta make the first one in 1800 by stacking layers of zinc, cloth and silver.
In the 20th century, heavy but long-lasting lead-acid batteries were developed for vehicles, while portable yet disposable alkaline batteries were commercialised for torches, smoke detectors and almost everything else.
Improvements to rechargeable lithium-ion batteries appear to have the most promise, at least right now. These batteries, used in most consumer electronics, including mobile phones and iPads, have a limited life span and charge capacity. But researchers say they can be made tremendously more efficient and long-lasting.
Researchers at the University of Texas developed the first lithium-ion rechargeable battery in the early 1980s,
And while today’s lithium-ion batteries last longer than older nickel-metal-hydride rechargeables, some experts say there’s plenty of room for improvement.
“Lithium-ion is only at the halfway point of what’s theoretically possible,” said Dane Boysen, director of the US Department of Energy’s Advanced Research Projects Agency-Energy battery program, which has awarded $US36 million to 10 projects since 2010. One of the grantees, Envia Systems of Newark, California, said in February that it could now more than double the power stored in its rechargeable lithium-ion battery, thanks to its new manganese-based cathode and silicon-carbon anode. The claim was verified by the Naval Surface Warfare Center in Crane, Indiana, a federal lab that evaluates engineering and electronics projects for the Pentagon.
General Motors has an agreement with Envia to use its new advanced lithium-ion battery for the Chevy Volt in the next two to three years. Boysen says the technology could make its way further into the consumer market relatively quickly, allowing laptops to run for 12 hours straight instead of six hours as is common now, for example.
Meanwhile, Pellion Technologies, started by scientists from the Massachusetts Institute of Technology, is building a manganese-based battery. Pellion claims it will have twice the energy of existing lithium-ion batteries, for both small consumer products and electric cars.
Toyota researchers in Michigan say they are developing a magnesium battery that can run 400 to 500 kilometres, twice the range of today’s batteries.
Magnesium is considered superior to lithium as an anode because it can store more of a charge, lasts longer and doesn’t build up dendrites, tiny chemical deposits that can be a safety problem.
The obstacle facing developers is finding the right kind of cathode and electrolyte to use with magnesium. An Israeli scientist put together the first rechargeable magnesium-sulphur battery in 2000, but it didn’t hold much of a charge. Pellion has used high-powered computers to screen 10,000 substances to see if they would work together with magnesium. Pellion officials said recently that they have narrowed it down to a few dozen candidates, while Toyota reported in August that it is using magnesium, sulphur and a special electrolyte.
Then there are lithium-air batteries, which use carbon for their cathodes instead of metal oxides. Carbon is lighter and reacts with oxygen in the air to produce an electrical current. Although such a battery promises a 1500-kilometre range for electric cars, engineers haven’t yet figured out how to make it recharge properly, according to New Scientist magazine.
Lithium can also have issues. It ignites in contact with moist air. But IBM researchers in California and Switzerland reported this year that they have solved a key problem by finding a way to get rid of water vapour. IBM hopes to have a prototype lithium-air car battery by 2013, with commercialisation by 2020.
Hitting a home run in battery technology takes decades, not just years, of research, Boysen said.
“In batteries, every chemistry is different,” he noted. “Every battery will need a different manufacturing infrastructure. Batteries are a much harder problem to solve” than other technologies, such as building faster computers or new kinds of electronics, Boysen said.
In fact, two battery companies have had trouble commercialising their rechargeable lithium-ion battery technology, even after getting government help. Ener1 filed for Chapter 11 bankruptcy in January after its main customer, a Norweigan electric car manufacturer, went under. Ener1 had received $US118 million in federal stimulus funds. A123 Systems recently said that it had to replace some faulty batteries in the new Fisker Automotive luxury electric plug-in vehicles. The company received $US249.1 million in federal funding in 2009.
Despite the potential for failure, some entrepreneurs just won’t give up. Nowhere is that more clear than in the track record of PolyPlus, which has been hunting for the holy grail of battery technology, lithium-air and lithium-water batteries, since the early 1990s. After pursuing lithium-sulphur for years, the company switched to lithium-air in 2003.
PolyPlus chief executive Steve Visco is finally building a pilot manufacturing plant in Berkeley, California, not far from the Lawrence Berkeley Laboratory, where he works as a fuel cell researcher. He expects to have the first lithium-seawater batteries available in two years; they will power long-distance probes that cruise ocean currents and send back oceanographic data to help scientists make climate predictions.
The next application will be lithium-air battery pouches that can be inserted into soldiers’ radios. It will take five years before rechargeable lithium-air batteries are ready for the consumer market, Visco said. Scientists need to make sure they can hold up to everyday use without overheating, something that plagued lithium-ion batteries when they were introduced in the 1990s.
But Visco has one caution for harried consumers who want a longer-lasting phone or laptop. He said that any gains in efficiency – less weight or more run time, for example – will probably get eaten up by the demands of the more and more complex gizmos coming to market.
“If you put the lithium-air battery in your laptop, it would run twice as long,” Visco said. “But the guys who design laptops will just put more bells and whistles inside it.”