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Brimstone and Nanotech May Boost Batteries

Lithium-sulfur batteries could give EVs 500-kilometer range

2 min read
Brimstone and Nanotech May Boost Batteries
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Batteries that pair lithium with sulfur may now be a major step closer to propelling electric vehicles three times farther than the lithium-ion batteries used to do so today, researchers say.

For electric vehicles to have a 500-km range, their batteries would need to store nearly double the energy they do now. One possible solution are lithium-sulfur batteries, which store more electrons kilo for kilo than lithium-ion batteries. Moreover, sulfur is extremely abundant, relatively light, and cheap, making it potentially very attractive for use in novel batteries.

Despite its many advantages, lithium-sulfur batteries are plagued with problems that have hampered practical realization. One challenge lithium-sulfur batteries face is how the electrode that contains the sulfur often gets depleted after only a few cycles of discharging and recharging. This is because the sulfur disintegrates in the electrolyte liquid in which the lithium and sulfur electrodes both sit, dissolving to form sulfurous molecules called polysulfides.

Now scientists from the University of Waterloo in Canada and BASF SE in Germany say that nanotechnology can help entrap this sulfur. Their battery contains sheets of manganese dioxide only nanometers or billionths of a meter thick coated with sulfur. The manganese dioxide reacts with the sulfur to generate compounds known as thiosulfate groups. These compounds grab onto and chemically bond with polysulfides, preventing them from leaking into the electrolyte.

Electric vehicle batteries ideally need to survive 1500 recharge cycles. This new battery can recharge more than 2000 cycles. The scientists are now investigating other oxides to find the best sulfur-retaining material. Such batteries could also have applications in mobile electronics, they noted.

The researchers cautioned this new technology is too premature to be showcased at the Detroit Auto Show this month. "The batteries in the cars at the Detroit Auto Show were developed about 15 years ago," said researcher Linda Nazar, a materials electrochemist at the University of Waterloo. "The technology takes a while to reach maturity and commercialization."

The scientists reported their findings in the Jan. 6 issue of the journal Nature Communications, and will detail their research at the American Association for the Advancement of Science annual conference on Feb. 14 in San Jose, Calif.

The Conversation (0)

We Need More Than Just Electric Vehicles

To decarbonize road transport we need to complement EVs with bikes, rail, city planning, and alternative energy

11 min read
A worker works on the frame of a car on an assembly line.

China has more EVs than any other country—but it also gets most of its electricity from coal.

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Green

EVs have finally come of age. The total cost of purchasing and driving one—the cost of ownership—has fallen nearly to parity with a typical gasoline-fueled car. Scientists and engineers have extended the range of EVs by cramming ever more energy into their batteries, and vehicle-charging networks have expanded in many countries. In the United States, for example, there are more than 49,000 public charging stations, and it is now possible to drive an EV from New York to California using public charging networks.

With all this, consumers and policymakers alike are hopeful that society will soon greatly reduce its carbon emissions by replacing today’s cars with electric vehicles. Indeed, adopting electric vehicles will go a long way in helping to improve environmental outcomes. But EVs come with important weaknesses, and so people shouldn’t count on them alone to do the job, even for the transportation sector.

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