Megalodon Extinction May Have Been Driven by Hungry Great White Sharks

The largest shark that ever lived may have vanished in part because the comparatively smaller great white had a taste for the same prey.

#endangered-and-extinct-species, #fossils, #isotopes, #nature-communications-journal, #paleontology, #research, #sharks, #teeth-and-dentistry, #your-feed-animals, #your-feed-science, #zinc

New battery chemistry results in first rechargeable zinc-air battery

Image of three chunks of zinc metal.

Enlarge (credit: Wikimedia Commons)

Most of the disposable batteries you’ll come across are technically termed alkaline batteries. They work at high pH and typically use zinc as the charge carrier. Zinc is great because it’s very cheap, can be used to make one of the two electrodes, and, in the right context, allows the use of air at the other electrode. These latter two items simplify the battery, allowing it to be more compact and lighter weight—so far, attempts to do similar things with lithium batteries have come up short.

The problem with all of this is that the batteries are disposable for a good reason: the chemistry of discharging doesn’t really allow things to work in reverse. Carbon dioxide from the air reacts with the electrolyte, forming carbonates that block one electrode. And the zinc doesn’t re-deposit neatly on the electrode it came from, instead creating spiky structures called dendrites that can short out the battery.

Now, an international team has figured out how to make zinc batteries rechargeable. The answer, it seems, involves getting rid of the alkaline electrolyte that gave the batteries their name.

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#batteries, #chemistry, #materials-science, #science, #zinc

Carmakers want to ditch battery packs, use auto bodies for energy storage

A stylized image of an automobile.

Enlarge (credit: Viaframe / Getty Images)

Elon Musk made a lot of promises during Tesla’s Battery Day last September. Soon, he said, the company would have a car that runs on batteries with pure silicon anodes to boost their performance and reduced cobalt in the cathodes to lower their price. Its battery pack will be integrated into the chassis so that it provides mechanical support in addition to energy, a design that Musk claimed will reduce the car’s weight by 10 percent and improve its mileage by even more. He hailed Tesla’s structural battery as a “revolution” in engineering—but for some battery researchers, Musk’s future looked a lot like the past.

“He’s essentially doing something that we did 10 years ago,” says Emile Greenhalgh, a materials scientist at Imperial College London and the engineering chair in emerging technologies at the Royal Academy. He’s one of the world’s leading experts on structural batteries, an approach to energy storage that erases the boundary between the battery and the object it powers. “What we’re doing is going beyond what Elon Musk has been talking about,” Greenhalgh says. “There are no embedded batteries. The material itself is the energy storage device.”

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#batteries, #cars, #evs, #li-ion, #science, #zinc

Zinc: It Helps With Colds, But Not Coronavirus

Maybe! It may help with the common cold. There is no definitive scientific evidence suggesting it will help Covid-19.

#colds, #drugs-pharmaceuticals, #vitamins, #your-feed-selfcare, #zinc