https://arstechnica.com/cars/2020/11/carmakers-want-to-ditch-battery-packs-use-auto-bodies-for-energy-storage/
Ars Technica said:...
But for Greenhalgh and his collaborators, the more promising approach is to scrap the battery pack and use the vehicle’s body for energy storage instead. Unlike a conventional battery pack embedded in the chassis, these structural batteries are invisible. The electrical storage happens in the thin layers of composite materials that make up the car’s frame. In a sense, they’re weightless because the car is the battery.
“It’s making the material do two things simultaneously,” says Greenhalgh. This new way of thinking about EV design can provide huge performance gains and improve safety because there won’t be thousands of energy-dense, flammable cells packed into the car.
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Unlike the carbon-fiber and lithium-ion sheets being developed by Asp and Greenhalgh, Kotov and his students created a zinc-air structural battery for their automatons. This cell chemistry is able to store much more energy than conventional Li-ion cells. It consists of a zinc anode, a carbon cloth cathode, and a semi-rigid electrolyte made from polymer-based nanofibers that is nanoengineered to mimic cartilage. The energy carriers in this type of battery are hydroxide ions that are produced when oxygen from the air interacts with the zinc.
While structural batteries for vehicles are highly rigid, the cell developed by Kotov’s team is meant to be pliable to cope with the movements of the robots. They’re also incredibly energy-dense. As Kotov and his team detailed in a paper published earlier this year, their structural batteries have 72 times the energy capacity of a conventional lithium-ion cell of the same volume. For now, their batteries are being used to power robotic toys and small drones as a proof of concept. But Kotov says he expects they’ll be used in midsize robots as well as larger hobby drones in the not-so-distant future. “Drones and medium-size robots need to have new solutions for energy storage,” Kotov says. “I can guarantee you that structural batteries will be a part of that.”
The battery has always been an addendum, a limiting factor, and a parasite. Today, it’s vanishing before our eyes, melting into the fabric of our electrified world. In the future, everything will be a battery, and stand-alone energy storage will seem as quaint as landline telephones and portable CD players. It’s a disappearing act worthy of a great magician: now you see it—and soon you won’t.
