The Anonymous
Bag On My Head
Will charging electric cars ever be as fast as pumping gas?
Charging EVs is slow.
While drivers today are accustomed to filling their gas tank in less than five minutes, EVs, depending on the size and specifications of the battery, typically take at least 30 minutes to get 80 percent charged at the fastest charging stations out there.
The batteries inside today’s EVs are composed of thousands of lithium-ion cells with the ability to store and release energy thousands of times. Each of those cells consists of two electrodes—a metal cathode and a graphite anode—separated by a liquid electrolyte. While the battery is charging, lithium ions flow through the liquid from the cathode to the anode, filling up spaces between the graphite layers like wooden blocks fitting into a Jenga tower.
The speed at which lithium ions move from the cathode into the anode dictates how quickly the battery charges. But just as placing blocks in a Jenga tower hastily can cause the structure to become unstable, if lithium is forced into the anode too fast, problems start to arise.
At high charging speeds lithium batteries can overheat, causing them to degrade over time. More problematically, lithium can start to build up on the surface of the anode instead of entering it, a phenomenon known as lithium plating. Not only can that drastically reduce the battery’s capacity, the lithium deposits eventually form filament-like structures known as dendrites. Once they start forming, those dendrites can grow across the electrolyte, touch the cathode and create a short circuit, causing the battery to catch fire or explode.
“Obviously that’s not particularly good from a safety point of view,” says Peter Slater, a professor of materials chemistry at the University of Birmingham.
https://www.nationalgeographic.com/...-electric-cars-ever-be-as-fast-as-pumping-gas
