Study shows dangers of fast-charging EVs

Engineers from UC Riverside (UCR) experimented on Panasonic NCR 18650B cylindrical lithium-ion batteries of the kind found in Tesla vehicles. Using the same industry fast-charging method as deployed along US freeways, they found that after just 40 cycles, the batteries were achieving just 60 per cent of their original capacity.

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"Industrial fast-charging affects the lifespan of lithium-ion batteries adversely because of the increase in the internal resistance of the batteries, which in turn results in heat generation," said UCR doctoral student Tanner Zerrin, co-author of the study, published in Energy Storage.

After 60 charging cycles, the industry method battery cases cracked, exposing the electrodes and electrolyte to air and increasing the risk of fire or explosion. High temperatures of 60 degrees Celsius/140 degrees Fahrenheit accelerated both the damage and risk.

"Capacity loss, internal chemical and mechanical damage, and the high heat for each battery are major safety concerns, especially considering there are 7,104 lithium-ion batteries in a Tesla Model S and 4,416 in a Tesla Model 3," said Mihri Ozkan, a professor of electrical and computer engineering at UCR.