One of the general public’s biggest hesitations about using electric vehicles centers on range anxiety, which is directly related to charging time. Most home outlets—a level 1 charger—require 40 hours to fully charge the average EV. Many level 2 chargers work at a rate of 15–25 miles of range per hour, which still requires several hours to fully charge. Some level 3 chargers can get the job done in 30 minutes using DC power, but at considerable cost.
Space technology could soon cut recharging time to 5 minutes or less, according to an October 2022 article from NASA. The space agency is partnering with Purdue University on a research project for future space missions that may find an application here on Earth.
The technique of “subcooled flow boiling” is used to bring “nuclear fission power systems for missions to the moon, Mars and beyond” and fuel vapor compression heat pumps to support lunar and Martian habitats and systems that provide thermal control and advanced life support onboard spacecraft, according to NASA. The process cools cables carrying high charges, permitting a faster flow of electricity without risk of overheating components.
This same technology could increase the amount of electrical current supplied to EV chargers by about 1,400A, which is almost five times the rate of the 520A currently provided to EVs.
According to NASA, the typical EV chargers purchased by consumers provide less than 150A. This new system could deliver 4.6 times the current of the fastest available EV chargers on the market by removing up to 24.22 kilowatts of heat.
With the number of EVs increasing to almost 9% of the global car market in 2021, and predicted to reach 13% of total light-duty vehicles this year, according to the International Energy Agency in a Tracking Clean Energy Progress update, rapid recharging could be a critical advancement for future sales.
This project is part of ongoing research by Purdue since 2017, with funding from Ford Motor Co. Last year, engineers at the Indiana-based university presented an alternative cooling method as part of a new charging station cable capable of fully recharging certain EVs in less than five minutes—or about the same time it takes to fill a gas tank. The cable uses liquid as a cooling agent to prevent battery overheating while delivering more power to recharge EVs.
While Purdue has created a prototype that replicates a charging station’s pump and cable with the same diameter, controls, instrumentation, flow rates and temperatures, the lab expects to test it with EV or charging cable manufacturers within the next two years.
Ultimately, however, charging times will depend on the “power output ratings of the power supply and charging cable, and the power input rating of the EV’s battery,” cautions Purdue researchers. To hit the sub-five-minute goal, all three components must be rated to 2,500A.