Electric vehicles could be fully charged in 10 minutes with machine learning method

Charging the lithium-ion batteries that fuel electric vehicles is a delicate balancing act. Ideally, drivers want to power up as quickly as possible to get back on the motorway, but with current technology, speeding up the process can cause damage to the battery.

When a lithium-ion battery is being charged, lithium ions migrate from one side of the device, the cathode, to the other, the anode. By making the lithium ions migrate faster, the battery is charged more quickly, but sometimes the lithium ions don’t fully move into the anode.

In this situation, lithium metal can build up, and this can trigger early battery failure or cause the cathode to wear and crack.

All of these issues will reduce the lifetime of the battery and the effective range of the vehicle — expensive and frustrating consequences for drivers.

“Fast charging is the key to increasing consumer confidence and overall adoption of electric vehicles,” said Eric Dufek, a researcher at Idaho National Laboratory’s Energy Storage & Electric Vehicle Department. “It would allow vehicle charging to be very similar to filling up at a gas station.”

The researchers used machine learning techniques that incorporate charging data to create unique charging protocols for the many different types of battery designs currently used in vehicles.

By inputting information about the condition of many lithium-ion batteries during their charging and discharging cycles, the scientists trained the machine learning analysis to predict lifetimes and the ways that different designs would eventually fail. They fed that data back into the analysis to identify and optimise new protocols that they then tested on real batteries.

“We’ve significantly increased the amount of energy that can go into a battery cell in a short amount of time,” Dufek said. “Currently, we’re seeing batteries charge to over 90 per cent in 10 minutes without lithium plating or cathode cracking.”

Going from a nearly dead battery to one at 90 per cent power in only 10 minutes is a far cry from current methods, which, at best, can get an electric vehicle to full charge in about half an hour. While many researchers are looking for methods to achieve this sort of super-fast charging, Dufek says that one advantage of their machine learning model is that it ties the protocols to the physics of what is actually happening in a battery. 

The researchers plan to use their model to develop even better methods and to help design new lithium-ion batteries that are optimised to undergo fast charging. The ultimate goal is for electric vehicles to be able to “tell” charging stations how to power up their specific batteries quickly and safely.