Long charging times and limited access to fast chargers can be the dealbreakers for electric vehicle buyers today. But technology advancements are often fast-paced, and it’s hard to predict how close, or far, we are from the next big breakthrough. However, battery scientists at Oak Ridge National Laboratory (ORNL) might have a solution for charging speeds.
ORNL’s paper highlights a new lithium-ion battery that can not only recharge to 80 percent in 10 minutes but also sustain the fast charging ability for 1500 cycles. For those new to the EV language, battery charge, and discharge occur when ions travel between the positive and negative electrodes through a medium called an electrolyte.
Getting to fifteen hundred charging cycles isn’t a new development. Tesla CEO Elon Musk tweeted in 2019 that the Model 3’s battery modules were designed to last 1,500 cycles or between 300,000 and 500,000 miles.
ORNL’s team claims to have developed a new type of electrolyte that enables fast charging over a sustained time period. The team developed “new formulations of lithium salts with carbonate solvents to form an electrolyte” for an improved ion flow over time and the ability to withstand the heat generated by the currents during fast charging.
“We found this new electrolyte formulation basically triples the Department of Energy’s target for the lifespan of an extreme-fast-charging battery,” ORNL’s Zhijia Du said. The high-performance electrolyte consists of “lithium bis(fluorosulfonyl)imide (LiFSI), lithium hexafluorophosphate (LiPF6), and carbonates in, two amp hour pouch cells.”
The formula apparently displayed excellent electrochemical stability at a high charging rate of 6C, which translates to one-sixth of an hour, or 10 ten minutes. However, there are many unanswered questions. It’s not clear how much this chemistry would cost to incorporate in an EV battery, what are the possible battery capacities, and if it can ever be democratised.
Earlier reports suggested that fast charging impacts a battery's longevity, but new findings reveal no significant difference in battery degradation between EVs that regularly fast charge, and ones that only occasionally fast charge.
Some OEMs appear to be in the advanced stages of battery development. Toyota revealed last week that its future EVs would rely on three new liquid electrolyte battery technologies and one solid-state battery. One of these lithium-ion batteries would be capable of delivering 497 miles of range, and attain 10-80 percent state of charge (SoC) in 20 minutes.