University of California, San Diego researchers say they have developed a way to better estimate what goes on inside lithium ion batteries -- a breakthrough that could lead to lower battery costs and faster charging times for electric vehicles.
Professor Miroslav Krstic and postdoctoral fellow Scott Moura devised the algorithms, or mathematical procedures, to clarify what goes on in the "complicated world" of lithium ion batteries, Krstic said in an interview last week.
There is still a limited understanding of how lithium ions behave in batteries, so engineers overcompensate by building batteries that are too large, said Krstic, a faculty member of the Department of Mechanical and Aerospace Engineering at the Jacobs School of Engineering.
But applying the algorithms could result in smaller lithium ion batteries and potentially cut costs by 25 percent. Charging times also could end up two times faster, according to the university.
Cost, weight savings
"If one could have a better knowledge or better estimation of what's going on inside, one could [safely] operate closer to the limits of performance, which means that the oversizing and overdesign would be less necessary," Krstic said. "That translates into savings in costs and in weight."
Moura said the best use of the algorithms is maximizing the power and energy of a battery, which is "exactly what you need in automobiles without question."
The UC San Diego researchers will use $415,000 of a $4 million U.S. Department of Energy grant they are sharing with supplier Robert Bosch GmbH and battery maker Cobasys to continue their work.
Krstic and Moura will try their algorithms on test beds from Bosch and Cobasys, according to the university.
Three-year test period
"Our goal is to develop a certain set of algorithms and to have Bosch test these algorithms within a three-year period," Krstic said. "The schedule is very aggressive."
The algorithms will provide more insight into how much power the batteries contain, how to better assess battery health and how to better control the charging rate.
"Ultimately, the idea here is you can either make better batteries with new materials, or we can take batteries that we have and try to operate them more efficiently," Moura said. "That's what this research is about."