Researchers probe power of nanotech

A research collaboration has studied effects of an additive used in electric car batteries.

Keaton Schmitt

As the popularity of electric cars grows, University of Minnesota researchers are poised to pull ahead with microscopic technology under the hood.
 
 
A team of researchers teamed up with others from the University of Wisconsin-Madison to improve the nanocompounds added to lithium-ion batteries like those in cellphones, computers and, more recently, electric cars.
 
 
The group published a paper last month in the journal Chemistry of Materials describing an additive’s effects on a bacterium, which could indicate negative environmental effects. 
 
 
The additive, nickel manganese cobalt or NMC, killed the bacteria and stopped its replication, said the study’s co-author and Minnesota chemistry professor Christy Haynes.
 
 
“In our experience, [the bacterium] is actually a pretty robust bacterium,” Haynes said. “This is something you could think of as a potential canary in the coalmine.” 
 
 
NMC is being used in batteries because it fills the same chemical function as cobalt — which is widely used in standard lithium-ion batteries — but is cheaper to produce.
 
 
“The problem is cobalt is a pretty expensive material. Lots of people who make batteries would love to find cheaper ways to get the same performance,” Haynes said. “NMC is well positioned to replace [cobalt in standard lithium-ion batteries], if it’s not already doing it, because it’s cheaper and its performance is still good.”
 
 
While NMC isn’t currently used in phones or laptops, it has recently been incorporated into the batteries of large electric cars, said Ian Gunsolus, a Minnesota graduate student who co-authored the study.
 
 
“This is the kind of scale of nanomaterial use in commercial use that is kind of unprecedented,” Gunsolus said.
 
 
Now, the Minnesota researchers want to develop an NMC alternative to keep its positive effects without posing a potential environmental hazard.
 
 
“This study is helping us think about how to design a material that doesn’t serve as a source of these contaminants,” Gunsolus said.
 
 
Finding alternatives early in the process lets researchers potentially “change the equation” and make better versions without negative biological impacts, said Bob Hamers, co-author and University of Wisconsin-Madison chemistry professor.
 
 
Haynes said the team created up to four alternatives that they plan to test.
 
 
“The whole idea is to obtain materials that are sustainable,” said Mimi Hang, a Wisconsin graduate student and study co-author. “We want to know exactly what are the environmental impacts so we can design a material that doesn’t have that impact but has just as good performance.” 
 
 
Haynes said nanomaterials are desirable because they often offer better performance than traditional materials. 
 
 
And at smaller scales, they can have unique properties, lending them to many possible uses, she said.
 
 
The team’s research was part of the Center for Sustainable Nanotechnology, which focuses on creating efficient and environmentally sound nanotechnologies, Gunsolus said.