RESEARCH & INNOVATION
Cyrus Rustomji , PhD ’ 15 ( right ), is bringing his battery breakthroughs to market with the startup South 8 Technologies , along with fellow alumnus Yangyuchen Yang , MS ’ 16 .
THIS BATTERY IS CRAZY
Taking portable power to new lows .
BY LIEZEL LABIOS , MS ' 10 , PHD ' 12
Cyrus Rustomji , PhD ’ 15 , has been called crazy on a couple occasions . He once drilled holes into his surfboard and installed electronics inside , creating a set of speakers he felt worthy of playing the Beach Boys . “ People gave me a hard time because it was a perfectly good surfboard ,” he says , “ but in my defense it was waterlogged . It no longer floats , but it ’ s really loud because the acoustics work well with the fiberglass and foam core .”
Rustomji was also called crazy for the idea that ultimately led to his own business , South 8 Technologies , which is aiming to make lithium batteries work better in extreme cold . Low temperatures are known to wreak havoc on current battery performance , as they slow down the chemical reactions inside the battery that produce and store power . This can be a big problem if you want to drive an electric car in places like Minnesota , or anywhere else winter temperatures regularly dip below freezing .
While he was a PhD student in professor Shirley Meng ’ s nanoengineering lab , Rustomji ’ s “ crazy ” idea for batteries was to create a new type of electrolyte — the chemical substance that moves charges back and forth inside batteries to create
power . Conventional lithium batteries contain liquid electrolytes , which freeze at low temperatures . So Rustomji had the unconventional idea to replace the liquid electrolyte with something far more cold-hardy : liquefied gases .
Liquefied gases are a lot more common than they sound — your barbecue grill is likely fueled by liquid propane . But Rustomji realized that liquefied gases were key to making battery electrolytes that weather the cold , as they stay liquid at temperatures where conventional electrolytes freeze . “ No one had ever done this in battery research ,” Rustomji says . “ Most battery scientists would say there are too many problems with using a gas . Even my advisor thought I was crazy . But I thought there might be a way .”
There were plenty of problems to overcome , such as finding a gas that could dissolve salts ( electrolytes are essentially salt solutions ) and designing new hardware and experiments for testing the liquefied gas electrolytes . Yet after years of trial and error , Rustomji formulated the ideal electrolyte using the gas fluoromethane . With it , lithium batteries tested in the lab not only worked better at record low temperatures , they could store more
14 TRITON | SPRING 2018