A bag of coffee beans might seem like an unlikely educational tool. So might a small pile of coffee grounds derived from the beans. But at Pittsburg State University, where textbooks and Powerpoints are supplemented with things like trail cams,  

fish seines, and cement trucks, it makes perfect sense. 

Those coffee grounds that inspired Jonghyun Choi, a student from South Korea, wound up as fuel. 

More than half of American adults drink coffee every day, or about 10 pounds per year per person. While coffee-drinkers may feel the effects of coffee as their own kind of “energy,” Choi figured out how to use coffee to create energy storage through research with Associate Professor Ram Gupta at the KPRC. It’s a place where students and scientists rub elbows often. 

“We found that the carbons could be made into a supercapacitor, a small battery, that can last 10 years,” Gupta said. 

It could power a small fan, for example, or perhaps someday soon, 

At the Kansas Polymer Research Center, senior Jonghyun Choi saw treasure in trash –  

coffee grounds, to be precise. 

  1. The process begins with coffee grounds that have been brewed. Any flavor will do! 
  2. Chemical activation happens when dried brewed coffee grounds are mixed with chemicals to synthesize activated carbon, and then heated.
  3. Activated carbon is then washed and dried. The performance of a supercapacitor depends on the surface area and porosity of the carbon used. The chemical activation process ensures it’s suitable.   
  1. Next, the carbon is used to fabricate circular electrodes for supercapacitors. Two dry-coated electrodes areseparatedand a coin-cell type supercapacitor is assembled using a hydraulic crimping machine. 
  2. The result: a supercapacitor tested using industrial standards found to be much better than many oxide and carbon-based devices and suitable for using more than 10,000 cycles of charge-discharge, or more than 10 years of performance.

soon, a cell phone. If they could produce hundreds in a day, Choi estimates, then industry could create thousands. 

Choi’s work was accepted for publication in an international journal, and his work to perfect the batteries is continuing at PSU as he seeks a graduate degree. 

“A professor like Ram — he’s an excellent researcher, but his biggest impact is what he does with students,” said Tim Dawsey, who directs the KPRC. “The work they’re doing together is inspiring the next generation.” 

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As a senior in chemistry, Jonghyun Choi conducted research at the KPRC that led to the creation of batteries from coffee grounds. Choi, who completed his bachelor’s degree last year, is now a graduate student at PSU furthering his research.