An Ordinary Cotton T-Shirt Could Someday Charge Your Cellphone

That Hanes Beefy-T you’re wearing could someday power your mobile device—that is, if researchers at the University of South Carolina have anything to do with it. Xiaodong Li, a professor of mechanical engineering, and Lihong Bao, a postdoctoral associate, transformed an ordinary cotton tee into a supercapacitor by soaking it in fluoride solution and baking it at high temperatures. The process didn’t just convert the cellulose fibers into activated carbon, however; it also allowed the material to flex without breaking. The erstwhile cotton T-shirt proved to be a repository for electricity, and one with an exceptionally high storage capacity at that. But Li and Bao didn’t stop there. To maximize the activated-carbon material’s potential, they coated the individual fibers with a nanometer-thick layer of manganese oxide, which boosted the textile’s electrode performance even further. “This created a stable, high-performing supercapacitor,” Li says in a statement.

The erstwhile cotton T-shirt proved to be a high-capacity repository for electricity.

Li, who published his team’s findings in the current issue of Advanced Materials, anticipates a future where electronics are part of our wardrobes. “We wear fabric every day,” he says. “One day our cotton T-shirts could have more functions; for example, a flexible energy storage device that could charge your cellphone or your iPad.”

Beyond its improved storage capability, the hybrid supercapacitor was also remarkably resilient: its performance didn’t weaken by more than 5 percent even after thousands of charge-discharge cycles. Li expects that by stacking the supercapacitors, we’ll be able to charge portable electronic devices such as cellphones.

As far as obtaining activated-carbon fibers go, Li’s method has the benefit of being more sustainable than conventional means. “Previous methods used oil or environmentally unfriendly chemicals as starting materials,” he says. “Those processes are complicated and produce harmful side products. Our method is a very inexpensive, green process.”