In a paper published in the Advanced Materials journal, Xiaodong Li and Lihong Bao, researchers from the University of South Carolina, have described a technique to convert a cotton T-shirt material into an electrical power source.
Xiaodong Li (foreground) demonstrates the flexibility of a swatch of activated carbon textile. (credit: Michael Brown, University of South Carolina)
The innovative process involves the immersion of a piece of a T-shirt in a fluoride solution, followed by drying and baking at high temperature in the absence of oxygen because oxygen presence will result in combustion or charring of the material. This process converts the surfaces of the fabric’s fibers from cellulose to activated carbon without affecting their flexibility. The researchers named the resulting material as activated carbon textile.
The researchers have demonstrated that this flexible material behaves as a capacitor by utilizing a small fabric piece as an electrode. Capacitors are capable of storing an electrical charge and are used in most of the electronic devices. According to the researchers, their activated carbon textile behaves as a double-layer capacitor or a supercapacitor as it can have especially high energy storage densities.
To further improve the activated carbon textile’s electrode performance, the researchers then applied ‘nanoflowers’ of manganese oxide on the fibers in the material. Li informed that this results in a stable, high-performance supercapacitor. The performance of this hybrid flexible supercapacitor did not drop over 5% even after several charge-discharge cycles. Li stated that mobile electronic devices like cell phones can be charged by these flexible supercapacitors when they are stacked up.
Li commented that the new technique is a low-cost green process whereas earlier techniques are complex and generated adverse side products as they utilize oil or adverse chemicals.