Flexible Battery Could Unlock Wearable Electronics

Engineers at Rice University have developed a thin, flexible, high-performance battery that could be a game changer for the world of wearable electronics.

Created by chemist James Tour, postdoctoral researcher Yang Yang and a number of other colleagues, the new battery is an amalgamation of a nanoporous nickel-fluoride electrode and solid electrolyte. Measuring in at around a hundredth of an inch thick, the pliable energy cell also has the properties of a supercapacitor, lending it the ability to absorb and discharge current at an incredible rate.

To engineer the new battery Tour and his team etched a 900 nanometer thick electrode wafer of nickel-fluoride creating regularly spaced 5 nanometer wide holes. Through their etching the researchers were able to expand the battery’s surface area giving the cell more storage potential. After maximizing the real estate on their electrode, the wafer was united with a solid, potassium hydroxide electrolyte creating an odd composition that is structured like a supercapacictor but behaves like a battery.

“Compared with a lithium-ion device, the [battery’s] structure is quite simple and safe,” said Yang. “It behaves like a battery but the structure is that of a supercapacitor. If we use it as a supercapacitor, we can charge quickly at a high current rate and discharge it in a very short time. But for other applications, we find we can set it up to charge more slowly and to discharge slowly like a battery.”

While the new battery’s composition might be unorthodox, its performance is right in line with expectations. After 10,000 charging cycles the mechanism was still capable of holding 76% of its original levels which were pegged at an energy density of 384 Wh/kg and a power density of 112 kW/kg.

According to the Rice team one othercritical feature of their device is its ability to scale easily. If a large storage capacity is required, the cell’s potential can be increased by either stacking on new layers or expanding the size of the battery itself.

Given its flexibility, storage potential and ability to scale, the new Rice battery could be just the thing to make wearable computers like smart watches or flexible electronics like e-magazines a reality. If adopted by industry the new Rice battery could do for 21st century electronics what the Li-ion battery did for 20th century machines.

Image Courtesy of Rice University