Carbon Nanofiber Electrode Material Reduces Corrosive Fluids

The carbon nanofiber electrode can replace corrosive electrolyte fluids. Photo courtesy of Drexel.

Researchers with Drexel University (Philadelphia, Pennsylvania) have created a solvent-free, fabric-like electrode material to make energy storage devices—batteries and supercapacitors—that are faster, more durable, and less susceptible to leaks.

Traditional electrolyte fluids can be corrosive, toxic, and even flammable. To keep up with mobile technologies, devices are subject to material shrinking during design, leaving them vulnerable to short-circuiting.

The Drexel electrode uses a thick, ion-rich gel electrolyte that is absorbed in a freestanding mat of carbon nanofibers to produce a liquid-free device.

“To allow industrially relevant electrode thickness and loading, we have developed a cloth-like electrode composed of nanofibers that provides a well-defined, three-dimensional open pore structure for easy infusion of the solid electrolyte precursor,” says Vibha Kalra, a professor in Drexel’s College of Engineering.

“The open-pore electrode is also free of binding agents that act as insulators and diminish performance,” he adds.

The key is a fiber-like framework created through electrospinning, which extrudes the solution through a rotating electric field. The ionogel is absorbed to create an electrode-electrolyte network.

The performance characteristics are tied to this combination, because contact is made over a larger surface area. This process also eliminates the need for scaffolding materials used to form the physical electrode, thereby reducing costs.

Their next step is applying this technique to the production of solid-state batteries.

Source: Drexel University, www.drexel.edu