Flexible batteries designed from carbon nanotubes
Researchers have built a flexible battery out of carbon nanotubes that could power electronic devices with flexible organic light-emitting diode (OLED) displays, such as televisions and computer tablets that literally fold or roll up.
The New Jersey Institute of Technology (NJIT) researchers were able to use standard electrochemicals to produce the charge in a flexible form factor that has no size limits.
"This battery can be made as small as a pinhead or as large as a carpet in your living room," said Somenath Mitra, a professor of chemistry and environmental science whose research group invented the battery. "So its applications are endless. You can place a rolled-up battery in the trunk of your electric car and have it power the vehicle."
The flexible battery, Mitra said, has another revolutionary potential: it could be fabricated at home by consumers using only a kit comprised of electrode paste and a laminating machine.
"One would coat two plastic sheets with the electrode paste, place a plastic separator between the sheets and then laminate the assembly. The battery assembly would function in the same way as a double-A or a triple-A battery," Mitra said.
Battery power does vary with size, Mitra said. The current flexible battery prototype is roughly 1.5-in. by 2-in. in size and can power a couple of LED lights. How long the flexible battery could hold a charge depends upon discharge rate, Mitra said in an email response to Computerworld.
The nanotube battery, given its flexibility and components, can be used to power a new generation of bendable electronics. The battery is made from carbon nanotubes and micro-particles that serve as active components—similar to those found in conventional batteries. It is designed, though, to contain the electro-active ingredients while remaining flexible.
The battery uses any number of electrochemicals to produce a charge. For example, for an alkaline cell the researchers could use zinc and manganese dioxide; for lithium ion they would use lithium salts.
"The idea is to put a conventional battery in a flexible platform," Mitra said. "Our current work that is going to be published utilizes over 92 percent of active ingredients, so that is important."
The NJIT researchers said a patent application on the battery has been filed, and the battery will be featured in an upcoming issue of the peer-reviewed scientific journal Advanced Materials. Mitra developed the new technology at NJIT with assistance from Zhiqian Wang, a doctoral student in chemistry.( "We have been experimenting with carbon nanotubes and other leading technologies for many years at NJIT," Mitra said, "and it's exciting to apply leading-edge technologies to create a flexible battery that has myriad consumer applications."