Electrochemical Micro-Capacitors Utilizing Carbon Nanostructures

The rapid advancement of microelectronics requires equivalently sized energy storage devices to provide energy for microelectromechanical system (MEMS) devices and other technologies. By using a novel approach to fabricate carbon nanotubes (CNTs), our electrodes have a high surface area with an aerial tube density up to 1,000 times greater than typical carpet-grown CNTs. By combining these electrodes with designer electrolytes, we have demonstrated ultracapacitors significantly better than the state-of-the-art micro-capacitors under development. The performance actually improves with increasing current withdraw that causes internal heating and would otherwise destroy traditional ultracapacitors. During Phase I, Mainstream determined the optimal electrode–electrolyte system to obtain high energy density micro-capacitors and demonstrated their performance at various temperatures. In addition, we demonstrated fabrication of our electrodes on a silicon chip, and used photolithography to successfully fabricate the chips in an interdigitated electrode design. Our work plan for the Phase II is designed to further improve our ultracapacitor design through modeling and experimental work. By the end of Phase II, we will produce an independently verifiable full-scale prototype on-chip device.