Battery research is being conducted in several different areas. Researchers at MIT are using viruses to create batteries that can hold more power and run for longer periods. Battery research is a hot bed of activity because the batteries can be used in automobiles to help reduce pollution and our need for oil. Improvements in battery technology will also lead to smaller computers and mobile phones that offer more run time with each charge.

One of the hallmarks of carbon nanotubes is that fact that the CNTs are just about perfect according to researchers. A professor and a graduate student at UC San Diego have discovered that by introducing purposeful defects into CNT structures the defective CNTs work better for the development of super capacitors.

Professor Prabhakar Bandaru said, "While batteries have large storage capacity, they take a long time to charge; while electrostatic capacitors can charge quickly but typically have limited capacity. However, super capacitors electrochemical capacitors incorporate the advantages of both."

Bandaru is working with graduate student Mark Hoefer on the research program studying CNTs. The pair discovered that introducing purposeful defects into the CNT structure created additional charge sites and enhanced the charge storage properties of the CNT.

Hoefer said, "We first realized that defective CNTs could be used for energy storage when we were investigating their use as electrodes for chemical sensors. During our initial tests we noticed that we were able to create charged defects that could be used to increase CNT charge storage capabilities."

The researchers also found that other methods could increase or decrease the charge capacity of the CNTs with defects such as bombarding them with argon or hydrogen.

Bandaru said, "It is important to control this process carefully as too many defects can deteriorate the electrical conductivity, which is the reason for the use of CNTs in the first place. Good conductivity helps in efficient charge transport and increases the power density of these devices."

The interesting part of this research is that one of the things that first drew scientists and researchers to study CNTs was the fact that the CNTs are nominally considered to be perfect structurally. In this instance, the CNTs are better when they have a certain amount of defects.

The two researchers think that their discovery could lead to electronics that charge faster and last longer than what we have today. Bandaru understands that much more research is required on the subject and hopes that more researchers and engineers will investigate the discovery.

Hoefer said, "We hope that our research will spark future interest in utilizing CNTs as electrodes in charge storage devices with greater energy and power densities."