Bring on the electric cars
The best argument against electric cars that I hear is that they take too long charge relative to the distance they can take you. A team at MIT is working on capacitor-based batteries that would charge in seconds and would need to be replaced much more rarely than chemical batteries.
They turned to the capacitor, which was invented nearly 300 years ago. Schindall explains, “We made the connection that perhaps we could take an old product, a capacitor, and use a new technology, nanotechnology, to make that old product in a new way.”
Rechargable and disposable batteries use a chemical reaction to produce energy. “That’s an effective way to store a large amount of energy,” he says, “but the problem is that after many charges and discharges … the battery loses capacity to the point where the user has to discard it.”
Schindall Battery Researcher But capacitors contain energy as an electric field of charged particles created by two metal electrodes. Capacitors charge faster and last longer than normal batteries. The problem is that storage capacity is proportional to the surface area of the battery’s electrodes, so even today’s most powerful capacitors hold 25 times less energy than similarly sized standard chemical batteries.
The researchers solved this by covering the electrodes with millions of tiny filaments called nanotubes. Each nanotube is 30,000 times thinner than a human hair. Similar to how a thick, fuzzy bath towel soaks up more water than a thin, flat bed sheet, the nanotube filaments on increase the surface area of the electrodes and allow the capacitor to store more energy. Schindall says this combines the strength of today’s batteries with the longevity and speed of capacitors.