Published on February 24th, 2012 | by Christopher DeMorro
New Polymer Could Increase Capacitor Storage And Discharge Rate
Though electric cars are still in their infancy, already many people are seeing the potential for performance in the instant torque of electric motors. It’s not the motors that are the problem though; the batteries just can’t keep up. That is why some companies believe that capacitors, not batteries, are the future.
But capacitors face their own challenges, like lower energy density. But new research has uncovered a polymer that increases capacitor energy storage seven-fold, as well as the pace at which capacitors can discharge, making them ideal for performance vehicles.
Researchers at North Carolina State University have found that a polymer known as PVDF enables capacitors to store and discharge as much as seven-times as much energy as current capacitor technology. Unlike batteries, which use chemical reactions to produce electricity, capacitors use lots of separate electrical charges that can be charged and discharged quickly. The problem is that in general they cannot store as much energy as larger batteries, though they can provide enough short-term power for some serious performance.
Dr. Vivek Ranjan was the first to find that capactiors which contained the polymer polyvinylidene fluoride, or PVDF, along with another polymer called CTFE, could store a lot more energy than conventional capacitors. Other researchers ran a simulation at the atomic level, and found that the atoms within capacitors containing these two polymers performed a “synchronized dance”, flipping from polar to non-polar, discharging energy with very little electrical input.
Usually the atoms respond to a chain reaction of other atoms flipping, like a domino effect, and it requires a lot more energy to do. If all the atoms flip polarity in a synchronized way though, it vastly improves energy storage and discharge rates while requiring a lot less energy to flip the atoms.
I don’t think there is enough talk about the potential for capacitors to change the electric vehicle field, though companies like Maxwell Technologies and Ioxus are making major progress on capacitor technology. If this research pans out though, it could reshape electric vehicle technology, and help EV’s overcome a potentially devastating design flaw. And while battery technology definitely has performance potential, capacitors have even more capacity to develop fast, fun, and efficient electric cars.
Source: Science Daily