Imagine a world in which the battery—that lowly, all-important refugee from the era of Leyden jars and Geissler tubes—no longer consists of a sealed package of chemicals which react to produce voltage, but is instead a high-tech product of the modern era. It charges in just a few minutes or even seconds, can be recharged indefinitely, and is far better for the environment. It sounds like science fiction, but it may not be for long if Joel Schindall has his way.
Schindall is an electrical engineer working at MIT. He and his team have taken a closer look at another classic electronic component—the capacitor—with an eye toward bringing the battery into the 21st century and beyond.
Among the many useful properties of capacitors is the ability to store an electrical charge and release it very quickly. In its most basic form, a capacitor consists of two conductive surfaces (or electrodes) separated by an insulator (or dielectric). If the electrodes have a voltage difference between them, then are connected by means of a wire or other conductor, current flows to equalize the difference. Capacitors—and their ability to jolt us—are one reason it’s a good idea not to randomly jam screwdrivers into electronic components. Although most capacitors are small and don’t store much charge, larger capacitors can injure or even kill you.
The problem with using a capacitor in place of a battery is that they normally can’t hold nearly as much energy as batteries do. Capacitors with more storage capability require the electrodes to have greater surface area, making them physically bigger—a lot bigger. A capacitor with enough capacity to run a laptop for a reasonable amount of time would be at best unwieldy and at worst totally stationary.
Schindall believes he and his team have found the solution to making capacitors work as batteries, and the key involves covering the electrodes with millions of carbon nanotubes. The nanotubes vastly increase the surface area of the electrodes without taking up much more space, producing a capacitor with storage rivaling that of batteries in a nice, tight, little package.
If he succeeds—and he expects to have a working prototype soon—Schindall believes the devices could be on the market in just five years or so. Currently, even our most high-tech batteries are tremendously inefficient and archaic devices at heart. With so much to be gained from the development of a truly modern battery, we should all be cheering Schindall on—all of us but those employed by Duracell and Energizer, at least.