FYI.

This story is over 5 years old.

Tech

New Nanotechnology Turns Your Charger Cable Into Its Own Battery

The applications for wires that store their own electricity are endless.

Copper wire and other chemically similar metallic materials are excellent conductors because it's extraordinarily easy for electrons to bounce from copper atom to copper atom, owing to ample electron "holes" available to be filled on the atoms' outermost electron shells. The result, from an electron's perspective, is like a pipeline without friction. And as a frictionless pipe would be a terrible place to store water, so too is a copper wire a terrible place to store electricity. Hence, we have batteries, which store electricity as reactive potential between a pair of typically way toxic chemicals.

Advertisement

Batteries make everything bigger in our technological world, whether it's a laptop, iPhone, or pacemaker. Now, consider all of those things without the need for batteries at all. This is the promise of a new technology unveiled in this month's edition of Advanced Materials. The replacement for all of those batteries is none other than the copper (or other conductor) wires used to charge the device in the very first place, a method of storage made possible by a coating of sorts that might one day be portable to fabrics in addition to conventional wires.

The process works like this. Copper nanowhiskers are first grown on the outside of the copper wire, and then treated with a special alloy. The result is a fuzz of electrodes coating the wire's exterior, or one half of a very peculiar capacitor. The fuzzy wire is then wrapped with a thin sheet of metal, manganese dioxide, which is also made to grow nanowhiskers, but on the inside of the sheath facing the copper wire. So you have two sets of fuzzy nanoscale electrodes facing each other, which is together the basic makings of a supercapaciter.

First, understand that a capacitor is just a pair of electrodes separated by some insulator, in this case a very thin sheet of plastic. The effect is that electric charge can be imprisoned between the electrodes. The nanowhiskers coating the copper wire develop a negative charge in accordance with the current flow in the wire itself, while the outside whiskers hold the positive charge. The result is an electrostatic field held between them, and so long as the current is maintained the electrostatic field will store electric charge.

All of these layers are then glued together and the result is a copper wire that still conducts electricity but is now coated in a supercapacitor capable of storing very large amounts of power. In the end, there's no extra component to charge, and you can use your imagination to come up with a pile of applications without much effort. In the near term, suggestions might include smart-phones, biometric devices, and space launch vehicles. The energetic sky is the limit.

"Compared to other energy storage devices like batteries, supercapacitors have faster charge-discharge rates, higher power densities, and longer life times," write co-authors Zenan Yu and Jayan Thomas.

One can also imagine the technology being deployed with new solar panels. A solar cell is after all just an electrical conductor with a few unusual properties (one of which being the translation of photonic energy to electrical energy). Self-storage of electricity is not one of them, however, and solar panels require batteries to store unused power. With this technology, it might be possible to have the panel store its own juice. A press release accompanying the study even imagines clothing made of flexible solar panels that's capable of keeping your devices powered even when you dip into the subway. It's a nice thought, but still a ways in the future. Phones without batteries, however, are likely coming fast.