by Emil Morhardt
Maybe someday you will be able to recharge your gadgets by plugging them into your jacket, which you charged up in a few seconds from a convenient wall plug. I wrote earlier about storing energy in wires that were configured to be capacitors. Now Yu et al. (2014), at the School of Chemistry and Chemical Engineering, Nanjing University, in China, have fabricated experimental sheets of flexible layered conductive and non-conductive materials (diagram above is from their paper) that they envision as eventually wearable. We all get tired of waiting around for batteries to charge, but supercapacitors charge almost instantly. They don’t usually have much energy storage capacity though—you don’t get as much energy storage per unit weight or volume as you presently can from batteries—but if they are built into something that you need to carry around with you anyway, that might not be so important. A good example is the plug-in electric boat I wrote about on October 11. Boats don’t care much about how large or heavy something is, but they need to be fueled rapidly. So if you could store all the energy you need quickly in your jacket, your battery-powered devices could recharge in your pocket, wherever you are.
Yu et al.’s flexible supercapacitors, however, have very good energy storage capacity (50–60 Watt hours per kilogram), as good as the lead-acid batteries in your car, but unlike your car battery, they are quite thin and flexible.
Yu, C., Ma, P., Zhou, X., Wang, A., Qian, T., Wu, S., Chen, Q., 2014. All-solid-state flexible supercapacitors based on highly dispersed polypyrrole nanowire and reduced graphene oxide composites. ACS Applied Materials & Interfaces.
DOI: 10.1021/am5059603 Full paper at http://pubs.acs.org/doi/pdf/10.1021/am5059603