Scientists develop flexible paper batteries
Troy (NY) - In a story which could easily be mistaken for science fiction, researchers at the Rensselaer Polytechnic Institute in New York have developed an amazing new energy storage device. Designed to operate from -100F to over 300F, it looks like a small, black postage stamp, but is actually a new type of flexible battery capable of providing enough electricity for the gadgets of tomorrow.
Made of 90% cellulose fused to aligned carbon nanotubes, and an electrolyte layer bonded at the molecular level, the new device is very comparable in design, appearance and strength to actual paper. It’s just as flexible and durable allowing it to be rolled, twisted, folded, even cut into unique patterns and shapes without losing any integrity or efficiency. And when stacked or rolled in layers, it increases the power output in a manner similar to putting regular batteries together in series or parallel.
The battery paper is deposited into an ionic liquid containing no water, essentially a type of liquid salt. This electrolyte will not freeze or evaporate allowing a stunning operational temperature range. Since the product is of a flexible material, possible end-uses could mean that it is being molded into structural members. These would provide strength and support for the actual application while also powering it. As a result, cellphone cases, car doors, boat hulls, even the walls of our very homes could easily be created and used to store electricity.
No toxic chemicals apparently are used in manufacturing or production, making it environmentally friendly. While the components themselves are very inexpensive and easy to mass produce, the researchers haven’t yet worked through the technical issues of cost-effective mass production. In the end, they would like to see a type of roll-to-roll printing operation like newspaper printing. This would create huge quantities of materials which would supply what would inevitably be a complete shift in the way we think about most everything electronic today. Our future laptops, cellphones, PDAs and wearable devices, such as shirts, jackets, backpacks, etc., could all be made of materials which double-up as a battery.
The new device also exhibits some unique electrical properties. While it can act like a traditional lithium-ion battery in that it stores energy and releases it as needed, it also has properties of a super-capacitor. These allow for quick discharges when necessary.
Details of this project were published in a paper called "Flexible Energy Storage Devices Based on Nanocomposite Paper" in the journal "Proceedings of the National Academy of Sciences". Research for this project was funded by New York Office of Science, Technology and Academic Research (NYSTAR) as well as the National Science Foundation (NSF) through the Nanoscale Science and Engineering Center at Rensselaer, New York.