Folding batteries increases energy density
Researchers have found that by folding paper-based Li-Ion batteries, the energy density of the cells can be increased 14 times.
By folding a Lithium-Ion paper-based battery in a Miura-ori pattern (a folding pattern similar to how maps are often folded), one can increase the energy density and capacity of the cell by 14 times. The reason for this is the decrease in the battery’s footprint. Paper-based batteries have a lot of advantages over traditional batteries, including low manufacturing costs and flexibility.
Qian Cheng of Arizona State University recently published a paper on the folding technique in a recent issue of Nano Letters. “Foldable batteries may be useful for powering devices that have limited space on board,” explains coauthor Candace Chan, who is an assistant professor of Materials Science and Engineering, “Furthermore, with the development of foldable paper-based electronics demonstrated by other research groups recently, a battery that also can be folded may become important for integration of the power source and other components into a single, entirely foldable device.”
The Li-Ion batteries in the study were constructed using carbon nanotube ink to lead the current and lithium-based powders as the electrons. The paper substrate used was a thin, porous material known as Kimwipes. The researchers also coated the substrate in polyvinylidene flouride to help adhere the ink to the paper.
The folded battery sure has its advantages
The paper battery was folded in a number of ways, giving various results, but ultimately, folding it 25 times gave an energy density 14 times greater than a conventional battery, all on a square of just 1.68cm^2