Batteries remain a constant source of innovation for science, as our increasingly-mobile future with devices demands improvements upon improvements with our methods of power storage. Currently, targets are set towards several fronts: alternative materials, like lithium-sulfur batteries, flexible electronics, like the supercapacitor that’s partially inspired by the design of an accordion, and environmental friendliness.
Researchers from Nanyang Technological University (NTU) didn’t seem to get the memo of “choose a side,” since these scientists decided to just cut the middleman and attack two fronts at once: they instead made a relatively thin, biodegradable battery. Their ambitious and promising find was published in the journal Advanced Science.
This particular battery, measuring a measly 4 cm by 4 cm (1.6 in by 1.6 in) in one of its iterations, is “reportedly capable of powering a small electric fan for 45 minutes,” according to a statement by New Atlas. Power delivery is also reportedly uninterrupted, even if you twist, bend, or even cut off a piece of the battery.
And if that sounds weird to you, they can do so to the battery since its heart is composed of cellulose paper that had the gaps between its fibers filled with hydrogel. Screen-printed on opposing sides of the paper are the battery electrodes: the anode made of zinc (Zn) and carbon black, while the cathode is composed of manganese (Mn) and nickel (Ni) in two separate cases.
The entire battery is immersed in an electrolyte solution, then had gold (Au) applied to both its electrodes to give them a conductivity boost. All in all, the entire battery measures a very thin 0.4 mm (0.016 in) thick. And, since it’s made of organic cellulose material, it can be broken down by soil microorganisms in under a month—meaning yes, this thin battery is biodegradable, too.
Lead author Prof. Fan Hongjin is confident that the materials of the battery will do no harm to the environment, as the nickel and manganese used in the cathodes will return to the soil in a form not too different from their naturally-occurring minerals. The zinc, on the other hand, gets naturally oxidized to form a non-toxic hydroxide.
In the words of Prof. Fan himself: “This points to the battery’s potential as a more sustainable alternative to current batteries.” He and the team also believe their new technology to be useful to implementations like flexible devices.
References
- Batteries of the future could be paper-thin and biodegradable. (2021, December 14). Nanyang Technological University. https://www.ntu.edu.sg/news/detail/batteries-of-the-future-could-be-paper-thin-and-biodegradable
- Coxworth, B. (2021, December 14). Flexible paper-based battery is designed to biodegrade once discarded. New Atlas. https://newatlas.com/environment/paper-based-biodegradable-battery/
- Yang, P., Li, J., Lee, S. W., & Fan, H. J. (n.d.). Printed zinc paper batteries. Advanced Science, n/a(n/a), 2103894. https://doi.org/10.1002/advs.202103894
