We love our electronics, but the increasing demands of high end gadgets put a huge amount of stress on their Li-ion batteries, to the point where it's not uncommon to have to charge your smartphone every day, and your laptop every couple of hours. We keep waiting for the next big thing in batteries, but what might make your gadgets keep going even longer could be a small tweak from an unexpected place.
Current battery electrodes are made from graphite, but it's hoped by switching to silicon, larger capacity and longer life Li-ion batteries could be a reality. The only problem is that we need to find something that can can bind effectively onto silicon electrodes. Current batteries use Polyvinylidene Fluoride (PVDF) which in addition to being toxic isn't very good at binding to silicon.
Luckily, they've found something that works better, and is substantially more environmentally friendly. Alginate is a polymer harvested from fast growing brown seaweed, and it's more efficient than PVDF with both silicon and graphite. The way it works is that the alginate forms a protective film on top of the silicon electrode to stop the electrolyte solvent from washing onto the surface of silicon particles, preventing the battery from decomposing.
"We specifically looked at materials that had evolved in natural systems, such as aquatic plants which grow in saltwater with a high concentration of ions," said Igor Luzinov, a professor in Clemson's School of Materials Science and Engineering. "Since electrodes in batteries are immersed in a liquid electrolyte, we felt that aquatic plants — in particular, plants growing in such an aggressive environment as saltwater — would be excellent candidates for natural binders."
With any luck, this will mean better, longer lasting batteries, and they might even be cheaper, too.