Cladophora is the name of an alga that could be the key to a new revolution in energy storage systems… and not just any storage, but batteries so thin you would have them printed on a paper and charged in about 11 seconds, with net superior capacities above anything that exists on the market.
There have been attempts to make paper-like batteries in the past, but they stumbled on the inconvenience of degrading their capacity over use. In other words, they have not been able to hold their charge for long after they’ve been used for a while, phenomena that we can observe in our laptops’ or our cellphones’ batteries.
Cladophora is a hairlike freshwater plant and causes bad-looking, bad-smelling beaches – maybe you’ve had the unconscious opportunity of meeting her. Cladophora is an alga characterized by producing a kind of cellulose with a very large surface area (of course, in its microscopic details). Scientists say it has 100 times the surface of the cellulose found in paper.
If you have such a wide surface, then it’s easier to understand you can put more conducting polymer on it, and have it recharged. Not only the battery’s capacity will be enhanced, but also its lifetime, since the power is distributed over that huge surface. While a comparable polymer battery showed a 50 percent drop in the amount of charge it could hold after 60 cycles of discharging and recharging, the new battery showed just a 6 percent loss through 100 charging cycles.
“We have long hoped to find some sort of constructive use for the material from algae blooms and have now been shown this to be possible,” said researcher Maria Stri¸mme, a nanotechnologist at Uppsala University in Sweden. “This creates new possibilities for large-scale production of environmentally friendly, cost-effective, lightweight energy storage systems.”
They new Cladophora-based battery’s polymer layer is very thin: 40 to 50 nanometers, and its own cellulose fibers are only 20 to 30 nm, so they were collected into paper sheets.
The difference in charge capacity is extreme: the Cladophora paper battery could hold 50 to 200 percent more charge than usual conducting polymer batteries. Once optimized, the scientists say, they could even surpass the capacity of lithium batteries, also having the convenience of very fast recharging, because of their thickness. “When you have thick polymer layers, it’s hard to get all the material to recharge properly, and it turns into an insulator, so you lose capacity,” said researcher Gustav Nystri¶m, an electrochemist at Uppsala University. “When you have thin layers, you can get it fully discharged and recharged.”
The paper battery could be used anywhere from electronic thin birthday cards to very fast car batteries, so their potential is immense, if harvested to the maximum.