Skip to comments.Super-thin batteries made from paper and algae
Posted on 09/16/2009 10:27:28 PM PDT by neverdem
Algae, paper and salt-water are the key components of thin and flexible new batteries, report Swedish researchers. Cellulose obtained from the bright green Cladophora algae proved to be key to the project, as it boasts a unique nanostructure with a high surface area.
Although the batteries have lower voltage and power density than conventional batteries, their low cost and flexibility hold great promise for applications where metal-based batteries are impractical.
The research is the product of a collaboration between two teams at Uppsala University in Sweden: Maria Strømme's group, who identified the potential of the algal cellulose, and Leif Nyholm's group, who were searching for new ways to improve the performance of conductive polymers.
© Uppsala University
To make the batteries, the team separated two cellulose electrodes with filter paper soaked in salt water. One of the electrodes is coated with a very thin layer of oxidised polypyrrole (PPy) while the other is coated with reduced polypyrrole. The potential difference between the two layers provides the voltage of the battery, as during charging and discharging, chloride ions move from one electrode to the other, similar to the way lithium ions cycle in lithium batteries.
A major advantage of the research is the simple and environmentally-friendly production method. 'Our batteries mainly consist of paper and salt water,' Strømme told Chemistry World. 'So they can theoretically be made in your own kitchen, if you had a very strong mixer!'
Diagram of the battery configuration (left), and photograph of the composite paper battery cell before and after sealing into a polymer coated aluminium pouch
© Nano Letters
The team have already started optimising the batteries, showing that they can comfortably withstand 1000 charge cycles. They are confident that further developments could lead to many exciting applications. 'Try to imagine what you can create when a battery can be integrated into wallpaper, clothing, or the packaging of your medicines,' Strømme says.
'The concept of an all-polymer battery has long been attractive compared to metal-containing systems,' says Duncan Gregory at the University of Glasgow in Scotland. 'The current approach has moved a long way towards overcoming many of the challenges. It will be very interesting to see how this work develops: ultimately, is this energy storage device a rechargeable battery, a capacitor or both?'
Hiroyuki Nishide, an expert on novel battery design at Waseda University in Tokyo, Japan, is also interested by the research - noting that while charging and discharging rates are good, the capacities still need to be improved. Nishide also adds that the work should inspire more research in this important field. 'Battery innovations like this will have an important role in realising future sustainable technologies,' he says.
So that’s how they kept the radio going on Gilligan’s Island. Credit this one to the professor!
Stick a penny and a nickel in a lemon or potato and you have a kitchen battery. Clothing or wallpaper or packaging would be better served by a conventional button cell. (The wallpaper could also be connected to house power.) This is barking up a curious tree, but one that doesn’t seem to have any practical advantages.
I wear hearing aids. The place where I bought my hearing aids, “Accurate Hearing Center”, sells their own brand of batteries for $5 per 8 pack, but they told me I could probably buy batteries cheaper at W-M, so I checked it out.
The only brand W-M sells in my style are made by “Eveready” and are hyped on the packaging as being “environmentally friendly” and “green” at $6.79 per 8 pack.
The pharmacist gave me 3 sample 4 packs, so I did a comparision putting one in each aid, I did this 12 different times and the store brand always lasted 8-9 days while the Eveready lasted only 7 days at most.
On the other hand, think about it this way ~ we are now able to use algae as components in batteries and certain DNA strands as components in micro switches. It's only been recently that we've had a need/use for exceedingly low powered non-maintenance batteries, or nano-scale micro switches.
We may be doing nothing more but picking up trashed technology from intergalactic wreckage and refurbishing it for use in "new stuff".
Algae, paper and salt-water are the key components of thin and flexible new batteries...
They’ll go perfectly with my chewing gum, rubber band and toothpick flashlight.
I’ll be thinking about that all night.
Anybody, have any other actual use reports of the kind we buy everyday?
I'm always looking for battery solutions.
Hearing aid batteries too? Where do you buy them?
Another gripe I have concerning hearing aid batteries is; That you can put in a pair at the same time and one will last a number of hours longer than the other one, over the course of time I have to change a battery and then a few days later change the other one, a minor nuisance to be sure. No two batteries will last exactly the same amount of time.
(It's still better than having to say,"HUH" all the time.)