Unwanted blooms of Cladophora algae throughout the Baltic and in other parts
of the world are not entirely without a positive side. A group of researchers
at the Ångström Laboratory at Uppsala
University have discovered that the distinctive cellulose nanostructure
of these algae can serve as an effective coating substrate for use in environmentally
friendly batteries. The findings have been published in an article in Nano
Letters.
 | | The researchers Albert Mihranyan, Maria Strømme, Gustav Nyström, Leif Nyholm.
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“These algae has a special cellulose structure characterised by a very
large surface area,” says Gustav Nyström, a doctoral student in nanotechnology
and the first author of the article. “By coating this structure with a
thin layer of conducting polymer, we have succeeded in producing a battery that
weighs almost nothing and that has set new charge-time and capacity records
for polymer-cellulose-based batteries.”
Despite extensive efforts in recent years to develop new cellulose-based coating
substrates for battery applications, satisfactory charging performance proved
difficult to obtain. However, nobody had tried using algal cellulose. Researcher
Albert Mihranyan and Professor Maria Strømme at the Nanotechnology and
Functional Materials Department of Engineering Sciences at the Ångström
Laboratory had been investigating pharmaceutical applications of the cellulose
from Cladophora algae for a number of years. This type of cellulose has a unique
nanostructure, entirely different from that of terrestrial plants, that has
been shown to function well as a thickening agent for pharmaceutical preparations
and as a binder in foodstuffs. The possibility of energy-storage applications
was raised in view of its large surface area.
“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,” says Maria
Strømme, Professor in Nanotechnology and leader of the research group.
“The battery research has a genuinely interdisciplinary character and
was initiated in collaboration with chemist professor Leif Nyholm. Cellulose
pharmaceutics experts, battery chemists and nanotechnologists have all played
essential roles in developing the new material.”
The article in Nano Letters, in effect, introduces an entirely new electrode
material for energy storage applications, consisting of a nanostructure of algal
cellulose coated with a 50 nm layer of polypyrrole. Batteries based on this
material can store up to 600 mA per cm3, with only 6 per cent loss through 100
charging cycles.
“This creates new possibilities for large-scale production of environmentally
friendly, cost-effective, lightweight energy storage systems,” says Maria
Strømme.
“Our success in obtaining a much higher charge capacity than was previously
possible with batteries based on advanced polymers is primarily due to the extreme
thinness of the polymer layer,” says Gustav Nyström.
Posted September 10th, 2009
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