Soon, disposable batteries made from salt and paper
A piece of wet, salty paper can make a battery that could actually hold up to one volt of electricity, say researchers.india Updated: Oct 19, 2009 17:48 IST
A piece of wet, salty paper can make a battery that could actually hold up to one volt of electricity, say researchers.
Swedish scientists hope that the new disposable battery would one day be used to power remote and biodegradable sensors.
"We wanted to make a battery that was very simple and used the same material for both electrodes," ABC Online quoted Professor Leif Nyholm of Uppsala University in Sweden and co-author of a study as saying.
"To make it simple we just put NaCl (table salt) in," Nyhlom added.
The battery, as thin as a single piece of paper is made up of multiple layers of cellulose, coated in a conductive polymer 50 nanometres thick, and sandwiched between layers of filter paper.
Water conducts the chlorine ions to the negative electrode, and electrons to the positive electrode.
While, the battery prototype can generate one volt of energy, including more layers might provide more voltage, said Nyhlom.
However, it won’t be used to power a laptop or a cell phone.
Its environmentally friendly components will more likely be used for fabrics that heat up or remote sensors that monitor temperature or humidity.
Since, wood pulp, the traditional source of paper, doesn''t have enough surface area for ion exchange, the scientists used noxious marine algae that clogs up harbours.
The marine algae produces cellulose with 100 times the surface area, compared with terrestrial plants.
The salt and cellulose assembly could also be used as a capacitor, a device able of dumping all its electrical charge at once, instead of a battery, which releases power more slowly.
The study appears in the journal Nano Letters.