There are more than 15 billion batteries in landfills worldwide, according to an article published by the Hamilton Institute. About 89 percent are estimated to be common household batteries, or the alkaline variety. This poses a variety of problems to the environment. Battery acid is highly toxic, heavy metals may leak into the water supply and, if incinerated, the components cause air pollution.
The invention of the paper battery has been hailed as an efficient "green," or environmentally friendly, technology. The battery, which is made of up to 90 percent cellulose, is no thicker than a common sheet of printer paper, about .025 mm (.00098 inches) thick. Because of its composition, the paper battery is completely non-toxic and fully biodegradable.
Created in 2007 by a group of students at the Rensselaer Polytechnic Institute in Troy, New York, the paper battery is the result of paper infused with carbon nanotubes, which allow the paper to conduct electricity. A carbon nanotube is a small cylinder-shaped wire made from carbon, a naturally occurring substance that is the basis of most life on the planet. The introduction of carbon nanotubes into the paper battery gives it a unique property. Unlike most batteries in use, the paper battery can be twisted, crumpled, molded or contorted into a variety of shapes and not lose any integrity. The flexibility of nanotubes allows these actions to occur, and the battery will be just as efficient no matter what form it is twisted into.
The paper also is infused with electrolytes in the form of liquid salt, which furthers the conductive properties of the battery. Because of their highly conductive state, paper batteries can function as both a normal lithium-ion battery and a supercapacitor. This means that the battery can store and regulate higher amounts of electricity.
There is no water involved in the process of creating the battery. Because of this, the battery has a functional temperature range of -100 to 300 degrees Fahrenheit (-73 to 149 degrees Celsius). The wide temperature range presents an array of options for use, including high heat and freezing environments in which normal batteries might be subject to breaking, bursting or cracking. Also, given the unique construction of the battery, the medical community has its eye on the battery for use in pacemakers.
A paper battery is made as a completely integrated device, unlike most alkaline batteries, which contain several components. The nanotubes are embedded into the paper upon creation, and the electrolytes are soaked into the cellulose. This means that all the components are bonded to each other on a molecular level, giving paper batteries yet another level of durability.