Ultra-thin batteries can be printed out

Posted by Emma Woollacott

Chemnitz, Germany - German scientists have created batteries so thin that they can be printed out, and reckon they'll be doing it on a commercial scale by the end of the year.

The research team, led by Professor Reinhard Baumann of the Fraunhofer Research Institution for Electronic Nano Systems (ENAS), has already produced the batteries on a laboratory scale. "Our goal is to be able to mass produce the batteries at a price of single digit cent range each," said Dr Andreas Willert, group manager at ENAS.

The batteries weigh less than one gram and are under a millimeter thick. They contains no mercury, so aren't particularly environmentally unfriendly. They are printed using a silk-screen method just like that used for t-shirts and signs. A rubber lip presses the printing paste through a screen onto the substrate, with a template covering the areas that are not to be printed on. The individual layers are slightly thicker than a hair.

The battery is composed of different layers: a zinc anode and a manganese cathode, among others, which react with one another to produce electricity. The voltage is a reasonable-enough 1.5V, and by placing several batteries in a row, voltages of up to 6V can be achieved.

However, the anode and the cathode layer dissipate gradually during this process. As a result, the battery is really only suitable for applications which have a limited life span or a limited power requirement - greeting cards or bank cards, for example.