Printed batteries suit disposable applications

Paul Boughton
Traditionally batteries have been bulky and heavy. Now, a new battery is under development that is less than 1mm thick, weighs less than 1g and can be produced cost-effectively using a printing process.

Printable batteries of this type could, for example, be incorporated within credit-card sized devices, together with switch and display components. The new type of battery has been developed by a research team led by Professor Dr Reinhard Baumann of the Fraunhofer Research Institution for Electronic Nano Systems (ENAS) in Chemnitz, Germany, together with colleagues from TU Chemnitz and Menippos GmbH. Dr Andreas Willert, group manager at ENAS, states: "Our goal is to be able to mass-produce the batteries at a price of single-digit cent range each."

The characteristics of the new battery differ significantly from those of conventional batteries. The battery contains no mercury and is in this respect environmentally friendly. Its voltage is 1.5V, which lies within the normal range. By placing several batteries in series, voltages of 3V, 4.5V and 6V can also be achieved. The new type of battery is composed of different layers: a zinc anode and a manganese cathode, as well as others. Zinc and manganese react with one another and produce electricity. However, the anode and the cathode layer dissipate gradually during this chemical process. Therefore the battery is suitable for applications that have a limited life span or a limited power requirement - for instance, greeting cards.

Each battery is silk-screen printed, with the individual layers being slightly thicker than a human hair. The researchers have already produced the batteries on a laboratory scale. At the end of 2009, the first products could be finished.

For more information, visit www.fraunhofer.de