Biological-based batteries can extract energy in the same way that our bodies extract energy from metabolism.

Batteries containing heavy metals pose a danger to both the environment and human health. Even the more environmentally friendly batteries that have been developed in recent years need to be placed in separate compartments for waste separation. But in the near future, it may be possible to completely avoid metals in our batteries.

Researchers at Uppsala University in Sweden have developed a prototype battery consisting of cellulose from algae, conductive polymers and salt water. The advantage of these batteries is that they are much more environmentally friendly compared to the metal-based batteries used today. Sony has recently gone a step further by presenting a cellulose-based battery that has been in development for several years.

Energy from paper and cardboard boxes

At the end of 2011, schoolchildren at a product fair in Tokyo put paper in a mixture of water and enzymes, shook it up, and after a few minutes the solution generated enough electricity to power a small fan. The process also worked with cardboard. This so-called bio-battery is more environmentally friendly to recycle than metal-based batteries as it creates its own energy from the cellulose found in cardboard and paper.

The same source of energy in our bodies

Bio-batteries work similarly to the metabolic process in our bodies, or more specifically the metabolic processes in ruminants and termites that have the ability to digest cellulose.

Enzymes break down cellulose into glucose, a central energy source in both animal and plant metabolism and a clean energy source. Sony’s bio-batteries are based on enzymes that also degrade glucose to generate hydrogen ions and electrons. The electron’s motion in turn creates current for the bio-battery. The advantage of Sony’s bio-battery is that it introduces eco-friendly ingredients to create energy from a natural source.

Need for development

As a researcher in Uppsala has shown, another advantage of cellulose-based batteries is that they can be quickly recharged. Their one disadvantage is that they are less able to retain their energy compared to conventional metal-based batteries. The technology needs to be developed further to be a real alternative. In the coming years, Sony plans to develop its bio-based batteries for commercial usage. But the application will initially be limited to toys and other products that have limited energy needs. Looking down the road, Sony hopes its bio-batteries could be used in laptops and cell phones, for example.

Hopefully batteries based on cellulose and other biological materials will become real alternatives to today’s metal-based batteries.

This article was published in July 2012