Rechargeable battery made from food
(Nanowerk News) A research team at Istituto Italiano di Tecnologia (IIT-Italian Institute of Technology) has created an edible and rechargeable battery, starting from materials that are commonly consumed as part of our daily diet.
A proof-of-concept battery cell has been described in a paper, recently published in Advanced Materials (“Edible Rechargeable Batteries”). Possible applications are in health diagnostics, food quality monitoring, and edible soft robotics.
The study was realized by Mario Caironi’s group, coordinator of the Molecular and Printing Electronics laboratory of the IIT Center in Milan (Italy); Caironi has focused on studying the electronic properties of food and its by-products, in order to integrate them with edible materials and create new edible electronic materials. In 2019, Caironi won a 2 million euro ERC consolidator grant for the ELFO Project, which explores the field of edible electronics.
Edible electronics is a recently developing field that can have a major impact on the diagnosis and treatment of diseases of the digestive tract, as well as monitoring of food quality. One of the most exciting challenges in the future development of edible electronic systems is realizing edible power sources.
The IIT research group took inspiration from the biochemical redox reactions that occur in all living things, and developed a battery that utilizes riboflavin (vitamin B2, found for example in almonds) as an anode and quercetin (a dietary supplement and ingredient, found in capers). , among others) as the cathode. Activated charcoal (a widespread over-the-counter drug) is used to increase electrical conductivity, while the electrolyte is water based. The separators, which are required in every battery to avoid short circuits, are made of nori seaweed, the type found in sushi. Then, the electrodes are wrapped in beeswax from which two food-grade gold contacts (foil used by pastry chefs) on a cellulose-derived support come out.
The battery cells operate on 0.65 V, a low enough voltage not to cause problems to the human body when ingested. It can provide 48 µA of current for 12 minutes, or a few microamps for more than an hour, enough to supply power to small electronic devices, such as low-power LEDs, for a limited time.
This example of a fully edible rechargeable battery, the first to be made, will open the door for new edible electronics applications.
“Potential future uses range from edible circuits and sensors that can monitor health conditions to powering sensors to monitor food storage conditions. Also, given the safety level of this battery, it can be used in small children’s toys, where there is a high risk of swallowing it. In fact, we’ve developed devices with greater capacity and reduced overall size. This development will be tested in the future also to drive soft edible robots,” said research coordinator Mario Caironi.
“Edible batteries are also of great interest to the energy storage community. Making batteries that are safer, without using toxic materials, is a challenge we face as demand for batteries soars. While edible batteries won’t power electric cars, they are proof that batteries can be made from safer materials than today’s Li-ion batteries. We believe they will inspire other scientists to build safer batteries for a truly sustainable future,” added Ivan Ilic, co-author of the study.