Scientists believe that half of the sun’s energy that hits the earth is used to evaporate water from its surface. The Australian company Strategic Elements has set itself the goal of using at least part of this energy in the form of electricity. Together with local scientists, the company developed a battery that charges solely through the difference in humidity at its electrodes: the higher the humidity, the faster the charge.
In a post on its website, Strategic Elements is silent on the details of the technology behind its “Energy Ink” development. However, information about scientific partners from the University of New South Wales (UNSW) and the State Association for Scientific and Applied Research (CSIRO) makes it clear which development can be spoken of.
The fact is that not so long ago a group of scientists from UNSW and CSIRO in the journal nano energy released article via a battery operated with a humidity gradient (difference). The development is based on graphene oxide, which Energy Ink also speaks of. Graphene oxide in the battery plays the role of an ion carrier and a medium for their appearance when absorbing moisture from the air. The electrodes are a layer of fluorine-doped tin oxide (FTO) and silver.
In the dry “functional” layer of graphene oxide, the protons are immobilized (fixed) and immobile. When there is a difference in humidity, one side begins to absorb water molecules from the air, ionizing them, also producing carboxylic acid (COOH) and positively charged hydrogen ions (hydrides). There are more hydrides on the wet side and ions migrate to the dry side of the graphene oxide layer, resulting in the creation of a potential difference or voltage across the electrodes. Upon drying, the hydrides return to their original state. Moisture build-up restarts the process and the device is recharged and ready to use.
According to the developers, the battery prototype will be presented in the third quarter of this year. During the experiments, the battery was able to generate a voltage of 0.85 V and a current of 92.8 μA per square centimeter of surface. To clarify, the battery is made of flexible materials and promises to be the first in the electronic medical patch market. In theory, even today it is still capable of powering the vast majority of wearable electronics by working through sweat on human skin.
For the manufacture of a flexible, self-charging battery from atmospheric moisture with a capacity of one ampere-hour, it is necessary to create an element with an area of \u200b\u200b36 cm2. To demonstrate the concept, the company will produce a 100cm element2 and has the potential to produce an element with an area of 3m2. We look forward to interesting results.