It was claimed in this article in 2019 that a nano-battery using water splitting technology is developed. It is described as:
The battery gains its charge by interacting with water molecules present in the surrounding air. When a water molecule comes in contact with the reactive, outer metal section of the battery, it is split into its constituent parts — one molecule of oxygen and two of hydrogen. The hydrogen molecules become trapped inside the battery and can be stored until they are ready to be used. In this state, the battery is "charged." To release the charge, the reaction reverses. The hydrogen molecules move back through the reactive metal section of the battery and combine with oxygen in the surrounding air.
There are hardy any details on the article regarding the mechanism of this reaction and what the material of “the reactive, outer metal section” is. And I have found no paper published with this research. The description makes this battery sounds like a perpetual machine: splitting waters from environment into oxygen and hydrogen, and make hydrogen and oxygen react to create electricity. What would be a good explanation of the mechanisms that makes this possible? I guess there must be other things going on to keep this described mechanism going, which limits the life of this battery.
It is also claimed that:
The batteries have also demonstrated a power density that is two orders of magnitude greater than most currently used batteries.
But no experimental data is provided (since there’s no paper found).
Is this result somehow exaggerated? Since no application of this battery has been recorded. Also what is the water-splitting mechanism? If it is really this amazing I believe it can be applied inside human bodies to split water and power devices as well, since both nanoscale and larger scale such batteries can be made. But is such technology really practical and applicable now?