If you take two vessels, fill them with electrolytes with different charges and put a jumper-membrane between them, then an electric current will arise when the liquids interact. The movement of electrons from one pole to another - this principle, according to archaeological research, was known thousands of years ago. The only question is the material from which the battery is made, and recently at Harvard they proposed a new efficient type of organic battery.
Traditionally, the best materials for electrolytes in flow batteries are bromine and vanadium compounds dissolved in acid. The components are expensive, corrosive, requiring corrosion protection for the entire battery structure. Scientists have been struggling to find their replacement for a long time and in 2014 at Harvard they began a large-scale project to study quinones. This is the general name for organic molecules that are used to store energy - researchers had to study more than 10, 000 species in search of suitable ones.
At first, scientists managed to replace bromine with ferrocyanide and switch from acid to alkali, then they modified vitamin B2, last year they abandoned caustic mixtures in favor of neutral aqueous solutions. And today they are introducing the world to a new quinone, a man-made organic molecule with outstanding capacity and durability. She was named "Methuselah", in honor of the biblical old man-long-lived.
In tests, a battery with Methuselah molecules in a weak alkaline solution showed a loss level of 0.01% per charge-discharge cycle, no more than 0.01% per day of operation. This means that the degradation of the battery will be only 3% per year and it will be able to compete with other types of batteries. The prime cost of such a battery is also low, which allows us to speculate about its future mass use, when the technology is transferred to commercial rails.