cross-posted from: https://slrpnk.net/post/37619927
A battery usually hides its nastiest chemistry from view. Inside many rechargeable systems, useful energy moves through liquids that are strongly acidic, alkaline, flammable, corrosive, or difficult to discard. The battery works, until the same chemistry that made it powerful begins to eat away at its parts.
A team in China and Hong Kong has now built a very different kind of battery. Its electrolyte is a neutral water-based solution of magnesium and calcium salts, chemically close to the brines used to coagulate tofu. In tests, the device ran for 120,000 charge cycles, used nonflammable ingredients, and met several disposal safety standards, the researchers in China report.
It is not ready to replace the battery in your phone. But it points toward a cleaner kind of battery for the place where longevity matters most: the electric grid.
the electrode retained 72.67% of its capacity after 120,000 charge cycles MgCl2 and CaCl2 Hex-TADD-COP, short for hexaketone-tetraaminodibenzo-p-dioxin covalent organic polymer. - the tricky part. 48.3 watt-hours per kilogram compare to LFP @90-160 Wh/kg
An aqueous battery using an electrolyte with a pH of 7 and suitable for direct environmental discard https://www.nature.com/articles/s41467-026-69384-2
Appreciate the link! 48Wh/kg feels like it’s in the realm of being usable for some applications! And also sounds more environmentally friendly than other battery chemistries. And also helps diversify the mining/mineral needs for making batteries.
ETA: also omg they included that image in the article 🙂
use of water as a solvent limits maximum voltage
wanted to use water to get electricity anyway for a laugh? we have a tool for that: it’s called STEAM TURBINE
What is the problem with low voltage?
How high is that limit? 4.2V for lithium cells isn’t exactly stunning
4-5V is state of the art and pushing it there or beyond that gets very tricky very quickly. pure water has electrochemical window of 1.23V, but you can go a bit over that because at low overvoltage water splitting is slow at most electrode materials. that’s why lead battery can have 2V per cell and will generate hydrogen when charged much over nominal voltage