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.
or you could go with sodium battery, or LiFePO4, or thermal energy storage at this scale. hell maybe even pumped hydro
Possibly, question is which one fits a given area the best. Pumped hydro needs some place high to pump it. Many places are incredibly flat, but in hilly or mountainy places it has some clear advantages. Thermal has the issue of losing the heat. You need to insulate a “battery” a lot, and at some point it just becomes incredibly expensive for very little results. It’s not impossible, but it can be a very expensive solution. LiFePO4 has the drawback of needing lithium, which is pretty rare in most of the world. If what the article says is true, the “water battery” seems to be pretty inexpensive to build with quite available ressources, but the drawback is that it likely needs more space than other options.
storage of heat is also very cheap compared to some other options and can just be using ground around boreholes, especially considering that most of residential energy use is in form of heat. if you have a hill that you don’t need you can even put an artificial lake on top of it
there’s a speciality resin (that new material) in that battery. resins are nonrecyclable. i don’t think it can be 4x cheaper per kg than LiFePO4 battery because of that material
What if we build a mountain with a lake on top.