These Water Batteries Release Lithium And Can Eliminate Fire Hazards Effectively

We have been very good at making batteries that hold a lot of energy. Unfortunately, we have not been very successful in making those that do not end up rusting, catching fire, or poisoning the soil. A new development is trying to change that: a new type of battery that runs on water and tofu brine. Even better, it lasts 120,000 charging cycles in the lab. That’s 40 times higher than your typical lithium-ion batteries, which last up to 3,000 cycles before degrading. In theory, if you charge one of these once a day, you can keep it running for over 300 years. Obviously, a human phone or EV takes that much longer, but the promise is real.

So how does this actually work? The electrolyte – that liquid inside the battery that is responsible for moving the electric charge between the two electrodes – is made of neutral salts of magnesium and calcium. Those are the same minerals found in tofu brine, the stuff used to freeze soy milk during tofu production. The researchers also kept the solution at a neutral pH of 7.0, which helps avoid the side corrosion that destroys conventional batteries internally.

That said, fluids were only one part of the puzzle. The researchers also replaced the metal-based negative electrode in their battery with organic polymers, which are plastics. To get a good electrode, they go with the analog of Prussian blue paint pigment. In the end, as shown in the full study of Nature Communications, they came down to an amazing energy capacity of 112.8 millimeter hours per gram, which is impressive for this type of battery.

There is reason for researchers to look at water-based alternatives. Lithium-ion batteries power everything right now, but they come with a problem. Flammable solvents used as electrolytes can catch fire if batteries overheat or are damaged. That has led to incidents on airplanes where portable batteries caught fire mid-flight, and some airlines have already started banning power banks from airplanes. The rise in EV fires – notorious for putting them out – has also sparked debate about whether lithium-ion is really safe for long-term use.

Water-based batteries avoid that entirely. There is no risk of fire because the electrolyte is non-flammable. There is also no need for hazardous waste processing when you dispose of them. The researchers ensured that the batteries met international standards for disposal, including the US Resource Conservation and Recovery Act.

These liquid batteries are generally cheap to produce. They rely on materials that are much less expensive than what goes into a standard lithium-ion cell, which makes them especially attractive for large-scale grid storage – think solar farms and wind energy balancing – where you need something long-lasting and affordable rather than compact and energy-dense. That said, there are still obstacles. Power density must increase before these can compete in applications where size and weight are important. Scaling up the production of those organic polymers is another challenge the team clearly acknowledges. But if they can figure that out, this could be a real powerhouse contender down the line. And it’s just one of the new battery technologies out there that could eventually transform everything from EVs to smartphones.