Water and Tofu Brine Could Power the Next Generation of Batteries

We’ve made significant progress in increasing battery power, but durability and safety remain challenges. A new battery technology aims to address these issues, utilizing water and tofu brine as its core components. Lab tests display these batteries can withstand an impressive 120,000 charge cycles – roughly 40 times more than conventional lithium-ion batteries, which typically degrade after around 3,000 cycles. Theoretically, a daily charge could keep one of these batteries running for over 300 years.

How It Works: The Chemistry Behind the Breakthrough

The key to this innovation lies in the electrolyte, the liquid that facilitates charge transfer within the battery. Instead of flammable solvents, this new battery uses neutral salts of magnesium and calcium – minerals also found in tofu brine, a byproduct of tofu production. Researchers maintained a neutral pH of 7.0, preventing the corrosive reactions that plague traditional batteries.

Beyond the electrolyte, the battery employs a negative electrode made of organic polymers (essentially plastics) and a positive electrode based on Prussian blue, a pigment commonly used in paints. The combination resulted in an energy capacity of 112.8 milliamp hours per gram, a promising figure for this type of battery, as detailed in a study published in Nature Communications.

Why Water-Based Batteries Matter

The search for alternatives to lithium-ion batteries is driven by safety concerns. The flammable solvents used in lithium-ion batteries pose a fire risk, leading to incidents on airplanes and sparking debate about their suitability for electric vehicles (EVs). EV fires, in particular, are difficult to extinguish.

Water-based batteries eliminate the fire hazard due to the non-flammable nature of water. They also simplify disposal, meeting international standards like the U.S. Resource Conservation and Recovery Act.

These aqueous batteries also offer potential cost advantages. The materials used are significantly cheaper than those found in standard lithium-ion cells, making them attractive for large-scale grid storage applications – such as balancing energy from solar and wind farms – where durability and affordability are paramount. However, increasing energy density remains a challenge for applications where size and weight are critical. Scaling up production of the organic polymers is another hurdle the research team acknowledges.

This technology represents one of several emerging battery innovations that could revolutionize energy storage for EVs, smartphones and beyond.