Battery Made With Tofu Brine Lasts 300+ Years

Imagine charging your phone once and having the battery outlast your great-great-great-grandchildren. That's the promise of a new water-based battery developed by researchers in Hong Kong.

Scientists at the City University of Hong Kong and Southern University of Science and Technology swapped harsh battery chemicals for something surprisingly ordinary: minerals similar to those used in making tofu. The breakthrough could solve two major problems with modern batteries—they wear out quickly and leak toxic chemicals into the environment.

Traditional batteries rely on corrosive acids and alkalis that eat away at internal components over time. When thrown away, these harsh chemicals seep into soil and water, contaminating ecosystems for years.

The research team took a different approach. They used neutral salts of magnesium and calcium, the same minerals found in tofu brine, to create the battery's liquid electrolyte. By keeping the solution at a neutral pH of 7.0, they prevented the corrosive reactions that typically destroy batteries from the inside.

The real innovation came with the electrodes. Instead of traditional metal-based materials, the researchers engineered special structures from covalent organic polymers, essentially creating conductive plastic-like materials. They paired this with a positive electrode made from Prussian blue analog, a compound commonly used as blue pigment in paint.

The results stunned even the research team. Standard batteries typically fail after a few hundred or thousand charges. This new battery remained stable for 120,000 charge cycles. That means charging your phone once daily for over 300 years without the battery wearing out.

The battery also packed impressive power for its weight, reaching an energy capacity of 112.8 mAh/g. That's a high score for water-based organic batteries.

Why This Inspires

This breakthrough shows how rethinking everyday problems with nature-inspired solutions can create transformative change. The battery meets international safety standards and poses minimal environmental risk if discarded, thanks to its non-toxic materials and neutral liquid.

Parents could buy devices for their children knowing the battery won't end up poisoning groundwater decades later. Electronic waste, one of the fastest-growing pollution problems worldwide, could shrink dramatically if batteries lasted lifetimes instead of years.

The team acknowledges hurdles remain before store shelves see these batteries. They need to increase energy storage capacity in smaller spaces and scale up manufacturing of the organic polymers. But the peer-reviewed research, published in Nature Communications, proves the concept works.

Sometimes the most advanced solutions come from looking backward at simple, time-tested ingredients—like the minerals that have helped make tofu for thousands of years.