Researchers have created a new, non-toxic water battery that uses minerals similar to those used in tofu brine. This innovative battery is theoretically capable of operating for centuries without losing its efficiency, while being fully compatible with strict environmental standards for waste disposal, which represents an important step towards a more sustainable energy future.
Conventional batteries rely heavily on harsh, corrosive acids and alkalis, which not only deteriorate the internal components over time, but also pose severe environmental pollution risks upon disposal. To address this problem, a team of researchers from the City University of Hong Kong and the Southern University of Science and Technology have successfully engineered this safe and effective water alternative.
The new design relies on replacing toxic liquids with an electrolyte consisting of neutral magnesium and calcium salts, while maintaining a pH of 7.0 to completely eliminate internal corrosion. The scientists used a covalent organic polymer to make the negative electrode to ensure high conductivity, while the system was completed with a positive electrode made of a material similar to Prussian blue to enhance energy storage efficiency.
Tests showed that the complete cell provides a voltage of 2.2 volts and a specific energy of 48.3 watt-hours per kilogram. What’s even more impressive is that the battery remains stable across 120,000 charging cycles, meaning that if charged once a day, the unit could theoretically last for over 300 years, dramatically outperforming standard batteries.
The system has a specific capacity of 112.8 mAh per gram, and thanks to the non-toxic internal materials, the battery can be disposed of directly in accordance with stringent international safety frameworks such as the ISO 14001 standard. However, developers have to overcome remaining challenges related to scaling up organic polymer manufacturing and increasing the total power capacity in tight spaces before commercializing it.
