From lithium to zinc? A step forward towards greener batteries

Currently, lithium-based batteries are widely used, but their high price and flammability are major issues. Thus, scientists are turning to a promising option: zinc-based batteries.

Zinc is an abundant, inexpensive and recyclable metal that offers high storage capacity for batteries. Unlike lithium-ion batteries, zinc-based batteries do not require flammable organic solvents, which makes them safer. However, there are still technical obstacles to overcome before seeing them integrated into our electronic devices.

When zinc batteries are charged at high voltage, the water contained in the electrolyte can indeed react to form hydrogen, resulting in a decline in performances and a potentially dangerous excessive pressure. Zinc dendrites can also form and cause courts-circuits.

To solve these problems, engineers have added salts to the aqueous electrolyte, but this can slow down the charging and discharging processes by making the fluid viscous. In addition, salts containing fluorine can be toxic and harmful to the environment. In short, science is on the move, but all the obstacles have not yet been removed.

An international team of researchers from ETH Zurich has developed a new approach for zinc-based batteries using low salt concentration and environmentally friendly acetate salts to minimize electrolyte depletion and prevent the formation of dendrites.

This method has thus made it possible to speed up the process of charging and discharging the batteries. Laboratory tests have been successfully carried out, but there are still challenges to be overcome in order to produce zinc batteries that are durable, 100% recyclable and efficient for storing energy in electrical networks or individual homes. Lithium-ion technology still has a bright future ahead of it.