Cheap and powerful rechargeable batteries are used for anything from generating electricity in solar and wind farms to powering smartphones to the energy source of electric cars.
Currently, the batteries used in these devices are lithium-ion. The problem is that lithium prices are soaring, and they continue to have issues with being highly flammable.
Enter water-based zinc batteries.
As an alternative to lithium-ion batteries, these are designed to be more powerful, safer and even more environmentally friendly.
According to researchers from ETH Zurich, which is developing water-based zinc batteries, these batteries offer several advantages over traditional lithium-ion devices. These include:
- Zinc is an abundant raw material
- Low priced
- Mature recycling infrastructure
- Stores a significant amount of energy
- No highly flammable organic solvents
However, there are some issues with these batteries.
When zinc batteries are charged at high voltage, the water in electrolyte fluid reacts on one of the electrodes to form hydrogen gas. Because of this, the electrolyte fluid dwindles and battery performance decreases. Other issues include excess pressure build up and the formation of spikey deposits of zinc during charging of the battery, known as dendrites that can pierce the battery.
Fast charging, high performance
In the development of the water-based zinc battery, ETH Zurich didn’t use any environmentally harmful salts opting instead for environmentally friendly salts of acetic acid, called acetates.
“With an ideal concentration of acetates, we were able to minimize electrolyte depletion and prevent Zinc dendrites just as well as other scientists previously did with high concentrations of toxic salts,” said Dario Gomez Vazquez, a doctoral student at ETH Zurich involved in the research. “Moreover, with our approach, the batteries can be charged and discharged much faster.”
Researchers tested the battery at a small laboratory scale and the next step will be to scale up the approach and see if it can be translated for large batteries.
This could be used one day as storage units in the power grid to help with power outages or in the basements of single-family homes to allow solar power produced during the day to be used in the evening.
The full research can be found in the journal Royal Society of Chemistry.
