Rechargeable zinc-based batteries could be a promising option for grid-scale energy storage, but for one thing. They have an annoying habit of growing dendrites on their anodes leading to short-circuits. Researchers at Concordia University in Canada, are trying a new approach. Because they believe it is possible to ‘go for gold’ with zinc batteries.
Zinc Storage and Spidery Dendrites
Dendrites are tiny, tree-like structures with ‘branches’. They work their way through electrolyte and eventually reach the cathode. When this happens the current flows directly between the electrodes, and the battery fails prematurely.
The solution to dendrites is clearly to prevent this happening. The Canadian scientists applied a microscopically thin layer of gold to a zinc anode. This made it possible to ‘go for gold’ with zinc batteries, and could even be a winner!
Now gold as we know is a very expensive metal, which we only find in a few places in Earth’s crust. But the Concordia University scientists had another trick up their sleeve. They dusted a very thin layer of tiny gold particles on the anode surface, and this worked a treat.
This invention prevented dendrites forming on the anode, while preserving its operational ability. The Concordia zinc battery kept working for over 6,000 hours. This extended its lifetime by a factor of 50 times!
Gold and Zinc in Energy Storage
Zinc is widely available, relatively inexpensive, and the fourth most commonly-used metal. Zinc batteries use this material to store energy in their anodes, and release it on demand.
Currently, we find zinc batteries in hearing aids, remote controls, and back-up systems. Cathode materials vary, but include manganese, oxygen, nickel, silver, and iron.
This novel approach offers potential for grid-scale energy storage. Zinc batteries’ safer chemistry makes them attractive compared to lithium-ion, and their materials recycle more easily.
Legend tells us of the story of a King Midas. Everything he touched, they said, turned to gold. Who would have thought we could ‘go for gold’ with zinc batteries this way?
More Information
Ageing in Sodium-Zinc Batteries Decoded
Novel Cathode For Zinc-Ion Batteries
Preview Image: Everything King Midas Touched
