Ellen Phiddian
Cosmos science journalist
Zinc-sulphur batteries are a promising way to ease the strain on lithium: they have very high energy density, but are made of more sustainable materials.
But for now, while researchers have been able to design small zinc-based batteries, it’s been difficult to make zinc-sulphur batteries capable of competing with large commercial batteries.
These aqueous zinc batteries are constrained by the materials that surround the zinc: often expensive and prone to degradation.
Researchers have figured out 2 additions to a zinc-sulphur battery that make them more stable. Their findings are published in Angewandte Chemie.
“Aqueous zinc-sulphur batteries offer the potential to power a wide range of applications – from renewable energy systems to portable electronics – with reduced environmental impact and reliance on scarce materials,” says co-author Dr Chase Cao, a researcher at Case Western Reserve University in Cleveland, Ohio, USA.
The researchers found that adding propylene glycol methyl ether and zinc iodide to the battery mix allowed the batteries to store 20% more energy.
The batteries were also more stable and conductive, and stopped dendrites from growing. Dendrites are tiny crystal structures that form inside the battery, disrupting its ability to charge and – if they get big enough – shorting the battery and causing a fire.
“These additives not only enhance battery efficiency, but also address long-standing safety concerns by mitigating dendrite formation,” says co-author Professor Guiyin Xu, from Donghua University, China.
“The result is a compact, higher-density battery that can recharge more times without significant degradation.”
The researchers used this discovery to build a cheap zinc-sulphur battery in the lab. The battery could stay stable for 1,200 charge-recharge cycles.
“We have successfully demonstrated an aqueous zinc-sulphur battery that combines low cost with excellent performance,” write the researchers in their paper.
“This research marks a major step forward in the development of safer and more sustainable energy storage solutions,” says Cao.
