Ellen Phiddian
Cosmos science journalist
Australian researchers have constructed a safe, cheap zinc battery – using an office laminator!
They say their “aqueous zinc-ion batteries” could be recyclable, easy-to-make power sources for small devices.
“We made it on my desk, once,” Associate Professor Zhongfan Jia, a nanotechnology researcher at Flinders University, tells Cosmos.
Most commercial batteries, like lithium-ion batteries, need carbon-based (organic) electrolytes to transfer electricity inside them. These electrolytes are the main reason batteries are flammable.
Water would be a safer and more sustainable option for an electrolyte, but it tends to react with the metals in the battery and become unusable.
Jia says that zinc is a prime candidate for making an aqueous battery, because it doesn’t interfere with water electrolytes, but it still has a property called a low “redox potential”.
“It means the electric potential at which the reaction will happen,” says Jia.
As well as being safer, zinc is 10 times more abundant than lithium in the Earth’s crust.
Other researchers have developed aqueous zinc-ion batteries that use zinc in the negative side of the battery (the anode) but rely on more expensive and less safe metals, like vanadium and magnesium, to form the positive side (the cathode).
“What we’re trying to do is to get rid of those metals and only use zinc,” says Jia.
“But, therefore, we need something for our positive side.”
The team’s solution was to use cathodes made of an industrial polymer.
“Tonnes of this polymer is used in other areas. We took that polymer and we did one simple modification,” says Jia.
“People who have less knowledge in polymer chemistry can still make this electrode material and use it for zinc-ion batteries.”
The team worked out ways to make other parts of the battery more sustainable.
“We also replaced the PVdF binder, which is like a glue,” says Jia.
“PVdF is a very commonly used polymer in batteries, for example in lithium-ion batteries. But it makes the recycling of the battery difficult because it often produces a fluorine component.”
This means that, like other polyfluoroalkyl substances (PFAS), it’s very difficult to break down.
The battery powering a small car. Credit: Gamage et. al., 2024, Energy Storage Materials, doi:j.ensm.2024.103731
The team built a pouch battery that could power a small electric fan and a model car. The process was so simple, says Jia, that they could construct a battery with a photo laminator. Both experimental and industrial batteries often need airless environments and other complex conditions to manufacture.
Jia hopes industry will be interested in producing these batteries.
“I hope that this can be adopted and produce a real battery for small electronic devices like toys and small household electronics,” he says.
The research is described in a paper published in the journal Energy Storage Materials.
