Apr
10
Coming Up A Metal Air Battery For Wearable Devices
April 10, 2024 | Leave a Comment
Tohoku University’s Advanced Institute for Materials Research (AIMR) group of researchers has created a paper-based magnesium-air battery that can be used in GPS sensors or pulse oximeter sensors. Drawing inspiration from the way plants breathe, they took advantage of paper’s recyclability and lightweight nature making the engineered battery hold promise for a more environmentally friendly source of energy.
The research reporting paper Rare-metal-free high-performance water-activated paper battery: a disposable energy source for wearable sensing devices has been published in the journal RSC Applied Interfaces. (The paper is open access at posting)
For over two millennia, paper has been a staple of human civilization. But these days, the usage of paper is not limited to writing. It is also playing a pivotal role in ushering in a greener future.
Lightweight and thin paper-based devices help reduce dependence on metal or plastic materials, whilst at the same time being easier to dispose of. From paper-based diagnostic devices that deliver economical and rapid detection of infectious diseases to batteries and energy devices that offer an environmentally friendly alternative for power generation, scientists are finding ingenious ways to put this versatile material to use.
Now, a team of researchers at Tohoku University has reported on a high-performance magnesium-air (Mg-air) battery that is paper-based and activated by water.
“We drew inspiration for this device from the respiration mechanism of plants,” pointed out Hiroshi Yabu, a corresponding author of the study. “Photosynthesis is analogous to the charge and discharge process in batteries. Just as plants harness solar energy to synthesize sugar from water in the ground and carbon dioxide from the air, our battery utilizes magnesium as a substrate to generate power from oxygen and water.”
To fabricate the battery, Yabu and his colleagues bonded magnesium foil onto paper and added the cathode catalyst and gas diffusion layer directly to the other side of the paper.
The paper battery achieved an open circuit voltage of 1.8 volts, a 1.0 volt current density of 100 mA/cm², and a maximum output of 103 milliwatts/cm².
“Not only did the battery demonstrate impressive performance results, it operates without using toxic materials — instead using carbon cathodes and a pigment electrocatalyst that have passed stringent assessments,” added Yabu.
The researchers put the battery to the test in a pulse oximeter sensor and a gps sensor, illustrating its versatility for wearable devices.
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This is pretty impressive! A pair of these in series would yield better than 3.5 volts, the zone where a lot of today’s cool stuff runs. OK the wattage isn’t a screaming wow, but for a wearable device, is big watts a major issue for now?
One hopes the production costs are dirt cheap. There could be quite a demand for these and the technology will improve. So one hopes that some product designers investigate and fine opportunity here kick starting some market energy.