For over two millennia, paper has been a fundamental element of human progress. Today, its purpose has evolved beyond mere writing to become a key driver in advancing a more sustainable and greener future.
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Lightweight and thin, paper-based technologies are reducing our dependence on metals and plastics while also simplifying disposal methods. Innovations include paper-based diagnostic tools that provide cost-effective and quick detection of infectious diseases, along with batteries and energy devices that serve as eco-friendly alternatives for power generation. Scientists are leveraging the versatility of paper in remarkable ways to address contemporary challenges
Recently, a group of Tohoku University researchers reported on the development of a high-performance paper-based magnesium-air (Mg-air) battery that is activated by water.
We drew inspiration for this device from the respiration mechanism of plants, points out 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.
Hiroshi Yabu, Study Corresponding Author, Tohoku University
To construct the battery, Yabu and his team attached magnesium foil to one side of the paper and applied the cathode catalyst along with a gas diffusion layer to the opposite side. The paper battery produced a maximum output of 103 milliwatts/cm², an open circuit voltage of 1.8 volts, and a current density of 100 mA/cm² at 1.0 volts.
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.
Hiroshi Yabu, Study Corresponding Author, Tohoku University
The research team conducted experiments using the battery in both a pulse oximeter sensor and a GPS sensor, demonstrating its adaptability for use in wearable technology.
Journal Reference:
Ishibashi, K., et al. (2024) Rare-metal-free high-performance water-activated paper battery: a disposable energy source for wearable sensing devices. RSC Applied Interfaces. doi.org/10.1039/D4LF00039K