Wednesday, October 5, 2022

Researchers turned used face masks into flexible, low-cost batteries

The COVID-19 pandemic has impacted every aspect of human life and the global economy. The outbreak not only has had a positive impact on the world environment – for example, in many cities, the air has become cleaner during the period of strict quarantine – but also had some negative consequences. An increase in medical waste, haphazard use and disposal of personal protective equipment (PPE), disinfectants, mask, and gloves, and the burden of untreated wastes is continuously endangering the environment.

To overcome this, the researchers are looking for ways to recycle medical masks into useful things, such as eco-friendly bricks and road material. Now, a team of researchers from the National University of Science and Technology, “MISIS,” along with colleagues from the US and Mexico, have developed a new technology for producing cost-effective, flexible, and efficient batteries from medical waste. Researchers claim that their technology could turn waste that is difficult to recycle into raw materials.

The new technology enables the production of thin, low-cost batteries that are also disposable. According to the researchers, they are superior in several ways to heavier, metal-coated conventional batteries, which require more manufacturing costs. The new batteries can be used in household appliances, from clocks to lamps.

To create the battery of the supercapacitor type, the team first disinfected the masks with ultrasound, then dipped in ‘ink’ made of graphene, which saturates the mask. Then the material is pressed under pressure and heated to 140°C to form pellets to work as the electrodes of the battery. A separator (also made of mask material) with insulating properties is then placed between the two electrodes made of the new material. It is saturated with a special electrolyte and then finally covered in a protective shell created from different types of medical waste – drug blister packs. Thus, medical waste forms the basis for creating batteries; all that needs to be procured is graphene.

Researchers claim that the new batteries have a high density of stored energy and electrical capacity compared to traditional accumulators. They have managed to achieve 98 watt-hours/kg.

The researchers improved the battery by adding nanoparticles of a calcium-cobalt oxide perovskite to the electrodes obtained from the masks. This further increased the energy capacity of the battery up to 208 watt-hours/kg. It also presented moderate capacitance retention of 82.1% after 1500 cycles of charge/discharge and long discharge times of at least 10 hours (at a maximum output voltage of 0.54 V).

In the future, the scientific team plans to apply the new technology for the production of batteries for electric cars, solar power stations, and other applications.

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