Abandoned masks turn into batteries with energy density close to lithium-ion batteries

COVID-19 mask does not leave the body is already our daily routine, but a mask a day also brings a rather alarming amount of waste, now Russian scientists into the discarded mask “recycling”, developed low-cost and efficient battery, energy density is closer to today’s common lithium-ion batteries.

The effectiveness of masks is reduced when they get wet from breathing or sweat. They are mostly single-use and come with a huge environmental cost in the context of COVID-19.

The Moscow State Institute of Steel and Iron Alloys (MISiS) in Russia intends to revive discarded masks and other discarded medical supplies. First, since masks are epidemic-proof medical supplies, it is important to ensure that they are free of germs before reusing them. The team used ultrasound to completely disinfect the masks, then soaked them in graphene ink, compressed and heated to 140°C to form conductive particles that act as battery electrodes.

The team pointed out that conventional supercapacitor batteries usually rely on ultra-high temperatures to carry out thermal cracking and carbonation, requiring temperatures as high as 1000~1300°C and consuming ten times more energy than the new technology.

Many of the materials used in the new batteries come from discarded medical supplies, including isolation films made from discarded masks and protective cases made from pharmaceutical packaging. The team also noted that the results of the study were surprisingly good, with an energy density of 99.7 watt-hours per kilogram (Wh/kg), which is very close to the 100-265 Wh/kg of lithium-ion batteries.

Then, in order to increase the energy density, calcium cobalt oxide inorganic calcium titanite nanoparticles were added to the electrodes, and the energy density jumped two times to 208 Wh/kg, maintaining 82% capacity after 1,500 charge/discharge cycles, and providing more than 10 hours of power even at a voltage of 0.54 V.

The team believes that the use of discarded masks can significantly reduce material costs and create a thin, flexible battery, and hopes to apply the technology to electric vehicles, solar power and other applications in the future.

Although how to collect discarded masks is still a problem, the Russian team’s idea does give masks a home beyond the garbage can, and in the past the Royal Melbourne Institute of Technology (RMIT University) in Australia also discovered the benefits of discarded masks, finding that they can be made into stronger road materials, effectively improving the ductility and flexibility of recycled concrete aggregate (RCA).