Method of recycling, turning old masks into lithium batteries

Scientists from Russia, the US and Mexico have developed a method to recycle old masks into a high-performance battery like a lithium-ion battery.

A team of researchers from Russia's National University of Science and Technology (NUST MISiS) collaborated with colleagues in the US and Mexico to develop a new way to turn used masks into cheap, flexible batteries. active and efficient. They published the study in the February 2022 issue of the journal Energy Storage.

The new recycling method promises to reduce the amount of waste from disposable masks.

With the arrival of Covid-19, people became dependent on personal protective equipment (PPE). While disposable masks make up the majority of PPE around the world, the disposal of the used product is neglected, often ending up in landfills and in the ocean, releasing harmful gases. In 2020 alone, the world produced 52 billion masks, and 1.56 billion of them ended up in the sea.

To recycle the masks, the team first disinfects the masks with ultrasonic waves and dips them in ink made from graphene. They then compressed the mask and heated it to 140 degrees Celsius to form a small pellet that acted as the battery's electrode. These pellets are separated by an insulating layer also made from used masks. The final step is to immerse the entire object in the electrolyte and cover it with a shell manufactured from discarded medicine. In this way, medical waste becomes the core of the battery, the only thing that needs to be added is graphene, according to Professor Anvar Zakhidov, scientific director of the infrastructure project "High-Performance, Flexible, Photovoltaic" Devices Based in Hybrid Perovskites" at NUST MISiS.

Zakhidov et al. found that the new battery is quite efficient with an energy density of 99.7 Wh/kg, which is close to the energy density of lithium-ion batteries, which is in the range of 100 - 265 Wh/kg. The researchers improved the battery design by adding nanoparticles of a calcium-cobalt oxide perovskite material to the electrode. That improvement nearly doubled the energy density, reaching 208 Wh/kg. The battery version gives the best performance with 82% of capacity remaining after 1,500 cycles and can provide more than 10 hours of power at 0.54 V.

The new method could pave the way to more efficient production of batteries than conventional metal-coated and heavier batteries that cost more. NUST MISiS's thin, low-cost batteries can also be disposable and used in future home appliances from watches to lights.