Recycling Microplastics to Fabricate Anodes for Lithium-Ion Batteries: From Removal of Environmental Troubles via Electrocoagulation to Useful Resources

Electrocoagulation is an evolving technology for the abatement of a broad range of pollutants in wastewater owing to its flexibility, easy setup, and eco-friendly nature. Here, environment-friendly strategies for the separation, retreatment, and utilization of microplastics via electrocoagulation are investigated. The findings show that the flocs generated by forming Fe3O4 on the surface of polyethylene (PE) particles are easily separated using a magnetic force with high efficiency of 98.4%. In the photodegradation of the obtained flocs, it is confirmed that Fe3O4 shall be removed for the efficient generation of free radicals, leading to the highly efficient photolysis of PE. The removed Fe3O4 can be recycled into iron-oxalate compounds, which can be used in battery applications. In addition, it is suggested that heat treatment of Fe3O4-PE flocs in an Ar atmosphere leads to forming Fe3O4 core-carbon shell nanoparticles, which show excellent performance as anodes in lithium-ion batteries. The proposed composite exhibits an excellent capacity of 1123 mAh g(-1) at the current density of 0.5 A g(-1) after 600 cycles with a negative fading phenomenon. This study offers insight into a new paradigm of recyclable processes, from environmental issues such as microplastics to using energy materials.

Automated summary

Electrocoagulation is an emerging technology that offers flexibility, easy setup, and eco-friendliness for pollutant removal in wastewater. This study explores environment-friendly strategies for the separation, retreatment, and utilization of microplastics through electrocoagulation. The findings demonstrate efficient separation of Fe3O4-formed flocs on polyethylene (PE) particles using magnetic force and effective photolysis of PE after removing Fe3O4. The removed Fe3O4 can be recycled into iron-oxalate compounds for battery applications, while heat treatment of Fe3O4-PE flocs leads to the formation of Fe3O4 core-carbon shell nanoparticles with excellent anode performance in lithium-ion batteries.