A sustainable strategy for organic waste upcycling: Concurrent production of energy and Li-ion battery anode from chicken litter

Improper disposal of organic waste is a serious matter of concern due to its disruptive influences on the environment and human health. Thus, extracting value from such waste to deliver high-end products should eventually be essential as a new class of disposal strategy. Herein, reclaiming value from chicken litter (organic waste surrogate) was sought by recovering energy and synthesizing Li-ion battery anode materials through a pyrolysis process. Pyrolytic products other than battery anode materials, such as gas and liquid, were considered fuels given that they had higher heating values from 7 to 8.7 MJ/kg. Three different chicken litter samples were prepared as the feedstock to investigate the effects of inorganic species contained in chicken litter on the Li-ion battery anode performance and pyrolytic product characteristics, including (1) chicken litter without acid pretreatment, (2) chicken litter washed with 0.05 M HCl, and (3) chicken litter washed with 0.25 M HCl. The HCl pretreatment of chicken litter led to more pyrolytic gas and less solid residue. Among the three, the carbon residue derived from the chicken litter without acid pretreatment exhibited a large capacity of 280 mA h/g at a 50 mA/g, most likely associated with its graphitic morphology and high surface area of 821.5 m²/g. On the other hand, carbon residue derived from the chicken litter with 0.25 M HCl pretreatment showed improved cycle stability because ash, which causes cycling decay, is sufficiently removed. This approach is potentially applied to modulate the production of energy and battery material concurrently, devising a strategy for organic-waste-to-energy. Additionally, the chicken litter upcycling process would contribute to the reduction in greenhouse gas emissions from organic waste treatment.