Approach for Upcycling Textile Waste for Simultaneous Energy Recovery and Li-ion Battery Electrode Production

The growing volume of textile waste, driven by fast fashion, presents significant environmental and economic challenges owing to limited recycling and high landfilling rates. This study introduces a sustainable upcycling strategy that converts denim waste (textile waste surrogate) into functional carbon materials for lithium-ion battery (LIB) anodes, using pyrolysis followed by KOH activation. The pyrolysis process yielded 13 wt% gas, 63 wt% liquid, and 24 wt% solid residues. The activated denim-waste-derived carbon electrode (DWCE) exhibited excellent electrochemical performance, including an initial discharge capacity of 141.6 mAh/g, high rate capability (38.3% capacity retention at 1000 mA/g), and stable cycling over 200 cycles. Material characterizations revealed a high surface area (691.4 m²/g), enhanced graphitization, and nitrogen doping, which contributed to improved Li-ion storage and conductivity. Additionally, the pyrolytic byproducts could serve as renewable energy sources, reducing the dependence on external energy. Compared with traditional disposal methods, denim pyrolysis can offer reduced CO₂ emissions and economic advantages with DWCE production costs. Overall, this study highlights the potential of denim waste as a sustainable, low-cost precursor for high-performance LIB anodes, contributing to a circular economy and carbon-reduction goals.