A Nickel‐Assisted Catalytic Graphitization of PET Waste Into High‐Performance Carbon Anodes for Lithium‐Ion Batteries

The growing accumulation of polyethylene terephthalate (PET) waste has stimulated interest in sustainable approaches for converting plastic waste into functional carbon materials. In this work, PET waste was upcycled into structurally ordered carbon through nickel‐assisted catalytic graphitization. PET was first precarbonized at 600 °C to obtain an amorphous carbon precursor, followed by catalytic treatment at 1400 °C to induce structural ordering. Structural analyses revealed a significant improvement in graphitic ordering after Ni‐assisted treatment, evidenced by the sharpening of the (002) diffraction peak and the reduction of interlayer spacing from 0.374 to 0.343 nm. Raman spectroscopy further confirmed the structural evolution, with the I _D / I _G ratio decreasing from 1.26 to 0.51. As an anode for lithium‐ion batteries, the Ni‐PET‐1400 electrode delivered an initial reversible capacity of 228.9 mAh g ⁻¹ and maintained 323.7 mAh g ⁻¹ after 250 cycles at 0.2C. In addition, the material exhibited improved rate capability, retaining approximately 79% of its initial capacity at high current densities. The enhanced electrochemical performance is attributed to the improved structural ordering and surface roughness that facilitate lithium‐ion diffusion and reduce charge transfer resistance. This work demonstrates an effective strategy for transforming plastic waste into value‐added, structurally ordered carbon for energy storage applications.