Scientific Study

The reduction of NCM cathode materials by waste biomass is currently a hot topic in the field of energy recovery. In China, large quantities of hazelnut shells are discarded every year, which, if as a reducing agent, can achieve the eco-friendly goal of “treating waste with waste”. While there is currently a lack of comprehensive studies on the kinetic and thermodynamic characteristics of NCM reduction using hazelnut shells. In this study, the thermodynamic feasibility of reducing NCM cathode with pyrolysis products from hazelnut shells was confirmed. Subsequently, based on thermogravimetric analysis, the entire reduction process was divided into four stages, in which the reactions including dehydration, pyrolysis, and reduction. Kinetic analysis, which via the Coats-Redfern method in the segments with distinct reaction characteristics in the stages, indicated that the Random nucleation (n = 1) model (A1) consistently exhibited the highest correlation coefficient across all four segments. At heating rates ranging from 5 ~ 20°C/min, Ea remained between 40.6 and 405.9 kJ/mol. And the ranges of A from segment I to segment IV are 7.4 × 105 ~ 1.6 × 106, 8.7 × 108 ~ 6.1 × 1011, 1.8 × 1020 ~ 7.9 × 1030, and 8.5 × 1018 ~ 4.7 × 1019 min−1, respectively. The thermodynamic parameter ΔG and ΔH values are positive, ΔS changes from negative to positive in segment I to Ⅳ. The information obtained in this study presents a preliminary theoretical framework‌ for the potential industrial application of hazelnut shells reducing NCM cathode materials.

https://doi.org/10.1007/s11814-026-00671-w