Regensburg 2022 – wissenschaftliches Programm
KFM 15.3: Vortrag
Mittwoch, 7. September 2022, 10:10–10:30, H7
Elucidation of the Pore Formation Mechanism in Hard-Carbon Microspheres — •Martin Wortmann1, Waldemar Keil2, Michael Westphal1, Elise Diestelhorst3, Jan Biedinger1, Bennet Brockhagen3, Günter Reiss1, Claudia Schmidt2, Klaus Sattler4, and Natalie Frese1 — 1Bielefeld University, Bielefeld, Germany — 2Paderborn University, Paderborn, Germany — 3Bielefeld University of Applied Sciences, Bielefeld, Germany — 4University of Hawaii, Honolulu, USA
Micro-spherical hydrochar can be carbonized by pyrolysis to produce hard-carbon microspheres with excellent electrochemical properties for the application as anode material in batteries. In this contribution, a temperature-resolved study of the chemical and morphological evolution of saccharide-derived hydrochar during pyrolysis up to 1000°C is presented. By combining a wide range of characterization methods all aspects of the structural transition are examined. The chemical processes occurring both in the bulk and at the surface of the carbon spheres are shown to affect the transition from an amorphous-polymeric to a nanocrystalline carbon-structure. The study focuses on the pore formation mechanism, which is driven by the aggregation of nanometer-sized oxygen-rich clusters at the sphere surface, which disintegrate in a narrow temperature range, leaving behind a mesoporous structure. The revealed molecular mechanisms provide key insights into the pyrolysis of carbonaceous materials.