Gyroid Structured Globugraphite Carbon Foam With Hierarchical and Tailored Pore Size

Ordered polymer printed sacrificial templates are employed to get tailored carbon foam structures called Globugraphite for electrode applications. The Globugraphite synthesis is based on the carbon replication of a porous zinc oxide template while simultaneously reducing the template material in the chemical vapor deposition by hydrogen etching introduced by Marx et al. Previously polyvinyl butyral filler was used to create a statistical distribution of pores. In order to create additional macropores up to 1000 μm in the ceramic template, additive manufactured nets and lattices are used to imprint an ordered pore network. Besides polylactic acid, a lightweight foaming filament is used to reduce internal stresses during sintering. Additive manufacturing proves as a viable procedure to imprint interconnected networks with defined macropores into Globugraphite. The pore size distribution is analyzed via mercury intrusion and microcomputed tomography, morphology changes by scanning electron microscopy. Based on these analysis methods a clear correlation between the structure of the lattice used for template imprint and imprint in Globugraphite can be observed. Furthermore, the thermal stability of Globugraphite have been analyzed via thermogravimetric analysis. Individual tailoring of the pore size distribution and the overall morphology of Globugraphite are accomplished.