Stereolithography 3D Printed Carbon Microlattices with Hierarchical Porosity for Structural and Functional Applications.

Abstract

Hierarchically porous carbon microlattices (HPCMLs) fabricated by using a composite photoresin and stereolithography (SLA) 3D printing is reported. Containing magnesium oxide nanoparticles (MgO NPs) as porogens and multilayer graphene nanosheets as UV-scattering inhibitors, the composite photoresin is formed to simple cubic microlattices with digitally designed porosity of 50%. After carbonization in vacuum at 1000°C and chemical removal of MgO NPs, it is realized that carbon microlattices possessing hierarchical porosity are composed of the lattice architecture (≈100µm), macropores (≈5µm), mesopores (≈50nm), and micropores (≈1nm). The linear shrinkage after pyrolysis is as small as 33%. Compressive strength of 7.45 to 10.45MPa and Young's modulus of 375 to 736MPa are achieved, proving HPCMLs a robust mechanical component among reported carbon materials with a random pore structure. Having a few millimeters in thickness, the HPCMLs can serve as thick supercapacitor electrodes that demonstrate gravimetric capacitances 105 and 13.8 Fg-1 in aqueous and organic electrolyte, reaching footprint areal capacitances beyond 10 and 1 Fcm-2 , respectively. The results present that the composite photoresin for SLA can yield carbon microarchitectures that integrate structural and functional properties for structural energy storages .