Abstract
Additive manufacturing enables 3D architected materials in which geometry, rather than bulk composition alone, drives properties, and vat photopolymerization (VPP) offers a low-cost, high-resolution route to such architectures, though viscosity, UV penetration, and cure depth constrain filler loading. This dissertation establishes a characterized VPP-derived pyrolytic carbon platform and demonstrates its transfer, using high solid particle loaded resins, across two energy domains.
A parametric study of heating rate, gyroid unit-cell size, and porosity down-selects a 50% porosity, 0.5 C/min recipe. A 500-900 C sweep resolves the microstructural evolution: interlayer spacing remains turbostratic (d002 > 3.35 A) with no true graphitization, the Raman ID/IG ratio rises from approximately 0.75 to 1.0, and two-probe resistance falls by orders of magnitude as a conductive network percolates. Final pyrolysis temperature, not pore size, is the dominant control on microstructure and conductivity, while geometry and heating rate govern dimensional fidelity.
Cu2S-carbon thermoelectric legs are then printed at 25 vol% loading, the first VPP-printed Cu2S leg reported, and sequential sulfur infusion raises the peak Seebeck coefficient from 9.61 to 37.58 uV/K, though the fired composition remains sulfur-deficient at a 2.9:1 Cu:S ratio. Free-standing, binder-free hard-carbon anodes are also fabricated for sodium-ion batteries, where a glass-substrate method resolves a first-layer adhesion limit rather than a cure-depth limit, making a lignin-derived slurry printable at 10 vol%. Because the photopolymer loses roughly 95% of its volume during firing, that loading becomes 68.6 vol% (73.8 wt%) of the fired electrode, decoupling printable loading from that required for electrical continuity. The composite delivers approximately 137 mAh/g against 40 mAh/g for the neat coin, a 3.4-fold improvement, with initial Coulombic efficiency falling from 71% to 62.5%. The neat baseline was fired at 800 C and the composite at 1100 C.