Dataset: Design and Fabrication of 3D-Printed Structural Supercapacitors with Vertically Aligned Carbon Nanotube-Enhanced Carbon Fibers

This dataset accompanies research on the design and fabrication of 3D-printed structural supercapacitors (SSCs) that integrate vertically aligned carbon nanotube (VACNT)-functionalized carbon fiber (CF) electrodes into a continuous fused filament fabrication (FFF) composite architecture. The dataset encompasses multi-scale experimental measurements spanning material, component, pouch cell, and full device levels, as well as structural design data from finite element analysis and topology optimization. Data were collected using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to characterize VACNT morphology on T300 carbon fiber substrates grown by aerosol-assisted chemical vapor deposition. Single-fiber electromechanical properties were measured by simultaneous tensile testing and four-point probe conductivity recording. Electrochemical data include impedance spectra (EIS) and cyclic voltammetry (CV) curves acquired at component level (three-electrode, 1 M H2SO4), intermediate pouch cell level (PVA-NaCl GPE), and full 3D-printed demonstrator level (LCR meter, 1 kHz). Rheological frequency sweep data characterize the gel polymer electrolyte (PVA-NaCl). Mechanical tensile data with digital image correlation (DIC) and infrared thermography cover both the PETG-CF reinforcement hull and recycled rPETG-CF specimens. Finite element simulation outputs include representative volume element (RVE) homogenization data and topology-optimized geometry with deformation and stress maps. Micro-CT images document the printed composite interface quality. The dataset enables independent validation of the reported electrochemical, mechanical, and structural performance metrics, and supports reuse in modelling of multifunctional composites, electrode engineering for structural energy storage, and sustainability assessment of thermoplastic composite systems.