Fabrication and Electrochemical Performance of Cement-Based Structural Supercapacitors

To solve the incompatibility issue between electrodes and separators in cement-based structural supercapacitors (CSSC), a CSSC was fabricated by utilizing integrated cementitious electrodes and separators. The electrochemical enhancement mechanism was systematically explored. The results indicated that the CSSC showed an electric double-layer capacitance-dominated behavior. Its mass-specific capacitance was measured at 38.6 F g −1 when the current density was 0.1 mA cm −2 , with power and energy densities of 9.77 W kg −1 and 10.26 Wh kg −1 , respectively. After 400 cycles at a current density of 0.2 mA cm −2 , a capacity retention rate of 96.65% and a Coulombic efficiency of 98.36% were maintained. The modified cement-based separator, which incorporated PAA/PVA, graphene oxide (GO), carbon nanotubes (CNTs), and H₂O₂, presented a bimodal pore structure that synergistically matched the electrode porosity. This research advanced the development of building-integrated energy storage systems.