Engineered cementitious composites (ECCs) exhibit superior mechanical properties (MPs) and excellent crack control capabilities, making them widely used in practical engineering applications. However, the MPs of ECCs in frozen states (FSs), particularly their flexural properties (FPs), still need to be better understood. MP tests were designed for frozen ECC samples to investigate the service performance of ECCs in an FS. The samples underwent 0 to 300 freeze–thaw cycles (FTs), followed by compressive and flexural tests at a constant freezing temperature of −18 °C. The compressive properties (CPs) and FPs of the samples and their influencing mechanisms were analyzed. Based on this analysis, a life prediction model (LPM) for freeze–thaw-damaged (FTD) ECCs was established using the entropy weight method and the GM(1,1) model to predict the durability changes of ECCs in FS. The results indicate that with an increasing number of FTs, the uniaxial compressive strength (CS), elastic modulus (E), initial crack strength, and ultimate strength of ECCs in the FS are higher than those in the thawed state (TS), with a notable increase in brittleness at ultimate failure. The overall stiffness of the specimens increased under high FTs. The established model effectively predicts the durability changes of ECCs in the FS.

To address the challenges of energy shortages and environmental pollution, this study developed a sustainable and rechargeable cement-based battery utilizing alkali-activated cementitious materials (AAMs) as solid electrolytes. The AAM electrolytes were synthesized from blast furnace slag (BFS) and waste glass powder (GPP). By adjusting the silicate modulus and the slag-to-glass ratio, the mechanical and electrochemical properties of the AAMs were systematically investigated. Furthermore, the electrochemical performance of the cathode was significantly enhanced through the optimization of Ni–Co alloy electrodes. The results showed that the M0.6–SG64 electrolyte achieved a compressive strength of 17.27 MPa and an ionic conductivity of 3.52 mS/cm after 28 days, exhibiting a dense gel structure and continuous ion-transport channels. The modified Ni–Co alloy electrode exhibited a microspherical cluster morphology, which substantially increased the number of electroactive sites. Among all samples, the N4–C1 electrode demonstrated the highest areal capacitance (5.86 F/cm2) and excellent redox reversibility owing to the synergistic effect between Ni and Co. The constructed Ni–Co@MF // AAMs // Fe oxide@MF battery exhibited significantly excellent energy storage performance, with a discharge energy density of 15.72Wh/m2 and a Coulombic efficiency of 65.68% after 100 cycles, which was significantly better than that of the ordinary Portland cement system (OPC). Overall, the AAM-based cement battery effectively integrates structural support with energy storage capability, providing a new pathway toward carbon-neutral and multifunctional construction materials.