Integration of zinc anode and cement: unlocking scalable energy storage

The significant volume of existing buildings and ongoing annual construction of infrastructure underscore the vast potential for integrating large-scale energy-storage solutions into these structures. Herein, we propose an innovative approach for developing structural and scalable energy-storage systems by integrating safe and cost-effective zinc-ion hybrid supercapacitors into cement mortar, which is the predominant material used for structural purposes. By performing air entrainment and leveraging the adverse reaction of the ZnSO₄ electrolyte, we can engineer an aerated cement mortar with a multiscale pore structure that exhibits dual functionality: effective ion conductivity in the form of a cell separator and a robust load-bearing capacity that contributes to structural integrity. Consequently, a hybrid supercapacitor building block consisting of a tailored cement mortar, zinc metal anode and active carbon cathode demonstrates exceptional specific energy density (71.4 Wh kg^-1 at 68.7 W kg^-1), high areal energy density (2.0 Wh m^-2 at 1.9 W m^-2), favorable cycling stability (∼92% capacity retention after 1000 cycles) and exceptional safety (endurance in a 1-hour combustion test). By demonstrating the scalability of the structural energy-storage system coupled with solar energy generation, this new device exhibits great potential to revolutionize energy-storage systems.