Redox active cement-based electrolyte towards high-voltage asymmetric solid supercapacitor

The energy storage devices in civil engineering field are limited by low ionic conductivity and capacity. Herein, a kind of bifunctional redox active cement-based composite serving as electrical energy storage and building structural component function was developed. The effect of K3Fe(CN)6 on the ion migration, pore structure, mechanical and electrochemical property were investigated. Results show that the appropriate incorporation of K3Fe(CN)6 increases the pores number, ion penetration and ionic conductivity of samples. In addition, two sizes of all-solid-state devices assembled by rGO/Fe2O3 electrode and redox active cement-based electrolytes both deliver an extended operating potential window (OPW) of 1.5 V. The 1 cm2 cell with 0.04 redox active cement-based electrolyte delivers superior areal capacitance of 166 mF cm−2 at an areal energy density of 51.87 μWh cm−2 and areal power density of 7.5 mW cm−2. The 100 cm2 cell exhibits a high energy density of 23.10 μWh cm−2, together with power density of 75 μW cm−2. As an application, with three 100 cm2 devices connected in series, a green light emitting diode (LED) can be successfully lit up for the first time and last for 260 s after being charged to 4.5V. The vision of using large buildings to store solar energy can greatly reduce the carbon footprint of building and achieve sustainable development.