Integrated construction improving electrochemical performance of loadable supercapacitors based on porous cement-based solid electrolytes

Emerging integrated loadable supercapacitors (ILSs) are prominent candidates for zero-energy buildings with both load-bearing/energy storage capacity. However, the development of solid electrolytes with good mechanical and electrochemical performance remains a major challenge in realizing an integrated electromechanical system. Herein, the porous cement-based solid electrolytes (PCSEs) with the combined characteristics of high ionic conductivity and certain compressive strength are successfully developed by a facile "killing two birds with one stone" chemical foaming strategy using potassium iodide (KI) as the reaction modifier, and hydrogen peroxide (H2O2) and Portland cement as the foaming agent and substrate, respectively. The KI is introduced to balance the paradoxical relationship between ionic conductivity and compressive strength while improving the pseudocapacitance of the electrode. Benefiting from these intriguing integrated characteristics, the symmetrical ILS assembled with PCSE and reduced graphene oxide (rGO) electrodes can deliver a maximal energy density of 21.6 Wh kg- 1 and a power density of 1106.2 W kg- 1. Meanwhile, the ILS exhibits stable electrochemical behavior when withstanding external forces, which is a rarely studied aspect in other reports.