Polymer/cement composite electrolyte with high strength and high ionic conductivity for structural supercapacitors

All-solid-state structural supercapacitors (ASSC) based on polymer/cement electrolytes (PCE) are promising energy storage devices in buildings due to the tremendous demand for zero-energy buildings. However, the challenge of PCE remains in well balancing the mechanical properties and ionic conductivity. Herein, an integrated electro-mechanical PCE introducing PAM (20 wt%, synthesized by in-situ polymerization) and PAM (5 wt%, commercial) simultaneously largely improves the ionic conductivity (68.54 mS/cm) and mechanical properties (47.96 MPa). Surprisingly, PAM (20% wt%, in-situ polymerization synthesis) and PAM (5% wt%, commercial) were introduced simultaneously to modify PCE, which not only had a synergistic effect on compressive strength but also had a synergistic effect on ionic conductivity. Moreover, an assembled ASSC based on 20-AM-5-PAM PCE exhibits excellent performance with an areal energy density of 25.17 μWh/cm2 at a power density of 50 μW/cm2 and ～96% capacitance retention after 5000 cycles. These results demonstrate the great potential for the application of 20-AM-5-PAM PCE in high-strength and large-volume building structure energy storage devices.