High areal energy density structural supercapacitor assembled with polymer cement electrolyte

Structural supercapacitors (SSCs) have attracted increasely interests due to tremendous demand of zero-energy buildings. Yet the challenge of SSCs remains in well balancing the electrochemical energy storage and loadbearing capacity. Herein, an integrated electro-mechanical SSC with high areal energy density and mechanical strength is developed using carbon fiber and building materials. The rGO/CuO on carbon fiber incorporates excellent electrochemical energy storage behaviors of redox-active material and carbon based material. The electrolytes in the form of PAA-PC-LiOTf composites are fabricated to expand the operating voltage of SSCs, which further boost energy density. By regulating the contents of PAA and LiOTf, the polymer cement electrolyte presents the optimal multifunctionality with a compressive strength of 23.65 MPa and ionic conductivity of 7.48 mS cm-1. An assembled SSC with the polymer cement electrolyte can not only bear high external load, but also extend to a voltage window of 4 V, exhibiting maximum areal energy density of 0.65 mWh cm-2 at areal power density of 0.58 mW cm-2. It has the best multifunctionality among the reported SSCs in the form of civil engineering even better than most reported solid-state supercapacitors, which brings new insights into the high performance SSCs.