A graphdiyne based separator toward high performance activated electrolyte-enhanced supercapacitors

Abstract

Active electrolyte enhanced supercapacitors (AEESCs) are highly valued for their high specific capacitance and energy density. However, the practical applications of AEESCs are hindered by large potential decay and leakage current caused by their rapid self-discharge (SDC) process. Herein, a novel class of separators fabricated from poly(vinyl alcohol) and wafer-level area (diameter 5.5 inch) graphdiyne (GDY/PVA) composite membranes, which afford a strong mechanical strength, two-dimensional (2D) network, hierarchical porous structure, and enhanced thermal stability, is reported. The adoption of such separators considerably suppresses the SDC of AEESCs and increases the specific capacitance. The assembled AEESCs have an impressive SDC time of 484 700 s (1.0 V to 0.3 V), 111.6 times that of the commercial separator, and the specific capacitance is up to 443.5 F g⁻¹, which is nearly 25% higher than that of the commercial separator, while the capacitance retention is still 79.99% after 20 000 cycles and the specific capacitance is 443.5 F g⁻¹, nearly 25% higher than that of the commercial separator, while the capacitance retention is still 79.99% after 20 000 cycles. This strategy provides a potential avenue for the industrialization of high performance AEESCs.