Tailoring Highly Flexible Hybrid Supercapacitors Developed by Graphite Nanoplatelets-Based Film: Toward Integrated Wearable Energy Platform Building Blocks

We report a new type of highly flexible hybrid supercapacitors (SCs) developed by graphite nanoplatelets (GNPs)-based films with a practicable fabrication method for mass production. In this report, GNP/carbon black films are featured with excellent free-standing and conductivity characteristics, thus capable of working as both active and interconnection layers (∼20 μm) in our integrated GNP-SCs. The hybrid GNP-SCs are constructed by two distinct assembling methods, series and parallel connection, which are synergistic to enlarge the working voltage window and boost up the areal energy density of the supercapacitor. With tailored thickness, the areal capacitance ∼27.5 mF/cm2 of three-parallel GNP-SCs is ∼2.3 times higher than that of the single GNP-SC. On the other hand, the gap-coating fabrication method is utilized to achieve low cost, easy operation, and simplified process, enabling large-scale free-standing GNP-SCs films to be the most promising candidate for wearable energy-storage devices. Our studies and complementary investigations demonstrate the feasibility of innovative GNP-SCs applications in a variety of fields with optimized performance and low cost, e.g., energy supply, smart wearable devices, and human–machine interfaces.