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.