  The fabrication of electrochemical double-layer capacitors (EDLCs) with high
areal capacitance relies on the use of elevated mass loadings of highly porous
active materials. Herein, we demonstrate a high-throughput manufacturing of
graphene/nanotubes hybrid EDLCs. Wet-jet milling (WJM) method is exploited to
exfoliate the graphite into single/few-layer graphene flakes (WJM-G) in
industrial volume (production rate ~0.5 kg/day). Commercial single/double
walled carbon nanotubes (SDWCNTs) are mixed with graphene flakes in order to
act as spacers between the graphene flakes during their film formation. The
latter is obtained by one-step vacuum filtration, resulting in self-standing,
metal- and binder-free flexible EDLC electrodes with high active material mass
loadings up to 30 mg cm-2. The corresponding symmetric WJM-G/SDWCNTs EDLCs
exhibit electrode energy densities of 539 uWh cm-2 at 1.3 mW cm-2 and operating
power densities up to 532 mW cm-2 (outperforming most of the EDLC
technologies). The EDCLs show excellent cycling stability and outstanding
flexibility even under highly folded states (up to 180 degrees). The
combination of industrial-like production of active materials, simplified
manufacturing of EDLC electrodes, and ultrahigh areal performance of the
as-produced EDLCs are promising for novel advanced EDLC designs.
