Bridging the Gap between Charge Storage Site and Transportation Pathway in Molecular-Cage-Based Flexible Electrodes

Porous materials have been widely applied for supercapacitors;
however, the relationship between the electrochemical behaviors and
the spatial structures has rarely been discussed before. Herein, we
report a series of porous coordination cage (PCC) flexible supercapacitors
with tunable three-dimensional (3D) cavities and redox centers. PCCs
exhibit excellent capacitor performances with a superior molecular
capacitance of 2510 F mmol–1, high areal capacitances
of 250 mF cm–2, and unique cycle stability. The
electrochemical behavior of PCCs is dictated by the size, type, and
open–close state of the cavities. Both the charge binding site
and the charge transportation pathway are unambiguously elucidated
for PCC supercapacitors. These findings provide central theoretical
support for the “structure–property relationship”
for designing powerful electrode materials for flexible energy storage
devices.