a) I–V
curve for the PG ink before and after the annealing
process. b) Electrical conductivity of the PG ink before and after
the annealing process compared with three different DIW inks based
on GO (references were included in Table S3). c–i) Electrochemical performance of printed electrodes
in a three-electrode system. c) CV curves for a 4-layer woodpile (green)
and compact (orange) PG structures, d,e) CV and GCD curves for woodpile
electrodes at an increasing number of layers, and f) comparison of
the areal and gravimetric capacitance of the woodpile electrodes with
a different number of layers. g) Areal capacitance of PG electrodes
(2 to 8 layers) at different current densities, h) EIS curves on 2-
to 8-layer electrodes between 0.01 Hz and 100 kHz, (i) EIS fitting
circuit, and j) Bode plots for the woodpile electrodes with different
numbers of layers.