Integration of microsupercapacitors
(MSCs) with on-chip sensors
and actuators with nanoenergy harvesters can improve the lifetime
of wireless sensor nodes in an Internet-of-Things (IoT) architecture.
However, to be easy to integrate with such harvester technology, MSCs
should be fabricated through a complementary-metal-oxide-semiconductor
(CMOS) compatible technology, ubiquitous in electrode choice with
the capability of heterogeneous stacking of electrodes for modulation
in properties driven by application requirements. In this article,
we address both these issues through fabrication of multielectrode
modular, high energy density microsupercapacitors (MSC) containing
reduced graphene oxide (GO), GO-heptadecane-9-amine (GO-HD9A), rGO-octadecylamine
(rGO-ODA), and rGO-heptadecane-9-amine (rGO-HD9A) that stack through
a scalable, CMOS compatible, high-wafer-yield spin-coating process.
Furthermore, we compare the performance of the stack with individual
electrode MSCs fabricated through the same process. The individual
electrodes, in the presence of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfony)imide
(EMIM-TFSI), demonstrate a capacitance of 38, 30, 36, and 105 μF
cm
–2
at 20 mV s
–1
whereas the
fabricated stack of electrodes demonstrates a high capacitance of
280 μF cm
–2
at 20 mV s
–1
while retaining and enhancing the material-dependent capacitance,
charge retention, and power density.