Abstract
The construction
of electrochemical energy-storage devices by scalable
thin-film microfabrication methods with high energy and power density
is urgently needed for many emerging applications. Herein, we demonstrate
an in-plane hybrid microsupercapacitor with a high areal energy density
by employing a battery-type CuFe-Prussian blue analogue (CuFe-PBA)
as the positive electrode and pseudocapacitive titanium carbide MXene
(Ti
3
C
2
T
x
) as the
negative electrode. A three-dimensional lignin-derived laser-induced
graphene electrode was prepared as the substrate by laser exposure
combined with an environmentally friendly water lift-off lithography.
The designed hybrid device achieved enhanced electrochemical performance
thanks to the ideal match of the two types of high-rate performance
materials in proton-based electrolytes and the numerous electrochemically
active sites. In particular, the device delivers a high areal capacitance
of 198 mF cm
–2
, a wide potential window (1.6 V),
an ultrahigh rate performance (75.8 mF cm
–2
retained
even at a practical/high current density of 100 mA cm
–2
), and a competitive energy density of 70.5 and 27.6 μWh cm
–2
at the power densities 0.74 and 52 mW cm
–2
, respectively. These results show that the Ti
3
C
2
T
x
/CuFe-PBA hybrid microsupercapacitors
are promising energy storage devices in miniaturized portable and
wireless applications.