Nanocellulose fiber-based composites have been studied
as supercapacitor
electrodes due to their mechanical and chemical stability. The non-conductivity
of nanocellulose has been tuned by MXene, a 2D nanomaterial, and its
composites, for use as electrode materials for energy storage applications.
This work reports the synthesis of polyindole-stabilized nanocellulose-wrapped
MXene nanocomposite-based electrodes for supercapacitors. Nanocellulose,
extracted from various renewable biowastes, is wrapped around MXene
nanosheets to prevent the restacking of Ti3C2T
x
layers with the structure being stabilized
with polyindole. The morphology, structure, and chemical composition
were confirmed with field-emission scanning electron microscopy (FESEM),
X-ray diffraction, and X-ray photoelectron spectroscopy, respectively.
Morphological analysis, by FESEM and transmission electron microscopy,
confirmed successful synthesis of the ternary nanocomposites. The
concentration of Ti3C2T
x
and nanocellulose was optimized to get best possible electrochemical
performance of the electrodes. The best electrochemical performance
was achieved with an MXene-grass cellulose-polyindole-1:1 composite
[MPC(G)-1:1] with a specific capacitance of 858 F g–1 at 1 A g–1, in a three-electrode setup. An asymmetric
device fabricated with developed nanocomposites as the cathode delivered
a specific capacitance of 90 F g–1 and an energy
density of 40.5 W h kg–1 at 1 A g–1 with 94.1% capacitance retention after 10,000 cycles. This study
established the conversion of biowaste to efficient supercapacitor
electrodes via a facile low-cost process.