Abstract
Two-dimensional siloxene sheets are an emerging
class of materials with an eclectic range of potential
applications including electrochemical energy conversion and
storage sectors. Here, we demonstrated the dehydrogenation/
dehydroxylation of siloxene sheets by thermal annealing at
high temperature (HT) and investigated their supercapacitive
performances using ionic liquid electrolyte. The X-ray
diffraction analysis, spectroscopic (Fourier transform infrared,
laser Raman, and X-ray photoelectron spectroscopy) studies,
and morphological analysis of HT-siloxene revealed the
removal of functional groups at the edges/basal planes of
siloxene, and preservation of oxygen-interconnected Si6 rings with sheet-like structures. The HT-siloxene symmetric
supercapacitor (SSC) operates over a wide potential window (0−3.0 V), delivers a high specific capacitance (3.45 mF cm−2),
high energy density of about 15.53 mJ cm−2 (almost 2-fold higher than that of the as-prepared siloxene SSC), and low
equivalent series resistance (compared to reported silicon-based SSCs) with excellent rate capability and long cycle life over 10
000 cycles.
