All Si₃N₄ Nanowires Membrane Based High‐Performance Flexible Solid‐State Asymmetric Supercapacitor

Abstract

Recently, much attention has been drawn in the development of flexible energy storage devices due to the increasing demands for flexible/portable electronic devices with high energy density, low weight, and good flexibility. Herein, vertically oriented graphene nanosheets (VGNs) are in situ fabricated on the surface of free‐standing and flexible Si3N4 nanowires (NWs) membrane by plasma‐enhanced chemical vapor deposition (PECVD), which are directly used as flexible nanoscale conductive substrates. NiCo2O4 hollow nanospheres (HSs) and FeOOH amorphous nanorods (NRs) are finally prepared on Si3N4NWs@VGNs, which are served as the positive and negative electrodes, respectively. Profiting from the structural merits, the synthesized Si3N4NWs@VGNs@NiCo2O4HSs and Si3N4NWs@VGNs@FeOOHNRs membrane electrodes exhibit remarkable electrochemical performance. Using Si3N4NWs membrane as the separator, the assembled all Si3N4NWs membrane‐based flexible solid‐state asymmetric supercapacitor (ASC) with a wide operating potential window of 1.8 V yields the outstanding energy density of 96.3 Wh kg−1, excellent cycling performance (91.7% after 6000 cycles), and good mechanical flexibility. More importantly, this work provides a rational design strategy for the preparation of flexible electrode materials and broadens the applications of Si3N4NWs in the field of energy storage.

Oxygen Vacancies Enhanced NiCo2O4 Nanoarrays on Carbon Cloth as Cathode for Flexible Supercapacitors with Excellent Cycling Stability

“…In these XRD patterns, except the obvious diffraction peak located at 2 θ of 26° is ascribed to the carbon cloth substrate, all the other diffraction peaks of the pristine and solvothermal treated NiCo 2 O 4 @CC samples are exclusively assigned to NiCo 2 O 4 (JCPDS No. 20–0781) and no peaks from any impurities are detected, indicating that pure NiCo 2 O 4 crystals are exclusively formed in these samples [25–27] . These results are also well consistent with the HRTEM analyses.…”

“…20-0781) and no peaks from any impurities are detected, indicating that pure NiCo 2 O 4 crystals are exclusively formed in these samples. [25][26][27] These results are also well consistent with the HRTEM analyses. Moreover, it is interesting to note that, compared to the pristine NiCo 2 O 4 @CC, the (400) Bragg diffraction peak at 2θ of 45°for samples Vo-NiCo 2 O 4 @CC gradually shifts to lower 2θ angles as the solvothermal treatment time increased, indicating the expansion of lattice spacing during the solvothermal treatment process, which may attribute to the introduction of oxygen vacancies in Vo-NiCo 2 O 4 @CC samples.…”

Superhydrophilic edge-rich graphene for the simultaneous and disposable sensing of dopamine, ascorbic acid, and uric acid

“…S2, ESI †), which is matched well with that in the previous report. 35 The as-prepared fs-ERG shows an extremely low bulk density (B20 mg cm À3 ) and high porosity up to 99%. It is well known that graphene produced via the CVD method generally generates a hydrophobic surface, which would limit its application in an aqueous environment.…”

Epitaxial Grown Carbon Nanotubes Reinforced Pyrocarbon Matrix in C/C Composites with Improved Mechanical Properties

“…Since the fabrication temperature was higher than 1000 °C and the CTE of pyrocarbon is much larger than that of carbon fibers along the radial direction, the intrinsic stress caused by the mismatching of CTE was inevitable between carbon fibers and the pyrocarbon matrix. Usually, Raman spectroscopy is an effective method to analyze the structure of carbon-based materials [ 31 , 32 ], and Raman mapping of the shift in the G peak is used to evaluate the stress distribution in and around carbon fibers [ 33 ]. As displayed in Figure 5 a, before densification, there was no obvious difference in the Raman spectra of carbon fibers, and no stress was applied to the carbon fiber.…”