Herein,
a novel asymmetric supercapacitor (ASC) with high energy
density is fabricated based on the NiSe@MoSe2 nanosheet
arrays and the nitrogen-doped pomelo mesocarps-based carbon nanosheet
(N-PMCN) as a positive electrode and a negative electrode, respectively.
The novel NiSe@MoSe2 nanosheet arrays are designed and
prepared by a facile one-step hydrothermal growth method from nickel
foam as a nickel precursor and nucleation framework. The N-PMCN is
prepared using simultaneous CaCl2 activation and urea nitrogen-doped
processes from thepomelo mesocarps as a biomass-based carbon precursor.
Because of the unique nanosheet array architecture of NiSe@MoSe2 and interconnected sheet-like porous morphology with high
nitrogen content (∼9 wt %) of N-PMCN, they exhibit a maximum
specific capacity of 128.2 mAh g–1 and high specific
capacitance of 223 F g–1 at a current density of
1 A g–1. Moreover, the assembled novel NiSe@MoSe2//N-PMCN ASC device with a maximum operating voltage of 1.65
V has demonstrated a high energy density of 32.6 Wh kg–1 at a power density of 415 W kg–1 and outstanding
cycling stability with 91.4% capacitance retention after 5000 cycles
in aqueous electrolyte.
The next-generation portable and wearable energy-storage devices are expected to withstand distinguished mechanical strain and damage. Hence, the electrolytes with superior self-healability, outstanding stretchability, and excellent electrochemical performance are the necessary requirements for achieving advanced supercapacitors, but it still remains a huge challenge to develop the electrolytes. Herein, a novel type of multifunctional supramolecular hydrogel electrolyte (3-dimethyl (methacryloyloxyethyl)ammonium propane sulfonate (DMAPS)−poly(acrylic acid) (PAA)/H 2 SO 4 /bromamine acid sodium (BAAS)) cross-linked by reasonably designed hydrogen bonds and ionic associations is prepared by facile one-pot copolymerization. The obtained hydrogel displays a high ionic conductivity of 40 mS cm −1 , a significant self-healing behavior within only 8 min, and a large stretch strain of more than 2000%. Surprisingly, it also demonstrates robust self-adhesiveness on the electrodes, which not only avoid the relative displacement and delamination between the electrolyte and electrode layers during the repeated mechanical deformation but also is convenient for achieving the lightweight and portable energy-storage devices. Furthermore, the carbon-based supercapacitor with the DMAPS−PAA/H 2 SO 4 /BAAS hydrogel electrolyte can achieve a large electrode-specific capacitance of 240 F g −1 benefited from the introduction of the BAAS redox additive. Simultaneously, the specific capacitance maintains 96 and 89% of its initial value after 400 bending/releasing cycles and 5000 charge/discharge cycles, respectively. The investigation provides a versatile strategy to design a multifunctional hydrogel electrolyte applied to promising power sources for personalized electronics.
A stable and effective redox-mediator gel electrolyte has been prepared by doping indigo carmine (IC) into a polyvinyl alcohol sulfuric acid polymer system (PVA–H2SO4), and a high performance solid state supercapacitor is fabricated by utilizing activated carbon as electrodes and the prepared gel polymer (PVA–H2SO4–IC) as an electrolyte and separator.
Integrated configuration can greatly improve the stability of an energy-storage device in a large or repeated mechanical deformation process, but there is little attention paid to develop this conceptual energy-storage device. Here, we successfully design two embedded polypyrrole (PPy) layers as electrodes and a boron cross-linked PVA(poly(vinyl alcohol))/KCl hydrogel film as electrolyte to construct an integrated electrode−electrolyte−electrode flexible supercapacitor (so-called all-in-one supercapacitor). The boron cross-linked PVA/KCl hydrogel film (B-PVA/KCl) is prepared by simple physical and chemical cross-linking methods. Then, the conducting PPy is embedded in the B-PVA/KCl film by in situ growth to form a PPy/B-PVA/KCl composite film, which shows superior toughness and strength when it undergo large deformations, such as stretch, twist and compression. The integrated flexible supercapacitor can obtain a large areal capacitance of 224 mF cm −2 and a remarkable energy density of 20 μWh cm −2 . Furthermore, such device exhibits excellent electrochemical stability under various bending angles (0°, 90°, and 180°) or 500 bending-releasing cycles, which due to the integrated electrode−electrolyte−electrode configuration can avoid the fall-off of electrode materials from the substrates and overcome the relative displacement between electrode and electrolyte layers during the consecutive bending cycles.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.