721 research outputs found
Cycling stability of a hybrid activated carbon//poly(3- methylthiophene) supercapacitor with N-butyl-Nmethylpyrrolidinium bis(trifluoromethanesulfonyl)imide ionic liquid as electrolyte
A long cycle-life, high-voltage supercapacitor featuring an activated carbon//poly(3-methylthiophene) hybrid configuration with N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ionic liquid, a solvent-free green electrolyte, was developed. The cyclability of a laboratory scale cell with electrode mass loading sized for practical uses was tested at 60 °C over 16,000 galvanostatic chargeâdischarge cycles at 10 mA cmâ2 in the 1.5 and 3.6 V voltage range. The reported average and maximum specific energy and power, specific capacitance and capacity, equivalent series resistance and
coulombic efficiency over cycling demonstrate the long-term viability of this ionic liquid as
green electrolyte for high-voltage hybrid supercapacitors
Increased Performance of Electrodeposited PtRu/C-Nafion Catalysts for DMFC [Electrochem. Solid-State Lett., 8, A110 (2005)]
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Electrodeposited Cobalt-Copper mixed oxides for supercapacitor electrodes and investigation of the Co/Cu ratio on the electrochemical performance
In this study, different Cobalt-Copper mixed oxides compositions for supercapacitor electrodes have been prepared, by means of electrodeposition and thermal annealing. The chemical-physical and electrochemical characterization of electrodes, as well as the effect of different Co/Cu in the ratios on the crystal lattice, electrode morphologies, and electrochemical performance of the electrodes, were investigated using X-ray diffraction (XRD), scanning electron microscopic (SEM) and cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge/discharge (GCD) tests. The results indicated that the electrode prepared from 0.06 M CoSO4 center dot 7H(2)O + 0.04 M CuSO4 center dot 5H(2)O solution (CC4) had a better electrochemical performance. The initial capacity of the CC4 electrode was 28.3 mAh/g at a scan rate of 5 mV/s with a coulombic efficiency of 94%. CC4 electrode featured capacity retention of 79.2% at a constant current density of 1 A/g after 5000 cycles
Parametric Nonlinear Optics with Layered Materials and Related Heterostructures
Nonlinear optics is of crucial importance in several fields of science and
technology with applications in frequency conversion, entangled-photon
generation, self-referencing of frequency combs, crystal characterization,
sensing, and ultra-short light pulse generation and characterization. In recent
years, layered materials and related heterostructures have attracted huge
attention in this field, due to their huge nonlinear optical susceptibilities,
their ease of integration on photonic platforms, and their 2D nature which
relaxes the phase-matching constraints and thus offers a practically unlimited
bandwidth for parametric nonlinear processes. In this review the most recent
advances in this field, highlighting their importance and impact both for
fundamental and technological aspects, are reported and explained, and an
outlook on future research directions for nonlinear optics with atomically thin
materials is provided
Parametric Nonlinear Optics with Layered Materials and Related Heterostructures
Nonlinear optics is of crucial importance in several fields of science and technology with applications in frequency conversion, entangledâphoton generation, selfâreferencing of frequency combs, crystal characterization, sensing, and ultraâshort light pulse generation and characterization. In recent years, layered materials and related heterostructures have attracted huge attention in this field, due to their huge nonlinear optical susceptibilities, their ease of integration on photonic platforms, and their 2D nature which relaxes the phaseâmatching constraints and thus offers a practically unlimited bandwidth for parametric nonlinear processes. In this review the most recent advances in this field, highlighting their importance and impact both for fundamental and technological aspects, are reported and explained, and an outlook on future research directions for nonlinear optics with atomically thin materials is provided
Air-breathing cathode self-powered supercapacitive microbial fuel cell with human urine as electrolyte
In this work, a membraneless microbial fuel cell (MFC) with an empty volume of 1.5 mL, fed continuously with hydrolysed urine, was tested in supercapacitive mode (SC-MFC). In order to enhance the power output, a double strategy was used: i) a double cathode was added leading to a decrease in the equivalent series resistance (ESR); ii) the apparent capacitance was boosted up by adding capacitive features on the anode electrode. Galvanostatic (GLV) discharges were performed at different discharge currents. The results showed that both strategies were successful obtaining a maximum power output of 1.59 ± 0.01 mW (1.06 ± 0.01 mW mLâ1) at pulse time of 0.01 s and 0.57 ± 0.01 mW (0.38 ± 0.01 mW mLâ1) at pulse time of 2 s. The highest energy delivered at ipulse equal to 2 mA was 3.3 ± 0.1 mJ. The best performing SC-MFCs were then connected in series and parallel and tested through GLV discharges. As the power output was similar, the connection in parallel allowed to roughly doubling the current produced. Durability tests over â5.6 days showed certain stability despite a light overall decrease
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