Nanofluidic voidless electrode for electrochemical capacitance enhancement in gel electrolyte

Porous electrodes with extraordinary capacitances in liquid electrolytes are oftentimes incompetent when gel electrolyte is applied because of the escalating ion diffusion limitations brought by the difficulties of infilling the pores of electrode with gels. As a result, porous electrodes usually exhibit lower capacitance in gel electrolytes than that in liquid electrolytes. Benefiting from the swift ion transport in intrinsic hydrated nanochannels, the electrochemical capacitance of the nanofluidic voidless electrode (5.56% porosity) is nearly equal in gel and liquid electrolytes with a difference of ~1.8%. In gel electrolyte, the areal capacitance reaches 8.94 F cm−2 with a gravimetric capacitance of 178.8 F g−1 and a volumetric capacitance of 321.8 F cm−3. The findings are valuable to solid-state electrochemical energy storage technologies that require high-efficiency charge transport.

2D-on-2D core-shell Co3(PO4)2 stacked micropetals@Co2Mo3O8 nanosheets and binder-free 2D CNT-Ti3C2TX–MXene electrodes for high-energy solid-state flexible supercapacitor

The structural instability and sluggish kinetics of conventional positive electrodes with the lower capacitance of carbon-based negative electrodes result in an inferior performance for state-of-art supercapacitors (SCs). A general yet...

Varying Impedance “Orbital Impedance Stability“ Graphene Based Supercapacitor Nanofiber Electrodes – Utilizing A New Direct Method of Studying Impedance Based on Actual Experimental Data

Single cell supercapacitors with electrodes of varying amounts of graphene and carbon black, formed via the electrospinning process with a carbon-based Polyacrylonitrile (PAN), were tested in 1M H2SO4. From the tested samples, the overall data indicates no correlation between impedance and capacitance energy values. However, the breakdown of the various samples showed mixed results of; good correlations between lower impedance resulting in higher and lower capacitance; while other samples showed higher impedance correlating to both higher and lower capacitance. No correlation was observed between the Impedance value and the thickness of the samples. Furthermore, carbon mole content was not a major factor in determining impedance; therefore, structure is not a major contributor to impedance. Whereas, carbon mole content is a major contributor to capacitance energy; Hence, impedance provides an alternative control point to increasing energy ( 2-10X times ), that can be retrofitted to existing systems, or to increase the energy storage beyond current levels by adjusting/controlling impedance in new designs. The data is indicating impedance is not constant and is varying. The mechanism of varying impedance is unclear and requires further research. However, it is thought to mimic the energy level and stability of matter (atoms). Therefore, impedance varies or oscillates accordingly to achieve an impedance level stability, and hence the term “Orbital Impedance Stability”. Thoughts into Impedance being an Energy Field, to be provided in next publication (In-sha’-ALLAH). This research is concluding that our conventional understanding of impedance is limited in scope. New approaches and further research is needed to better understand impedance behavior. A better understanding of impedance is essential to a breakthrough in energy storage devices from capacitors and batteries, to electric generation and distribution of energy, to magnetic levitation, medical drugs and other energy improvements.

Improvement of Photoresponse in Organic Phototransistors through Bulk Effect of Photoresponsive Gate Insulators

In this study, we investigate the bulk effect of photoresponsive gate insulators on the photoresponse of organic phototransistors (OPTs), using OPTs with poly(4-vinylphenol) layers of two different thicknesses. For the photoresponse, the interplay between the charge accumulation (capacitance) and light-absorbance capabilities of a photoresponsive gate insulator was investigated. Although an OPT with a thicker gate insulator exhibits a lower capacitance and hence a lower accumulation capability of photogenerating charges, a thicker poly(4-vinylphenol) layer, in contrast to a thinner one, absorbs more photons to generate more electron–hole pairs, resulting in a higher photoresponse of the device. That is, in these two cases, the degree of light absorption by the photoresponsive gate insulators dominantly governed the photoresponse of the device. Our physical description of the bulk effect of photoresponsive insulators on the performance of OPTs will provide a useful guideline for designing and constructing high-performance organic-based photosensing devices and systems.

Redução da capacitância de barramento em driver para alimentação de LEDS

This paper presents the performance evaluation of control techniques for the reduction of capacitors in drivers for actuation LED.Through the active control of the driver output current, the ripple from the PFC stage of the current can be controlled, keeping itat levels appropriate to the technical standards, being IEC 61000-3-2 Class C and IEEE 1789. This control allows the outputvoltage ripple to vary at higher amplitude levels, allowing the use of a lower capacitance bus capacitor, therefore longer life usefuland reliability.The analyzed electronic system consists of the Buck-Boost converter was performed at the power control stagefor different bus voltages and output power. Different controller structures were analizes, in order to obtain an analysis of theinfluence of these controllers in the reduction of bus capacitance. Thus obtaining a greater ripple in the bus voltage, maintainingagreement with IEEE 1789 standard regarding current ripple limits on LEDs.

Comparison of colonic and ileal propulsive capabilities under conditions requiring hydrostatic work

The intrinsic ability of cat colonic segments to do hydrostatic work to expel fluid was investigated in vitro and compared with the propulsive ability of ileal segments evaluated under identical conditions. Colonic segments spontaneously produced propulsive complexes at an average interval of 4.8 min when basal intraluminal pressure was set at 5 cmH2O. These complexes produced a net ejection of fluid in the aboral direction. When the capacitance of the evaluation system was set at 0.025 ml/cmH2O, colonic segments ejected only 5% of their content. This percentage increased to 23% when evaluation capacitance was increased to 0.125 ml/cmH2O. Peak aboral pressure associated with these complexes was approximately 37 cmH2O at both capacitances. Ileal segments aborally ejected almost twice as much fluid (44% of their luminal content) as did colonic segments at a capacitance of 0.025 ml/cmH2O even though ileal luminal content was five times less than colonic content. The aborally ejected volume per complex did not change when ileal segments were evaluated at two different capacitances even though higher pressures were required to eject fluid at the lower capacitance than at the higher capacitance. These results indicate that the propulsive behavior of ileal and colonic segments has some qualitative aspects that are similar but that only the propulsive ability of colonic segments is pressure limited under the conditions tested. Possible mechanisms that might produce this limitation are considered.