The application of multiple parallel diodes to control large currents

This paper discusses a few issues concerning diodes and their application in electric circuits. Considering voltage and current restrictions, experimental and theoretical efforts are made to safely apply semiconducting diodes in circuits working with large current regimes. Combinations of diodes and protecting resistors connected in series and parallel have demonstrated to be of great help with the task of controlling electric currents. To this aim, several activities have enabled participants to observe and measure, or to calculate and display valuable data. Therefore, important class conclusions are stated.

A three-dimensional coral-like Zn,O-codoped Ni3S2 electrocatalyst for efficient overall water splitting at a large current density

A three-dimensional coral-like Zn,O-codoped Ni3S2 nanostructure is grown on nickel foam via a facile solvothermal method, exhibiting excellent electrocatalytic performance at high current density.

Improvement of the detectivity in an Fe-Sn magnetic-field sensor with a large current injection

A ferromagnetic nanocrystalline Fe-Sn is an excellent platform for magnetic-field sensor based on anomalous Hall effect (AHE) owing to simple fabrication and superior thermal stability. For improvement of the magnetic-field sensitivity, doping impurity and increasing injection current are effective approaches. However, in the light of magnetic-field detectivity, the large current may increase the voltage noise. In this study, a maximum allowable current of was improved by employing the overlayer electrode configuration on a Ta-doped Fe-Sn AHE sensor. In noise measurements, the 1/f noise becomes significant with increasing the current at low frequency, resulting in saturation of the detectivity to 240 nTHz-1/2 at 120 Hz. At high frequency, the detectivity reaches 48 nTHz-1/2 at 3.1 mA showing ten times improvement of the detectivity compared with the non-doped Fe-Sn AHE sensor. Material design and device structure optimization will accelerate further improvement of the sensing properties of the Fe-Sn-based AHE sensor.

High Specific Energy Li7La3Zr2O12 Solid Electrolyte Based Thermal Battery

Garnet-type Ta-doped Li7La3Zr2O12 (LLZTO) solid electrolyte has been widely investigated for secondary Li ionic or metal batteries at ambient temperature. Because of the increasing ionic conductivity of LLZTO with temperature, we applied the LLZTO solid electrolyte to thermal battery working at 550℃. The LLZTO presents ultrahigh specific energy as the discharge specific energy and specific power is 605 W h/kg and 2.74 kW/kg at 100 mA/cm2 with a cut-off voltage of 1.8 V, respectively. This is larger than the LiF–LiCl-LiBr electrolyte which is commonly used in thermal battery with a specific energy of 514 W h/kg. The internal resistance of the single cell reaches 0.65 Ω, but the specific energy remains at about 400 W h/kg as the current density increases to 400 mA/cm2. We report the application of LLZTO in thermal battery with high specific energy, large current, and high voltage discharge for the first time, broadening the application range of solid electrolytes.

Heterostructure of core-shell IrCo@IrCoOx as efficient and stable catalysts for oxygen evolution reaction

Although researches on non-noble metal electrocatalysts have been made some progress recently, their performance in proton exchange membrane water electrolyzer (PEMWE) is still incomparable to that of noble-metal-based catalysts. Therefore, it is a more practical way to improve the utilization of precious metals in electrocatalysts for oxygen evolution reaction (OER) in the acidic medium. Herein, nanostructured IrCo@IrCoOx core-shell electrocatalysts composed of IrCo alloy core and IrCoOx shell were synthesized through a simple colloidally synthesis and calcination method. As expected, the hybrid IrCo-200 NPs with petal-like morphology show the best OER activities in acidic electrolytes. They deliver lower overpotential and better electrocatalytic kinetics than pristine IrCo alloy and commercial Ir/C, reaching a low overpotential (j = 10 mA/cm2) of 259 mV (vs. RHE) and a Tafel slope of 59 mV dec−1. The IrCo-200 NPs displayed robust durability with life time of about 55 h in acidic solution under a large current density of 50 mA/cm2. The enhanced electrocatalytic activity may be associated with the unique metal/amorphous metal oxide core-shell heterostructure, allowing the improved charge transferability. Moreover, the *OH-rich amorphous shell functions as the active site for OER and prevents the further dissolution of the metallic core and thus ensures high stability.

Simplified cascade multiphase DC-DC buck power converter for low voltage large current applications: part II --- output current controller

<span lang="EN-US">This paper proposes a control method for new simplified cascade multiphase direct current-direct current (DC-DC) buck power converters used for low-voltage large-current applications such as cathodic protection. To control the proposed converter, a proportional-integral (PI) controller is used to regulate the output current of the converter. The control scheme analysis is carried out by linearizing the small-signal model of the proposed converter to form the output current transfer functions. This transfer function will be analyzed by using phase and gain margin approach to obtain the control parameters (Kp, Ki, and Ti). Simulation and experiment results are included to show the validity of the proposed concept.</span>

Bias-induced reconstruction of hybrid interface states in magnetic molecular junctions

Based on first-principles calculations, the bias-induced evolution of hybrid interface states in π-conjugated tricene and insulating octane magnetic molecular junctions is investigated. Obvious bias-induced splitting and energy shift of the spin-resolved hybrid interface states are observed in the two junctions. The recombination of the shifted hybrid interface states from different interfaces makes the spin polarization around the Fermi energy strongly bias dependent. The transport calculations demonstrate that in the π-conjugated tricene junction, the bias-dependent hybrid interface states work efficiently for large current, current spin polarization, and distinct tunneling magnetoresistance. But in the insulating octane junction, the spin-dependent transport via the hybrid interface states is inhibited, which is only slightly disturbed by the bias. This work reveals the phenomenon of bias-induced reconstruction of hybrid interface states in molecular spinterface devices, and the underlying role of molecular conjugated orbitals in the transport ability of hybrid interface states.