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Given the global demand for green energy, the battery industry is positioned to be an important future technology. Lithium-ion batteries (LIBs), which are the most widely used battery in the market, are the focus of various research and development efforts, from materials to systems, that seek to improve their performance. The separator is one of the core materials in LIBs and is a significant factor in the lifespan of high-performance batteries. To improve the performance of present LIBs, electrochemical testing and related surface analyses of the separator is essential. In this paper, we prepared a ceramic (Boehmite, γ-AlOOH) coated polypropylene separator and a porous polyimide separator to compare their electrochemical properties with a commercialized polypropylene (PP) separator. The prepared separators were assembled into nickelmanganese-cobalt (NMC) cathode half-cell and full-cell lithium-ion batteries. Their cycling performances were evaluated using differential capacity and electrochemical impedance spectroscopy with ethylene carbonate:dimethylcarbonate (EC:DMC) electrolyte. The ceramic coated polypropylene separator exhibited the best cycle performance at a high 5 C rate, with high ionic conductivity and less resistive solid electrolyte interphase. Also, it was confirmed that a separator solid electrolyte interface (SSEI) layer formed on the separator with cycle repetition, and it was also confirmed that this phenomenon determined the cycle life of the battery depending on the electrolyte.

Developing high-performing oxygen evolution reaction (OER) electrocatalysts under high-current operation conditions is critical for future commercial applications of alkaline water electrolysis for clean energy generation. Herein, we prepared a three-dimensional (3D) bimetallic oxyhydroxide hybrid grown on a Ni foam (NiFeOOH/NF) prepared by immersing Ni foam (NF) into Fe(NO3)3 solution. In this unique 3D structure, the NiFeOOH/NF hybrid was composed of crystalline Ni(OH)2 and amorphous FeOOH evenly grown on the NF surface. As a bimetallic oxyhydroxide electrocatalyst, the NiFeOOH/NF hybrid exhibited excellent catalytic activity, surpassing not only the other reported Ni–Fe based electrocatalysts, but also the commercial Ir/C catalyst. In situ electrochemical Raman spectroscopy demonstrated the active FeOOH and NiOOH phases involved in the OER process. Profiting from the synergy of Fe and Ni catalytic sites, the NiFeOOH/NF hybrid delivered an outstanding OER performance under challenging industrial conditions in a 10.0 mol∙L−1 KOH electrolyte at 80 °C, requiring potentials as small as 1.47 and 1.51 V to achieve the super-high catalytic current densities of 100 and 500 mA∙cm−2, respectively.

We have been developing a no-insulation (NI) coil technology to achieve high thermal stability and high current density. NI coils can continue to operate even if a part of the coils degrades; however, a charging delay occurs in the coils. Moreover, the turn-to-turn contact electrical resistance of the NI coils must be increased to shorten the charging delay; however, a large turn-to-turn contact electrical resistance reduces thermal stability. In this study, using turn-to-turn contact electrical resistance and IOP / IC ratios as parameters, we analyze thermal stability and consider the possibility that NI coils can continue to operate even if they have local defects. Furthermore, to establish an evaluation criterion for determining turn-to-turn contact electrical resistance that can shorten charging delay and ensure high thermal stability, we analyze and evaluate the relationship between turn-to-turn contact electrical resistance and thermal stability, focusing on three types of heat generation.

In this study, we studied the surface and mechanical properties of multiple additives as well as the initial plating properties of individual additives. With the individual additive groups, copper crystals tended to converge at a stage above the critical amount of additive. When chloride ions were added, large crystals formed at several places on the surface. Thereafter, small crystals were attached to and grew on the surface of the large crystals. When collagen and JGB (Janes Green B) were added individually, the crystals were more uniformly distributed on the surface as compared with the group with added chloride ions. In addition, starlike crystals were grown depending on the amount of addition. It was necessary to use multiple additives, which is why it is difficult to make a uniform surface layer with individual additives. Large crystals of more than 10 μm formed unevenly on the surface treated with multiple additives of chloride ions and MPSA (3-mercapto-1-propane sulfonic acid). Large crystals disappeared on the surface treated with additional collagen along with multiple additives. However, valley like shapes were observed on this surface, due to the large crystals. But, addition of JGB additives to this reduced the valley and formed a uniform plating layer. MPSA and 20 ppm of collagen were added as multiple additives, grain sizes increased by 93.5% (220 peak) and 172.3% (311 peak) compared with the non-additive group. As a result, tensile strength decreased by 24.5% and elongation increased by 17.8%. The crystal size was reduced 25.0% on average by the addition of 10 ppm JGB, which contributed to a 5.4% increase in tensile strength and a 16.0% decrease in elongation. The grain size and surface properties could be controlled by adding multiple combinations of additives. As a result, It was confirmed that mechanical properties could be controlled by the proper amount and the optimum combination of additives.

Development of practical rechargeable Mg batteries (RMBs) is impeded by their limited cycle life and rate performance of cathodes. As demonstrated herein, a copper‐porphyrin with meso‐functionalized ethynyl groups is capable of reversible two‐ and four‐electron storage at an extremely fast rate (tested up to 53 C). The reversible four‐electron redox process with cationic‐anionic contributions resulted in a specific discharge capacity of 155 mAh g−1 at the high current density of 1000 mA g−1. Even at 4000 mA g−1, it still delivered >70 mAh g−1 after 500 cycles, corresponding to an energy density of >92 Wh kg−1 at a high power of >5100 W kg−1. The ability to provide such high‐rate performance and long‐life opens the way to the development of practical cathodes for multivalent metal batteries., Self‐conditioning: The metalloporphyrin based electrodes exhibit reversible insertion/deinsertion of Mg2+ and bulky anions as well as excellent capacity retention over several hundred cycles at very fast charge‐discharge rates. This opens the pathway for development of new organic electrode materials for stable high‐energy and high‐power multivalent metal‐based energy storage systems.

Sn-based perovskite solar cells have attracted much attention as the lead-free next generation of perovskite solar cells. However, their efficiency is still low (∼12%). One reason is that the carri...

It is shown that it is possible to obtain nanostructured layers with an increased thickness (up to 2 mm), suitable for the repair of worn surfaces of component parts made of aluminum alloys during electrospark alloying of the surface of the aluminum alloy (D1) by the processing electrode of an Al–Sn alloy (20% Sn) with the use of the high current density and two-phase technology for producing a multilayer coating (applying–melting).

In the present study, we report a simple method to prepare indium(III) selenide (In2Se3) nanocubes synthesized by laser ablation in aqueous medium. The morphological characterization carried out us...

Transition-metal (oxy)hydroxides with an abundance of redox metal sites are important for the development of electrochromic devices, rechargeable metal–air batteries, pseudo-capacitors, and industr...

Organic light-emitting diodes (OLEDs) are promising candidates for solid-state lighting but suffer from decreased efficiency at the high current density required for lighting applications. This dec...

Three-dimensional (3D) current collectors have shown great potential in realizing dendrite-free lithium (Li) metal anodes. However, the rigid 3D current collectors could not simultaneously suppress Li dendrite growth and allow Li plating/stripping under high capacities and large current densities. Here, we report a dynamic intelligent Cu (DICu) current collector that dynamically accommodates the volume change by changing the packing density of the assembled particles. The Li/DICu electrode achieves a high Coulombic efficiency of 99.6% after 800 cycles. The symmetrical cell shows exceptional cycling stability under the high current density of 10 mA cm-2. Notably, when assembled in full-cell batteries, the Li/DICu|LiFePO4 battery maintains a specific capacity of 139.5 mAh g-1 at 1 C for 500 cycles, and the Li/DICu|S battery delivers a specific capacity of 804 mAh g-1 after 500 cycles at 0.5 C, corresponding to the best performance among Li metal batteries with Cu-based current collectors to date.

SmTiO3/SrTiO3 interfaces are of potential interest for electronic devices as they exhibit novel electronic phenomena such as metal–insulator transitions. However, good transistor performance from t...

Although recent studies on the oxygen evolution reaction (OER) have achieved great progress, it remains a great challenge to achieve a smaller overpotential at high current density. In order to further improve the performance of the OER, we adopted a novel method to load Fe nanoparticles on a Ni3S2 nanoplate array grown on nickel foam (Fe NPs-Ni3S2 NA/NF) which formed an amorphous structure. In particular, this catalyst exhibited an overpotential of 206 mV at 150 mA cm−2, outmatching most non-noble OER catalysts reported so far; it also operates smoothly in various stability tests.

Electrochemical water splitting technology for producing "green hydrogen" is important for the global mission of carbon neutrality. Electrocatalysts with decent performance at high current densities play a central role in the industrial implementation of this technology. This field has advanced immensely in recent years, as witnessed by many types of catalysts designed and synthesized toward industrially-relevant current densities (> 200 mA cm-2 ). By discussing recent advances in this field, we summarize several key aspects that affect the catalytic performance for high-current-density electrocatalysis, including dimensionality of catalysts, surface chemistry, electron transport path, morphology, and catalyst-electrolyte interplay. We highlight the multiscale design strategy that considers these aspects comprehensively for developing high-current-density electrocatalysts. We also put forward our perspectives on the future directions in this emerging field. This article is protected by copyright. All rights reserved.

Highly selective electrochemical reduction of CO2 (CO2RR) to multi-carbon (C2+) products at high current density remains a big challenge. Herein we report copper oxide nanosheets (CuO-st) for selective electrochemical conversion of CO2 to C2+ products at high current density. Benefiting from the defect-rich structure verified by HR-TEM and XPS characterization and the designed gas diffusion electrode, such a CuO-st material exhibits CO2RR FE (C2+) of 86 and 80 % at 1.0 and 1.8 A cm−2, respectively, with excellent durability of 50 h @ 500mAcm−2 and storable lifetime for >10 months. Importantly, using quasi-situ XPS and in-situ Roman spectra, we have shown the first evidence for the presence of Cu (ǀ) during the eCO2RR on initial Cu (ǁ) material, and the proportion of Cu (ǀ) varies with the reaction current density. The rough and defective surface of CuO-st serves as a favorable reservoir to produce enough Cu (ǀ) to assist the C-C coupling, thus achieving selective CO2RR to C2+ products at high current density. Our study not only provides a new insight into CO2RR, but also suggests that in-situ forming active species from stable Cu (ǁ) materials during the reaction may be a good choice for the practical application, which will be very helpful to the development of cost-effective CO2RR electrocatalysts.

CuO nanorods were synthesized on copper foil substrate through wet chemical approach. The effect of growth time on the field electron emission properties of CuO nanorods was studied. The field electron emission tests were performed under AC bias on the CuO nanorod (CuO NR) samples. The growth reaction time was varied between 1, 3, 7 and 11 h. It was observed that CuO NR sample which was processed for 11 h demonstrates the optimum properties such as lowest turn on field (0.56 V/µm), high current density (1.52 mA/cm2) at low electrical field (9 V/µm), good field enhancement factor and excellent stability of emitters for extended working hours which makes it suitable for applications field emission devices.

Chromium plating has excellent corrosion resistance and is widely used in industry. However, it also has a high environmental load. As an alternative, electric Ni-W plating is attracting attention. However, it is not widely used because the stress is high and the film is prone to cracks. Furthermore, although it is necessary to thicken the film to improve the corrosion resistance, there are also problems that the current efficiency is low and the plating time is long. Therefore, we investigate a film with high corrosion resistance by using the jet-flow plating method that enables plating at a high current density. Our results show that the jet-flow plating enables plating of 50 µm, and high corrosion resistance is obtained by randomly generating fine cracks in the film at 20 A·dm−2. We also found that the stress changed depending on the current density and shape of the crack also changed.

В работе методами растровой электронной микроскопии и ультрамягкойрентгеновской эмиссионной спектроскопии были проведены исследования особенностейформирования многослойных структур пористого кремния и установлено влияние изменения плотности тока при электрохимическом травлении монокристаллических пластин кремния на фазовый состав поверхностных слоев сформированной пористой структуры. ЛИТЕРАТУРА1. Moshnikov V., Gracheva I., Lenshin A., Spivak Yu. Porous silicon with embedded metal oxides for gassensing applications // Journal of Non-Crystalline Solids, 2012 v. 358(3), pp. 590–595. DOI: https://doi.org/10.1016/j.jnoncrysol.2011.10.0172. Pacholski C. Photonic crystal sensors based on porous silicon // Sensors, 2013, v. 13(4), pp. 4694–4713.DOI: https://doi.org/10.3390/s1304046943. Harraz F. Porous silicon chemical sensors and biosensors: A review // Sensors and Actuators B, 2014,v. 202, pp. 897–912. DOI: https://doi.org/10.1016/j.snb.2014.06.0484. 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The electrochemical CO2 reduction reaction (CO2RR) towards CO allows to turn CO2 and renewable energy into feedstock for the chemical industry. Previously shown electrolyzers are capable of continuous operation for more than 1000 h at high faradaic efficiencies and industrially relevant current densities. However, the crossover of educt CO2 into the anode gas has not been investigated in current cell designs: Carbonates (HCO3 − and CO3 2−) are formed at the cathode during CO2RR and are subsequently neutralized at the anode. Thus, CO2 mixes into the anodically evolved O2, which is undesired from commercial perspectives. In this work this chemical transport was suppressed by using a carbonate-free electrolyte. However, a second transport mechanism via physically dissolved gases became apparent. A transport model based on chemical and physical absorption of CO2 and O2 will be proposed and two solutions were experimentally investigated: the use of an anode GDL (A-GDL) and degassing the anolyte with a membrane contactor (MC). Both solutions further reduce the CO2 crossover to the anode below 0.1 CO2 for each cathodically formed CO while still operating at industrially relevant current densities of 200 mA/cm2.

A promising electrode material for energy storage, the SnS2/g-C3N4 composite is reported, which is prepared by a simple hydrothermal route. The SnS2/g-C3N4 composite shows a good specific capacitance of 552 F g−1 at the current density of 0.5 A g−1 in 3 M KOH, and also exhibits excellent cycling stability of 95.8% capacitance retention after 15000 cycles even at a relatively high current density of 10 A g−1. The SnS2/g-C3N4 composite is proved to be a promising candidate for the electrode materials in supercapacitor applications.

In this article, the design approach for a miniaturized high-current-density sheet electron beam (SEB) source has been reported. A study through simulation using COMSOL Multiphysics has been carried out to analyze the role of geometrical parameters of the hollow cathode in miniaturized SEB generation. These geometrical parameters play a very important role in defining the discharge inside the hollow cathode geometry and subsequent beam generation through a rectangular aperture. The hollow cathode diameter “D”, the length of the hollow cathode “L”, and the aspect ratio of the sheet beam defined by the aperture size in front of the hollow cathode region have been optimized for the generation of a SEB. The ratio of the length to the width of the rectangular aperture defines the aspect ratio of the SEB. It has been found that the beam aspect ratio plays an important role in the penetration of the accelerating field inside the hollow cathode geometry, which affects the transient behavior of the discharge. The hollow cathode dimensions have been optimized for the applied gap voltage varying between 15 and 25 kV, while the beam aspect ratio has been analyzed for the range between 5:1 and 12:1 keeping the fill factor constant.

Mechanisms and characteristics of optimized main junction for 4H-SiC trench junction barrier Schottky (TMJBS) diodes were investigated by theories and experiments. From these simulation and experimental values, we can conclude that TMJBS device has better reverse performance, such as the best reverse blocking capability and lowest reverse surface leakage current than the conventional JBS and TJBS device while maintaining good forward characteristics. Furthermore, The large area TMJBS Diodes with high current density show the better reverse characteristics than the small area one at an acceptable forward characteristics. The TMJBS structure can significantly reduce the influence of the Schottky interface and is more suitable for manufacturing high current density and large area devices.

We developed a silicon carbide (SiC) power module that can switch large currents at high speed. The withstand voltage of this power module is 1200 V, and two SiC MOSFETs are built-in and constitute a circuit for one inverter phase. This power module incorporates a snubber circuit for reducing the surge voltage generated by the SiC MOSFET for high-speed switching. In this study, switching at 270 A (a current density of 1000 A/cm 2 or more for the SiC MOSFET) was performed to evaluate this module. The turn-off switching time tf was ~10 ns, and the maximum dv/dt was 80 kV/us. Furthermore, this research examines the design and performance of the proposed power module.

There are increasing interests in fabricating Fe2O3 anode materials in recent years owing to their high theoretical capacity and natural abundance. However, Fe2O3 anode materials encounter great challenges in association with their intrinsic poor electronic conductivity and drastic volume variation during cycling. Herein, rod-like Fe2O3 is prepared through a simple thermal decomposition method. When evaluated as anode material for LIBs, the rod-like Fe2O3 exhibits excellent rate capability (∼400 mAh g−1 capacity even at high current density of 7 A g−1). Furthermore, high reversible capacity of ∼500 mAh g−1 can be retained at 3 A g−1 after 1000 cycles. This work demonstrates that the thermal decomposition method is facile and efficient for the preparation of high-performance Fe2O3 anode materials for LIBs.

Carbon corrosion in catalysts is one of the main limitations of proton exchange membrane fuel cell (PEMFC) lifetime. Water flooding can accelerate the carbon corrosion rate in PEMFCs, especially at high current densities. Increasing the operation temperature can effectively mitigate water flooding and improve the water management performance of PEMFCs. However, elevated temperatures also increase the carbon corrosion reaction kinetics, accelerating the degradation of PEMFCs lifetime. To study the effects of temperature on carbon corrosion at high current densities, PEMFCs operating for 100 h at 65 °C and 90 °C under 1600 mA·cm−2 were investigated. The results showed that the electrochemical active surface area (ECSA) of the cathode catalyst layer decreased by 9.16% and 13.92% at 65 °C and 90 °C, respectively. The reduction rate of the catalyst layer in the nonflooding area increased as the operating temperature increased. However, the reduction rate decreased by 69.82% and 54.04% at 65 °C and 90 °C, respectively, at the outlet of the PEMFC. Therefore, water flooding is the key issue causing lifetime degradation, and water management is essential for PEMFCs that operate at high current densities, especially at the outlet of PEMFCs.

Ferroelectric tunnel junction (FTJ) with ultrathin 3 nm-thick Hf 0.5 Zr 0.5 O 2 (HZO) is investigated. The high current density up to 100 A/cm2 is at least 10 times higher than that in previously reported HZO FTJs. It is suitable for future nanoscale FTJ with a GΩ cell resistance for the application of in-memory computing. The insertion of a thin Al 2 O 3 interfacial layer is found critical to alter the switching polarity and increase current density.

Highlights N-doped graphene-coated structure and mesoporous nano-sheet can efficiently boost active sites and stability for hydrogen and oxygen evolution reaction.NiCo@C-NiCoMoO/NF exhibits low overpotentials for HER (266 mV) and OER (390 mV) at ± 1000 mA cm−2.For water electrolysis, it can hold at 1000 mA cm−2 for 43 h in 6.0 M KOH + 60 °C condition. Supplementary Information The online version contains supplementary material available at 10.1007/s40820-021-00607-5., Developing highly effective and stable non-noble metal-based bifunctional catalyst working at high current density is an urgent issue for water electrolysis (WE). Herein, we prepare the N-doped graphene-decorated NiCo alloy coupled with mesoporous NiCoMoO nano-sheet grown on 3D nickel foam (NiCo@C-NiCoMoO/NF) for water splitting. NiCo@C-NiCoMoO/NF exhibits outstanding activity with low overpotentials for hydrogen and oxygen evolution reaction (HER: 39/266 mV; OER: 260/390 mV) at ± 10 and ± 1000 mA cm−2. More importantly, in 6.0 M KOH solution at 60 °C for WE, it only requires 1.90 V to reach 1000 mA cm−2 and shows excellent stability for 43 h, exhibiting the potential for actual application. The good performance can be assigned to N-doped graphene-decorated NiCo alloy and mesoporous NiCoMoO nano-sheet, which not only increase the intrinsic activity and expose abundant catalytic activity sites, but also enhance its chemical and mechanical stability. This work thus could provide a promising material for industrial hydrogen production. Supplementary Information The online version contains supplementary material available at 10.1007/s40820-021-00607-5.

Electrochemical alcohols oxidation offers a promising approach to produce industrial-relevant chemicals and facilitate coupled H 2 production. However, the corresponding current density is very low at moderate cell potential that substantially limits the overall productivity. Here, we report enrichment of alcohols in local environment over a cooperative catalyst of Au nanoparticles supported on cobalt oxyhydroxide nanosheets (Au/CoOOH), enabling alcohols electrooxidation at high current density. Specifically, the current density of benzyl alcohol electrooxidation can reach 523 mA cm− 2 at potential of 1.5 V vs. RHE. Experimental and theoretical results suggest that benzyl alcohol molecules are enriched on Au/CoOOH interface via strong d-π interaction. The enrichment has a broad substrate scope that involves alcohols with α-π bond including α-phenyl, C = C and C = O groups. Based on these findings, we design an intermittent potential (IP) strategy for long-term alcohol enrichment, achieving electrooxidation with current density of > 250 mA cm− 2 over 24 hours and promoted productivity.

Micro bumps, through Si vias (TSV), and redistribution layers (RDL) or back-end-of-line (BEOL) layers that connected to the TSV are unique interconnects connecting the stacked Si dies in 3D packaging. Electromigration (EM) failure has been a concern for these interconnects due to high current density and joule heating. In this chapter, the key EM failure modes in these interconnects are summarized. By leveraging the EM learning from flip chip first-level interconnect solder joints and damascene Cu interconnects, failure mechanisms and factors that modulate the EM of micro bumps, TSV, and its connected Cu layers are also summarized. The impact of the unique micro bump dimensions and structures on EM will be highlighted.

Lithium-sulfur battery is one of the most promising next-generation energy storage devices due to its low cost and ultrahigh energy density. However, the uncontrolled formation of Li dendrites and shuttle effect seriously hinder its practical applications. To simultaneously address both fatal issues, herein, for the first time, we present a novel Mo2C quantum dots (MQDs) anchored N-doped graphene functionalized interlayers (MQD@NG). The DFT calculations show that lithiophilic feature of Mo2C QDs, which can construct a fast electrolyte diffusion pathway for Li+ transportation and achieve uniform Li deposition. Moreover, the polar Mo2C QDs possess strong chemical adsorption of polysulfides. As a result, the lithium symmetric cells with MQD@NG interlayers achieve a dendrite-free lithium deposition over 1600 h at a high current density of 10 mA cm−2. The Li-S cells exhibit a high capacity of 1230 mAh g−1 at 0.2 C and a highly stable cycling performance over 400 cycles without obvious capacity fading. This work provides a new insight to design and fabricate high-energy and safe Li-metal-based batteries.

Dynamic Avalanche (DA) effects in the Super-Junction Trench IGBTs are analyzed through 3-D TCAD simulations for the first time. A DA free solution for high power density and low loss is proposed and demonstrated in detail. Furthermore, simulation results show that DA results in significant increase in turn-off losses in the Super-Junction Trench IGBTs at high current density operations, which poses a fundamental limit on the power density of IGBT applications. In contrast, the Super-Junction Trench Clustered IGBTs remain DA free at high current density and show low switching losses due to enhanced PMOS action. Therefore, the Super-Junction Trench IGBTs are well suitable for high power density operations with a potential to operate beyond the 1-D unipolar 4H-SiC limit.

The high degree of order in organic single crystals often leads to optimum charge transport properties and their robustness under high current density which is attractive for solid state lighting and laser technology. However, conventional method of single crystal growth based on physical vapour transport is unsuitable for device integration and large area applications. Here, we present a vacuum processed approach to prepare organic single crystals on inch sized substrates and integrate them into organic light emitting devices (OLED). The device performance are characterized in comparison to standard OLED based on amorphous materials.

Alkaline water electrolysis is a cost-effective approach to hydrogen production, but it suffers from low operational current densities (typically ⤠500 mA cm-2) and thereby a low hydrogen production rate. Herein, we report the fabrication of self-supported porous cobalt phosphide (Co-P) foam by electrochemical anodization of commercially available cobalt foam, followed by thermal oxidation and subsequent phosphorization. The as-obtained porous Co-P foam, compared to other control samples prepared under different conditions, shows outstanding electrocatalytic performance in alkaline electrolyte for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), requiring an overpotential of 290 mV for HER and 380 mV for OER, respectively, at a high current density of 1000 mA cm-2. Moreover, the electrolyzer consisting of two symmetric porous Co-P foam electrodes only requires a cell voltage of 1.98 V to operate at 1000 mA cm-2 for overall water electrolysis, with extraordinary stability of 4000 h, showing great potential for use in industrial alkaline water electrolysis., L. Liu acknowledges the financial support of Fundação para a Ciência e a Tecnologia (FCT, Portugal) Exploratory Grant (IF/01595/2014/CP1247/CT0001) and I.C.N. thanks to project BioTecNorte (operation NORTE-01-0145-FEDER-000004) and Centre of Chemistry, University of Minho (UID/QUI/00686/2013 and UID/QUI/0686/2016). Z. P. Yu acknowledges the financial support of China Scholarship Council (Grant No. 201806150015)., info:eu-repo/semantics/publishedVersion

One of the major problems with phase change memory (PCM) is the high current density required for the crystal–amorphous transformation via a melt-quench process. However, alternative low-energy pat...

HTS CrossConductor is a compact stacked-tape REBCO conductor of high current density. In this contribution, a non-concentric three-phase cable design based on HTS CroCos is presented, which offers the possibility to reduce the cable diameter significantly. One of the important aspects of HTS-AC power cables are the AC-losses, which are investigated both theoretically and experimentally. For the measurement of the dissipated power loss in both single-phase and three-phase conductor arrangements, a calorimetric method is used. The results indicate that it is possible to reduce the outer cable diameter compared to concentric cables designs by a factor of two. When the losses of such a cable with HTS CroCo design shall not exceed 2 W/m for all three-phases, the maximum ampacity results in a current of 600 A(rms) per phase. Depending of the target there are many potential applications for such an ultra-compact HTS CroCo-based power transmission cable design.

A series of 1,2,4-thiadiazole core-based bipolar materials, 2,2′-(1,2,4-thiadiazole-3,5-diyl)bis(N,N-diphenylaniline) (o-TPATHZ), 3,3′-(1,2,4-thiadiazole-3,5-diyl)bis(N,N-diphenylaniline) (m-TPATHZ) and 4,4′-(1,2,4-thiadiazole-3,5-diyl)bis(N,N-diphenylaniline) (p-TPATHZ) were developed as the host matrixes for the deep red phosphorescent emitters tris(1-phenylisoqiunoline) iridium (Ir(piq)3) and [bis(2-methyldibenzo-[f,h]-quinoxaline) Ir(III)(acetylacetonate)] (Ir(MDQ)2(acac)). By systematic studying, we demonstrated that there are two types of charge-trapping effect within the emissive layers through adjusting the host-guest compatibility. And, it is revealed that a symmetric charge-trapping effect can contribute to realizing a stable charge-balance, which led to a mitigating efficiency roll-off at high current density. Consequently, a maximum external quantum efficiency (EQE) of 16.2% was achieved by an optimized device with p-TPATHZ-Ir(piq)3 emissive layer. Remarkably, the EQE still remained as high as 15.7% at the high luminance of 1000 cd/m2.

Carbon coated SnO2 hollow nanocubes were synthesized by a facile hydrothermal route. The sample with large surface area exhibits a hollow cube particle shape with an average length of ~400–500 nm. It is found that the SnO2@C−HNC shows a high discharge capacity of 799.1 mA h g−1 with the first cycle coulombic efficiency of 53.4% at the current density of 100 mA h g–1. At the high current density of 2 A g–1, it can still deliver a discharge capacity of 203.1 mA h g–1. The SnO2@C−HNC composite exhibits a good rate capability and stable cycling performance, indicating potential available as large-scale storage device.

Ti3C2(OH)2 coated nickel-rich LiNi0.6Co0.2Mn0.2O2 cathode material is prepared with wet coating process. The effects of the Ti3C2(OH)2 concentration on the structure and electrochemical performance of LiNi0.6Co0.2Mn0.2O2cathode materials are investigated. The microanalyses show that Ti3C2(OH)2 is successfully coated on the surface of LiNi0.6Co0.2Mn0.2O2 cathode material. All cathode materials display the excellent hexagonal ordering and the low ratio of I(006+102)/I(101). Furthermore, the Ti3C2(OH)2 coated cathode materials presents excellent cycling capability and rate capability. Among them, the 3.0 wt.% Ti3C2(OH)2 coated LiNi0.6Co0.2Mn0.2O2 displays the highest discharge capacity of 124.5 mAh/g with the capacity retention of 86.4% after 200 cycles at 0.5 C, and the best rate performance at high current density. So Ti3C2(OH)2 coating is good promising material for LiNi0.6Co0.2Mn0.2O2 to improve the long-life and rate capability.

Summary Although the Li-metal anode holds the key to overcoming the bottleneck of current Li-ion rechargeable batteries, the trade-off between safety and practicality, especially at high current densities, is a major barrier because of the formation of hazardous Li dendrites arising from inhomogeneous Li electrodeposition. Herein we demonstrate the feasibility of achieving homogeneous Li electrodeposition by implementing porous metal-organic framework (MOF) species in pristine liquid electrolyte. The MOF host provides considerable natural angstrom-level pores that preferentially control the migration of large-sized anions. Consequently, the “caged” electrolyte anions facilitate a homogeneous Li-ion flux, which illustrates a stable Li-metal plating/stripping at a practically high current density (10 mA cm−2). As a proof of concept, the high areal-loading Li-Li4Ti5O12 batteries (∼10 mg cm−2) with the MOF-modified electrolyte deliver excellent long-life cycling at high current densities (∼7 mA cm−2). Our results underline the great potential of MOFs in tuning the electrolyte properties to achieve desirable Li-metal battery performance.