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排序方式: 共有255条查询结果,搜索用时 296 毫秒
1.
The switchable optical properties of Pd-protected RCo2-type Ho0.6Mm0.4Co2 alloy thin films have been investigated in a KOH electrolyte. The reversible optical switching has been carried out simultaneously by measuring transmitted light through the thin film during electrochemical charging–discharging of hydrogen. The dependence of switching speed and cyclic durability of the film on the charging and discharging current density as well as concentration of KOH electrolyte has been studied. In addition, cyclic voltammetric measurements have been performed to examine the hydride formation and decomposition reactions. 相似文献
2.
Shalu Kataria Yogendra L. Verma Himani Gupta Shishir K. Singh Nitin Srivastava Ravindra Dhar 《Polymer-Plastics Technology and Engineering》2020,59(9):952-958
ABSTRACTNano-composite polymer gel electrolytes (NPGEs) based on polymer poly(vinylidene fluoride-co-hexafluoropropylene) PVdF-HFP, ionic liquid, 1-butyl-3- methylimidazolium bis(trifluoromethanesulfonyl)imide BMIMTFSI, Li-salt along with the addition of SiO2 nanoparticles have been synthesized and characterized by various techniques. Prepared NPGEs show high room temperature ionic conductivity (~10?3 S/cm) and have a wide electrochemical window (ECW) (~3.3–3.5 V). The galvanostatic charge/discharge profile was studied by sandwiching best performing NPGEs between a LiFePO4 cathode and lithium metal anode. The specific discharge capacity of the cell (Li/NPGE/LiFePO4) room temperature at 0.1C rate is found to be 138 mAh/g. 相似文献
3.
NaBiO3 crystal of high purity has been synthesized through chemical oxidization. The morphology and thermal stability of NaBiO3 were examined with scanning electron microscope (SEM) and thermogravimetry-differential scanning calorimetry (TG-DSC). The electrochemical properties of MnO2 electrodes with and without doping NaBiO3 were studied through galvanostatic charge/discharge and cyclic voltammetry. The results indicate that the MnO2 electrode doped with NaBiO3 possesses remarkably higher discharge voltage and capacity and better reversibility than the pure MnO2 electrode and Bi2O3 doping MnO2 electrode. 相似文献
4.
Mechanochemical synthesis of α-MnO2 was carried out with KMnO4 and Mn(CH3COO)2 in 1:1 mole ratio. The electrochemical performance of MnO2 electrode was investigated by cyclic voltammograms and alternating current impedance. The charge-discharge process of MnO2 supercapacitor in 6 mol/L KOH was studied within 1.2 V at 200 mA/g, suggesting that it displays double-layer capacibility in low potential scope and pseudo-capacitance properties in high potential scope. It is found that Mn3O4, an electrochemical inert, mainly forms in the initial 40 charge-discharge cycles. During cycling, the pseudo-capacitance properties disappear and the discharge curves are close to ideal ones, indicating double-layer capability. The maximum capacitance of MnO2 electrode is as high as 416 F/g, and retains 240 F/g after 200 cycles. The equivalent series resistance increases from 17 to 41Ω. 相似文献
5.
E.E Abd El Aal 《Corrosion Science》2003,45(4):759-775
The effect of Cl−, Br− and I− anions as aggressive agents on the anodic behaviour of nickel electrode in deaerated Na2B4O7 solutions have been investigated by galvanostatic polarization technique. Lower concentrations of the halide anions have no effect on the mechanism of nickel passivation. An increase in the halide anions concentration causes oscillation of the potential in the oxygen evolution region. This could be attributed to the destruction of the passivity by halide anions and repassivation of the film by anodic current and/or OH− anions. Higher aggressive anion concentrations cause breakdown of the passive film and initiated pitting corrosion. As the temperature increases, the breakdown potential is shifted towards the more negative direction. On the other hand, as the pH of the solution increases, the breakdown potential is shifted toward more positive direction, indicating increased protection of the passive film. The activation energy, , of the oxide film formation in the presence of Cl− anions was calculated and was found to be 21 kJ/mol. 相似文献
6.
针对电动汽车(electric vehicle,EV)时空转移随机性造成的电网波动问题,计及车主的性别差异、车主实时出行目的地不同和车辆双向行驶,提出了一种基于出行随机性双向出行链的EV充放电调度策略。考虑车主实际出行过程,建立EV双向出行链模型;考虑到男女车主出行过程中的性别差异,确定男女实时出行概率模型;以降低电网的波动为目标函数,考虑车主实时出行需求和EV实时荷电状态(state of change,SOC)建立调度模型,并依据所建立模型对EV进行充放电调度。在约280 m2的区域进行仿真分析,结果表明:双向出行链模型更接近用户实际出行规律,其调度策略能够在满足用户实际出行需求的同时,更好地抑制电网波动性。 相似文献
7.
8.
《Journal of the European Ceramic Society》2019,39(2-3):624-630
Single phase PbHfO3 antiferroelectric ceramics were prepared via rolling process. It is revealed that the rolling process can reduce the grain size and increase the bulk density, which lead to the enhanced breakdown strength up to 268 kV/cm versus 219 kV/cm of samples using the conventional solid-state method. As a result, high recoverable energy density of 7.6 J/cm3 with an efficiency of 80.8 % was achieved. Meanwhile, a large current density of 1381 A/cm2 and an ultrahigh peak power density up to 170 MW/cm3 were observed under 250 kV/cm. In addition, unique electrical polarization response characteristics at different electric fields and temperature-induced structural phase transitions were also investigated. The energy storage performance and charge-discharge properties of PbHfO3 were first studied in this communication and all the results indicate that PbHfO3 ceramic is a promising candidate for pulse power applications. 相似文献
9.
Jean-François Vanhumbeeck He Tian Dominique Schryvers Joris Proost 《Corrosion Science》2011,(4):1269-1277
The relationship between the microstructural and internal stress evolution during Ti anodising is discussed. Samples anodised galvanostatically to 12 V and 40 V, corresponding to different stages of the internal stress evolution, were examined by in-plane and cross-section transmission electron microscopy. Electron diffraction patterns have been complemented with stoichiometry data obtained from energy loss near edge structure spectra. The sample anodised to 40 V was observed to consist of two regions, with a crystallised inner region adjacent to the metal/oxide interface. Crystallisation of this region is associated with the presence of large compressive internal stresses which build up during anodising up to 12 V. 相似文献
10.