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Fe-based amorphous alloys are an eco-friendly alternative to Ni- and Co-based amorphous alloys, which are not sustainable. Herein, amorphous Fe–P alloys were electrodeposited from an eco-friendly aqueous electrolyte. The influence of bath temperature on the electrochemical behaviour during Fe–P alloy deposition was investigated using linear-sweep voltammetry, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry. The morphology, P content and phase structure were characterized via scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and differential scanning calorimetry. The electrochemical corrosion behaviour in 3.5 wt% NaCl solution was studied using potentiodynamic polarization curves and EIS spectra. The results showed that an increase in bath temperature leads to a positive shift in the inductive co-deposition potential and increases the reaction rate. At bath temperatures of 20–60°C, the P content in deposits varied in the range of 17.07–21.13 wt% and the phase structure was amorphous. Although the amorphous alloys lacked crystalline defects, the P content had a marginal effect on the corrosion properties, whereas the surface morphology significantly influenced the corrosion properties. The amorphous Fe–P alloys fabricated in this study exhibit superior corrosion properties to almost all electrodeposited amorphous alloys reported in the literature, demonstrating their potential for corrosion protection. [ABSTRACT FROM AUTHOR]

For clarifying the electrochemical deposition mechanism of corrosion-resistant aluminum coating on surface of cast iron , the aluminum coating was electrodeposited on cast iron surface in AlCl3-[EMIM]Cl ionic liquid, and the deposition electrode process and nucleation growth mechanism of aluminum electrochemical coating on surface of cast iron were studied by cyclic voltammetry and chronoamperometry. Subsequently, aluminum coating was prepared by constant current density electrodeposition, and the effect of the current density and deposited time on the corrosion resistance of cast iron deposited with aluminum coating was investigated by the AC impedance, polarization curve and salt spray test methods. Results showed that the precipitation overpotential of aluminum on the surface of cast iron was close to zero. The deposition was dominated by the mass transfer process, and the nucleation confirmed with three-dimensional instantaneous nucleation model. Comparing the cast iron sample, the self corrosion potential of the cast iron sample deposited aluminum coating shifted negatively, and the corrosion current also became smaller than that of cast iron. Moreover, the deposition current density was the decisive factor affecting the corrosion resistance of cast iron. With the increase of current density, the corrosion resistance of cast iron increased. The corrosion current value of the cast iron sample deposited aluminum coating under constant current density 30 mA/cm2 was lower one order than that of the cast iron substrate. The aluminum coating deposited for 20 min possessed small crystal grains and excellent corrosion resistance.

The electrochemically mediated amine regeneration (EMAR) for CO 2 capture presents a promising CO 2 capture approach. However, there is a lack of systematic research on the EMAR electrode process, particularly regarding the diffusion of Cu2+ and [Cu-Am]2+, the characteristics of electrode reactions, and the impact of desorbed CO 2 bubbles on electrode process. In this work, we investigated the Cu-EDA based EMAR process by the combination of electrochemical measurements and multi-physics simulation. The experimental results revealed that the anode process is controlled by both mass transfer and charge transfer process, while the mass transfer process in the cathode process is the rate-controlling step. A lower anode copper loading and a higher cathode copper loading are conducive to the EMAR process. A reasonable simplification method for the electrode process was proposed by referencing the equilibrium reactive model results of Cu(II)–EDA–CO 2 –H 2 O system. A multi-physics model was constructed using COMSOL software, which coupled the Tertiary Nernst-Planck model and the Bubbly Flow model to simulate the complex electrode process and its effectiveness has been verified. Simulation results show that the formation of CO 2 bubbles has a negative impact on the electrode process, while the disturbance caused by the bubbles may have a certain promotion effect on the electrode process. The CO 2 desorption and the desorption rate is greatly affected by the the applied potential, and the desorption energy consumption mainly keeps a linear relationship with the applied potential. This work supposes to provide an effective guidance for the improvement of the vital electrodes process of the EMAR system. [Display omitted] • Combined experimental and computational method is used to study electrode process. • A chemistry equilibrium model of Cu(II)–EDA–CO 2 –H 2 O was developed. • A model simplification method for the complex electrode process is proposed. • A multi-physics model for the EMAR system is implemented in COMSOL. [ABSTRACT FROM AUTHOR]

LiFePO/C was prepared via solid state reaction and characterized with X-ray powder diffraction and charge-discharge test. As-prepared LiFePO/C has a triphylite structure and exhibits an excellent rate capability and capacity retention. Electrochemical impedance spectroscopy (EIS) was applied to investigate LiFePO/C (0< x<1) electrode on temperature variation. The valid equivalent circuit for EIS fitting was determined which contains an intercalation capacitance for Li+ ion accumulation and consumption in the electrode reaction. The surface layer impedance needs to be included in the equivalent circuit when LiFePO/C is deeply delithiated at a relatively high temperature. EIS examination indicates that a temperature rise leads to a better reversibility, lower charge transfer resistance, higher exchange current density J0 and greater Li+ ion diffusion coefficient for the LiFePO/C electrode process. The Li ion concentration in LiFePO/C is potential to impact the Li ion diffusion coefficient, and a decrease in the former results in an increase in the latter. [ABSTRACT FROM AUTHOR]

LiNiCoMnO nanocrystallites were synthesized by a one-step hydrothermal method, and uniform second particles were formed by a subsequent calcination process. X-ray diffraction results indicate that the as-synthesized material can be indexed by α-NaFeO layered structure with R-3 m space group. The results of Rietveld refinements show the I/ I value of the material is 2.032, and the nanostructured material presents low cation mixing, small cell volume, and a consequent suppression of lattice strain. The rate performances of the as-synthesized material can be further improved by coating AlO. The discharging capacity of AlO-coated material reaches 154.4 mAh g, and the capacity retention maintains 80.3 % after 50 cycles at 5 C in the voltage range of 2.5 to 4.5 V, while those of the bare one is only 139.0 mAh g and 71.6 %, respectively. The transmission electron microcopy observation shows no zigzag layer exists on the surface of particle after cycles for AlO-coated LiNiCoMnO. Compared to bare LiNiCoMnO, the de-intercalation potential difference before and after cycles of AlO-coated one is smaller. This indicates that AlO coating can reduce the electrochemistry polarization in the electrode bulk. [ABSTRACT FROM AUTHOR]

Abstract: The robustness of conductive networks and the accessibility of electrolyte into the network are important factors in designing the cathode electrode for lithium/sulfur (Li/S) batteries containing liquid electrolytes that involve liquid phase electrochemical reactions. We show that the performance of Li/S cells can be significantly improved by simply optimizing the electrode processing conditions to have open pore structures and mechanical integrity of the electrode architecture. It is demonstrated that the capacity of 1000 mAh g−1 at 0.1 C and the stable capacity retention of >700 mAh g−1 after 200 cycles at 0.5 C can be achieved with relatively high sulfur content of 68%. 417 Wh kg−1 in specific energy and 623 Wh l−1 in energy density are achievable with this new technology. [Copyright &y& Elsevier]

Using the method of cyclic voltammetry, the electrode process of Ni, Pb, Cu and pyrocatechin on a poly(o-aminophenol) (PoAP) modified glassy carbon electrode (GCE) was investigated. The PoAP polymer was found to affect the redox process of copper and pyrocatechin. The use of polymer of different thicknesses showed that the obtained film has a dense, nonporous structure. The redox process of the examined substances may be considered as proceeding on the polymer surface. The PoAP polymer obtained in the described conditions takes part in charge transfer. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]