Journal of Solid State Electrochemistry最新文献

This paper presents the preparation and performance evaluation of two closed-loop nickel-based catalysts. The (hydro)oxide coatings of nickel-molybdenum and nickel-iron were electrodeposited onto industrial nickel meshes, which were subsequently used as the cathode and anode (NiMo@NM and NiFe@NM) in alkaline water electrolysis. Both catalysts formed a fully closed-loop configuration, surrounding each nickel wire on the nickel mesh, thereby enhancing the bonding strength with the substrate. The NiMo@NM||NiFe@NM assembly achieved a current density of 200 mA cm⁻² at a cell voltage of only 1.91 V and room temperature, maintaining this level of performance for over 280 h. A single-stack flow cell was used to examine the changes in cell voltage in relation to temperature, current density, and electrolyte flow rate and concentration. The specific energy consumption for hydrogen production can be reduced to 4.1 kWh Nm⁻³ (H₂) under near-industrial conditions (70 °C, 6 M KOH, 400 mA cm⁻²). We hope that this study can help bridge the gap between catalyst studies and practical industrial applications.

The advanced soft magnetic material Fe-Co-Si ternary alloy has become a research hotspot in recent years due to its excellent balanced magnetic properties. When used in an environment where oceans and magnetic fields interact, the corrosion behavior of this alloy is currently not well understood. In this study, immersion experiments and electrochemical tests have been used to explore its corrosion behavior under conditions of no magnetic field, a uniform parallel magnetic field, and a vertical magnetic field with a magnetic field. The results indicate that the presence of a magnetic field accelerates corrosion while suppressing pitting and intergranular corrosion of the alloy. Moreover, compared to the perpendicular magnetic field, the impact is more pronounced when applying a parallel magnetic field due to the synergistic effect of Lorentz force and magnetic field gradient force. Additionally, the presence of Si elements affects the formation of Co oxide passivation film, which reduced the corrosion resistance of the alloy under both magnetic and non-magnetic field conditions. This finding contributes to filling the theoretical gap in the corrosion failure behavior of Fe-Co-Si alloy under magnetic field conditions.

In the present work, the indole derivative, namely, 3,3′,3″-methane-triyl-tris-1H-indol (tris-Ind), is synthesized and characterized as an organic electrode material in rechargeable lithium-ion batteries (RLIB). The structural characterization of the synthesized molecule is carried out using physicochemical techniques. The ball milling method is used for the lithiation process to form electroactive lithiated tris-Ind (Li-tris-Ind). The electrochemical activity of Li-tris-Ind is measured in aqueous and non-aqueous electrolytic media, and the results are compared. The aqueous cell system delivers an average cell potential of 0.76 V with a discharge capacity of 189 mAhg⁻¹, whereas the non-aqueous cell system delivers an average potential of 1 V with 506 mAhg⁻¹. The potentiostatic electrochemical impedance spectroscopic studies reveal the kinetics of finite diffusion. The organic electrode shows good cyclic stability and reproducibility in both systems, making it a significant practical material for RLIB applications.

The development of new electrocatalysts for the oxygen evolution reaction (OER) is fundamental for water-splitting devices. In this work, a novel composite based on Ca₃Co₄O₉ (C349) and Ba_0.5Sr_0.5Co_0.8Fe_0.2O₃ (BSCF) was synthesized and characterized using XRD with Rietveld refinement, SEM, EDX, and FTIR. The electrochemical properties were evaluated in a KOH alkaline medium. The composite exhibited exceptional OER electrocatalytic activity, showing an overpotential of 389 mV at 10 mA cm⁻², which is lower than the pristine BSCF and C349 samples. Tafel slope of 77 mV dec−1 and double-layer capacitance (Cdl) of 4.37 mF were obtained, indicating an ECSA of 109.25 cm². The composite also demonstrated a high turnover frequency (TOF) of 1.9 × 10⁻³ mol O₂ s⁻¹, underscoring its superior catalytic efficiency. Impedance spectroscopy revealed that the C349 and BSCF samples exhibited greater limitations in charge transfer compared to the composite. These results highlight the composite’s potential as a highly effective OER electrocatalyst, leveraging the synergistic effects of C349 and BSCF.

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This study assessed tungsten-based materials with and without dispersed CeO₂ for potential use as pH sensors. Specifically, three types of tungsten electrodes were characterized: tungsten electrodes without CeO₂ but with native oxide, tungsten electrodes without CeO₂ that were oxidized, and a tungsten electrode containing dispersed CeO₂ that was oxidized, resulting in a mixture of WO₃, CeO₂, and Ce₂O₃. The characterization was performed using SEM/EDAX, X-ray photoelectron spectroscopy (XPS), and electrochemical techniques. The oxide coatings showed higher oxygen contents compared to native tungsten. XPS confirmed the presence of a thick layer of WO₃ and cerium oxides. The electrodes exhibited good reproducibility and stability in pH measurements. A linear relationship was found between the open circuit potential and pH, with slopes of 44.9, 40.8, and 46.9 mV pH⁻¹ for native oxide, WO₃, and WO₃ with CeO₂ and Ce₂O₃, respectively. The latter showed the highest sensitivity and lowest hysteresis. The response times ranged from 14.5–23.5 s and were faster in acidic solutions. Overall, the inexpensive tungsten-based electrodes demonstrated promising capabilities for pH sensing, but in particular ceriated tungsten electrodes.

The flexible lithium-ion batteries (LIBs) are revolutionizing the consumer market mandatory due to their versatility, high energy and power density, and lightweight design. The rising demand of expedient electronic and wearable devices has driven the widespread application of these flexible batteries in view of convenience and efficiency for users. The market demand for next-generation devices has incited the innovative investigation on novel flexible lithium-ion batteries to fulfill evolving needs. In this study, the performance of flexible lithium-ion battery made with PLA-graphite/graphite semi-solid electrodes has been investigated. The semi-solid electrodes were prepared by combining the active and conductive electrode materials with the liquid electrolyte. This setup of viscous and thick slurry enabled an efficient movement for all solid particles within the battery with the application of bending, shear, or pressure forces. In order to investigate the battery’s enactment, the heterogeneous 3D model was developed with the consideration of all electrical and electrochemical parameters of semi-solid electrodes. The COMSOL Multiphysics® software was employed for the finite element analysis (FEA) of the governing equations. The specific discharge capacity of the proposed model has been validated with the experimental results under half- and full-cell modes. Furthermore, the deformation characteristics, battery discharge rate, and operating temperature have been examined using the model of flexible electrodes under half- and full-cell modes. The results of this study suggested the level of optimal functional temperature and rate of discharge for the flexible LIB.

The improvement of the water oxidation capability of bismuth molybdate (BM) with selective metal addition under illumination was examined. BM and its Zn-modified (different atomic %) photoanodes were developed over conducting glass substrate through the cost-effective drop-cast method. The maximum photocurrent of ~ 240 µA/cm² at an applied potential of 1.3 V vs Ag/AgCl was recorded for the 2% Zn modified sample in 0.1 M Na₂SO₄ solution (PBS, pH 7) under 100 mW/cm² illuminations. Surface characterizations like scanning electron microscopy, X-ray diffraction, energy dispersive X-ray analysis, and optical analysis such as UV–vis absorbance, photoluminescence, FT-IR, and Raman spectroscopic analyses were performed to determine the physicochemical properties of the semiconductor. The pure bismuth molybdate shows an optical band gap of ~ 2.78 eV, which decreases for the Zn-modified sample, and a minimum of 2.55 eV is detected for the optimized sample. The XRD analysis also reveals that Zn addition into the bismuth molybdate matrix decreases crystallite size with variation in proportions of the constituent metal oxides. The stability of the semiconductors regarding the PEC water oxidation reaction indicates promising results even under continuous illumination for 1 h. The Mott-Schottky study reveals the n-type nature of the semiconductors, whereas the Nyquist analysis indicates minimum charge transfer resistance for the 2% Zn-BMO sample. The PEC action spectra for the optimized photoanode indicate a maximum of 34% incident photon to current conversion efficiency with corresponding 38% absorbed photon to current conversion efficiency, which is more than three times than that of the pure bismuth molybdate.

The electrochemical performance of gold electrode in sulfuric acid was studied with addition of different concentrations of dissolved fullerenol-d with C₆₀(OH)₂₄ chemical formula. Based on the cyclic voltammetry data, the conclusion of surface complexation of Au(III) with fullerenol was made. The scheme was suggested to describe the electrode process, based on catalysis of anodic Au dissolution by fullerenol molecules. The technique was suggested to detect fullerenol-d (C₆₀(OH)₂₄) in concentration range from 2.6·10^–9 M to 2.0·10^–7 M by means of cyclic voltammetry of gold in aqueous sulfuric acid solution.

This study reports that hot pressing a high loading (9.375 mg cm⁻²; > 5 mAh cm⁻²) all-solid-state FeS₂ composite cathodes at 240 °C and 47 MPa improved initial cycle performance. At 25 °C, a cold-pressed cell delivered negligible capacity whereas a hot-pressed cell delivered 332 mAh g⁻¹ (2.34 mAh cm⁻²). At 60 °C, a cold-pressed cell delivered 666 mAh g⁻¹ (4.70 mAh cm⁻²) whereas a hot-pressed cell delivered 782 mAh g⁻¹ (5.52 mAh cm⁻²). Hot-pressed cathode composites had a 20% porosity whereas cold-pressed cathode composites had a 30% porosity. Increased initial discharge capacity was attributed to better solid–solid interfacial contact between sulfide solid-state electrolyte (SSE) particles and between SSE and FeS₂ active material particles. Cell failure occurred upon extended cycling due to the stresses generated by the expansion of lithiated FeS₂. FIBSEM cross-sectional imaging of post mortem cathode composites revealed horizontal cracking indicative of electrode delamination due to electrode expansion.