Journal of Solid State Electrochemistry最新文献

Thermo-electromotive force (thermo-EMF) of Pd–Ag, Rh-Ag, Pt–Ag and Ag-C couples was measured in temperature range 45.5—715.2 ºC at the cold end temperature of 25 ºC. A cold-end temperature of 25 °C proved to be the most convenient and stable in the following electrochemical experiments. All measurements were carried out by Autolab PGSTAT 302N potentiostat/galvanostat with using the chronopotentiometry method. Thermo-EMF values of Pd–Ag, Rh-Ag, Pt–Ag and Ag-C couples have the same sign. It leads to additive effect for these values for platinoid – C couple and enlarged shift to negative side value of electrode potentials up to 20 mV in electrochemical experiments. These data were used for correction of thermodynamic data on noble metal chloride formation in low-temperature LiCl–KCl-CsCl melt. When thermo-EMF is taken into account, formal electrode potentials have a shift of values up to 10 mV. Recalculation of ∆G*, ∆H*, ∆S* also demonstrates the shift of its values up to 2 kJ·mol⁻¹, 3 kJ·mol⁻¹ and 7 J·mol⁻¹·K⁻¹, correspondingly. These are important changes for building the mathematical model of platinoid separation process in low-temperature LiCl–KCl-CsCl melt at working temperature of 450 ºC.

Symmetrical solid oxide fuel cells (S-SOFCs) are energy-efficient electrochemical power sources that open up new possibilities for clean energy. In this work, the physicochemical properties of fluorite-like Nd₅Mo₃O_16+δ (NMO) have been investigated for the first time to evaluate its potential as an electrode material for S-SOFC. Electrical conductivity measurements under reducing conditions (Ar/H₂) at 100–900 °C have revealed thermally activated behavior with predominant electronic conductivity of 1.7 S/cm at 800 °C. The thermal expansion coefficient of NMO in Ar/H₂ at 25–900 °C has been determined to be 10.7 ppm/K. No new phases formed when NMO was heated with conventional electrolyte materials up to 950 °C with Ce_0.9Gd_0.1O_1.95 (GDC) and 850 °C with Zr_0.84Y_0.16O_1.92 (YSZ). The polarization resistance (R_η) of the NMO electrode at 800 °C has been recorded as 15.1 Ω·cm² in air and 5.6 Ω·cm² in an Ar/H₂ atmosphere. An electrolyte-supported S-SOFC with the NMO/GDC/YSZ/GDC/NMO configuration has achieved a power density of 14 mW/cm² at 900 °C. Replacing the NMO cathode with (La_0.75Sr_0.25)_0.95MnO_3-δ has led to the increase of the power density to 100 mW/cm² at 900 °C. Long-term stability tests carried out on both fuel cells under a constant voltage of 0.7 V showed no significant degradation in performance. Thus, the obtained results demonstrated that NMO is a promising candidate for use as an anode material in SOFCs.

In order to prevent the aggregation of ZIF-67, increase the electrochemical reaction sites, promote the diffusion of lithium-ions, improve the cycling stability of the electrode, and avoid the negative impact of conductive agents and binders, a copper-supported network with ZIF-67 derivative encapsulated in a carbon matrix was synthesized by sintering the copper foil coated by the suspension containing ZIF-67, polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), and N-dimethylformamide (DMF). The obtained copper-supported coating is CoO_x/C composite. Being sintered in an inert atmosphere at high temperature, ZIF-67 decomposes to form Co₃O₄/C composite, PAN decomposes to form carbon, and PMMA volatilizes. The volatilization of PMMA at high temperatures leads to the network structure of the ZIF-67 derivative/PAN-derived carbon coating. The ZIF-67 derivative/PAN-derived carbon coating exhibits a high capacity of 1149 mAh g⁻¹ and good cycling stability. Its good electrochemical performance depends on the following factors: (1) the steric hindrance effect of PAN-derived carbon avoids the aggregation of the ZIF-67 derivative; (2) the copper-supported coating is free of conductive agents or binders; (3) the network structure is beneficial for increasing the electrochemical reaction sites for lithium storage, promoting the diffusion of lithium-ions, and improving the cycling stability of the electrode.

As an alternative to lithium-ion batteries, sodium-ion thin film batteries are very attractive for energy storage applications driven by financial limitations. The materials, like Sn, Sb, SnO₂, and Sb₂O₃, have gained much attention in this area because of their distinctive electrical characteristics. SnO₂ stands out among them as a potential material for next-generation storage systems due to its non-toxicity, low cost, distinctive crystal structures, and superior electrochemical performances. By using physical vapour deposition processes, it is quite difficult to obtain crystalline and stoichiometric tin compounds. Radio frequency (RF) sputtering was employed in this study to deposit SnO₂ thin films. Thin films of pure phase and crystalline nature were produced using the annealing process. The cathodic and anodic reactions are confirmed from electrochemical studies along with high capacity retention (95%) and charging capacity ~ 577 mAh.g⁻¹, which indicates that SnO₂ would be a promising anode material for Na-ion thin film batteries.

A Fe/Cu bimetal composite catalyst self-supported on commercial copper foam (Fe₂O₃/CuO@CF) is synthesized by chemical oxidation followed by calcination and evaluated for electrochemical nitrite sensing. The surface of the copper foam is uniformly covered with submicron sphere arrays composed of the hetero-interfacing Fe₂O₃ and CuO crystals. This unique structure presents good local wetting, surface hydrophilicity, and nitrite enrichment, thereby heightening nitrate capture efficiency and underpinning the ultrasensitive detection of nitrite. Electrochemical measurements uncover that Fe₂O₃/CuO@CF exhibits a broad detection range (4–1377 µM), a low detection limit (0.72 µM), and high sensitivity (3573 µA mM cm⁻² or 2379 µA mM cm⁻² within a low or high nitrite concentration range) for nitrite. This design concept offers new insights for building superb electrochemical sensor electrodes with promising applications in environmental monitoring and food safety analysis.

This study demonstrates the fabrication of TiO₂-based photoanodes for dye-sensitized solar cells (DSSCs) with the incorporation of reduced graphene oxide (rGO) at varying weight percentages (0.5, 1, and 3 wt%) using a direct and straightforward approach. In this work, rGO was synthesized using a simple, cost-effective, and environmentally friendly method previously reported in the literature, offering an alternative to conventional Hummers and modified Hummers methods. Systematic structural, morphological, compositional, and optical studies confirmed the incorporation of rGO on TiO₂ films. The power conversion efficiency (PCE) of DSSCs improved with rGO incorporation, with the optimal concentration identified as 1 wt%. Electrical conductivity measurements revealed that rGO incorporation enhanced conductivity, while electrochemical impedance spectroscopy (EIS) analysis indicated reduced charge transfer resistance, leading to suppressed recombination and improved electron transport. Additionally, incident photon-to-current efficiency (IPCE) measurements confirmed the enhanced efficiency of the 1 wt% rGO-incorporated sample. The simplicity and sustainability of the rGO synthesis method, along with the direct integration approach, highlight the potential of rGO as an effective and practical additive for enhancing the performance of DSSCs.

Self-healing polymer electrolytes are in high demand for enhancing the cycle stability and reliability of flexible and wearable electronics. Herein, a healable, nonflammable poly(ionic liquids) (PIL) electrolyte is fabricated. It is based on an imidazolium-type PIL copolymer that contains cross-linkers with a disulfide bond and hydrogen bond (SSH), ionic liquid, and lithium salt. The prepared SSH-PIL electrolytes display high ionic conductivity and outstanding self-healing capacity due to multiple dynamic interactions. The optimized SSH-PIL2 electrolyte films exhibit superior ionic conductivity (exceeding 10^–4 S cm⁻¹ at 30 °C), a wide electrochemical stability window (5.2 V vs. Li/Li⁺), and a high lithium-ion transference number (0.43). The assembled LiFePO₄/SSH-PIL2/Li cell delivers a specific discharge capacity of 153.3 mAh g⁻¹ at 0.1 C, and a capacity retention of 93.3% after 100 cycles. More significantly, the SSH-PIL2 electrolyte can quickly repair mechanical damage (within 20 min at 60 °C). The healing efficiency in terms of mechanical properties and specific discharge capacity is as high as 94.6% and 98.0%, respectively. This work presents a promising approach for developing reliable and safe electronic devices.

Composite solid polymer electrolytes (CSPEs) are ideal candidates for metal batteries, offering flexibility, stability, high ionic conductivity, and compatibility with lithium metal. In this work, we developed a dual polymer-based (PVDF-HFP/PEO)/Li_6.25La₃Ga_0.25Zr₂O₁₂ (LLGZO) based CSPE using an easily scalable solution casting method. The integration of dual polymer (PEO in PVDF-HFP matrix) and active ceramics (Ga doped LLZO) demonstrates a good Strategy to balance mechanical strength, ionic conductivity, and electrochemical stability for solid-state Lithium metal batteries. This Synergistic design led to a remarkable enhancement in room-temperature ionic conductivity of 1.08 × 10^–4 S·cm⁻¹, the lowest activation energy of 0.304 eV, a wide electrochemical Stability window of 5.23 V vs. Li/Li⁺, and a high transference number (0.74) at 60 °C for 10 wt% LLGZO-coated dual-polymer-based CSPE (LZ10). Additionally, it exhibited lower metal/electrolyte interfacial resistance (52.55Ω) and improved tensile Strength of 2.63 MPa. As a consequence, LZ10 enabled an excellent plating/stripping Stability for more than 900 h at varying current densities at 60 °C, with lower changes in bulk and interfacial resistance during long-term cycling. Moreover, the fabricated solid-state cell (Li/LZ10/LiFePO₄) delivers superior capacity and cycling stability at various current densities at elevated temperatures. Cells also maintained ~ 84% capacity retention after 50 cycles with an excellent coulombic efficiency of > 98%. Thus, the compiled data suggest that the PVDF-HFP/PEO/LLGZO CSPE is a highly promising candidate for developing metal batteries.