Journal of Solid State Electrochemistry最新文献

Two-dimensional (2D) layered nanomaterials exhibit unique performance as supercapacitor electrode materials owing to their outstanding conductivity, exclusive physicochemical properties, and unique compositions. 2D layered materials are highly suitable for supercapacitor applications due to their large surface area, short ion diffusion paths, and excellent electrical conductivity. The present work aims on the hydrothermal synthesis of MoS₂/Ti₃C₂ MXene heterostructure nanohybrid that could synergize the energy storage aspects. XRD pattern signifies the widened interlayer spacing of MXene as a result of the intercalation of MoS₂. SEM and HRTEM micrographs endorse flower like MoS₂/MXene with the crystallite size of 0.65 nm developed successfully by way of facile hydrothermal technique. BET studies reveal the enlarged specific surface area of the material. XPS divulges the strong contact between MXene and MoS₂, united with ordered structure that interprets stable chemical states. The specific capacitances of MoS₂/Ti₃C₂ MXene attained from the CV curves are 152, 135.6, 114.8, 101.1, 90.1, and 80.4 F/g at 10, 20, 40, 60, 80, and 100 mV/s, respectively, and from the GCD curves, the specific capacitances of the MoS₂/Ti₃C₂ MXene were obtained to be 123.5, 61, 58.6, 55.5, and 46.6 F/g at various current densities ranging from 0.33 to 1 A/g. The electrode material, MoS₂/MXene, showed a capacitive retention of 88% after 5000 cycles. The electrochemical impedance analysis indicates that the integration of MoS₂ declines the charge transfer resistance. Inclusively, the electrochemical behavior of MoS₂/MXene unveiled outstanding cycle stability, reversibility, and performance of rate. The achieved results expose MoS₂/MXene as auspicious electrode materials for supercapacitor applications.

Polymer electrolytes emerged as a viable candidate for advanced battery technologies. Incitation to develop polymer electrolytes emanate from the issues faced by the liquid and solid electrolyte based lithium ion batteries (LIBs). Polymer electrolytes highlighted the improvement in ion conductivity, electrochemical stability, enhanced safety, strength and flexibility. Different polymers are being explored for their remarkable performance in the LIBs. In this context, the key polymer used in modern batteries is poly(vinylidene fluoride-co-hexafluoropropylene), i.e., PVDF-HFP, which has excellent features like thermal stability, mechanical strength, Li-ion conductance, metal salt absorption, and other properties measured in battery formations like discharge capacity, coulombic efficiency, etc. This polymer is used in both solid (including the composite solid electrolyte) and gel polymer electrolytes. Keeping in view the energy demand and material scarcity in renewable energy storage, various properties of the polymer electrolytes need to be improved. This progress demands the addition of certain additives in sole PVDF-HFP. In this context, this article exhaustively reviewed the role of mixing other plasticizers, active and passive fillers in PVDF-HFP with their effect on the various parameters along with future materials. The role of future materials like metal organic frameworks (MOF) will certainly revolutionized the progress in electrolyte material thus focusing on the real-world performance and commercialization of the LIBs.

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A systematic approach was adopted to synthesize cobalt hydroxide (Co(OH)₂) blended bismuth oxide (Bi₂O₃) nanocomposites in three different compositions as negative electrodes for supercapacitor applications. The influence of Co(OH)₂ on the structural, morphological, and electrochemical properties of Bi₂O₃ are examined and reported. The pure and Co(OH)₂-included samples fall to the monoclinic structural symmetry, while a higher composition of Co(OH)₂ exhibits fewer native peaks in XRD. The full survey spectrum of XPS confirms the existence of bismuth, cobalt, and oxygen. SEM images show very thin sheet-like morphology, stacked one over the other, which provides higher surface area and facilitates enhanced ion diffusion, which improves the electrochemical properties of the prepared sample. The electrochemical performance of the samples was examined via half-cell configuration for their suitability as negative electrodes in supercapacitor applications. The maximum specific capacity of 984.6 F g⁻¹ is estimated at a specific current of 2 A g⁻¹ for the electrodes consisting of Bi₂O₃ and 5 mole percent of Co(OH)₂, and it is 22.9% higher than the bare Bi₂O₃ electrodes. These efficient nanocomposites exhibit better cycle life by estimating 94% retention at the end of 5000 GCD cycles. The asymmetric supercapacitor device could yield a maximum energy density of 31 Wh kg⁻¹ at a power density of 918 W kg⁻¹. Thus, crafting Bi₂O₃ electrodes by incorporating Co(OH)₂ can be an effective strategy for developing advanced negative electrodes.

For direct dimethyl ether fuel cells (DDFCs), the anti-poisoning ability of anodic Pt toward reaction intermediates plays a key role in electrocatalytic performance of direct dimethyl ether (DME) oxidation reaction (DOR). Here, we report a novel triple-phase Pt/SnO₂-porous carbon (PC) catalyst constructed through accurately controlled Pt deposition on a core–shell SnO₂-PC support. By reducing oxygen functional groups on the PC surface, Pt nanoparticles are preferentially anchored at SnO₂-PC interfacial boundaries rather than on the carbon surface, creating abundant triple-phase interfaces (Pt/SnO₂-PC) for DOR. The triple-phase interface structure of Pt/SnO₂-PC can effectively anchor the Pt nanoparticles, ensuring both their uniform dispersion and maintaining excellent electronic conductivity. The mass activity (MA) of the Pt/SnO₂-PC reaches 236.4 mA· mg_pt⁻¹, which is 2.2 times of Pt/C. The accelerated potential cycling tests (APCT) after 5000 cycles reveal that the electrochemically active surface area (ESA) of Pt/SnO₂-PC decreases only 36.82% less than Pt/C (60.40%). This study presents a new light on tuning Pt location and constructing triple-phase interface structure of Pt-based catalyst, which can enhance the electrocatalytic performance of DOR.

The kinetics and mechanism of the indole oxidation reaction (IOR) on a highly oriented pyrolytic graphite (HOPG) electrode were investigated using various electrochemical techniques. The HOPG electrode exhibited excellent electrocatalytic activity, reaching current densities of up to 35 µA/cm² over a concentration range of 0.1 and 200.0 µM and a detection limit of 0.02 µM. Chronoamperometric transients were analyzed through a kinetic model that described the relationship between the observed current density and the distribution of free and occupied active sites on the electrode surface. The number of active sites was quantified, revealing a moderate turnover frequency (TOF) under non-saturating conditions, showing the efficiency of the electrode during IOR. Electrochemical impedance spectroscopy (EIS) was employed to characterize the electrode surface and electrode/electrolyte interface. The EIS spectra, fitted using an equivalent circuit model, allowed the evaluation of charge transfer resistance and effective capacitance as a function of indole concentration. This study highlights the technological importance of understanding IOR, especially in the development of sensors for clinical and environmental applications requiring precise detection and quantification of indole.

With the rapid development of energy storage technology, there is an increasing demand for high-performance capacitive carbon materials. However, the traditional preparation methods often have defects such as high cost and complex processes. Using coal tar pitch (CTP) as raw material, the optimal conditions for preparing purified coal tar pitch (PCTP) by solvent centrifugation were identified. Subsequently, using PCTP as the carbon source and potassium hydroxide (KOH) as the activator, purified pitch-based capacitive carbon was prepared by the one-step carbonization-activation method. Its performance was much better than conventional pitch-based capacitive carbon (the specific surface area, micropore specific surface area, pore volume, and micropore pore volume were 2106.96 m²/g, 1824.85 m²/g, 0.87 cm³/g, and 0.71 cm³/g). When the current density was 0.5 A/g, the specific capacitance was as high as 634.50 F/g. A series of physical and electrochemical characterizations have shown that the purification of coal tar pitch reduced the content of impurity metals, which changed the pore structure of the activated carbon and increased the specific surface area. As a result, more opportunities are provided for the contact and reaction between C and O, facilitating the formation of C-O bonds. In addition, when the content of metal elements decreased, their interaction with functional groups such as hydroxyl groups reduced, which allowed the hydroxyl group to form more C-O bonds with the C. The significant increase of C-O bonds effectively enhanced the specific capacitance of the capacitive carbon. This work provided a cheap and simple method for the preparation of capacitive carbon with excellent performance.

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Reversible solid oxide cells (RSOCs) can switch between solid oxide fuel cell (SOFC) and solid oxide electrolysis cell (SOEC) based on grid demand, enabling energy storage and release to improve energy utilization. This study develops a three-dimensional electro-chemical-gas-thermal coupling model for RSOC and identifies oxygen electrode thickness, electrolyte thickness, GDL porosity, and oxygen-electrode-side interconnect rib width as dominant factors governing RSOC operational characteristics through parametric analysis. Aiming at the different requirements of gas flow characteristics of RSOC under various operating modes, this study proposes a novel interconnector design, the Tesla Valve-Shuttle Interconnector (TVSI). The TVSI features a two-segment design on the oxygen electrode side, comprising a multi-stage Tesla Valve flow channel and a rectangular straight channel, while the hydrogen electrode side is equipped with discrete staggered, shuttle-shaped platforms. Gas velocity distribution, component distribution, pressure distribution, electrical performance, and temperature of both Conventional Rectangular Interconnector (CRI) and TVSI are compared under identical operating conditions and a countercurrent flow arrangement. The conclusions indicate that the TVSI enhances gas mass transfer, improves component distribution, reduces polarization overpotentials, and increases output performance and durability in both SOFC and SOEC modes, providing valuable insights for future cell design.

In this work, the impact of pH (ranging between 2 and 5) on the electrochemical behavior of a prepared stable suspension of nanopolyaniline (nPANI) particles, which were dispersed as a stable phase in HCl solutions on the gold electrode surface, was investigated and compared using electrochemical methods, including cyclic voltammetry (CV) and chronoamperometry examinations. The obtained results for both pH = 2 and 3 showed two redox conversions within the polyaniline structure, which are controlled by the adsorption and diffusion mechanisms of nPANI particles. The total number of redox-active sites per nPANI particles increased with a decrease in pH, and the corresponding adsorption parameters (θ_max and ΔG⁰_ads) were calculated. Moreover, the electrochemical results for the effect of pH on the adsorption of nPANI particles on the gold electrode surface were complemented using surface analysis methods, including field emission scanning electron microscopy (FE-SEM) and EDX analysis. The stability of suspensions prepared in hydrochloric acid was examined over time using UV–vis spectrum technique and zeta potential measurement.

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Rich-Ni cathode NCM811 can significantly enhance the energy. However, the higher Ni content easily leads to the thermal instability. In this study, the electrochemical and thermal performance of cylindrical 18,650 LiNi₀.₈Co₀.₁Mn₀.₁O₂/graphite batteries with different state-of-health (SOH) were investigated. The key factors considered for the performance include high temperature storage, surface temperature, impedance, heat generation power, material structure and morphology. The batteries show excellent cycle efficiency of 88.7%, 88.5% and 88.4% after 500 cycles with 0.5 C/1 C/2 C current, respectively. In short-term high-temperature storage, the voltage of 80%SOH battery is reduced by 0.09 V, and the H1 peak strength is significantly reduced in dQ/dV curves. The temperature rise show that the 80% SOH battery’s maximum temperature rise up to 40.8 °C at 3 C. The state-dependent EIS analysis reveals a strong positive correlation between impedance growth and cycle aging, where R_hf (SEI resistance) and R_lf (charge transfer resistance) exhibit temperature-dependent escalation rates. Heat generation was quantitatively analyzed through DC internal resistance and entropy coefficient measurements, revealing significant SOH-dependent characteristics. The 80% SOH battery exhibits 10.3% higher maximum reversible heat power (1.202 W vs. 1.090 W) and 5.6% greater irreversible heat power (0.948 W vs. 0.898 W) compared to pristine cells (100% SOH). The findings in this work are important to evaluate their thermal behavior and promote the development of battery management systems.

The study evaluates the performance of binder-free Pt-based catalysts for oxygen reduction reaction (ORR) using cavity microelectrode (CME) techniques. The use of binders during the deposition of an electrocatalyst on conducting support can adversely affect the mass transport properties, including the diffusion of reactants and products, to and from the catalyst surface. To mitigate these effects, pristine catalysts are employed, avoiding any performance loss. By employing CME, pristine powder catalysts were evaluated without the need of binders, demonstrating superior activity compared to Nafion^®-coated variants, which suffer from active site blockage. The commercial Pt/C catalyst and the emerging 2D Pt/Ti₃C₂T_x catalyst have been utilized to showcase these effects in ORR electrocatalysis. Notably, Pt/Ti₃C₂T_x showed superior ORR activity than Pt/C in both systems, which is attributed to the strong metal support interaction (SMSI) in the catalyst. This interaction has been experimentally confirmed via X-ray Photoelectron Spectroscopy (XPS) and Ultraviolet Photoelectron Spectroscopy (UPS), demonstrating a downshift in the Pt d-band center for Pt/Ti₃C₂T_x. The superior performance of the catalyst and the enhanced catalytic activity via CME technique are attributed to the downshift of the d-band center and the exclusion of binders, respectively.