Journal of Solid State Electrochemistry最新文献

Although Ti₃C₂Tx MXene offers enhanced capacitive properties, the restacking of monolayered MXene nanosheet is a main obstacle for further improving their electrochemical performance. To address this issue, we introduced carbon nanotube (CNT) and TiO₂ nanoparticles (NPs) as interlayer spacers by using an ultrasound-induced approach, in which ultrasonication is proven to be effective for tuning the electronic structure of Ti₃C₂Tx MXene, which allows superior capacitive properties of the Ti₃C₂Tx MXene. Ti₃C₂Tx MXene/carbon nanotube/nanosized TiO₂ (abbreviated as MCT) ternary hybrid is firstly synthesized together with Ti₃C₂Tx MXene/CNT and Ti₃C₂Tx MXene/nanosized TiO₂ binary hybrids for comparison. The as-prepared ternary hybrid shows a specific capacitance of 489 F/g at 10 mV/s in 1 M H₂SO₄ electrolyte, which is 210 F/g, 186 F/g, and 101 F/g higher than the Ti₃C₂Tx MXene, Ti₃C₂Tx MXene/TiO₂ NPs, and Ti₃C₂Tx MXene/CNT hybrids. A mix of diffusion-controlled and surface-confined energy storage mechanisms is probed with the latter serving as the dominant one for the charge storage process. 98.9% of the capacitance is retained after 20,000 cycles of tests. The results in this work suggest the acquired MCT ternary hybrid is a promising energy storage material.

In this study, for the first time, the electrochemical properties of vindesine (VDS), a vinca alkaloid, were investigated on boron-doped diamond electrode by cyclic voltammetry and square-wave voltammetry techniques. On this electrode surface, vindesine gave two irreversible peaks at approximately + 0.80 V and + 1.12 V vs. Ag/AgCl with the cyclic voltammetry technique. When the electrode was activated at + 1.5 V in a 0.5 M H₂SO₄ medium, the voltammetric signals were enhanced. Using an anodically pretreated boron-doped diamond electrode, square-wave anodic stripping voltammograms were obtained at a deposition potential of 0.0 V for 60 s in BR buffer (pH 2, with 0.1 mM SDS), focusing on two regions within the linear dynamic range of the electroanalytical method developed for VDS. In the first linear dynamic range (6.45 nM to 73.2 nM), the following relationship between concentration and anodic current was obtained: Ip (μA) = 22.68 C (μM)—0.026, r = 0.999 (n = 5). In the 2nd linear dynamic range (0.0732 μM to 0.586 μM), the relationship between concentration and anodic current was as follows: Ip (μA) = 10.43 C (μM) + 0.47, r = 0.994 (n = 7). Both linear dynamic ranges correlate well. The limit of detection was calculated to be 1.25 nM. At the same time, the applicability of the developed electroanalytical technique for the quantification of vindesine was illustrated for pharmaceutical and urine samples. The results of the voltammetric technique developed for the analysis of VDS in pharmaceutical samples were supported by spectrophotometric results.

Graphical abstract

A molecularly imprinted electrochemical sensor based on poly-l-arginine (L-Arg) electroreduced graphene oxide (rGO) was constructed for the detection of vitamin B1. The composite film with its abundant hydrophilic groups loaded with the excellent electrical conductivity of Au nanoparticles (AuNPs) provides an efficient platform for the formation of molecular-imprinted polymer films. The linear fitting curve between the current response of the sensor and the concentration of vitamin B1 was obtained by analyzing and optimizing the experimental conditions. The linear range was 10⁻¹² to 10⁻⁷ mol/L, and the detection limit was 1.4 × 10⁻¹³ mol/L. The recovery experiment showed that the sensor could be used for the detection of VB1 in peanut samples.

This work identifies previously neglected factors and their impact on solid electrolyte interphase (SEI) formation on graphite and cathode electrolyte interphase (CEI) formation on lithium manganese oxide (LiMn₂O₄). These factors are active materials’ surface area and particle size. They were investigated by galvanostatic charging/discharging and electrochemical impedance spectroscopy (EIS) on the following examples: graphite (25.2 m² g⁻¹, 12.3 m² g⁻¹, 6.0 m² g⁻¹), LiMn₂O₄ (particle size < 0.5 µm) 11.7 m² g⁻¹, and LiMn₂O₄ (particle size < 5 µm) 3.3 m² g⁻¹, respectively. The test cells were worked in 1 M LiPF₆ solution in a mixture of ethylene carbonate (EC) with dimethyl carbonate (DMC) (1:1) electrolyte. The other aspect of this study features the assessment of optimal current for the SEI layer formation. For this purpose, five electrode materials were cycled galvanostatically with current densities between 5 and 100 mA g⁻¹. As observed, the lower current causes the formation of a more resistive SEI layer. Changes in SEI resistance do not necessarily lead to the corresponding changes in diffusion impedance. The current rate of the SEI formation cycle should be correlated not with the system capacitance but rather with the specific surface area of the active material.

Tin (Sn)-based alloys are among the most promising candidates as alternative anode materials for lithium-ion batteries (LIBs). In this study, cobalt-tin (Co-Sn) alloys were obtained by an electrodeposition method on a Cu foil substrate from a polyligand citrate–chloride electrolyte. The effect of the chemical composition and thickness of the alloys on their electrochemical characteristics as anode material for LIBs is investigated. The tested Co-Sn alloy electrodes exhibit an initial specific capacity from 474 to 606 mAh g^–1 at a current density of 100 μA cm^–2. It was found that an increase in the thickness/mass loading and saturation of the Co-Sn alloy with Sn leads to a higher tendency for structural degradation, resulting in a more rapid decrease in specific capacity during cycling. The thinner Co-Sn electrodes with the thickness up to 1.2 μm demonstrate good cyclability with 75% of capacity retention after 70–80 cycles and exhibit excellent rate capability with discharge current densities of up to 20,000 mA g⁻¹. The change in the kinetic properties of lithium ions in the alloy electrode during cycling has been studied.

The electrochemical reduction method was employed to address the issue of excessive nitrate pollution in groundwater by removing nitrate from water. The Cu-Bi-Pd trimetallic electrode was fabricated via the electrodeposition method. SEM, EDS, and XRD characterized the Cu-Bi-Pd electrodes of different metal ratios. The effects of Cu-Bi-Pd electrodes on NO₃⁻-N removal ratio and N₂ selectivity were studied under different metal ratios, electrodeposition current density, electrodeposition time, and solution electrodeposition temperature. The results showed that Cu, Bi, and Pd were uniformly loaded on the Ti matrix. Increased Bi content led to a more complete coating, a larger electrode surface grain size, and a higher degree of crystallization. The addition of the Bi element significantly improved the electrocatalytic nitrate reduction performance of the Cu-Bi-Pd electrode. The removal rate of nitrate has increased by approximately 1.28 times. The Cu-Bi-Pd trimetallic electrode with a mass ratio of 90:9:1 had better catalytic activity for nitrate, under the preparation conditions of the electrodeposition current density of 4 mA cm⁻², electrodeposition time of 50 min, and solution electrodeposition temperature of 28 ℃. The NO₃⁻-N removal ratio and N₂ selectivity were 97.6% and 57.7%, respectively. The Cu-Bi-Pd trimetallic electrode exhibited strong stability and corrosion resistance, especially for electrodes with a metal ratio of 90:9:1. For certain real groundwater (NO₃⁻-N concentration was 100 mg L⁻¹), the NO₃⁻-N removal ratio exceeded 70% after electrolysis for 6 h. The addition of Bi enhances the adsorption of N and O in nitrate, thereby improving the NO₃⁻-N removal ratio and N₂ selectivity. In this investigation, the Cu-Bi-Pd trimetallic electrode, exhibiting excellent electrocatalytic performance, has been successfully prepared, which provides theoretical insights for the development of electrocatalytic nitrate reduction.

The alluaudite-type compound Na_3.4Co_1.3(MoO₄)₃ has been successfully synthesized by a solid-state process route. It crystallizes in the monoclinic system (C2/c), cell parameters (Å,°): a = 12.582(5) Å, b = 13.449(8) Å, c = 7.119(7) Å, β = 112.02(4)°, V = 1116.8(14) Å3, and Z = 4. Its crystal structure consists of octahedral [MO₆] (M = Co, Na) and tetrahedral [MoO₄] that share corners and/or edges to build the 3D framework. The sample was also characterized by X-ray powder diffraction, which confirmed crystal data, and infrared (FT-IR) and Raman spectroscopies. Its morphology was analyzed using scanning electron microscopy (SEM). The vibrational study confirms the existence of the (Mo{O}_{4}^{2-}) functional groups. The title compound was determined to be paramagnetic. In addition, the compound was characterized by cyclic voltammetry (CV), and its electrochemical performance and impedance were analyzed by electrochemical impedance spectroscopy (EIS). The electrochemical reaction mechanism and the limiting factors of Na_3.4Co_1.3(MoO₄)₃ as electrode material in Na-ion batteries at room temperature were also discussed. The prepared electrocatalyst showed modest hydrogen evolution reaction (HER) performance with an overpotential of 309 mV required to afford a current density of 10 mA cm⁻².

Graphical Abstract

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.

Graphical Abstract

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.