Ionics最新文献

Ionic liquids (ILs) represent a suitable category of electrolytes in new energy batteries and supercapacitors. Although mono-cation ionic liquids have been extensively studied, the electrochemical properties of Gemini ionic liquids (GILs) have not been thoroughly explored. In this study, GILs containing functional hydroxyl group in spacer chain and different alkyl chain in imidazolium cation were synthesized. The physicochemical properties, including melting point, density, thermogravimetric (TGA) analysis, electrical conductivity (EC), molar electrical conductivity, and electrochemical stability window (ESW) of GILs, were evaluated. The introduction of hydroxyl group on spacer chain enhanced the melting point and ESW, while decreased the density, EC, and the thermal stability of bis(trifluoromethyl sulfonyl)imide (TFSI)-based GILs. ESW of TFSI-based GILs increased as the length of alkyl chain changed from methyl to butyl. TFSI-based GILs showed wider ESW than those of Gemini imidazolium bromide salts. Density functional theory (DFT) was used to study the relationship between the change of structure (hydroxyl group in spacer chain, alkyl chain length, and anions) and ESW values of GILs. These results will shed light on potential application of TFSI-based GILs in batteries as lithium-ion or supercapacitors as electrolytes.

This study introduces a novel approach to synthesizing Ni²⁺-doped Polypyrrole (Ni²⁺-PPy) films using the Successive Ionic Layer Adsorption and Reaction (SILAR) technique—a method previously unexplored for this purpose. By leveraging the innovative integration of Ni²⁺ ions, we developed low-cost, binder-free composite materials with enhanced electrochemical properties, such as higher specific capacitance and improved cycling stability. Compared to traditional methods, this work demonstrates significant improvements in the structural and electrochemical characteristics of the synthesized films. The use of stainless-steel substrates and a simple SILAR technique enables scalable, uniform, and controllable deposition of PPy films, which offers a clear advantage over other conventional doping techniques. Characterization using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), confirms the formation of highly porous films that allow efficient ion diffusion. Electrochemical studies in 1 M H₂SO₄ using a three-electrode system reveal that Ni²⁺-PPy films exhibit a specific capacitance of 584 F/g at a scan rate of 5 mV/s, significantly higher than the 465 F/g observed for pure PPy. Additionally, the Ni²⁺-PPy films maintain 66% stability after 1000 cycles, demonstrating their superior energy storage potential. This work highlights the synergistic effects of Ni²⁺ incorporation, which improves the electrochemical performance and stability of PPy-based materials, marking an innovative step in the development of efficient supercapacitor electrodes.

In this paper, PbO₂ anode was prepared by pulse electrodeposition. The effect of temperature and current density on the thickness, micromorphology, crystal structure and grain size, and the deposition process was proposed and demonstrated by XPS. Furthermore, the effect of temperature and current density on the current efficiency, overpotential, and charge transfer resistance was systematically investigated by electrochemical properties, and the corresponding mechanism was analyzed. The results exhibit that the optimized temperature of the plating solution is about 50 °C. The electrode prepared at the current density of 400 A/m² exhibits the highest current efficiency, while the electrode prepared at the current density of 300 A/m² presents lower overpotential (0.7548 V) and smaller charge transfer resistance. This work provides a reference for the efficient electrodeposition of PbO₂ composite electrodes.

The excellent properties of organic–inorganic nanocomposites garnered extensive attention in energy storage applications. In this regard, polyaniline-nickel oxide (PANI-NiO) has been synthesised using a chemical oxidation technique for supercapacitor applications. The structural, optical, and morphological properties of the PANI and PANI-NiO electrode materials were elaborated using X-ray diffraction (XRD), ultraviolet–visible (UV–Vis.), Fourier transform infrared (FTIR) spectroscopy, and field effect transmission (FESEM) techniques respectively. The electrochemical properties of the developed materials were explored via cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) techniques. The PANI and PANI-NiO exhibited the specific capacitance values of 223.92 and 522.45 F/g respectively, at a current density of 1 A/g. The stability study of the electrodes shows a high capacitance retention of 79.5% after 3000 GCD cycles for the PANI-NiO electrode and 62.2% for the PANI electrode. Thus, the obtained results of the electrochemical test confirmed the exciting potential of the PANI-NiO compared to PANI in supercapacitor applications.

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Pt-free dye-sensitized solar cells (DSSCs) have emerged as cost-effective alternatives in energy storage technologies, attracting considerable research interest over the past two decades. In this study, we successfully fabricated a NiSe/Co₃Se₄ hybrid counter electrode (CE) using a facile ultrasonic-assisted hydrothermal method, demonstrating its potential for enhancing the performance and stability of DSSCs. X-ray diffraction (XRD) investigation showed hexagonal NiSe and monoclinic Co₃Se₄ phases in the composite, with smaller crystallite sizes indicating better interfacial contacts. SEM and TEM micrographs show a well-defined nanostructure with spherical NiSe particles and rod-like Co₃Se₄ particles. This results in a large surface area and improved porosity, as validated by BET analysis. Electrochemical studies, such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Tafel polarization, show that the NiSe/Co₃Se₄ composite has superior electro catalytic activity compared to individual NiSe and Co₃Se₄ electrodes, closely matching the performance of the Pt electrode. When integrated into DSSCs, the NiSe/Co₃Se₄ composite CE obtained an energy conversion efficiency of 9.01%, with notably enhanced short-circuit current density (J_sc) and open-circuit voltage (V_oc). The NiSe/Co₃Se₄ combination is a good contender for large-scale DSSC applications due to its strong photovoltaic performance and stability over 42 days under one-sun illumination.

Supercapacitor is a kind of energy storage device between secondary battery and physical capacitor, which has the advantages of fast charging and discharging speed, high power density and excellent cycle stability. Compared with combustion batteries, the energy density of supercapacitors is low and needs to be further improved. The electrochemical performance of supercapacitors mainly depends on the electrode materials. Porous carbon (PCs) materials are currently one of the most widely used supercapacitor electrode materials due to their high specific surface area, good chemical stability and low cost. The best morphology of the sample was obtained when the temperature was 800 ℃ and the alkali carbon ratio was 1:1. Specimen PC800-1 has the largest specific surface area of 1894.97 m²g⁻¹. In the three-electrode test system, the specific capacitance of sample PC800-1 is as high as 217.5 F g⁻¹ at 0.5 A g⁻¹, and the multiplicity performance is 46.1% at 20 F g⁻¹. In the two-electrode test system, the sample has a specific capacitance of 115 F g⁻¹ at 0.5 A g⁻¹, an energy density of 13.33 Wh kg⁻¹, and a power density of 499.88 W kg⁻¹. This green and efficient synthesis of sodium lignosulfonate-based is a promising alternative strategy for the production of carbon-based supercapacitors.

In recent years, two-dimensional (2D) materials such as graphene, MXene, MOF, and black phosphorus have been widely used in various fields such as energy storage, biosensing, and biomedicine due to their significant specific surface area and rich void structure. In recent years, the number of literatures on the application of 2D materials in electrochemistry has gradually increased. To help people better understand 2D materials and facilitate the subsequent development of 2D materials, this paper focuses on several mainstream 2D materials. It mainly includes the following three aspects: synthesis and energy storage mechanism, preparation scheme, and the role played in each electrochemical device. In this paper, the synthesis mechanism of most 2D transition metal compounds, carbon materials, and organic materials is described by focusing on the 2D structure of transition metal compounds, carbon materials, and organic materials, including two processes of high-dimensional structure stripping and low-dimensional structure self-assembly. The energy storage mechanism of most 2D materials was revealed through the mechanism of ionic (in) sertion reaction and redox. The synthesis methods of physical, chemical, and physicochemical combination of most 2D materials and the advantages and disadvantages of different methods are summarized. The great effects of 2D materials on electrode materials, electrolyte, and diaphragm are summarized in terms of operating voltage window, rate capacity, dynamic behavior, specific discharge capacity, cycle stability, and so on. Finally, we also introduce the current challenges and future research directions of 2D materials, and hope to see the figure of 2D materials in more fields.

The material used for electrodes greatly affects the electrochemical performance of a supercapacitor. This study utilized electrospinning to create ZnO/Polyacrylonitrile (PAN) composite-based nanofibers, which were then heat-treated to form carbon nanofibers (CNFs). The ZnO/PAN-NFs and the resulting ZnO and PAN CNFs were thoroughly characterized for their crystallographic and morphological properties. Electrodes made from ZnO and PAN-based CNFs demonstrated a peak capacitance of 163.44 F g⁻¹ at a scan rate of 10 mV s⁻¹, which is a 64% increase over electrodes made from PAN CNFs, in addition to enhanced cyclic stability and rate capability. An asymmetric supercapacitor constructed with ZnO/PAN-CNFs//AC showed an energy density of 6.1 Wh kg⁻¹ and a power density of 1000 W kg⁻¹. The device also exhibited outstanding longevity and electrochemical reversibility, maintaining 84% of its specific capacitance after 5000 cycles. This research seeks to investigate the unique structural and electrochemical properties of the electrospun ZnO/PAN nanocomposite material, contributing to the advancement of high-performance supercapacitor electrodes.

In this study, CuFe₂O₄/CuO@rGO nanocomposites were prepared using the hydrothermal technique. In order to investigate these nanocomposite electrochemical properties, researchers constructed two-electrode and three-electrode configurations. The nanocomposite CuFe₂O₄/CuO@rGO showed an impressive specific capacitance of 2110 F/g at 1 A/g. This asymmetric capacitor showed an impressive 40.44 Wh kg⁻¹ energy density at a power density of 780 Wkg⁻¹, with activated carbon (AC) as the negative electrode and CuFe₂O₄/CuO@ rGO as the positive electrode. It also had a prolonged cycle life, with 93% retention after 10,000 cycles. By illuminating light-emitting diode (LED) lights, the asymmetric cell demonstrated the practical use of this nanocomposite as an active electrode material. This device demonstrated its structural durability by maintaining a constant electrochemical activity. To our knowledge, the synthesised nanocomposite demonstrated superior performance. The impressive electrochemical capability of the produced nanocomposite makes it an attractive electrode for use in high-performance hybrid capacitors.

Due to their superior properties, lithium-ion batteries (LIBs) have become the primary energy storage medium for electric vehicles (EVs), driven by widespread adoption. Nevertheless, a significant barrier hindering EV uptake lies in accurately assessing power LIBs’ health status and lifespan under prolonged demanding conditions. The neural network–based prediction method can increase the model’s prediction accuracy. However, because of the model’s complexity and abundance of features, current data-driven prediction technology frequently requires a lot of processing power to predict the battery’s health state. This study discusses recent approaches to life prediction using lightweight neural networks, with an emphasis on the aforementioned issues. The LIB’s aging mechanism and state of health (SOH) definition are first explained. A number of neural network models are then presented, followed by a summary of the available lightweight neural network prediction techniques and the machine learning framework for the prediction model, which aims to produce a more flexible and accurate model. This research provides references for predicting the health condition of LIBs and posits that in the future, more creative lightweight neural network models will become the standard in SOH prediction.