Ionics最新文献

The electrochemical properties exhibited by the zinc-doped alumina nanoparticles suggest their potential as another viable alternative for supercapacitor electrode applications. The strategic placement of Zn²⁺ ions within the interstices of the alumina lattice forms potential barriers between Al³⁺ and Zn²⁺ ions, acting as effective centers for trapping charges. The structural changes report a decrease in the average crystallite size from 9 to 5 nm. The formation of trapping centers is confirmed by the enhancement in optical band gap value from 1.89 to 4.21 eV. The XPS data confirms the oxidation state of + 3 and + 2 for Al and Zn ions, respectively. A prolonged charge retention and an increased energy storage density are evidenced by the observed value of 1237 F g^–1 at 1 A g^–1. Furthermore, the stability of alumina gets enhanced on doping, demonstrating for the first time an impressive 92% stability over 10,000 cycles. The 5% Zn-doped Al₂O₃ electrode has the highest diffusion coefficient of 8.9 × 10^–12 cm² s^–1, showing efficient active sites for electrolyte ion intercalation. The asymmetric supercapacitor device analysis with 5% Zn-doped alumina as one of the electrodes attains a stability of 85% after 5000 repeated cycles. The device achieves a better energy density value of 47.63 W h kg^–1 at a power delivery rate of 996.9 W kg^–1. This study offers valuable insights into the electrochemical performance of zinc-doped alumina nanoparticles, underscoring their potential for high-performance energy storage applications in supercapacitor devices.

Lithium-sulfur batteries have not been widely commercialized due to issues with poor conductivity of the active material and the shuttle effect, both of which are effectively addressed in this study. The porous carbon CoNi-NC, derived from high-temperature carbonization of the cobalt–nickel metal–organic framework CoNi-ZIF, was utilized as the carbon substrate. It exhibits excellent specific surface area and a well-developed pore structure, thereby optimizing the conductivity and sulfur-loading capacity of the material. The incorporation of polar Bi₂S₃ effectively adsorbs polysulfides, retards the shuttle effect, and enhances the reaction kinetics of lithium-sulfur batteries. Electrochemical tests revealed that the CoNi-NC@Bi₂S₃ electrode achieved a specific discharge capacity of 1107 mAh/g at 0.1 C rate, demonstrating excellent rate capability. Moreover, the cathode material maintained a specific discharge capacity of 796.5 mAh/g after 200 cycles at 0.2 C, indicating robust cycling stability.

Dual carbon batteries (DCB) are gaining traction in energy storage research due to their cost-effectiveness, better safety, eco-friendliness, and rapid charging capability. Despite these merits, carbon-based electrode systems face many challenges, particularly in their relatively lower energy density. Researchers are addressing this by exploring innovative strategies, with a focus on electrolyte additives. One noteworthy additive is ethylene sulfite (ES), recognized for its protective effect on electrodes. This study compares two LiTFSI-based electrolytes, one of which is enhanced with ES, to determine their potential in improving DCB capabilities. The LiTFSI-ES electrolyte demonstrates a higher conductivity (7.29 × 10⁻³ S cm⁻¹) and a broader potential window (5.554 V) compared to LiTFSI alone. Cyclic voltammetry (CV) and dQ/dV analysis confirm the intercalation of TFSI⁻ anions in the graphite electrode, indicating DCB behavior. This research contributes valuable insights into enhancing DCB performance through the incorporation of ES and sheds light on the electrochemical behavior of the LiTFSI-ES electrolyte.

Accurate state of charge (SOC) estimation of lithium-ion batteries can effectively help battery management system better manage the charging and discharging process of batteries, providing important reference basis for the use planning of power vehicles. In this paper, an improved chaotic particle butterfly optimization-cubature Kalman filtering (CPBO-CKF) algorithm is proposed for accurate SOC estimation of lithium-ion batteries. Considering the hysteresis characteristics and polarization effects, an improved hysteresis characteristics-dual polarization (HC-DP) equivalent circuit model is established, which can more accurately characterize the internal characteristics of battery. To achieve high-precision SOC estimation, an improved chaotic particle butterfly optimization algorithm is introduced for dynamic optimization of noise in the cubature Kalman filtering algorithm, and the proposed CPBO-CKF algorithm can more accurately describe the actual noise characteristics, thereby reducing estimation errors. The proposed algorithm is validated under complex working conditions at different temperatures, and the results show that it has good accuracy. Under BBDST condition at 15 °C, 25 °C, and 35 °C, the mean absolute errors (MAEs) are 0.80%, 0.56%, and 0.71%, while the root mean square errors (RMSEs) are 1.09%, 0.70%, and 0.88%. Under DST condition, the MAEs are 0.73%, 0.49%, and 0.52%, and the RMSEs are 0.86%, 0.67%, and 0.63%.

A series of ether-functionalized paramagnetic ionic liquids, 1-(2-methoxyethyl)-3-alkylimidazolium tetra thiocyanate cobalt [C_n2O1IM]₂[Co(NCS)₄] (n = 1, 2, 3), was synthesized and characterized. The density, surface tension, refractive index, and electrical conductivity of these ionic liquids were measured at 293.15 to 343.15 K at intervals of 5 K, and their thermal expansion coefficients α were calculated. The molecular volume was obtained by measuring the pore volume and porosity. Based on Glasser theory, the standard entropy S₀ (298 K), lattice energy U_POT, surface entropy S_a, and surface enthalpy, H of the ionic liquids were calculated, and the reason why the ionic liquid is in a molten state at room temperature was explained from the perspective of lattice energy. The molar surface Gibbs energy was introduced to improve the traditional Eötvös equation, which was combined with the refractive index to estimate the surface tension, obtaining a fitting index exceeding 0.99. Finally, the relationship between the electrical conductivity of the ionic liquids and temperature was investigated, and the activation energy, molar electrical conductivity, and electrical conductivity diffusion coefficient of the ionic liquids were obtained. The relationship between their properties was summarized. Compared with previously reported ionic liquids using 1-(2-methoxyethyl)-3-methylimidazolium as a cation, this type of ionic liquid has higher density and a smaller coefficient of thermal expansion.

Free standing nanocomposite polymer electrolytes (NCPEs) based on the polymer host poly(vinyl) chloride (PVC) were successfully prepared using the solution casting technique. Lithium nitrate (LiNO₃) and nano-sized silica (SiO₂) (< 100 nm) were employed as the electrolyte and filler, respectively. Impedance studies revealed a maximum ionic conductivity value of 1.226 × 10⁻⁴ S/cm at room temperature for the PVC/LiNO₃ with 5 wt.% nano-SiO₂. X-ray diffraction (XRD) analysis verified the sample’s amorphous nature. Dielectric permittivity and relaxation time values were consistent with impedance results. Additionally, parameters such as diffusion coefficient, mobile concentration, and mobility were evaluated for the prepared samples. Differential scanning calorimetry (DSC) studies confirmed a change in glass transition temperature (T_g) of PVC/LiNO₃/SiO₂ sample. The scanning electron micrograph (SEM) images revealed a honeycomb morphology, indicating ease of Li⁺ ion transportation.

The performance of fuel cells is greatly influenced by the design of the flow channels, making it one of the most significant factors impacting their overall performance. In this work, numerical simulations on serpentine, parallel, and interdigitated geometries are carried out using an open-source toolbox at 0.5, 0.4, and 0.3 V to observe the liquid water saturation distribution at the cathode side of a three-dimensional multiphase non-isothermal model of a protonic exchange membrane fuel cell. The results indicate that the serpentine flow channel shows the maximum current density and the minimum saturation distribution. Also, it is shown that maximum saturation values are located at the edges of the membrane-electrode assembly. There is an important change in the ionic distribution which directly impacts the current density.

Graphical Abstract

Tributyl borate (TBB) is among the widely used film-forming electrolyte additives in lithium-ion batteries (LIBs). It possesses the capability to produce an inorganic solid electrolyte interphase with abundant polar boron-containing compounds, functioning as a solid electrolyte interlayer (or cathode electrolyte interlayer), thus effectively isolating the electrode material from the electrolyte and averting parasitic reactions. Herein, the TBB could contribute to the formation of an inorganic solid electrolyte interphase rich in polar B-F and B-O bonds, thus enhancing the stability of the interface between the electrolyte and cathode materials. The findings demonstrate that the inclusion of 0.5 wt% TBB significantly enhances the stability of the electrode/electrolyte interface in Li‖LiMn_0.8Fe_0.2PO₄ batteries. After 600 cycles, the specific capacity reaches 107.9 mAh g⁻¹ with a capacity retention of 86.45%. This indicates outstanding electrochemical performance and excellent cycling stability. Consequently, TBB exhibits potential as an electrolyte additive for future high-energy density lithium batteries.