Ionics最新文献

Herein, we report the synthesis of calcium-doped cobalt oxide (Ca-CoO) nanocomposites using the simple and effective solution combustion method, and casting of polyvinyl pyrrolidone and polyvinyl alcohol (PVP-PVA) was done by solution intercalation method. Here, 0.5. 1.0, 2.0, and 4.0 wt% of nanofillers were introduced to polymer host. Polymer nanocomposites (PNCs) were subjected to various characterizations, where Fourier transform infrared spectroscopy (FTIR) reveals the positive interaction between the added nanofillers and polymer blends; meanwhile, scanning electron spectroscopy (SEM) analysis reveals the morphological behavior and particle size of 100–140 nm which was confirmed using DLS study. The PNCs reveal the steep UV absorption behavior using the optical absorbance study, while optical and electrical parameters were evaluated as they support the scope of engineering, the band gap, and dopant-dependent optical properties. The band gap energies were decreased from 5.0 to 3.60 eV as the weight % of nanofiller was increased. Dielectric properties along with AC conductivity were increased as the weight percentage of nanofiller increases. Additionally, PNCs were tested for the production of citric acid using Aspergillus niger, which shows that an increase in the wt% of PNCs increases citric acid production and 4% PNCs yields 17.0 g/L.

The cathode material of Na_2/3Ni_1/3Mn_2/3O₂ composition (NNMO) was obtained by the carbonate coprecipitation followed by solid-phase reaction and characterized by XRD analysis, ICP-MS, and electron and impedance spectroscopy. NNMO crystallizes in a P2-type layered hexagonal structure (sp. gr. P63/mmc), consists of spherical agglomerates of ~ 1–3 microns in size, and forms from the plate-like primary grains. The NNMO ionic conductivity value at room temperature was 1.8*10⁻⁴ and 1.3*10⁻⁴ S cm⁻¹ when measured perpendicularly and parallel to the compression axis, respectively. The estimated in dc mode values of electronic conductivity were by 2–3 orders of magnitude less than ionic conductivity. The obtained materials were tested as cathodes in sodium-ion battery cells versus sodium metal. The discharge capacity of NNMO was 160 mAh g⁻¹ and 86 mAh g⁻¹ in the potential range of 1.5–4.0 V and 2.3–4.0 V, respectively (20 mA g⁻¹). NNMO was shown to be stable under cycling in the potential range of 2.3–4.0 V.

There are two cooling tube arrangements were designed, and it was found that the double-tube sandwich structure had better cooling effect than the single-tube structure. In order to analyze the effects of three parameters on the cooling efficiency of a liquid-cooled battery thermal management system, 16 models were designed using L₁₆ (4³) orthogonal test, and the major and minor factors in the models were analyzed. The results show that among the three parameters, the coolant mass flow rate has the most significant impact on the maximum temperature of the battery module, followed by the inlet coolant temperature, and the coolant thermal conductivity has the least effect. In terms of temperature uniformity, the effects of all three factors on module temperature differences are very remarkable, with coolant mass flow rate and inlet temperature having particularly significant effects. The double-tube structure achieved a maximum temperature reduction of 6.7 °C and improved temperature uniformity with a maximum temperature difference reduction of 2.4 °C. Based on a comprehensive balancing method, parameter optimization was performed to determine the optimal combination of factors, further enhancing the cooling performance of the battery module.

With the continuous development of new energy application technology, there is an increasingly urgent need for the safety and affordability of new energy storage products. In recent years, aqueous zinc-ion batteries based on mild aqueous electrolytes have garnered widespread attention as a potential replacement for traditional lithium-ion batteries. However, the limited capacity and low operating voltage of aqueous zinc-ion batteries restrict their widespread application. For this reason, sulfuric acid was added to the electrolyte, which effectively promotes the two-electron conversion of MnO₂/Mn²⁺ during the discharge process. This enhancement results in the high voltage segment of the batteries’ discharge phase offering a higher reversible specific capacity. The results showed that the batteries with 0.1 M H₂SO₄ added to the electrolyte had a reversible discharge-specific capacity of up to 536.07 mAh·g⁻¹ at a current density of 100 mA·g⁻¹. The activated batteries exhibited a reversible specific capacity of 85.11 mAh·g⁻¹ even at a high current density of 1 A·g⁻¹. Furthermore, the capacity retention rate after 1000 cycles was 88.3%. Moreover, the activation rate of the batteries was faster with the addition of H₂SO₄, and the average operating potential increased compared to the batteries without H₂SO₄ in the electrolyte. This provides an effective solution for the practical application of aqueous zinc-ion batteries in power grids.

This research used bibliometric method to analyze the development characteristics of PEMFC during the past 10 years from 2014 to 2023. The results show that the number of articles related to PEMFC in both the CNKI database and the WOS database has a steady growth trend. The top 20 units in terms of the number of articles in the CNKI database were universities and scientific research institutions, and the Wuhan University of Technology came first. In the WOS database, the number of papers published, the number and ranking of highly cited papers, and the in-depth analysis index and ranking of cited references from China were all first. China has the largest cumulative number of papers published (5926 papers in total, accounting for 41.6% of the total number of papers published in this field in the past 10 years), occupying the core position in the international cooperation network, and the quality of papers published by European and American countries was relatively high; keyword cluster analysis has shown that the proton exchange membrane, catalyst, gas diffusion layer, membrane electrode, and cost of PEMFC were the current research focus. Therefore, the development trend of PEMFC key materials was analyzed in detail in this study.

In response to the current issue of low accuracy and robustness in the remaining useful life (RUL) model of lithium-ion batteries. In the framework of AdaBoost, a lithium-ion battery life prediction model based on an improved whale optimization algorithm to optimize the Kernel Extreme Learning Machine (IWOA-KELM) is proposed. The IWOA-KELM model is used as a weak predictor. A weighted voting mechanism is used to set a weight coefficient for each weak predictor and then combine the strong predictor of battery RUL. Constant current charge time, constant voltage charge time, internal resistance, and incremental capacity curves peak were extracted from the Cycle data set as health features to accurately describe battery degradation. Pearson correlation coefficient and Savitzky-Golay filter preprocessed health features. Tent chaotic mapping is used to initialize whale populations and maintain their diversity. The iterative updating strategy of the hunting speed control factor is introduced to reduce the probability of the local optimal case of the whale optimization algorithm. The kernel function parameters and regularization parameters of KELM are optimized by IWOA to improve the model prediction ability. After verification, the RUL error of the method proposed in this article can be as accurate as 4 cycles.

Using non-renewable resources in energy storage has spurred the development of supercapacitors, widely applied in electric vehicles and portable electronic devices for their swift charge–discharge cycles and high-power density. Depending on their materials and energy-storage methods, supercapacitors are classified as either electrochemical double-layer capacitors or pseudocapacitors. This study synthesizes a bis(dimethyl pyridine oxalic acid)oxalate (BDPO) and evaluates its electrochemical properties through impedance analysis. The results reveal promising performance, with specific capacitance values peaking at 330.52 g/F. Scan rate optimization at 0.05 V/s proves crucial for the supercapacitor system’s highest efficient charge storage capacity. Additionally, structural confirmational analysis is done by optimized geometry, NMR analysis, and vibrational analysis also interactions are confirmed through ELF, LOL, AIM, and NBO analysis. Following an NBO assessment, crucial donor–acceptor interactions were examined. Notably, with stabilization energies of 33.36, 22.59, 10.24, 3.24, 1.73, 1.18, and 1.09 kcal/mol are caused by hyperconjugative contacts in lone pair LP (O₃₅) → σ*(N₁₄—H₁₅), LP (O₄₁) → σ*(N₂₉—H₄₂), LP (O₄₀) → σ*(O₃₃—H₃₄), LP (O₄₃) → σ*(C₁—H₂), LP (O₄₈) → σ*(C₈—H₉), LP (O₃₆) → σ*(C₂₅—H₂₈), LP (O₄₃) → σ*(C₁₆—H₁₇) significantly influenced various topological analyses, including AIM, ELF, LOL, RDG, and IGM, producing favorable outcomes.

In this research, we have conducted an in-depth investigation into the structural, electronic characteristics, and thermodynamic properties of the LiTi₂O₄ compound using first-principles calculations grounded in density functional theory with the generalized gradient approximation. Our findings reveal that the LiTi₂O₄ compound possesses a calculated lattice constant of 8.407 Å. Furthermore, we have derived critical battery-related properties, including an average voltage of 1.53 V versus Li/Li⁺ and an energy density of 245 Wh/kg. To deepen our understanding of LiTi₂O₄, we have explored its thermodynamic properties employing the quasi-harmonic Debye model. These properties encompass the Debye temperature, volume variation, compressibility modulus, specific capacity, and thermal capacity. Importantly, we have observed that the Debye stiffness of LiTi₂O₄ increases with rising pressure. Moreover, we have conducted measurements to assess various optical properties of the LiTi₂O₄ compound. These properties include the absorption coefficient, photoconductivity, and reflectivity.

This study investigates twin screw extruded multi-walled carbon nanotube (MWCNT)–infused polyaniline (PANI) composite–based bipolar plates (BPPs) for proton exchange membrane fuel cells (PEMFCs) fabricated via fused deposition modelling (FDM). The 3D-printed composite plates with varying MWCNT proportions (5–30 wt%) were subjected to extensive characterization, including morphological study, thermal, mechanical, electrochemical corrosion, and electrical characteristics analysis. The plates with 25 wt% MWCNT (MWCNT₂₅-PANI₇₅) outperformed the US Department of Energy (US DoE) objectives with their high mechanical strengths exceeding 40 MPa and high thermal conductivity of 20.29 W/mK at 80 °C. Corrosion analysis showed that MWCNT₂₅-PANI₇₅ substantially improved corrosion resistance with a corrosion potential (E_corr) of − 152.60 mV, a corrosion current density (I_corr) of 0.19 µA/cm², and a protection efficiency (P.E.) of 97.29%. However, the MWCNT₂₅-PANI₇₅ plate is deficient in electrical properties, with an in-plane conductivity exhibited at 80.15 S/cm, which falls short of the DoE objective of 100 S/cm, demonstrating the difficulties of combining conductivity optimization with other factors. In a single-cell PEMFC system, MWCNT₂₅-PANI₇₅ achieved power densities of 533.91 mW/cm², demonstrating its practicability. Further research is called for to enhance conductivity through covalent functionalization of MWCNTs, aiming to meet the US DoE targets and improve overall efficiency.

Graphical abstract

Composite electrode materials often have excellent electrochemical properties; however, their preparation often requires multiple steps. Therefore, to further reduce the time and preparation cost, a NiCo₂S₄@NiCo-layered double hydroxide (NiCo-LDH) composite electrode material was prepared by a one-step method in this study. In the three-electrode system, the specific capacitance was 7462.5 mF cm⁻² at a current density of 5 mA cm⁻². Moreover, the specific capacitance was maintained at 78.4% after 6000 cycles. To further verify its practical application, we assembled an asymmetric supercapacitor using activated carbon as the anode material and NiCo₂S₄@NiCo-LDH as the positive material. The results show that the capacity of the device can still be maintained at 80% of its original capacity after 5000 cycles. This shows that the NiCo₂S₄@NiCo-LDH@NF electrode material has good application prospects.