Ionics最新文献

Considering the increase in raw material prices and environmental pollution, the spent lithium-ion battery cathode material was leached with oxalic acid and sulfuric acid, and LiNi_0.9Co_0.05Mn_0.05O₂ (NCM955) was prepared from the leaching solution. Then, the Ni-rich cathode material NCM955 was doped with ZrO₂ and WO₃. The co-doping of Zr⁴⁺ and W⁶⁺ in Ni-rich NCM955 cathode exhibits exceptional cycle stability performance. Specifically, the Zr⁴⁺ and W⁶⁺ co-doped sample demonstrates a remarkable capacity retention improvement of 89.21% at 0.5 C after 100 cycles compared to the pristine sample (69.15%). Meanwhile, at a high rate of 5 C, the co-doped sample shows a significantly higher specific capacity of 125.37 mAh·g⁻¹ compared to the pristine sample’s value of only 63.98 mAh·g⁻¹. The results of XRD, XPS, and SEM indicate that the co-doping of Zr⁴⁺ and W⁶⁺ can enhance the stability of the material. Electrochemical impedance spectroscopy (EIS) results show that the co-doping of Zr⁴⁺ and W⁶⁺ effectively reduces the electrochemical impedance, and galvanostatic intermittent titration technique (GITT) shows that the co-doping of Zr⁴⁺ and W⁶⁺ increases the diffusion rate of Li⁺. Therefore, dual doping modification with Zr⁴⁺ and W⁶⁺ is beneficial for enhancing both structural stability and electrochemical performance of Ni-rich layered oxide cathode materials.

Lithium-ion conducting bio-membranes based on Moringa oleifera gum (MOG) and LiNO₃ are fabricated through the solution casting method. Samples containing 1 g MOG incorporated with 0.6 to 0.8 mol.wt% LiNO₃ salt concentrations are prepared. The amorphous nature of the prepared samples is verified through XRD analysis. The glass transition temperature of the prepared samples is measured by DSC technique. AC impedance spectroscopy indicates that the sample 1 g MOG + 0.8 mol.wt% LiNO₃ gives the highest ionic conductivity measured as 5.46 × 10⁻³ S/cm. Additionally, CV, LSV, and transference number studies are taken for the highest ion conducting sample to evaluate its electrochemical stability. A primary lithium-ion conducting battery is constructed by using the highest ion conducting sample as an electrolyte for the system and the open circuit voltage is observed as 2.19 V. Then, a rechargeable lithium-ion conducting coin cell is constructed, and its performances are studied.

Polyolefins like polypropylene (PP) and polyethylene (PE)-based separators are widely used in the lithium-ion batteries (LIBs). However, applying polyolefin separators is limited in high-performance batteries due to poor electrolyte wettability and thermal stability. In this study, on the basis of the concept of “waste to wealth,” a novel approach has been proposed by utilizing waste raw materials of calcium-magnesium mud (CM), incorporating in a slurry coating method applied to a commercial PP separator for enhanced performance surpassing that of the traditional separator. The CM-coated PP (CM@PP) separator demonstrated better thermal stability and electrolyte compatibility, higher Li-ion conductivity, and lower interfacial resistance than the uncoated PP separator. Cycling and rate performance of CM@PP separator assembled battery were higher compared to those of the uncoated PP separator assembled battery. The LiFePO₄|Li battery with the CM@PP separator rendered a high discharge capacity of 154 mAh g⁻¹ at 1 C and a capacity retention rate of 93.0% after 200 cycles. These results indicate that CM-coated PP separator is a promising strategy to improve the safety and electrochemical performance of LIBs. The low cost of CM emphasized the superiority of this facile separator modification method.

The operating temperature of high-temperature proton exchange membrane fuel cells (HT-PEMFC) exceeds 120 °C. The strategic addition of baffles in the HT-PEMFC flow channel can facilitate the diffusion of reactant gases towards the gas diffusion layer (GDL), increase the reaction area of the catalytic layer, improve the reaction rate, and enhance overall performance. The water drops curve baffle proposed in this study exhibits a more optimal curvature profile for gas flow compared to previous baffle designs. In this study, the optimal quantity, inlet and outlet orientations, and size parameters of the water drop curve baffles were examined by combining three-dimensional simulation modeling with genetic algorithm optimization. A comparison of net power density for configurations ranging from zero to four baffles in the HT-PEMFC demonstrated that the configuration with four baffles achieved superior performance, resulting in a net power density of 0.368 W/cm², which represents a 5.74% increase compared to the basic channel without baffles. Additionally, it was observed that reverse flow incurs an additional pressure drop of 1.12% compared to forward flow. Following optimization, with the variables set to a = 0.730123 and b = 0.317671, the net power density increased to 0.3759 W/cm², reflecting a 2.17% improvement over the non-optimized state, thereby achieving the optimal performance level for HT-PEMFC.

La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ (LSCF) perovskite with good stability and high oxygen diffusion coefficient has been extensively studied as oxygen electrode in reversible solid oxide cells (RSOCs). Significant promotion of oxygen reaction kinetics of the LSCF oxygen electrode was achieved by the addition of Ca_xCo₄O_9+δ (CCOx, x = 3, 1.5) nano-catalysts in the present study. The La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ-Ca_1.5Co₄O_9+δ (LSCF-CCO1.5) electrode exhibited the optimal electrochemical property among the LSCF-based electrodes and the lowest polarization resistance (R_p) of 0.039 Ω·cm² was attained at 800 °C, which was ~ 97% lower than that of the LSFM electrode. Furthermore, the LSCF-CCO1.5 oxygen electrode also manifested excellent thermal cycling stability and alternating polarization durability. The hydrogen production rate of the LSCF-CCO1.5 electrolytic cell was 946 mL·cm⁻²·h⁻¹ at 1.5 V at 800 °C, which was 2.6 times higher than that of the LSCF cell (362 mL·cm⁻²·h⁻¹). The results certified the enhancement of electrochemical properties for LSCF oxygen electrode by the addition of CCOx nano-catalysts.

The electrochemical performance of double perovskite oxides as cathode material for intermediate-temperature solid oxide fuel cells can be enhanced through structural modifications. The electrochemical performance of Sr₂CoNbO_6-δ-Sm_0.2Ce_0.8O_2-δ (SCNO-SDC) composite structurally assembled using various techniques, one-pot, electrospinning, and mixing have been studied to understand the structural change and performance relationship. The nanofiber composite exhibited superior cell performance of 0.996 W/cm² peak power density and 0.079 Ω cm² polarisation resistance compared to one-pot and the mixed composite, which yielded 0.831 W/cm² and 0.0908 Ω cm², and 0.706 W/cm² and 0.206 Ω cm², respectively, at a temperature of 700°C. The work emphasises a successful approach to modifying the structure of the SCNO-SDC cathode by identifying the rate-determining process to produce superior electrode materials. The improved electrochemical performance of the structurally modified cathode composite is a result of its cohesive interfacial interaction, which significantly improves the kinetics of the electrode reaction and stability.

In this work, Fe₃O₄ nanoparticles and Fe₃O₄@ZnO nanocomposites were prepared by co-precipitation and reflux techniques, respectively. Structural, magnetic, and photocatalytic properties were studied. The crystalline structure and morphology were confirmed by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) analyses. Fe₃O₄ had a cubic spinel structure with a crystal size of 37.5 nm. Fourier transform infrared spectroscopy (FTIR) showed the characteristic peaks corresponding to Fe–O, ZnO, and surface hydroxyl group, confirming that Fe₃O₄ and ZnO exist in nanocomposites. X-ray photoelectron spectroscopy (XPS) analysis confirmed Fe, Zn, and O elements as its surface composition. The vibrating sample magnetometer (VSM) confirmed that the magnetic properties of Fe₃O₄ nanoparticles exhibited superparamagnetism with saturation magnetization of 72 emu/g, whereas it was relatively lower (1.4 emu/g) for Fe₃O₄@ZnO due to the coating of ZnO. The nanocomposites showed the best photocatalytic activity, degrading 77% methylene blue dye in 20 min under natural sunlight, compared with 15% for Fe₃O₄ alone. These findings suggest that the Fe₃O₄@ZnO nanocomposite is a promising candidate for environmental applications, particularly in wastewater treatment.

Developing high-performance energy storage devices using sustainable materials is essential for their widespread application in electronic devices. The energy density of carbon-based electric double-layer capacitors (EDLCs) can be optimized through the integration of polymer-based electrolytes and ionic liquids. Poly(vinyl alcohol) (PVA)-based gel electrolytes, in particular, have attracted significant interest due to their solubility, biodegradability, and biocompatibility. In this study, we fabricated EDLC samples employing a PVA gel polymer electrolyte (GPE) enhanced with an ionic liquid and phosphoric acid. Our focus was on developing a proton-conducting PVA-based GPE and utilizing activated carbon as the electrode material. Optimal performance was achieved with an ionic liquid concentration of 25 wt% in a GPE film placed between the carbon-based EDLC electrodes. The device demonstrated a discharge specific capacitance of 45.8 F/g with stable performance over extensive cycling tests.

The global shift towards electric vehicles (EVs) underscores the critical need for reliable battery performance and safety. Lithium-ion batteries, particularly Li-NMC (lithium nickel manganese cobalt oxide), are widely adopted for their balanced functional and performance characteristics. However, the advancement of batteries with higher nickel content and reduced manganese and cobalt introduces challenges, including increased susceptibility to thermal runaway and degradation, especially under abusive conditions like over-discharge. This study addresses significant research gaps by developing a machine learning (ML) algorithm for the early detection and predictive maintenance of over-discharged Li-NMC batteries. Current methods often fail to identify and mitigate the effects of continuous cycling, which can release harmful free radicals such as singlet oxygen (¹ ({O}_{2})) and superoxide (({O}_{2}^{-})) that accelerate degradation. Our ML approach utilizes supervised learning, feature engineering, and model optimization, leveraging key input features such as voltage, time, and cycle count which are derived from extensive battery life testing. To validate our model, we conducted scanning electron microscopy energy-dispersive spectroscopy (SEM–EDS), galvanostatic charge–discharge (GCD) tests, and rate capability tests. The proposed ridge regression model achieved a mean absolute error (MAE) of 0.11422%, a mean squared error (MSE) of 0.02313%, and an R-squared (R²) value of 0.99, outperforming other models such as Decision Trees (DT), Recurrent Neural Networks (RNNs), Support Vector Machines (SVMs), Gradient Boosting (GB), and Lasso Regression. Our model addresses key shortcomings of existing methods, particularly in predicting degradation in precycled batteries subjected to fault induction. The insights gained contribute to a robust control strategy for EV battery management, enabling proactive maintenance, timely battery replacement, and enhanced system reliability and safety, effectively addressing the long-term challenges in battery health management.

Zinc ion hybrid capacitors (ZIHCs) have received much attention due to their low cost, safety, and green features. However, its development is seriously restricted by defects such as low energy density and insufficient cycle life. The selection of suitable capacitive materials can effectively enhance their electrochemical performance. Porous carbon materials become the choice of capacitive materials for ZIHCs due to their high ion adsorption capacity and fast kinetic behavior. In this paper, an oxygen-enriched biomass-derived nanoporous carbon was prepared by pyrolysis of Wedelia chinensis combining the chemical activation. The oxygen-rich functional groups on the surface of this nanoporous carbon can provide additional pseudocapacitance and improve the wettability of the material. The excellent electrochemical performance of the material in aqueous electrolyte was verified by assembling symmetrical capacitor (SCs) and ZIHC devices. Specifically, as high as 151 W h kg⁻¹ of energy density and 18 kW kg⁻¹ of power output as well as 25,000 cycles of long cycle life with 97.4% of capacity retention were demonstrated by as-assembled ZIHC.