Ionics最新文献

The state of health (SOH) of lithium-ion batteries is a decisive factor in ensuring the stability of electric vehicle systems. To solve the problem of low accuracy and robustness of lithium-ion battery SOH prediction models, this article proposes a differential evolution grey wolf optimization algorithm mixed kernel least squares support vector regression (MK-LSSVR) prediction model. Four health features were extracted from individual batteries from NASA and Cycle datasets. These features can describe the degradation properties of lithium-ion batteries. The Pearson correlation coefficient is used to detect the correlation between battery SOH and health features. Principal component analysis performs dimensionality reduction and fusion processing on the health feature dataset to reduce data redundancy. The genetic, selection, and mutation rules of the differential evolution algorithm are improved to enhance the grey wolf (DEGWO) search algorithm. The DEGWO algorithm optimizes the core parameters of the MK-LSSVR model to enhance its predictive ability. The research results indicate that the average absolute error of the prediction model is between 0.36 and 0.62%. The prediction model proposed in this article effectively improves the prediction accuracy and robustness of the battery health state.

Lithium-sulfur batteries (LSBs) represent an innovative type of secondary battery poised to surpass lithium-ion batteries owing to the exceptionally high theoretical specific capacity. However, widespread adoption faces challenges such as reduced Coulombic efficiency from the shuttle effect and poor conductivity of Li₂S₂/Li₂S. These challenges can potentially be addressed effectively by using functional separator layers. In this work, we designed a novel PP separator with a coating of Nd₂O₃-doped Ketjen Black (Nd₂O₃/KB/PP). Nd₂O₃ contributes to chemical adsorption and catalytic conversion, while KB enhances physical adsorption. Together, these components form an adsorption-catalytic bifunctional framework network. The experimental results demonstrate that Nd₂O₃/KB/PP significantly improves the performance of LSBs. At 2 C, the specific discharge capacity reaches 861 mAh/g initially, with an average decay rate of only 0.043% per cycle. Additionally, with a high sulfur load of 5.8 mg/cm², the initial area specific capacity was 5.5 mAh/cm², with 4.1 mAh/cm² remaining after 100 cycles at 0.1 C. This research contributes valuable insights toward advancing the commercial viability of LSBs.

Silicon has been the most ideal candidate anode material for high-capacity lithium-ion batteries owing to its higher theoretical capacity, relatively low potential, and rich resources. Unfortunately, the significant volume expansion (300%) and low intrinsic conductivity result in poor electrochemical performance during the charging-discharging process. Herein, one-dimensional linear polypyrrole-coated silicon nanoparticle (Si@PPy) composites are synthesized to elevate the lithium storage performance of silicon-based materials. The Si nanoparticles are coated by polypyrrole to form a one-dimensional linear structure, which not only enhances the electron/ion transfer rate, but also relieves the volume changes of Si. Simultaneously, the constructed interwoven network would be beneficial for the electrolyte immersion and provide more space for the expansion of the entire electrode. So the Si@PPy-2 composites demonstrated superior electrochemical performance with a discharge capacity of 1660.2 mAh g⁻¹ after 100 cycles at 100 mA g⁻¹ and the reversible specific capacity of 1047.0 mAh g⁻¹ at a high current density of 1000 mA g⁻¹ for 500 cycles. This simple in situ polymerization method to prepare high-performance Si anodes would be beneficial for the commercialization of silicon-based electrodes in LIBs.

Cathode materials play a vital role in lithium-ion batteries to evaluate its performance. LiNiPO₄ is one of the attractive cathodes due to its high voltage accompanied by olivine structure. The synthesis of LiNiPO₄ cathode materials using an oxalic acid-assisted sol–gel method resulted in pristine samples, which were subsequently coated with 1 wt.% and 2 wt.% Al₂O₃ to investigate the impact on electrochemical properties. Structural analyses employing X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy revealed that the Al₂O₃-coated LiNiPO₄ samples exhibited enhanced crystallinity and smaller crystallite sizes compared to the pristine material. The initial discharge capacities were measured at 119.05 and 115.48 mAhg⁻¹ for the 1 and 2 wt.% Al₂O₃-coated samples, respectively, slightly higher than the pristine sample’s discharge capacity of 110.71 mAhg⁻¹. During cycling, the Al₂O₃-coated samples initially demonstrated superior capacity retention and cycling performance. Specifically, the 1 wt.% Al₂O₃-coated sample maintained good capacity retention throughout the cycles, indicating improved lithium-ion diffusion and structural stability. In conclusion, the study highlights that an optimal amount of Al₂O₃ coating enhances the structural properties and lithium-ion diffusion within LiNiPO₄ cathode materials, significantly improving their electrochemical performance. The findings underscore the importance of controlled coating strategies in optimizing the functionality and longevity of battery materials for advanced energy storage applications.

Developing an efficient material as a counter electrode (CE) with excellent catalytic activity, intrinsic stability, and low cost is essential for the commercial application of dye-sensitized solar cells (DSSCs). Photovoltaic properties of DSSCs fabricated with cost-effective, platinum-free CEs composed of various carbon allotrope mixtures—including graphite (GR), activated carbon (AC), and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) films—were systematically investigated. DSSCs assembled with PEDOT:PSS/GR/AC showed an impressive photovoltaic conversion efficiency of 4.60%, compared to 4.06% for DSSCs with GR/AC CE or 1.66% for PEDOT:PSS alone or 6.56% for Pt under the illumination 100 mW cm⁻² (AM 1.5 G) due to the superior electrocatalytic activity and the conductivity of AC and PEDOT:PSS. The fabricated carbon counter electrodes were extensively characterized by using scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, cyclic voltammetry (CV), Tafel measurements, and electrochemical impedance spectroscopy (EIS). The CV, EIS, and Tafel measurements indicated that the PEDOT:PSS/GR/AC composite film has low charge-transfer resistance on the electrolyte/CE interface and high catalytic activity for the reduction of triiodide to iodide than the GR/AC CEs. It is potentially feasible that such a carbon configuration can be used as a counter electrode, replacing the more expensive Pt in DSSCs.

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The challenges faced in battery health management are caused by the occurrence of the capacity regeneration process (CRP) during battery degradation. This article suggests a combination method to predict the remaining useful life (RUL) of lithium-ion batteries, considering CRP. The proposed method starts by breaking down the original data into multiple intrinsic mode function (IMF) components using the improved complete ensemble empirical mode decomposition with the adaptive noise (ICEEMDAN) method. Then, the IMF components are categorized into high-correlation components (HC), which indicate the primary deterioration pattern of the battery, and low-correlation components (LC), which indicate CRP, based on the Pearson correlation coefficient (PCC). Next, the dataset is split into training, validation, and testing sets through data segmentation. The HC and LC data are separately utilized to train and predict using feedforward neural networks (FNN)-I and FNN-II, respectively. Throughout the experiment, the HC and LC data are treated as multiple sets of new capacity data, effectively enhancing the diversity of the dataset. Finally, the predictions from both models are combined to obtain the final capacity degradation curve, and the battery’s RUL is determined. Experiments are conducted on two distinct datasets, achieving a mean absolute error (MAE) of less than 1.31% and a root mean square error (RMSE) of less than 1.74%.

Here, we show how to make highly nitrogen-containing graphite carbon (g-C₃N₄)-coated rare earth metal oxide of CeO₂ nanotubes (CeO₂/g-C₃N₄), which is usable as a dual function of supercapacitor electrode and counter electrode for dye-sensitized solar cells (DSSCs). Transmission electron microscopy (TEM), field emission scanning electron spectroscopy (FESEM), and energy-dispersive X-ray spectroscopy (EDX) techniques have all been used to examine the surface morphology and chemical data of the catalyst. The CeO₂/g-C₃N₄-composited electrode exhibits high-specific capacitance of 614 Fg⁻¹ at 2 Ag⁻¹. Based on the Trassati method, the CeO₂/g-C₃N₄ electrode exhibits 92% capacitive behavior at 100 mVs⁻¹. The CeO₂/g-C₃N₄ electrode exhibits 91.6% cyclic stability after 10,000 cycles. The DSSCs made with CeO₂/g-C₃N₄ exhibited outstanding catalytic activity and a PCE of 8.13% compared to 8.02% for a standard electrode made of Pt. Due to the composite material’s outstanding catalytic performance and good electrical conductivity, this has occurred. However, the electrical conductivity of the titanium mesh is high. And compared to an FTO substrate, it can enhance the region of contact between the electrode material and the substrate. It can enhance I⁻/I⁻³’s capacity to speed up electron transmission by diffusion.

Double transition metal oxides and oxygen group element compounds are widely used in supercapacitor electrode materials. In this work, nanowire-like NiCo₂O₄ was synthesised using a hydrothermal method, and Ni₃Se₄ was deposited on a nickel foam using NiCo₂O₄ as the base material utilizing electrodeposition. Composites exhibit superior electrochemical properties with lower impedance values than single materials. Ni₃Se₄@NiCo₂O₄/NF composite showed an areal capacitance of 1404.17 mF cm⁻² at 1 mA cm⁻², outperforming both NiCo₂O₄/NF (735.83 mF cm⁻²) and Ni₃Se₄/NF (523.5 mF cm⁻²) electrodes. The asymmetric supercapacitor is formed by using Ni₃Se₄@NiCo₂O₄/NF composite electrode as anode and carbon electrode as cathode with 3 M KOH solution as electrolyte. The device has an energy density of 0.0864 mWh cm⁻² at a power density of 0.8 mW cm⁻² and 0.0231 mWh cm⁻² at a power density of 7.996 mW cm⁻². The capacitance retention of this asymmetric supercapacitor remained 91.76% after 5000 cycles at a current density of 10 mA cm⁻².

An alternative to create novel multifunctional materials with a broad range of applications in energy storage systems is the development of nano composite hybrid materials with good qualities from the right combination of chemically different components. Herein, Polyaniline hybrid composites containing nano pure TiO₂ and nano doped (Cu, N) TiO₂ (25 wt. %) were prepared using in situ chemical polymerization approach. All structural characterizations showed the addition effect of both nano pure TiO₂ and nano doped (Cu, N) TiO₂ on the polyaniline matrix. The well dispersion of spherical nano pure TiO₂ and nano doped (Cu, N) TiO₂ particles inside the rods structure of polyaniline chains, forming the core–shell exhibited good modification for both thermal stability and electrical properties enhancement. The results showed that all nanocomposites have high thermal stability compared to pure polyaniline. The sample containing nano nitrogen—doped TiO₂ (NDPC2) delivered AC- conductivity value of 5 × 10^–4 Ω⁻¹.cm⁻¹ at room temperature as well as exhibited the highest dielectric constant value compared to the other ones with a value of 26. The studied samples have low dielectric loss values, suggesting that they are effective shielding materials. The same sample exhibited the highest surface area (32.2 m²/g) and pore volume (0.119 cc/g) compared to the others, making it a promising sample for diverse applications of energy storage systems.

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