Journal of Power Sources Advances最新文献

Crystal orientation plays a crucial role in the performance of Sb₂S₃ thin-film solar cells (TFSCs). Among various deposition techniques, vapor transport deposition (VTD) stands out as a viable technique for producing scalable and uniformly deposited thin films, particularly in the solar industry. This study explores temperature-modulated VTD-Sb₂S₃ deposition to enable efficient carrier transport in photovoltaic cells. In the VTD process, the deposition temperature is altered between 480 °C and 540 °C. XRD, SEM, EDS, and AFM techniques are employed to obtain the characteristics of the Sb₂S₃ thin films at varying temperatures and evaluate critical features like crystal structure and orientation, surface morphology, composition, and roughness. The prominent crystal orientation changes from the (hk0) to the (hk1) plane after increasing the deposition temperature from 500 to 520 °C. The (211)- and (221)-planes become more prominent when the deposition temperature exceeds 520 °C. The device with the architecture SLG/Mo/Sb₂S₃/CdS/i-ZnO/AZO/Al, a substrate-configured TFSC, yields a maximum power conversion efficiency of 0.22% when the VTD-Sb₂S₃ absorber film is deposited at 520 °C. This study presents a promising approach to producing thin films with a preference for specific crystal orientations. The primary aim is to enhance the efficiency of solar cells that utilize VTD-Sb₂S₃ absorbers.

Sodium vanadium triphosphate (Na₃V₂(PO₄)₃, NVP) is a promising cathode material for Na-ion batteries. Due to its intrinsically low electronic conductivity, it is usually mixed or coated with carbon. However, so far there have been no systematic studies on the ionic and electronic conductivity of carbon-coated NVP particles. In this work, NVP with varying carbon contents are prepared. The powders are sintered as single pellets or sandwiched between a solid electrolyte for measurements in an ion blocking and non-ion blocking configuration. In these two different configurations, two different electrodes are attached and several electrochemical characterization techniques are applied such as impedance spectroscopy, chronoamperometry, and four-point measurements. The NVP/C composites with carbon content >0.1 wt% show a high degree of densification and an amorphous carbon network. The conductivity of NVP in composites with carbon content <0.1 wt% shows dominating ionic conduction with an average value of ∼2 × 10⁻⁶ S cm⁻¹. NVP/C samples with carbon contents >0.1 wt% show a dominance of electronic conduction in the range of 0.01–0.2 mS cm⁻¹ because of the percolated carbon network at the grain boundaries. The ionic conductivity, however, remains almost constant in the same order of magnitude (∼6 × 10⁻⁶ S cm⁻¹).

This study analyzes the field performance of various solar cell designs. Most research and development efforts concerning solar cells aim to increase their efficiency or power under standard test conditions (STC). However, conducting an actual field performance analysis is crucial because of the various ambient conditions present in the field, including temperature, irradiance, PV system installation, and albedo. These conditions can result in different performance results compared to STC. This study compares and analyzes case studies to assess field performance. One particular case study compares the field performance of monofacial modules with a monofacial passivated emitter and rear cell (PERC) and bifacial PERC at a carport system in the ambient conditions of the Korean Peninsula during summer and winter. The module material properties (white EVA and white backsheet) can impact module performance owing to the transmittance spectra at longer wavelengths. Certain transmittance values also contribute to the bifaciality number. Although the monofacial cell demonstrates better STC results, the field performance of the bifacial cell is superior in terms of energy yield and cost-effectiveness. Therefore, this study highlights the importance of considering the field performance (energy yield), in addition to STC, when designing solar cells and modules.

The dynamic behavior of potentials and currents in porous electrodes is crucial for optimizing the computational speed of lithium-ion battery models. Pseudo-two-dimensional (P2D) models, based on partial differential equations, offer insight but pose computational challenges. P2D equations are tackled with iterative algorithms, like the Newton or the shooting method. Yet, initiating the algorithm with random guesses for solid and electrolyte potentials can cause diverging ionic current values inside the electrolyte phase, increasing the computation time required to converge to the final solution. This study proposes a novel model order reduction using a galvanic pseudo-potential to prevent the occurrence of diverging currents. By sidestepping infinite values for ionic current inside the electrolyte phase, the method streamlines math and speeds up the shooting method used for solving battery model equations.

Lithium-ion batteries with silicon-graphite composite anodes feature an asymmetric and direction-dependent voltage hysteresis. Upon comparing established hysteresis models from literature, it was found that a separate modelling of charge and discharge direction is required for both the operator-based Preisach model and the differential equation-based one-state model, often referred to as Plett model. This paper presents the first bidirectional implementation of the one-state hysteresis model based on extensive measurements of first-order reversal branches of a Si/C NMC cell. The approach accounts for directionality but cannot deal with the complexity of the hysteresis traverses, so an extension of the Preisach model is discussed and found to be infeasible. This justifies the development of a novel hysteresis model, the trajectory correction hysteresis (TCH) model, that fulfils the identified requirements for bidirectionality, closed-loop property and direct data fit and can be generally applied to any cell chemistry. The TCH model considers the traverse starting point, which allows for the unambiguous definition of hysteresis states and enables the simulation of complex trajectories due to two correction mechanisms. The static and dynamic current profiles in complex hysteresis scenarios demonstrate superior performance with 4.5 mV mae compared to Preisach (19.6 mV mae) and Plett (11.7 mV mae) models.

In this study, we propose an effective strategy to improve the electrochemical performance of a P2-Na_0.67Mn_0.75Ni_0.25O₂ (P2-MNO) cathode material for Na-ion batteries based on MgO surface coating. The MgO coating, with a thickness of ∼20–50 nm, is obtained by means of a facile wet-chemistry approach followed by heat treatment carried out at comparatively low temperatures (400–500 °C) in order to avoid possible Mg doping in the bulk of the P2-MNO. Detailed electrochemical investigations demonstrate improved electrochemical performance of the MgO-coated material (M-P2-MNO) in comparison to pristine bare one at both room and elevated (40 °C) temperatures. Operando differential electrochemical mass spectroscopy (DEMS) demonstrate that the MgO coating is effective in suppressing unwanted gas evolution due to side reactions thus stabilizing the cathode/electrolyte interface.

A novel approach to develop a low-temperature lithium-ion battery (LIB) based on tin selenide (SnSe) and carbon (C) nanofibers as the active electrode material has been successfully achieved. The SnSe@C nanofiber anode exhibited excellent electrochemical properties, such as high capacity and good rate capability. The anode maintained a consistent charge capacity of ∼923 mAh g⁻¹ at a current rate of 0.1 A g⁻¹ over 100 cycles at room temperature. Furthermore, investigated for the first time at low temperatures, the SnSe@C nanofiber anode exhibited superior capacity (∼430 mAh g⁻¹ at −20 °C) compared to conventional graphite electrode (∼25 mAh g⁻¹ at −20 °C). The proposed SnSe@C nanofiber anode demonstrated a great potential to be applied for developing next-generation LIBs with improved low-temperature performance.

This study investigates the impact of water ratio on the direct aqueous recycling of NMC811. Three different ratios of NMC811 to water were examined. The results demonstrate that the water ratio significantly affects the electrochemical performance of NMC811. Capacity fading is observed in all water-exposed samples, with the sample having the lowest water ratio showing less fading compared to the samples processed with higher water ratios. Both samples with higher water ratios exhibit similar performance, suggesting an equilibrium at the NMC811-water interface is established. Characterization of the cathode materials reveals variations in the amount and type of surface species. The pristine sample, not exposed to water, only shows Li₂CO₃ and NiO as surface species, while the water-exposed NMC811 samples exhibit nickel carbonates and hydroxides along with associated water. The poorer performance of samples exposed to higher water ratios is likely due to higher amounts of these species forming on the particle surface. Additionally, lithium, cobalt, and manganese carbonates, as well as lithium hydroxide with associated water, are detected and could further contribute to the poorer performance.

Li-ion capacitors (LICs) have emerged as promising energy storage devices within the electronic industry. The performance of LICs is predominantly influenced by the electrode material utilized, making the proper selection and development of said material of utmost importance. This study focuses on fabricating a composite electrode material using a simple, cost-effective, and environmentally friendly technique, combining Manganese dioxide (MnO₂) nanotube and graphene oxide (GO). The low cost, high natural abundance, and high theoretical specific capacity (1230 mAh/g) of MnO2 enables it to be effectively used in energy storage systems. The resulting material showcases a distinctive architecture where MnO₂ nanotube nanorods are enveloped by GO nanosheets. By employing a binder-free buckypaper approach, the MnO₂ nanotube/GO composite anode exhibits exceptional electrochemical performance, including high energy (213.29 Wh/kg) and power density (28.5 kW/kg), improved rate capability, and excellent cyclic stability. These findings undoubtedly indicate a promising future for the MnO₂ nanotube/GO composite anode in lithium-ion-based energy storage systems.

The Proton Exchange Membrane Fuel Cell (PEMFC), known for its efficient energy conversion, minimal electrolyte leakage, and low operating temperature, shows great potential as a clean energy source. However, its lifespan is limited due to degradation during normal operation, which, if uncontrolled, can result in dangerous failures such as explosions. Hence, accurately estimating the remaining useful life (RUL) is vital. In this research, a combined prediction method using genetic algorithms (GA) and nonlinear autoregressive neural networks (NARX) with external inputs is proposed. The method's performance was trained and validated using the 2014 IEEE PHM Data Challenge dataset, and it was compared to two commonly used artificial neural network algorithms: GA-based backpropagation neural network (GA-BPNN) and GA-based time delay neural network (GA-TDNN). The findings demonstrate that the proposed approach surpasses the other two artificial neural network algorithms in terms of prediction accuracy. Although GA is known for its computational requirement, optimization is performed offline. Once optimal neural network (NN) hyper-parameters are determined, the optimized NN is used online for RUL prediction.