International Journal of Energy Research最新文献

Lithium-ion batteries (LIBs) have become a staple in modern technology, powering everything from advanced gadgets to hybrid vehicles. Their appeal lies in their impressive energy density relative to weight, minimal memory effect, and the ability to undergo numerous charging and discharging cycles effectively. Currently, treatments for used LIBs are still in development, and efforts to optimize recycling methods and technologies are yet to be fully realized. The primary goal of this bibliometric analysis is to systematically examine the domain of LIB energy storage systems from 2011 to 2022, aiming to identify prevailing trends, recycling practices, and emerging directions of the LIB sector. Initially, a dataset of 1149 publications was retrieved from Web of Science, focusing on the top 100 most-cited papers, which were comprehensively investigated through VOSviewer and CiteSpace software. The study offers additional value to the co-authorship map, network analyses of keyword co-occurrence network analysis, dissemination of articles across nations and journals, and impact of distinct research types. The findings reveal that the research output has steadily increased and peaked in 2022, with the leading global contributors being the People’s Republic of China (30%), the United States (26%), and Germany (10%). Emerging themes identified from the analysis include battery safety and thermal management, electrode material design and performance, as well as recycling and circular economy strategies. Recycling approaches, such as hydrometallurgy, can reduce the risk of heavy metal leaching from end-of-life (EoL) products, thereby effectively reducing toxicity. This study provides future directions for enhancing the effectiveness of LIB energy storage systems. It serves as a valuable reference point for identifying underexplored domains, guiding future innovations towards circular storage systems, and ultimately benefiting environmental sustainability, reliability, and adaptability.

This study focuses on the conversion of Red Sea water into hydrogen (H₂) fuel using a photoelectrochemical (PEC) approach. To achieve this, a photocathode was fabricated based on a bismuth (Bi)(III) oxide iodide–poly(2-aminobenzene-1-thiol) (P2ABT) multilayer spherical nanocomposite with intercalated iodide (Bi oxyiodide [BiOI]/I–P2ABT MLS-nanocomposite). The nanocomposite was characterized using XPS and XRD techniques to analyze its composition and structure, while FTIR provided detailed insights into its functional groups. Morphological and structural evaluations were performed using SEM, TEM, and cross-sectional modeling, revealing a multilayer spherical structure with a diameter of 80 nm, a wall thickness of approximately 12 nm, and an interlayer spacing of 10 nm. The performance of the BiOI/I–P2ABT MLS-nanocomposite photocathode was assessed in an electrochemical cell using both natural Red Sea water and artificially prepared seawater. Hydrogen production rates were determined, yielding 6.0 and 4.8 µmol h⁻¹ cm⁻², with corresponding current densities (J_ph) of −0.6 and −0.38 mA cm⁻², respectively. Additionally, the photocathode’s sensitivity was tested under varying photon wavelengths (340–730 nm), showing efficient photo response and variation in J_ph values across the spectrum. The BiOI/I–P2ABT MLS-nanocomposite offers significant advantages, including high efficiency, scalable synthesis, cost-effectiveness, and ecofriendly green chemistry, making it a promising candidate for industrial applications. This work demonstrates the potential of this innovative photocathode for the direct conversion of seawater into hydrogen fuel. The research team aims to advance this technology further by developing a prototype photocathode for large-scale hydrogen production directly from seawater.

Li- and Mn-rich layered (LMRL) oxide cathode materials are among the most promising candidates for next-generation lithium-ion batteries (LIBs) due to their high specific capacity and cost-effectiveness. However, their commercialization remains limited by several intrinsic challenges, including poor rate capability, surface-side reactions stemming from oxygen release during initial cycling, and subsequent voltage fading, all of which contribute to battery performance degradation. Addressing these limitations is essential to achieving improved electrochemical performance and cycling stability. In this study, we introduce a hybrid surface modification strategy involving LiNbO₃ coating and partial Nb ion doping, applied to Li_1.13Mn_0.57Ni_0.30O₂ cathodes via polydopamine (PDA)-assisted deposition. Characterization by XPS, XRD, and TEM confirms the formation of a uniform LiNbO₃ coating and a gradient distribution of Nb dopants near the inner surface region of the LMRL structure. This dual-modification strategy approach (coating and doping) for LMRL cathodes effectively enhances electrochemical performance, including fast-charging behavior, extended cycling stability, and high coulombic efficiency (CE). Furthermore, the modified cathodes exhibit enhanced thermal stability under high state-of-charge (SOC) conditions. These findings offer a valuable pathway for the development of cathode materials capable of simultaneously mitigating side reactions and improving rate capability in LMRL cathode materials during electrochemical processes.

Trade fragmentation (TDF) and bloc rivalries impact energy transition pathways through raw material trade and the decisions of major blocks. Democratic governance, whether centralized or populist, also influences trade, bloc decisions, and the energy transition. We investigate how regional energy transitions in Asia, Europe, and North America are shaped by global TDF and bloc rivalry (China-Russia and US-EU) while considering the role of democratic governance and its interaction with trade and bloc fragmentation. Using three sets of monthly data from January 2000 to December 2023 for these regions, we apply wavelet local multiple correlation (WLMC) and time-varying quantile causality (TV-QC) methods to address the non-normality and nonstationarity of the data. Results indicate that TDF negatively impacts Asian energy transition (AET) and European energy transition (EET) primarily during extreme booming markets, while North America experiences adverse effects across both slack and booming markets. The bloc rivalry between China and Russia disrupts Asia’s energy transition into extreme booming markets. Besides, the fragmentation of the US-EU bloc hampers Europe’s energy transition under similar conditions and has a milder effect on North America. Democratic governance strongly supports North America’s energy transition but yields mixed outcomes in Asia and Europe. Notably, Asian democratic governance (AGV) partially mitigates the effects of trade and China-Russia bloc fragmentation (CRF), where European and North American governance shows noninterference in both TDF and intrabloc rivalry issues. We suggest accountable democratic governance to effectively manage trade and bloc rivalries in promoting regional energy transition.

This study presents a comprehensive investigation of a biomimetic leaf vein-inspired flow field to enhance oxygen expulsion efficiency in proton exchange membrane electrolysis cells (PEMECs). Traditional flow fields face limitations in achieving uniform reactant distribution and efficient product removal, which significantly impact overall system performance. By combining computational fluid dynamics (CMD) simulation and experimental validation, this study evaluates the influence of critical geometric parameters—channel width, branch angle, and branch number on flow field performance. The numerical results reveal that gas volume fraction serves as an effective metric for evaluating oxygen discharge efficiency, with optimal performance achieved using a configuration of a 1 mm channel width, a 30^° inclination angle and two branches. Visualization experiments demonstrate that the downstream configuration significantly outperforms the upstream configuration in performance by enhancing synergistic effects between channels. The downstream strategy promotes faster oxygen transport and more uniform distribution, effectively suppressing slug flow formation and thereby improving overall bubble removal efficiency.

Brushless direct current (BLDC) motors have become the preferred choice for electric vehicle (EV) power trains due to their exceptional performance attributes, including fast dynamic response, high efficiency, durability, low acoustic noise, and minimized electromagnetic interference (EMI), which is critical for applications sensitive to electrical noise. BLDC motors achieve precise electronic commutation via an inverter and a rotor position sensor; however, to reduce costs, sensorless control methods that estimate rotor position without physical sensors are often employed. This study presents an advanced control strategy for sensorless BLDC motor speed regulation using a wavelet neural network (WNN) optimized with a fractional-order proportional integral derivative (WNN-FOPID) controller. WNNs are well-suited for detecting intricate patterns in system data, enhancing control accuracy. The FOPID gains are optimally tuned using the random weighted chimp optimization (RW-CHO) algorithm, an enhanced version of the classic chimp optimization algorithm (ChOA). Performance evaluations demonstrate that the proposed approach achieves rapid settling (0.29343 s) and response times (0.24013 s), a control signal peak of 6250 within 0.02 s, indicating the maximum control output generated by the proposed system. It also shows a superior convergence rate (1.21% improvement), minimal error statistics (−1.487), and enhanced stability (rise time of 0.29249 s; settling time of 0.3625 s). Compared with existing techniques, the proposed WNN-FOPID-RW-ChOA model consistently achieves superior rotor speed control and precision, establishing a robust solution for sensorless BLDC motor applications in EVs.

Under the carbon neutrality goals, this paper addresses the critical challenge of enhancing operational flexibility and low-carbon performance in northern China’s heating regions, where the power generation determined by heat for combined heat and power (CHP) unit restricts renewable energy consumption. To tackle this, a novel virtual power plant (VPP) framework is proposed by incorporating electric heat pump (EHP), carbon capture system, and shared energy storage. A leader-follower game model is also built between the VPP and multiple industrial users. The upper-level model optimizes VPP profit by designing differential electricity pricing strategies considering the synergistic effect of green certificate trading (GCT) and carbon emission trading (CET), solved using a self-adaptive immune genetic algorithm (SIGA). The lower-level model minimizes user costs through production process-based load management, solved via a dual ascent and alternating direction multiplier method. Example analysis from Tianjin, China, demonstrates that the proposed strategy increases VPP profit by over 110% compared to a baseline scenario, reduces carbon emissions by 13.9%, enhances the capacity of renewable energy utilization, and lowers total user costs by 4.56%. These results verify that the synergistic GCT-CET mechanism, combined with flexible equipment configuration and differentiated pricing, effectively coordinates low-carbon transition, economic efficiency, and renewable energy consumption. It can provide a viable pathway for VPP operation in northern heating regions.

The capture of solar radiation by troughs concentrating radiation onto absorbing cylinders placed in them is fundamental to applications in many industrial and urban environments. The efficiency of the collection of solar radiation depends strongly upon the design of the concentrating trough. In this article, the design of three types of concentrating troughs in their solar radiation capture properties is compared. The simplest design of a trough, a semi-circular form, has been largely ignored at the expense of troughs of compound parabolic or pure parabolic form. The methodology employed in the comparison is a numerical ray-tracing technique in which the percentage of incident radiation captured by the absorbing cylinder embedded in the trough is calculated. First, troughs which are fixed and so do not track the sun’s movement over the day are considered. A trough of semi-circular design is contrasted with the ubiquitous troughs of compound parabolic concentrator (CPC) form. Then the light-gathering characteristics of tracking parabolic troughs are compared with those of the semi-circular form. The calculations show that a truncated semi-circular trough (SCT) can give the same 100% capture of incident radiation as a CPC or truncated parabolic trough. The SCT does not require access to sophisticated manufacturing techniques.

RETRACTION: M. Al-Gabalawy, “Deep Analysis of the Influence of the Different Power System Structures on the Performance of the Energy Storage Systems,” International Journal of Energy Research 45, no. 12 (2021): 17805–17833, https://doi.org/10.1002/er.6915.

The above article, published online on 30 May 2021 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by John Wiley & Sons Ltd. The retraction has been agreed due to similarity with another published article [1].

The author did not respond to the retraction.