International Journal of Energy Research最新文献

Accurate prediction of battery performance is crucial for timely battery health management. However, it is challenging to forecast precisely battery’s performance due to its intricate degradation mechanisms and variability in the degradation rates. To overcome the challenges, we employed an artificial intelligence (AI)-driven approach. By training an indicator that reflects well structural degradation of a battery (self-discharge; SD), a model could predict battery performance metrics with a high accuracy compared to models using direct indicators (e.g., capacity). In a comparative analysis, the self-discharge model with the couple of bidirectional-long–short term memory demonstrates outstanding prediction accuracy with a mean absolute percentage error of 0.39% for capacity retention (CR) prediction and a root mean square error of 13.2 cycles for remaining useful life prediction. These findings underscore the significance of incorporating indicators reflecting the internal electrode health of batteries for accurate lifespan prediction.

Colloidal quantum dots (CQDs) are promising semiconductors for optoelectronic applications owing to their bandgap tunability and solution processability. Historically, ethanedithiol has been widely employed as a surface ligand to form a p-type CQD layer via a layer-by-layer process. However, the limited control of p-type characteristics reduces the device performance, and the high reactivity of ligand and processing solvents degrade the underlying layer. In this study, a thiol-free p-type CQD is demonstrated by creating native p-type CQDs during the synthesis process. Sulfurization of PbS CQD results in p-type properties that enable the avoidance of any further thiol-ligand treatment process. Further, alternative surface passivation of the sulfurized CQD using halide ligand yields a robust, p-type, morphologically uniform, and trap-suppressed film. The developed CQD film is then employed as a hole-transporting layer (HTL) for both broadband solar cells and photodetectors. The resulting CQD devices exhibit improved performance with a 65.7% increase in photovoltaic efficiency and a 1.7-fold improvement in responsivity for infrared photodetection. The devices also demonstrate higher ambient stability, retaining 85% of the initial performance after 1,000 hr owing to the uniform top HTL morphology, indicating the potential of the new p-type layer to be utilized in various emerging optoelectronics.

Given the growing demand for high-performance, stable, eco-friendly, and cheap lithium-ion batteries (LIBs), the development of affordable and environmentally friendly high-performance anode materials for LIBs has garnered considerable attention. Herein, to address this need, NiS (known for its high theoretical capacity) was grown on a porous biocarbon (BC) matrix to afford a highly conductive LIB anode material capable of accommodating the charge/discharge-induced volume changes and thus ensuring cycle stability. The cycling performance of this material (NiS–BC) was further enhanced by doping with Fe. The best-performing (Ni_0.8Fe_0.2S–BC) anode demonstrated an initial discharge capacity of 1,374.4 mAh g⁻¹ at 0.5 A g⁻¹, which further increased to 1,796.4 mAh g⁻¹ after 100 cycles, and the origins of this high performance were probed by instrumental analysis. The results contribute to the development of next-generation LIBs for applications requiring high capacity, high output, and long-term cycle stability, such as electronic devices, electric vehicles, and energy storage systems. Moreover, the use of BC aligns with a prominent trend in modern battery research, namely, the development of secondary batteries simultaneously exhibiting high performance and sustainability.

Peanut oil cake biomass is a major by-product of oil industry and can be a suitable precursor for the production of biomass-based porous carbon. Herein, dual-stage activation, physical activation at 400°C, and chemical activation using KOH between 600 and 900°C are adopted to prepare hierarchical porous carbons (HPCs) from peanut oil cake biomass for use as electrode material in electrochemical supercapacitors. The textural and structural properties of the HPC were evaluated by N₂-adsorption/desorption, X-ray diffraction, Raman, FT-IR spectroscopy, and scanning electron microscopy. The prepared HPC inherited sufficient micropores and mesopores distribution with a maximum BET surface area of 640 m²/g. The electrochemical properties of the HPC electrodes were evaluated by cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopic analysis. Among different HPC electrodes prepared, the carbon prepared at 800°C (HPC-P8) electrode material exhibited a high specific capacitance of 187 F/g at 0.5 A/g in 1M Na₂SO₄ electrolyte in three-electrode systems. Symmetric supercapacitors were also fabricated using HPC-P8//HPC-P8 as positive and negative electrodes using 1M Na₂SO₄ electrolyte, in a two-electrode cell configuration via split cell method. Maximum specific capacitance of 30 F/g was achieved with superior cycle stability of 93.8% capacitance retention over 5,000 cycles for the symmetric device. The device operated at a wide potential window (0–2.0 V) resulted in appreciable specific energy and power density of 15.89 Wh/kg and 493 W/kg, respectively. HPC-P8 had an ion diffusion coefficient of 7.79 × 10⁻⁸ cm²/s which is higher than the other prepared carbon samples. The symmetric device showed relatively high charge storage capacity and cyclic stability without any material degradation. The fabricated prototype portable supercapacitor module was tested for red LED glow with maximum intensity brightness up to 4 min. Thus, the present study reveals that HPC derived from peanut oil cake biomass can behave as a promising electrode material for supercapacitor applications.

The development of green energy sources, such as shallow geothermal energy, is one of the most important measures to reduce the environmental pollution caused by the use of traditional energy sources. At present, coastal cities in the east of the Yangtze River Delta, China, have favorable conditions for the development of shallow geothermal energy because of their abundant geothermal resources. However, the development and utilization of shallow geothermal energy are still in their infancy, and adaptability zoning is yet to be fully carried out. The study area is Nantong City, which is in the eastern coast of the Yangtze River Delta. A comprehensive analysis of the conditions of shallow geothermal energy is carried out based on the analysis of the regional geological, hydrogeological, and environmental geological conditions. The adaptability zoning index system of the groundwater source heat pump and buried pipe ground source heat pump system is then constructed, and the weight of evaluation factors is determined according to analytic hierarchy process. Finally, the adaptability zoning of shallow geothermal energy development and utilization mode is obtained by using the spatial analysis function of geographic information. The results showed that the areas with good suitability and better suitability account for 98.24% of the study area and those with good economy and better economy account for 99.67% of the study area. This method can provide reference suggestions for the orderly development and sustainable utilization of shallow geothermal energy in coastal cities in plain areas.

Sierra Leone struggles with electricity with a 38% electrification rate. The expanding distribution network with limited generation capacity leads to frequent power outages during peak hours. Demand response (DR), a widely recognized demand-side management strategy, has effectively balanced the electricity supply and generation worldwide. The primary objective of this study is to assess the potential for DR in the residential electricity sector, focusing on drivers such as security, environmental concerns, and incentives. The case study was conducted in Freetown, Sierra Leone. This study employs diversified demand modeling with household energy audit data to estimate the potential reduction in peak load achievable through voluntary demand response (VDR). This study generated load profiles for 12 household appliances and an aggregated load profile for the Freetown distribution network. Notably, the study achieved a substantial peak load reduction of 4.19 and 3.54 MW during the morning and evening peak hours, respectively. Additionally, this research highlights the significant roles of power security, price incentives, and environmental factors in encouraging residential consumers in Sierra Leone to participate in DR programs. This study underscores the response’s role in Sierra Leone’s electricity challenges, providing insights into peak load reduction and the motivation for residential consumer participation in DR programs.

Aiming at the energy inconsistency of each battery during the use of lithium-ion batteries (LIBs), a bidirectional active equalization topology of lithium battery packs based on energy transfer was constructed, and a bivariate equalization control strategy of adjacent SOC difference and voltage is proposed according to the corresponding relationship between open circuit voltage (OCV) and state of charge (SOC). The energy transfer between the inductor and the lithium battery is realized through the combination of the main circuit and the secondary circuit. Based on the Buck–Boost equalization circuit, the pulse width modulation (PWM) drive signal duty ratio is adjusted to improve the equalization speed and efficiency. The SOC is estimated by the unscented Kalman filter (UKF) algorithm, and the SOC of each single battery is estimated and sorted. The results of charge and discharge and static simulation and test of lithium battery show that the SOC difference between each cell is controlled within the threshold value of 3%, the voltage range is controlled within the range of 0.01 V, and the equalization speed is increased by 51% compared with the traditional unidirectional transfer of inductive energy balancing method. The change trend of the test results and the simulation results show a good consistency, avoiding the overcharge and overdischarge of the battery pack, and reducing the inconsistency. This method can complete the energy balance management of the battery well, the efficiency is relatively high, and the service life of the battery is improved.

Doublet system has been widely used in the geothermal system heat extraction, which mainly involved the hot groundwater extraction and geothermal water reinjection into the underground thermal reservoir. Many factors can influence the thermal reservoir performance, such as the production or injection mass flow rate, injection fluid temperature, and lateral well spacing. In this study, taking the specific heat capacity varying with the formation temperature, the rock porosity, and permeability variations into consideration, a three-dimensional thermo-hydraulic coupled numerical model was established to assess the influence of heat capacity variation with formation temperature and other correlation parameters on the sandstone and carbonate thermal reservoir performance over a period of 40 years. Results show that the influence of specific heat capacity variation on the thermal reservoir performance was less than the rock porosity variation and less than the rock permeability variation. On the other hand, the influence of the above three parameter variations is more significant on the sandstone reservoir than the carbonate formation, in which the specific heat capacity variation hardly made any difference for the carbonate thermal reservoir, but for the sandstone reservoir, the specific heat capacity and its temperature variation can yield a 1.3 K decreasing for the average output temperature and a 0.02 × 10⁷ W decreasing for the average energy production rate over the 40 years. Finally, in this case, the temperature and energy production rate from the production well is higher after considering the rock porosity variation no matter for the sandstone or the carbonate. But the result may be opposite after changing the initial and boundary conditions or parameter selection. The influence of rock permeability variation on the thermal reservoir performance was also studied, which can produce a decreasing 10.1 K for the average output temperature and 0.19 × 10⁷ W for the energy production rate over the 40 years.

This paper presents a tracking method to improve the performance of switched reluctance generators in areas with low wind speeds. The main contribution of this work is the proposal of an advanced control system that employs dynamic tracking techniques to optimize the energy efficiency and response of the switched reluctance generators under various operating conditions. The methodology encompasses the construction of the generator, the development of a wind turbine model, and the coupling of the turbine with the switched reluctance generators. Simulations are conducted using real wind speed data to evaluate the use of switched reluctance generators in wind energy generation. The performance of the switched reluctance generators is improved by applying a tracking technique that operates on the converter’s turn-off angle, which controls the generator’s switching. The tracking and optimization techniques implemented in this work maximize the performance of switched reluctance generators in wind energy generation, both in standalone and self-excited operations. The results demonstrate that satisfactory wind energy generation can be achieved using the SRG, with wind speeds of 5.40 m/s producing approximately 1.5 kW without optimization and around 1.65 kW with optimization, reaching about 70% efficiency with a custom-built generator. This makes the technology viable for regions characterized by low wind speeds.

Developing cost-effective, durable anode electrodes is essential for commercializing direct urea fuel cells (FCs). In the current study, standalone copper hydroxide nanograss was grown on the surface of the copper foam at room temperature. The surface morphology, elemental analysis, and crystalline structure were investigated. The prepared materials demonstrated a high activity towards urea electro-oxidation that increased with increasing urea concentration and slightly decreased at 4 M. The generated current using the modified electrodes is almost twice that obtained using the bare copper foam. The electrodes effectively operated for a prolonged current discharge (15 hr) using 3 M urea with outstanding stability. The morphology of the nanograss was retained even after such a very long time of operation. Moreover, the prepared materials are effectively used for the current generation from real urine with and without pH adjustment. Finally, real FC operation using urine was verified, showing an open circuit voltage of 1 V. The cell was operated for a long time, demonstrating the potential of the prepared electrodes for commercialization to realize simultaneous wastewater treatment and electricity generation from urine and other urea-contaminated wastewater.