Energy Storage最新文献

Graphene and graphyne electrodes exhibit considerable relevance in electrochemical energy storage applications owing to their distinct physical and chemical characteristics. Graphyne has garnered increased attention due to its larger specific surface area, enhanced electronic mobility, and intrinsic band gap compared to graphene. Our analyses unveil pertinent aspects of graphyne electrodes in interaction with ionic liquid (Emim-BF₄) and aqueous salt (NaCl) solution based electrolytes. Despite the existing body of research on graphyne, there remains a gap in the comprehensive analysis of its performance as an electrode for supercapacitors and its interactions with electrolyte. In this investigation, molecular dynamics were employed to explore properties of graphene/graphyne electrodes based supercapacitors. The characteristics of the EDL are elucidated through structural and energetic analyses, while the capacitive performance of the devices is discussed in light of electrostatic properties, total capacitance, and storage energy density. Throughout the analysis, key differences and underlying similarities between the models are delineated.

Cation phosphonium-based ionic liquids (PBILs) have recently gained attention since the 2000s due to their thermal stability and low viscosity for better ionic conduction in electrochemical devices. This paper introduces a new low-viscosity phosphonium-based ionic liquids (PBILs)—trihexyl (tetradecy) phosphonium dicyanamide—infused in polyethylene oxide: ammonium iodide (NH₄I) complex polymer electrolyte. The electrochemical impedance spectroscopy studies indicate that the ionic conductivity reaches 2.03 × 10⁻⁴ S/cm at 6 wt.% PBILs at ambient temperature. The PBILs-doped polymer electrolyte is predominantly ionic confirm by ionic transference numbers (t_ion) calculation. Also the electrochemical stability window was found to be 3.2 V suitable for energy storage devices. The highest achieve ionic conductivity PBILs-doped polymer electrolyte sandwich between the electrodes for dual energy devices like electric double layer capacitors (EDLCs) and dye-sensitized solar cells (DSSCs). This study shows improvements in ionic conduction, double-layer stability, and light-harvesting efficiency, resulting in higher energy density and power density in EDLCs and better photovoltaic performance in DSSCs. These findings highlight the versatility and efficacy of phosphonium-based ionic liquid-doped polymer electrolytes for advanced energy storage and conversion applications.

In this study, we synthesized ZnFe_2-xLa_xO₄ nanoparticles with varying lanthanum (La) content (x = 0, 0.01, 0.03, 0.05) via a cost-effective combustion method utilizing citric acid as a fuel. This method was selected for its cost-effectiveness and its capability to produce high-quality nanoparticles with tailored properties. X-ray diffraction (XRD) analysis confirmed the cubic structure of the synthesized ZnFe₂O₄ product, revealing planes (220), (311), (400), (511), and (440) within the Fd-3m space group, with no additional peaks observed, indicating phase purity. The study proceeded to calculate essential parameters including lattice parameter, particle size, and strain, utilizing the Williamson–Hall method, offering important insights into the structural features and behaviors of synthesized nanoparticles. The crystallite size and surface morphology were investigated by TEM analysis. Additionally, Raman spectroscopy revealed five distinct Raman-active modes (A1g + Eg + 3F2g), consistent with the spinel structure. The electrochemical properties of the electrodes were assessed using a three-electrode system in a 2 M KOH electrolyte, employing cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). At a scan rate of 2 mV/s, a specific capacitance of 109.58 F/g was achieved with the nanomaterial synthesized via the combustion technique.

The usage of solar photovoltaic (PV) systems for power generation has significantly increased due to the global demand for sustainable and clean energy sources. When combined with Battery Energy Storage Systems (BESS) and grid loads, photovoltaic (PV) systems offer an efficient way of optimizing energy use, lowering electricity expenses, and improving grid resilience. The study highlights the environmental and economic advantages, such as reduced carbon emissions, lower energy expenses, and job creation, while facilitating grid modernization through bi-directional power flow and enhanced energy management. The findings demonstrate the evolution towards a sustainable energy future by analyzing the incorporation of photovoltaic systems and battery energy storage systems, investigating standards for the secure and efficient integration of grid-connected solar photovoltaic systems, and evaluating the environmental and techno-economic implications of these systems. The techno-economic analysis, encompassing estimates of payback period, return on investment, and net present value, is utilized to evaluate the economic feasibility of the integrated system. The findings from this research aim to aid consumers, businesses, utilities, and legislators in making informed decisions that optimize solar energy advantages, diminish grid reliance, and alleviate environmental consequences.

In this study, we present the synthesis and characterization of a high-performance Zn₃(PO₄)₂·4H₂O/TiO₂ nanocomposite, designed as a versatile electrocatalyst for advanced energy storage and conversion applications. The synthesis of the Zn₃(PO₄)₂·4H₂O/TiO₂ nanocomposite was confirmed using various sophisticated analytical techniques such as powder x-ray diffraction, FTIR, UV spectroscopy, FESEM imaging, EDX, and XPS etc. Notably, the nanocomposite demonstrates exceptional performance in the oxygen evolution reaction (OER), with a low overpotential of 250 mV at a current density of 50 mV/cm² and a Tafel slope of 129 mV/dec, indicating superior kinetics. Furthermore, it demonstrates a specific capacitance of 112 F/g at a scan rate of 20 mV/s and remarkable cyclic stability, retaining 91% capacitance over 1000 cycles in supercapacitor applications. Additionally, in a practical application, the nanocomposite successfully powered a red light-emitting diode (LED) for 11 min. The combined effect of Zn₃(PO₄)₂·4H₂O₂ and TiO₂ contributes to its outstanding electrochemical properties. This makes it a promising candidate for sustainable energy solutions, with the potential to enhance the efficiency and durability of energy storage and conversion systems.

Lanthanum based alloys are used in this current work to store the low temperature (less than 120°C) thermal energy, as they absorb and desorb hydrogen gas reversibly. LaNi_5−xM_x (M = Al, Fe, Ga, and Zn) alloys are compared at constant energy storage and recovery temperatures based on their absorption characteristics. A comparison is made between a Simple Absorption System (SAS), a Compressor Operated Absorption system (CAS), and a Cascade Resorption System (CRS) to store thermal energy at low temperatures. van't Hoff relation is used to estimate the lowest temperature to store energy and the maximum temperature to extract it. The energy was successfully upgraded by CAS and CRS. For various La-based alloys, the three systems' performances were thermodynamically examined and compared. A maximum COP of 0.86 and 0.74 is obtained in a simple absorption and compressor operated absorption system, respectively, using LaNi_4.75Fe_0.25 due to low hysteresis. Maximum heat upgradation with the Al, Fe, Ga, and Zn substitution is reported as 50°C, 20°C, 48°C, and 60°C, respectively, at a compressor ratio of 5 with CAS. The CRS with same substitution gives the highest heat upgradation of 66°C, 43°C, 88°C, and 107°C at regeneration temperature of 120°C respectively.

This study presents a simple, scalable approach for synthesizing binary and ternary composites tailored for electrode materials, with a focus on supercapacitor applications. The composites were fabricated by integrating reduced graphene oxide (rGO) with NiCoFe₂O₄ metal oxides and the conductive polymer polypyrrole (PPy). The significance of this work lies in the development of supercapacitors, which are highly valued for their superior energy density, fast charge and discharge rates, prolonged life cycle, and cost-effectiveness. The binary composite, rGO/NiCoFe₂O₄, was synthesized using a sol–gel auto-combustion method, with carbon cloth serving as the electrode substrate for electrochemical testing. Electrochemical analysis showed that the rGO/NiCoFe₂O₄ binary composite exhibited a specific capacitance of 154 F/g at a scan rate of 10 mV/s. The addition of PPy resulted in the formation of the ternary composite, PPy/rGO/NiCoFe₂O₄, which demonstrated a markedly improved specific capacitance of 210 F/g under the same conditions, underscoring the synergistic effect of PPy. Furthermore, galvanostatic charge–discharge (GCD) analysis revealed specific capacitance values of 222.5 F/g at 1 A/g and 145 F/g at 2 A/g for the ternary composite, compared to 157.1 F/g and 110 F/g for the binary composite. The findings of this investigation emphasize the significant potential of the PPy/rGO/NiCoFe₂O₄ composite for the development of high-performance supercapacitors, leveraging the combined benefits of rGO, NiCoFe₂O₄, and PPy for superior energy storage capabilities.

In this study, the optimal shape for a gas storage cavern was determined by considering the elements that affect its stability and convergence. The considered factors influencing the stability of caverns include the bulk modulus of salt rock, ambient temperature, internal gas pressure, cavern depth, and cavern shape. By varying these parameters and creating various combinations, 45 scenarios were defined. Numerical models were constructed for each scenario to systematically investigate the factors affecting cavern stability. Through a comparison of the results from these numerical models, the most stable cavern shape under different conditions was determined. The study focuses on the pre-salt environments in the Santos Basin, southeast Brazil. The findings of this study may aid in the construction of gas storage salt caverns. The results indicate that the cavern's size and geometry have a greater effect on its volume loss in salt layers with a lower bulk modulus (between 5 and 15 GPa). Additionally, when the bulk modulus is low, the rate of change of the cavern convergence to the bulk modulus is larger. Moreover, the effects of the rock salt characteristics on the cavern convergence are much less pronounced at larger depths, so a depth of 1200 m can be ignored. In comparison to the bulk modulus of salt rock, internal gas pressure has a far greater effect on the convergence of salt caverns. At shallow depths, the salt creep phenomena primarily affect the cavern's roof area, and as the depth of the cavern deepens, it increasingly damages the floor and middle walls. When precise control of the gas pressure in proportion to the cavern depth is not attainable, the optimal form for designing gas storage salt caverns with varying depths based on the minimal convergence criterion is a horizontal ellipsoid. In contrast, the vertical ellipsoidal cavern always results in the greatest volume loss and displacement and is hence regarded as the least acceptable alternative. A downward pear-shaped cavern can be a good alternative to a horizontal ellipsoidal cavern for higher depths. The design and construction of the downward pear-shaped cavern instead of the upward pear-shaped cavern leads to better control and the reduction of the displacements.

This research explores the use of solid polymer electrolytes (SPEs) as a conductive medium for sodium ions in sodium-ion batteries, presenting a possible alternative to traditional lithium-ion battery technology. The researchers prepare SPEs with varying molecular weight ratios of polyacrylonitrile (PAN) and sodium tetrafluoroborate (NaBF₄) using a solution casting method with dimethyl formamide as the solvent. Through optical absorbance measurements, we identified the PAN:NaBF₄ (80:20) SPE composition as having the lowest energy band gap value (4.48 eV). This composition also exhibits high thermal stability based on thermogravimetric analysis results. Electrochemical impedance spectroscopy reveals an ionic conductivity of 1.02 × 10⁻⁴ S cm⁻¹ for the PAN:NaBF₄ (80:20) blend at ambient temperature. Additionally, linear sweep voltammetry demonstrates its good electrochemical stability up to 3.22 V. We assemble a primary sodium-ion battery using the optimal SPE composition (Na/(PAN + NaBF₄)/(I₂ + C + electrolyte)). This battery achieves an open-circuit voltage of 2.83 V and displays promising discharge performance.

In this study, the optimization of heat transfer in a metal hydride hydrogen tank to maximize hydrogen storage was investigated. A finite element model of a quarter tank was developed in COMSOL Multiphysics with parameterized geometry. The main objectives were to maximize stored hydrogen mass and minimize tank filling time while maintaining temperature uniformity within the tank. A design of experiments (DOE) approach was used with key geometrical parameters. Compared to the base case, the hydrogen stored mass increased from 0.26 to 0.46 kg, and the tank filling time reduced from over 1100 to 450 s. The optimal design (Design point 15) resulted in an absorbed hydrogen mass of 0.4624 kg, with a charging time of 450 s, showing the most balanced performance in terms of maximizing storage while minimizing filling time and better heat dissipation. This demonstrates the potential of optimizing heat transfer to significantly improve metal hydride hydrogen storage performance. The model can be further improved by exploring different cooling designs and materials.