Energy Storage最新文献

Polyvinyl chloride (PVC), one of the most widely produced synthetic polymers, has recently captured attention as a versatile precursor of carbon for energy storage applications. The transformation of PVC waste into functional carbon materials not only mitigates environmental concerns associated with plastic pollution but also provides a sustainable route for the development of advanced electrode materials. In this context, dechlorination strategies, temperature, and the use of activating agents are critical to controlling the carbonization process to obtain high-quality carbon materials while minimizing the release of HCl and other by-products. These parameters critically influence the structure, porosity, and electrochemical performance of the resulting carbons. Therefore, this review summarizes the latest advancements in PVC-derived carbons, highlighting their application in supercapacitors and batteries (Li⁺-ion, Na⁺-ion, and K⁺-ion), and further discusses existing challenges and emerging opportunities for their integration into next-generation energy storage technologies.

Phase change materials (PCMs) have garnered significant attention in thermal storage owing to their high latent heat, near-constant phase transition temperature, and negligible volumetric change during phase transition. However, their inherent disadvantages, such as leakage during melting, low thermal conductivity, poor photothermal response, and electrical insulation, have considerably limited their practical application in solar energy utilization and electrothermal conversion systems. In this study, we propose for the first time the design and fabrication of a lightweight biomass-derived carbon aerogel (CKA) with a highly porous structure and superior light absorption, prepared via controlled carbonization process using natural kapok fibers (KF) with sodium silicate as the structural binder. The resultant CKA was employed as the encapsulation of myristic acid-palmitic acid (MA-PA) binary PCM by a vacuum impregnation method. The obtained CKA/MA-PA composite PCMs (CMPPs) exhibit excellent form stability, enhanced thermal properties, and high energy storage density. These results show that the unique three-dimensional network structure of CKA enables a high PCM loading ratio (> 80%) and outstanding thermal cycling reliability. The carbonized structure forms continuous heat conduction pathways, yielding a thermal conductivity of 1.676 W m⁻¹ K⁻¹, which is 3.37 times higher than that of the noncarbonized samples (KMPP). Moreover, CMPPs demonstrate a high enthalpy of phase change (165.7–166.2 J/g) and significantly improved photo/electro-to-thermal conversion performance. The design offers a novel biomass-carbonization-based strategy for developing high-performance composite PCMs, which show great potential for applications in solar energy storage and building energy efficiency.

Incorporating energy aggregators is essential for reducing the strain placed on the system by coordinating Electric Vehicle (EV) charging activities. As EV adoption accelerates, their charging demand, particularly under Grid-to-Vehicle (G2V) operations, significantly alters the system's load profile. A Time-of-Use (TOU) tariff plan is used to alleviate the problems caused by peak demand and decrease the peak-to-valley load differential, promoting more balanced energy consumption patterns. To enable bidirectional power flow in Vehicle-to-Grid (V2G) applications, to enable energy exchange between EVs and the grid, certain chargers are needed, thereby providing economic incentives to users. In this work, a comprehensive bidirectional EV charging model is developed using the MATLAB/Simulink platform. The model comprises a DC-DC bidirectional converter, an AC-DC front-end, and an LCL filter, all configured for a Level 2 charger that supports a 32A bidirectional current. The Proportional-Integral (PI) controller, on which the control strategy is based, has its settings improved by a Genetic Algorithm (GA) to improve system performance. An evaluation of previous research informs the TOU tariff structure used for cost analysis. Simulation results demonstrate the efficacy of the proposed GA-based optimization framework in minimizing operational costs during both V2G and G2V modes, while considering the charger's power rating and dynamic pricing signals.

This research involved the synthesis and systematic evaluation of a series of ternary nanocomposites made from polypyrrole (PPY), sulphonated carbon quantum dots (CQDs), and yttrium oxide (Y₂O₃) as advanced electrode materials for high-performance supercapacitors. The combination of CQDs and Y₂O₃ within the conductive PPY matrix resulted in a synergistic enhancement of electrochemical properties, featuring excellent electrical conductivity, numerous redox-active sites, and superior structural stability. Among all formulations, the 0.4 PCY(PPY, sulphonated CQDs, and Y₂O₃) composite demonstrated the highest specific capacitance of 894.3 F/g at a rate of 2 mV/s, surpassing pure PPY (493.3 F/g), CQDs (128.2 F/g), and Y₂O₃ (398.2 F/g). This significant enhancement is attributed to the optimized charge transfer pathways facilitated by CQDs and the strong pseudocapacitive effect of Y₂O₃, which promote efficient ion diffusion and electron transport. Galvanostatic charge–discharge tests further validated the exceptional performance of 0.4 PCY, which achieved a specific capacitance of 860.16 F/g at 1 A/g, maintaining 42% (361.79 F/g) even at 5 A/g. The electrode reached an impressive energy density of 119.4 Wh/kg and a corresponding power density of 2022.5 W/kg, exhibiting remarkable cycling stability with 98.1% capacitance retention after 10 000 cycles. These findings illustrate the high reversibility and durability of the composite. An asymmetric supercapacitor (ASC) device constructed with 0.4 PCY as the positive electrode successfully powered a 1 V Light-emitting diode (LED) for 4.43 min following a 10-min charge at 3 V, demonstrating its practical applicability. In summary, the study emphasizes the 0.4 PCY nanocomposite as a promising and efficient electrode material for future flexible and high-energy-density supercapacitor systems.

Supercapacitors have gained substantial attention as devices for storing energy. This is because of their exceptional power density, rapid charging-discharging process, and longer lifetime. In this study, a hydrothermal synthesis procedure was followed to prepare two distinct nanostructures: cobalt ferrite (CoFe₂O₄) nanoparticles and cobalt ferrite-reduced graphene oxide (CoFe₂O₄/RGO) nanocomposite. Our results indicate that CoFe₂O₄ NPs has a specific capacity of 44.12 mA h g⁻¹ at 0.5 A g⁻¹, whereas CoFe₂O₄/RGO nanocomposite has a specific capacity of 198.62 mA h g⁻¹at the same current density. Subsequently, we utilized the positive electrodes as CoFe₂O₄/RGO nanocomposite and RGO as the negative electrode to fabricate asymmetric supercapacitor devices. For the CoFe₂O₄/RGO//RGO asymmetric supercapacitor device, we measure a specific capacity of 60.15 mA h g⁻¹ (@1 Ag⁻¹). The energy density and power density of the device are found to be 13.36 W h kg⁻¹ and 802 W kg⁻¹, respectively, at the same current density. Notably, when subjecting the CoFe₂O₄/RGO//RGO asymmetric supercapacitor devices to a 0.5 T external magnetic field, a significant enhancement in specific capacity was recorded, with an increase of ∼36% (81.96 mA h g⁻¹) at 1 A g⁻¹ of current density.

The global transition to sustainable energy systems demands high-performance thermal energy storage, with paraffin wax standing as a prominent phase change material (PCM) due to its high latent heat, chemical stability, and cost-effectiveness. However, its low thermal conductivity (about 0.2 W/m·K) and phase segregation significantly limit its practical application. While nanofillers and carbon additives can enhance conductivity, they often reduce latent heat, increase costs, and complicate processing. This study introduces a novel, sustainable solution by valorizing Algerian slack wax, a local petroleum refinery byproduct, as a multifunctional enhancer for paraffin. Composites with 6, 10, 15, and 20 mass% slack wax were formulated and characterized using the T-history method. The results demonstrate a breakthrough in simultaneous property enhancement, overcoming typical trade-offs. The 20% composite achieved a 35.65% increase in latent heat (from 106.93 to 145.06 kJ/kg), a 30.48% rise in specific heat (from 3.51 to 4.58 kJ/kg·K), and a 33% improvement in thermal conductivity (from 0.18 to 0.24 W/m·K in the solid state). Furthermore, the material's thermal responsiveness was enhanced, with a 25% reduction in solidification time (from 165 to 120 s) and a 20% faster melting rate (from 125 to 100 s). These improvements are attributed to molecular interactions that disrupt paraffin's crystalline order, facilitating more efficient phonon transport and energy distribution. By transforming an industrial waste into a high-performance PCM, this work provides a cost-effective, scalable, and circular pathway for advanced thermal storage, directly benefiting solar energy integration, building efficiency, and industrial waste heat recovery.

This study investigated metal-free organic dyes having D-π-A and D-A′-π-A frameworks for organic solar cells (OSCs). The influence of modifying the donor and internal acceptor in reference molecules (N, O, and S) on the structural, electronic, photovoltaic, and optical characteristics was analyzed by employing density functional theory (DFT). The UV–visible spectrum of the designed dyes was also simulated by employing time-dependent DFT (TD-DFT). The highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), and their energy gap (E_gap) are advantageous to understand the electron injection, electron transfer, and regeneration of the dye. The evaluated results suggest that short-circuit current density (J_SC), energy for dye regeneration (ΔG_reg), electron injection driving force (ΔG_inj), light harvesting efficiency (LHE), open circuit voltage (V_OC), density of state (DOS), and power conversion efficiency (η) are affected by the insertion of donors and internal acceptors. The dye N with Carbazole donor has an efficacy of 4.15% at J_SC of 15 mA cm⁻². The outcomes indicate that heteroatom-doped donors and inserting internal acceptors have an impact on absorption energies and improve the photovoltaic characteristics in the D-π-A arrangement, suggesting that these dyes are better sensitizers for the assembly of OSCs.

Effect of boron doping on the structure and hydrogenation-dehydrogenation characteristics of Ti₂CrV alloy has been investigated in detail. The alloys were prepared by arc melting method and were characterized using techniques such as XRD, SEM and EDX. With boron incorporation, the plateau pressure of hydrogen absorption increases with a decrease in enthalpy value, confirming destabilization of the hydride. The alloy, Ti_1.9CrVB_0.1, shows a maximum total hydrogen absorption capacity of 3.8 wt%, under ambient conditions with enthalpy and entropy of hydrogenation reactions, −48 kJmol⁻¹ and 112 Jmol⁻¹ K⁻¹, respectively. With further increase in B addition in the alloy, the hydrogen absorption capacity decreases to 3.5 wt% at room temperature. As prepared alloys exist in BCC structure which phase transforms into FCC structure up on hydrogenation. In situ hydrogen desorption temperature is found to decrease with an increase in B concentration. Around 30°C decrease in hydrogen desorption temperature was observed for Ti_1.9CrVB_0.1 alloy compared to parent Ti₂CrV alloy, confirming the improved dehydrogenation properties upon B addition. Compared to the parent alloy, Ti₂CrV, the hydrogen absorption rate of Ti_1.9CrVB_0.1 alloy improved significantly with an increase in the number of hydrogenation/dehydrogenation cycles due to the pulverization of the alloy. Studies confirmed that a small amount of B addition, (i.e., Ti_1.9CrVB_0.1 alloy) leads to better de-hydrogenation behavior, higher hydrogen absorption kinetics and improved cyclic stability compared to the parent Ti₂CrV alloy.

Metal-ion batteries (MIBs) are essential for transitioning to a cleaner and more sustainable energy future. By employing the density functional formalism, we have investigated the hexagonal (h) monolayer of BeS and BeTe as electrode materials for alkali (Li and Na) MIBs. The structural and thermodynamic stability, adsorption of Li/Na atoms, density of states, diffusion, and migration of atoms, as well as capacity, are investigated. The structures of h-BeS and h-BeTe remain stable upon adsorption of the adatoms, with improved electronic conductivity of these monolayers. The climbing image-nudged elastic band calculations estimate a low diffusion barrier of 0.16 eV (0.01 eV) for Li (Na) in h-BeS and 0.20 eV (0.16 eV) for Li (Na) in h-BeTe. Additionally, a maximum storage capacity of 580 mAh g⁻¹ for Li-ions and 1305 mAh g⁻¹ for Na-ions in h-BeS as well as 174 mAh g⁻¹ for both metal ions in h-BeTe, is estimated.