Energy Storage最新文献

Sodium-ion (Na-ion) batteries are considered a promising alternative to lithium-ion (Li-ion) batteries due to the abundant availability of sodium, which helps mitigate supply chain risks associated with Li-ion batteries. Many studies have focused on the design of Li-ion batteries, exploring their energy, power, and cost aspects. However, there is still a lack of similar research conducted on Na-ion batteries. A comparison of the cell voltage characteristics and rate capability of sodium and lithium-ion batteries using different types of electrodes and electrolytes. For sodium-ion batteries electrolytes used are NaPF₆ and NaClO₄ and electrodes used are NaCoO₂, NaNiO₂, NaFePO₄, (Na₃V₂(PO₄)₃), graphite, hard carbon, sodium metal, and sodium titanate. For lithium-ion batteries with LiPF₆ and KOH electrolytes and electrodes as LiCoO₂, NMC, LVP, Li₂MnSiO₄, graphite, silicon, lithium titanate (LTO), lithium metal. A thorough analysis of six important performance metrics is part of the investigation: Ragone plots, Electrolyte salt concentration versus spatial coordinate, electrolyte potential versus spatial coordinate, Cell voltage versus battery cell state of charge, Cell voltage versus time, and state variable versus time. Comparing operating voltage and rated capacity NMC and graphite is selected for lithium-ion batteries as this combination provides operating voltage up to 4.2 V and a rated capacity of 275 Wh/kg, for sodium-ion for NaCoO₂ and hard carbon which has an operating voltage of 2.5–3.8 V and rated capacity around 200 Wh/kg and another combination of electrode as NaFePO₄ and sodium metal with NaClO₄ electrolyte has a maximum operating voltage of 2.8–3.8 V and rated capacity around 200 Wh/kg. This paper shows significant influence of electrolyte selection on battery performance. The Ragone plots demonstrate that LiPF₆ electrolytes in lithium-ion batteries and NaPF₆ electrolytes in sodium-ion batteries both exhibit superior specific energy densities compared to their KOH and NaClO₄ counterparts, respectively. The work presented in this paper encourages researchers to select alternate electrolytes and electrodes for lithium-ion and sodium-ion batteries in order to obtain optimal device performance.

The present study numerically investigates the energy and exergy analysis of solidification of phase change materials within a double tube and triple tube latent heat storage unit using ANSYS Fluent. Double tube and triple tube thermal energy storage system's thermal characteristics are examined using MXene nano-enhanced phase change material to determine system efficiency, discharged energy, heat transfer rate, exergy destruction, entropy generation number, exergetic efficiency, liquid fraction, solidification temperature contours. The result revealed that the double tube thermal energy storage with pure cetyl alcohol PCM has 14.76% lower discharge exergy than MXene-based nano-enhanced phase change material in pure solidification. In a triple tube thermal energy storage system, the solidification time for MXene-based nano-enhanced phase change material is impressively reduced by 54.76% compared to a double tube system using pure phase change material. At a Fourier number of 0.00672, MXene nano-enhanced phase change material exhibits an 11.69% higher Stefan number (St) than cetyl alcohol phase change material in a double tube thermal energy storage system. At 2400 s, pure phase change material and MXene nano-enhanced phase change material generated 3.14% and 4.88% less entropy than pure cetyl alcohol in the triple tube thermal energy storage system. During the pure solidification process in a double tube thermal energy storage system, pure cetyl alcohol experiences 7.60% higher exergy destruction compared to MXene nano-enhanced phase change material at a solidification time of 2400 s. In a triple tube thermal energy storage system, the discharging temperature for pure cetyl alcohol phase change material is 2.92% lower than that in a double tube system. Double tube thermal energy storage with pure cetyl alcohol discharged more efficiently over 2400 s. The triple tube thermal energy storage system solidified cetyl alcohol PCM 20.83% faster than pure phase change material due to MXene nanoparticles' better thermophysical properties. Thus, MXene-based nano-enhanced cetyl alcohol phase change material solidifies faster per volume in a triple tube thermal energy storage latent heat system.

Molten salts (MSs) thermal energy storage (TES) enables dispatchable solar energy in concentrated solar power (CSP) solar tower plants. CSP plants with TES can store excess thermal energy during periods of high solar radiation and release it when sunlight is unavailable, such as during cloudy periods or at night. This capability allows these plants to provide reliable, dispatchable power, ensuring a continuous electricity supply to the grid. This paper examines the challenges and opportunities of utilizing higher-temperature molten salt formulations to enhance power cycle efficiency. Drawing on existing literature, performance analysis of existing power plants, and novel simulation results, we project the expected technological improvements by the end of this decade. By using 15 h of TES and a higher temperature MS formulation, with heat transfer fluid hot temperatures of 700°C, and a power cycle 350 bar 700°C of efficiency 48%, the annual electricity production from a 115 MW power plant in Daggett, California is 688 GWh, the total installed cost is $684 m while the 25-year LCOE is 6.37 c/kWh.

In this experimental research, a single-pass solar air heater comprising a porous curved channel is investigated to reveal the scope of high thermal performance during the winter season. The investigation explores the geometrical parameters for the porous channel maintained by using steel wiremesh layers of wire diameter of 0.45 mm and pitch of 2.35 mm, and the number of layers ranging from 3 to 12, which presents the channel porosity, $��\varphi �$, from 99% to 96%, respectively. The curved porous channel offers additional fluid mixing, thermal backup, and high heat transfer area, thereby increasing the convective heat transfer to the air and consequently the thermal performance. A series of experiments were carried out under real outdoor conditions to examine the various factors such as variable channel porosity, air flow rate, and the amount of solar energy received. The findings revealed that the curved porous channel with a channel porosity of 96% results in the maximum thermal and thermohydraulic efficiencies of about 85% and 79%, respectively, and the outlet air temperature of 79°C.

Long-term power system expansion planning aligned with current sustainable development policies plays a pivotal role in achieving global targets for energy transition, particularly in developing countries. This paper presents a comprehensive long-term expansion planning model for Brazil, taking into account decarbonisation pathways using OSeMOSYS integrated with Flextool. Four scenarios explore the potential benefits of increasing the share of variable renewable energy (VRE), specifically photovoltaic (PV) and offshore wind, to 40% of the total energy produced, both with and without a storage system. Results indicate that policies better aligned with net-zero strategies do not impose a significant cost burden.

In this research, the synthesis of a binary composite was conducted by combining Cu-MOF and Bi₂WO₆. The resulting composite, denoted as CuBW, was systematically prepared with varying weight percentages: CuBW20, CuBW50, and CuBW80. To assess the properties of the composites, multiple characterization techniques were employed, including FTIR, XRD, FESEM-Elemental Mapping, BET-BJH, TEM, HRTEM-SAED, and XPS. The composites were subjected to electrochemical testing utilizing a three-electrode system, with 3 M KOH serving as the electrolyte. Through the electrochemical study, various parameters were evaluated and subsequently compared to determine any differences or similarities among the different compositions. CuBW80 exhibits superior performance with a specific capacity of 1137 F g⁻¹, specific energy of 11 Wh kg⁻¹, and specific power of 4000 W kg⁻¹ at an operating current density of 0.5 A g⁻¹. In the cyclic stability test, CuBW80 demonstrated superior performance by retaining approximately 83% of its initial specific capacitance over 10000 cycles. This further highlights its resilience and durability, reinforcing its suitability for extended and reliable use in energy storage applications.

We investigate the influence of phosphoric acid (H₃PO₄) activation on physiochemical characteristics of activated carbons (ACs) as a function of number of activation steps such as two-step and three-step and impregnation ratio (IR). Scanning electron microscopy observations identified that different morphologies in the forms of graphene sheet-like, nano-granular, and flake-like carbon structure in the cases of ACs. FTIR spectroscopy confirmed that successful incorporation of phosphorous group in the ACs by H₃PO₄ activation. X-ray diffraction (XRD) profile exposed that irrespective of the activation method and IR, all AC samples showed narrow and sharp XRD crystalline peak along with the amorphous signals. Raman scattering analysis suggested that three-step activation create more defective structure as compared to two-step activation route. Nitrogen adsorption–desorption isotherm measurements indicated that upon fabricating ACs via three-step and two-step activation approach, around 6.5 times and 3-fold enhancement in the value of surface area of ACs as compared to that of carbon before activation. In addition, higher the IR value, lower the textural properties of ACs. This study demonstrated that three-step activation methodology is capable of generating highly porous AC when compared to two-step activation route. Cyclic voltammetry analysis showed that for the electrode developed from AC that fabricated via three-step activation, capacitance retention of 50% is achieved upon tuning the scan rate by 10 times. The same electrode exhibited the capacitance retention of 45% upon increasing the current density by 10 times. We have also compared the electrochemical performance of symmetric and asymmetric supercapacitors. Electrochemical capacitance retention of symmetric and asymmetric supercapacitors is determined to be 100% and 92% respectively after 1000 cycles at the current density of 1 A g⁻¹. Based on the Ragone plot study, it is observed that the maximum energy density of 5 W h kg⁻¹ and the maximum power density of 943 W kg⁻¹ are attained for the case of symmetric supercapacitors. Asymmetric supercapacitor displayed improved energy density of 7.15 W h kg⁻¹ and modest power density of 432 W kg⁻¹.

The development of the battery-type electrode for the hybrid supercapacitor is very challenging owing to poor cycle stability. To overcome this problem, heterostructures would be an excellent alternative attributed to the synergetic effect of different materials physical properties, including electrical conductivity, mechanical flexibility, and so forth. Furthermore, heterostructures also offer significant redox reactions on account of more active sites, enhanced charge transfers kinetics via extra electron carriers, and ion diffusion rates, along with improved cyclic stability. Herein, we prepared heterostructures of Co₃O₄ nanospheres and WO_3−x nanorods via a single-step wet chemical method at a reaction time of 1 h (CoW1) and 6 h (CoW2). The electrochemical investigations reveal improved specific capacitance of CoW1 (157 F g⁻¹) than CoW2 (188 F g⁻¹) at 0.3 A g⁻¹. Furthermore, an aqueous hybrid supercapacitor (AHS) shows the specific capacitance of 38 F g⁻¹ at 1 A g⁻¹. Notably, it exhibits a remarkable specific capacity retention of 93% up to 10 000 cycles at 100 mV s⁻¹. Thus, CoW2 have great potential of electrode materials for the next-generation energy storage devices.