Energy Storage最新文献

Poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP)-sodium thiocyanate (NaSCN) solid polymer electrolytes containing different weight ratios of ionic liquid (IL)—tributylmethylphosphonium iodide (TBMPI) were prepared using solution-cast approach. Electrochemical impedance data indicates that increasing ionic liquid into polymer electrolyte matrix increases ionic conductivity and the maximum value of ionic conductivity was obtained at 150 wt% TBMPI, having conductivity value of 8.3 × 10⁻⁵ S cm⁻¹. The dielectric measurement supports our conductivity data. Ionic transference number measurement affirms this system to be predominantly ionic in nature, while electrochemical stability window (ESW) was found to be 3.4 V. Polarized optical microscopy (POM) along with differential scanning calorimetry (DSC) suggest suitability of TBMPI as plasticizer, while infrared spectroscopy (FTIR) confirms ion interaction, complexation, and composite nature. The thermogravimetric analysis (TGA) shows thermal stability of these ionic liquid-doped polymer electrolytes (ILDPEs). Using maximum conducting ILDPE, a sandwiched supercapacitor has been fabricated which shows stable performance as high as 228 Fg⁻¹ using cyclic voltammetry (CV).

We utilized density functional theory (DFT) to ascertain the storage of hydrogen in Rh-decorated pristine (PG) and defective graphenes, primarily graphitic-N (GNG) and pyridinic-N (PNG). The binding energy of a single Rh atom on PG, GNG, and PNG was found to be −1.87, −2.18, and −4.01 eV, respectively. PG exhibits a weak adsorption energy of hydrogen molecules (−0.06 eV/H₂). On the other hand, Rh-decorated pristine and defective graphenes show incredibly higher hydrogen adsorption energy. As per the latest guidelines of the U.S. Department of Energy (DOE), the Rh-decorated GNG (Rh@GNG) is found to be the best hydrogen storage material out of the three systems investigated here. The single Rh atom-decorated GNG adsorbs up to 4H₂. Uniform decoration of graphene surfaces with Rh atoms is necessary to improve hydrogen storage performance. Both sides of GNG surfaces are decorated with 8Rh atoms, which can adsorb up to 24H₂ molecules, with an average adsorption energy of −0.33 eV/H₂. The mechanism of H₂ adsorption on the host system has been explored based on DFT-evaluated deformation of charge density, partial density of states (PDOS), and non-covalent interaction (NCI) plots. For a better understanding of the adsorption process, the diffusion energy barrier of Rh metal is computed using the climbing image nudged elastic band (CI-NEB) method, and the thermal stability has been evaluated through ab initio molecular dynamics (AIMD) simulations.

This study discusses the hydrogen storage and delivery capacity of Sc-decorated [6]cycloparaphenylene ([6]CPP) using dispersion-corrected density functional theory calculations (DFT + D3). The scandium atoms are decorated over [6]CPP via Dewar coordination with an average binding energy of 1.33 eV. Each Sc atom stores up to 5H₂ molecules in quasi-molecular form at an average adsorption energy ranging from 0.23 to 0.36 eV/H₂. The system's stability before and after H₂ adsorption is checked using reactivity parameters. The maximum hydrogen gravimetric capacity of the system is found to be 7.68 wt% at low temperatures at 1–60 bar pressure. With an increase in temperature (300–420 K), the gravimetric density is more than 5.5 wt% (US-DOE target) below 60 bar. Atom-Centered Density Matrix Propagation (ADMP)-molecular dynamics (MD) simulations reveal that the desorption of H₂ molecules from [6]CPP starts at around 300 K/1 bar, and complete desorption occurs above 480 K. The minimum Van't Hoff desorption temperature for [6]CPP-Sc is 296.9 K at 1 atm pressure. Insignificant change in the structure of [6]CPP-Sc during adsorption and desorption processes promises stability and reversibility of the system. Hence, we believe that Sc-decorated [6]CPP can be a promising candidate for hydrogen storage applications.

Adding thermal energy storage to nuclear power plants has been proposed as a way to allow nuclear plants to operate more flexibly and potentially be more competitive in deregulated electricity markets. The economics of these systems in deregulated markets are subject to uncertainties in capital costs, operating costs, and revenue. This study quantifies the uncertainty in the net present value of a nuclear power plant with integrated thermal energy storage in three U.S. deregulated electricity markets considering these sources of uncertainty and quantifies, for the first time, the relative contributions each source makes to the overall uncertainty. To accomplish this, a computationally efficient block bootstrap method is introduced to quantify uncertainty contributions from the stochastic time series of electricity prices, achieving a two order of magnitude decrease computational time compared to the model-based methods used in previous works while also relaxing several strict assumptions made by the model-based approach. Up to 18.5% of the overall variance in net present value is attributable to variance in the electricity price stochastic process, with this sensitivity varying significantly across markets.

The primary purpose of this research is to analyze and evaluate the effects of various discharge rates and cell configurations on the electrochemical and thermal behavior of a Li-ion battery pack that is exposed to ambient air throughout the discharge process. The three-dimensional numerical model is designed to accomplish this purpose and discusses two different cases. While the discharge rate is changed from 0.5 C to 2 C (stepping by 0.5 C) for each cell configuration considered in the first case, the numerical solutions are obtained for the various cell configurations (6S4P and 8S3P) by keeping the discharge rate constant at 1 C. The results obtained from these solutions show that the discharge rate affects a considerable amount of the battery performances and discharge times of the battery packs, activation, and ohmic losses occurring inside each battery cell. Moreover, 6S4P discharges over a longer period (about 25%) than 8S3P. While both activation and ohmic losses decrease with the increase of discharge rate, these losses remain almost constant at 0.5 C discharge rate in all analyzed conditions. As a result, having a battery pack with a long discharge time while maintaining low temperatures is useful and desired. With this in mind, while evaluating battery packs, the 6S4P battery pack looks to have the best arrangement.

Microgrids are a viable substitute for traditional power systems because they may deliver cleaner, more dependable, affordable power with fewer losses. However, the microgrid's performance is impacted by the variable nature of renewable energy sources. Battery storage is a crucial component of microgrid planning since it defines the system's techno-economic feasibility. A standalone rural microgrid is designed in the current study, employing three distinct battery types: lithium-ion, lead acid, and zinc-bromine flow. The suggested microgrid's techno-economic analysis employs three distinct dispatch mechanisms, that is, cycle charging, load flow, and complete dispatch. The case study of the suggested framework is carried out in Lucknow (India). The system comprises PV/battery/wind energy system/diesel and battery. The simulation results suggest that the optimal system with the least electrification cost is 0.113 $/kWh using complete dispatch strategies and a zinc-bromine battery. It has 206 kWh zinc-bromine flow batteries, a 10 kW converter, a 20 kW PV, a 13-kW diesel generator, and a Combined dispatch strategy. The system's net present cost per unit cost of energy is $40 275 and 0.113 $/kWh for the chosen region, respectively. Compared to the other two battery technologies for hybrid systems, the zinc-bromine flow battery technology is also shown to be the most environmentally friendly. Among the three battery technologies available, zinc-bromine flow is best used in a particular location's hybridized operation.

Energy storage is a group of technologies that decrease the gap between energy supply and energy demand. Thermal energy storage (TES) reduces this gap at not only different temperatures but also at different places or power. Design criteria include the integration of the storage system into the whole application system, maximum load, and high-energy density. Since energy density is given by the material used, the selection of the storage material is key to the success of any energy storage system. In this paper, the potential of sodium chloride (NaCl) to be used in TES, both using sensible TES and latent TES, is evaluated for low-temperature applications and for high-temperature ones. This material is found to have high potential for successful applications, both in buildings and in industry.

This work offers a fuel cell power system with the ability to distribute power to the load from the electrical source and charge an auxiliary battery utilizing regenerative power flows created by the load. The approach is established on a bidirectional closed-loop DC converter. A bidirectional DC–DC converter is presented as a means of achieving extremely high voltage energy storage systems (ESSs) for a DC bus or supply of electricity in power applications. This paper presents a novel dual-active-bridge (DAB) bidirectional DC–DC converter power management system for hybrid electric vehicles (HEVs). The proposed system makes it possible to charge an additional battery with regenerative power flows and distributes power from the electrical source to the load efficiently. The two main stages of the DAB converter, which are the focus of this work, are an interleaved buck/boost converter on the battery and a three-phase wye-wye series resonating converter on the DC bus. Each switch's current stress is greatly reduced by this design, which lowers transmission losses and enhances thermal performance. The interleaved buck conversion on the battery allows for lesser current stress in each switch, resulting in lower transmission loss. The increasing complexity and power of automotive embedded electronic systems have made the use of more potent power electronic converters in automobiles necessary. In recent years, many dual volt (42 V/14 V) bidirectional inverter topologies for automotive systems have been presented. However, the majority of them are either inefficient or use a huge number of transistors and magnetic devices in both parallel and series arrangements. As a result, in this study, a bidirectional high-efficiency inverter with fewer components is provided. The design, modes of operation, and performance metrics of the DAB converter are examined, emphasizing its ability to achieve zero-voltage switching (ZVS) and zero current switching (ZCS) throughout its operating range. The suggested system seeks to maximize EV power management, guaranteeing high dependability and efficiency. To test all of the aforementioned qualities, an evaluation version was created, with an average efficiency of 97.5%. This research could have a substantial impact on the advancement of power electronic converters for automotive applications, leading to better EV power management, increased system reliability, and increased overall efficiency.

Heusler alloys (HAs) are a well-known family of compounds generating promising interest due to their robust structure, ease of tailoring their unique properties, and potential applications. The investigations in the direction of the electrochemical performance of these materials as electrodes for rechargeable lithium-ion batteries (LIBs) have been established theoretically and experimentally. Alloying of alkali metal ions into half-HAs unit cells can be another route to improve LIBs performance. This work presents our investigations on thermodynamically stable half-HAs CoMnZ (Z: Sb/Sn) as electrode materials for rechargeable LIBs using the first-principle calculations based on the density functional theory. The negative formation energies validate the thermodynamic stability of the alloys considered in this study. With increasing Li doping, a structural change from cubic to tetragonal and orthorhombic phase is observed in the host structure, and upon full lithiation (LiMnZ), a cubic structure is attained. The band structure calculations of the host structure and its lithiated phase indicate a metallic nature in these alloys. The calculations are also performed to investigate the structural stability of parent alloys and corresponding lithiated phases. We calculated a storage capacity of around 14.5 Ah/kg for 0.125 atomic fraction of Li atoms, which is increased by nearly 10 times upon full lithiation. A maximum open circuit voltage of around 9.8 V is calculated for Li_0.125Co_0.875MnSb and CoLi_0.125Mn_0.875Sb. Thus, all these remarkable results suggest that these intermetallic compounds have a strong potential as the cathode material for LIBs with a robust life and a large capacity.

A thermoelectric generator (TEG) converts thermal energy into electrical energy when temperature gradients are created across its two surfaces. Integrating the TEG with a phase change material (PCM) and radiative cooling (RC) can increase the temperature gradient across its two surfaces. In this study, a two-layer RC paint has been developed and applied to the cold side of a TEG, and its performance was compared with TEG-white paint and TEG-no paint. The RC lowers the temperature of the cold side by 3.5°C and 4.7°C compared to TEGs with white paint and no paint, respectively. Integrating PCM with TEG–RC ensured a high electrical output, enabling continuous power for a typical weather sensor. The PCM–TEG–RC generated 2.7and 0.61 mW during summer and winter days in Istanbul, and nighttime outputs of 0.302 W and 0.395 mW, respectively. Despite similar costs, the electrical performance of TEG–RC was nearly double that of the TEG-white paint. It has also been determined that a storage capacitor with a value of 0.5 F can provide 24-h power backup to the typical weather sensor.