Energy Storage最新文献

Energy storage technology has been developed and produced for decades, particularly for lithium batteries. This technology remains a leading market due to its applications in electronic goods, electric vehicles, energy storage systems, and other fields. Research and development efforts in this field aim to improve lithium-ion energy density, energy and power density, and manufacturing costs. The present study addresses the development of lithium-ion batteries by synthesizing bio-self-healing electrolytes from methylcellulose (MC) and cellulose acetate butyrate (CAB) as polymeric matrices, combined with lithium perchlorate (LiClO₄) and an imidazolium-based ionic liquid (EMImTFSI) to enhance efficiency and functionality. Initial results are promising, since the synthesized electrolytes exhibit thermal stability at 216.4°C and 218°C, exhibit good self-healing, efficiency of 55% and 80%, ionic conductivities of 1.1 × 10⁻⁵ and 3.58 × 10⁻⁴ S/cm for 20%-doped and IL-plasticized CAB and MC, respectively; a good electrochemical stability window until 4.4 V, and good mechanical and flexural strength, ensuring varied applications.

In this study, MgO was incorporated into the extensively studied solid electrolyte material, lithium borohydride (LiBH₄), to enhance its poor ionic conductivity at ambient temperature. The addition of MgO was proved to significantly improve its ionic conductivity by approximately four orders of magnitude at 30°C compared to the low-temperature phase (less than 115°C) of pristine LiBH₄. Based on this electrolyte, all-solid-state batteries employing LiCoO₂ as the cathode and MgO-modified LiBH₄ as the electrolyte were successfully fabricated and operated in the low-temperature range. Moreover, the initial charging process exhibited anomalous electrochemical behavior, delivering a remarkably high specific capacity of 285.2 mAh/g with an unconventional charge plateau at 1.6 V, which deviates substantially from the typical electrochemical characteristics of LiCoO₂. To understand the charging mechanism from thermochemical and electrochemical views, a series of mechanistic characterizations was performed on the battery. Thermogravimetric analysis revealed a small amount of hydrogen evolution (≤ 0.2 wt%) at phase transition temperatures, while solid-state NMR spectroscopy confirmed the formation of BO bonds, providing evidence for redox reactions involving LiBH₄. However, comparative electrochemical experiments and X-ray diffraction (XRD) analysis excluded the influence of the thermal decomposition of LiBH₄ during the charging process. The charging mechanism that controlled the electrochemical behavior of this system was clarified in a detailed discussion.

[Ag(btt)₂(NO₃)] complex was synthesized using 1,2-benzodithiol-3-thione (btt) as a ligand depending on one-pot synthesis method. FTIR, ¹H-NMR, elemental analysis, and molar conductivity were used to characterize the silver complex structure. The characterization results prove that btt ligand is attached to the silver center with mono-dentate behavior through the exocyclic sulfur atom. The silver complex was utilized as a novel precursor for silver nanoparticles using ultrasound method on silver complex powder in 75 mL of deionized water and ultrasonication for 1 h at 90°C using an ultrasonic probe device with a power rating of 150 W. The solution underwent a noticeable color change to blackish-red. UV–Vis spectrum, XRD pattern, and TEM underscore resulting silver nanoparticles with a diameter range of 47–105 nm, this result from the capping agent effect of btt ligand. The hydrogen storage behavior of [Ag(btt)₂(NO₃)] was investigated under different pressures (10–100 bar) at 223 K. The results showed maximum storage of 3.66 wt% at an equilibrium pressure of 88 bar within only 9 s. The kinetic studies were applied on the hydrogen uptake and the results prove that hydrogen storage follows the pseudo-second-order kinetic model, as it showed a strong correlation with a value of R² = 0.996 and K₂ = 0.117 wt% s⁻¹.

Asymmetric hybrid supercapacitors integrating transition metal oxides with carbonaceous electrodes have attracted significant attention for advanced energy storage applications due to their ability to combine high energy density with rapid power delivery. In this study, an Al/Nb₂O₅ cathode and a Cu/graphene oxide (GO) anode were fabricated via slurry casting and electrophoretic deposition (EPD), respectively, and assembled with a paper separator in aqueous potassium hydroxide (KOH) electrolytes of varying concentrations (1, 2, and 3 M). Structural and morphological analyses confirmed the orthorhombic phase of Nb₂O₅ and the uniform deposition of GO films. Galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy (EIS) measurements revealed a strong dependence of electrochemical performance on electrolyte concentration. The device operating in 2 M KOH exhibited the most favorable balance between energy and power densities, achieving a specific capacitance of 30.7 F g⁻¹, energy density of 36.5 Wh kg⁻¹, and power density of 295 W kg⁻¹, with a relaxation time constant of 0.634 ms. In contrast, 1 M KOH provided moderate energy storage capability, while 3 M KOH suffered from reduced capacitance due to increased viscosity and ion–ion interactions. Comparative analysis with literature data highlights the competitive performance of the Al/Nb₂O₅//Cu/GO configuration, particularly in terms of energy–power trade-off. These findings underscore the critical role of electrolyte optimization and electrode design in advancing hybrid supercapacitors for sustainable energy storage applications.

The combustion synthesis approach has been used to successfully synthesize pure NiFe₂O₄ and chromium-doped NiFe₂O₄, that is, Ni_(1−x)Fe₂O₄:xCr³⁺ (1 ≤ x ≤ 4 mol%), to enhance the electrochemical performance. Various techniques were employed to characterize the synthesized samples such as X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR), X-Ray Photoelectron Spectroscopy (XPS), Field Emission Scanning Electron Microscopy (FESEM), and Energy dispersive X-ray analysis (EDAX). The formation of the cubic phase was confirmed by matching the XRD patterns of the samples with ICSD card number 00–003-0875. FESEM and EDAX analyses confirmed the presence of a porous surface morphology and precise elemental composition. The FTIR spectra exhibited an absorption peak at around 527 cm⁻¹, indicative of the tetrahedral FeO bond in NiFe₂O₄. The Ni2p core level spectra displayed from the XPS shift in binding energy as a result of Cr doping, which confirms the incorporation of Cr³⁺ ions in NiFe₂O₄. The electrochemical properties of the fabricated electrode were investigated using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) which confirmed the superior performance of the 3 mol% Cr-doped NiFe₂O₄ (N4) electrode. It delivered a specific capacitance of 745.6 F g⁻¹ at a current density of 4 A g⁻¹, with a bulk resistance (R_b) of 1.37 Ω. After 4000 cycles at 20 A g⁻¹, the electrode retained 79.86% of its initial capacitance and maintained 60.48% of its specific capacitance at higher current densities. These findings underscore the effectiveness of Cr³⁺ doping in improving the electrochemical characteristics of NiFe₂O₄ nanoparticles, establishing them to be potential candidates for high-performance supercapacitor applications.

Activated carbon derived from cocoa pod husk was engineered for solid-state energy storage applications through controlled KOH activation. The effects of KOH concentration and immersion duration were systematically evaluated to optimize pore development and electrochemical behavior. Carbonization at 500°C followed by activation at 700°C significantly enhanced textural characteristics, leading to a maximum surface area of 431.73 m² g⁻¹ and average pore radius of 1.759 nm at 12 h immersion. Electrochemical measurements using a PVA–K₂CO₃ gel electrolyte demonstrated improved charge storage performance, particularly for carbon activated with 5 M KOH for 12 h. The results confirm that optimized alkaline activation creates a hierarchically porous and conductive carbon network capable of efficient ion transport and charge accumulation. This work highlights cocoa pod husk as a promising and sustainable precursor for high-performance solid-state energy storage electrodes.

Thermal energy storage (TES) systems play a vital role in enhancing energy efficiency and reducing dependence on nonrenewable resources. This study investigates the synergistic integration of triangular fins and nanoparticle-infused phase change materials (PCMs) to enhance heat transfer in a large triplex tube heat exchanger (TTHX). Numerical simulations, conducted using ANSYS Fluent 15 software, supported by experimental validation with an average deviation of around 2%, were used to evaluate fin placement, fin geometry, and the effect of 10 wt% Al₂O₃ nanoparticles into the PCM. Results show that triangular fins significantly improve heat transfer, with external fins providing the fastest melting. The addition of nanoparticles increases thermal conductivity by nearly 25% and, when combined with optimized fins, reduces the melting time to 163 min. Energy-performance analysis confirms that nano-PCM accelerates charging due to enhanced conductivity, while pure PCM retains higher total stored energy. The optimal configuration, where eight external copper fins of 141 mm length and an 18% aspect ratio, delivered the best overall performance. These findings demonstrate that combining fin-geometry optimization with nanoparticle enhancement substantially improves TES efficiency. The proposed approach is well-suited for solar thermal systems, industrial waste-heat recovery, and compact TES applications.

The intelligent design of highly electrochemically active materials to achieve superior energy and power densities is always critical for energy storage systems. Herein, a novel strategy is developed to design unique metal chalcogenides (Bi–Zn–Se). A hierarchical design of chalcogenide adorned with coral reef-like copper structures via electrodeposition is directly used as the positive supercapacitor electrode. Moreover, biomass-derived hollow carbon structures synthesized via pyrolyzation are employed as a negative electrode in the hybrid device. The hierarchical architecture of both positive and negative electrodes, coupled with strong electroactivity and simple electrolyte permeation, results in significantly increased electrochemical performance, with specific capacitances of 230 F g⁻¹ at a current density of 1 A g⁻¹. The assembled Cu@Bi–Zn–Se//C battery-type device delivers superior energy density of 85.2 Wh kg⁻¹ and outstanding power density of 817.92 W kg⁻¹. Overall, creating heterostructures by combining electro-active materials was a fruitful approach to producing a high-performance battery-type hybrid energy storage device.

In this research, a homobinuclear complex (di-μ-chlorobis[2-[(dimethylamino)methyl]phenyl-C,N]dipalladium(II)) was used as a synthon to prepare a palladium/palladium oxide quantum dot composite. A novel method was employed to prepare the metal/metal oxide composite using an autoclave system in a microwave device with perchloric acid as an oxidizing agent. The nanocomposite was characterized using X-ray diffraction to determine the type of the composite and then it was characterized by TEM to determine the size and shape of the particles. The results confirmed the presence of palladium and palladium oxide peaks in XRD. Furthermore, the TEM measurement confirmed the presence of the material in the form of quantum dots with a size not exceeding 8 nm. The electrical properties of this composite were examined to confirm its suitability for use in supercapacitors. The results show that the real dielectric constant of Pd/PdO decreases as the frequency increases, indicating a weaker response at higher frequencies. The imaginary dielectric constant is relatively stable across different frequencies. The electrical conductivity gradually increases with frequency, especially at high frequencies. The real dielectric constant of Pd/PdO starts from 0.327 at Log Hz = 2.01101 and continues to decrease to 0.01219 at Log Hz = 5.01101. The imaginary dielectric constant ranges from 0.02644 to 0.02111 across frequencies from Log Hz = 2.01101 to Log Hz = 5.01101. The conductivity starts from 2.214E⁻¹ at Log Hz = 2.01101 and reaches 2.629E⁻¹ at Log Hz = 5.01101 with a noticeable increase at high frequencies. The prepared quantum dots were used as electrodes for supercapacitor application and the results demonstrate that the supercapacitor charged to 2.65 V using sodium sulfate as an electrolyte.

Various heat transfer augmentation techniques have been investigated to address the low thermal conductivity nature of phase change materials (PCMs). However, the techniques may also accelerate the heat exchange between the system and its surroundings, which increases the heat leak into the system during the cold holding process, particularly in prolonged cold thermal energy storage (CTES) systems. Hence, comprehensive evaluation is crucial for researchers to develop enhancement techniques that enable faster charging and slower discharging rates. This review comprehensively evaluates different passive heat transfer enhancement techniques, including fin addition, storage container optimization, nanomaterial dispersion, metal foam embedding, and hybrid methods. It identifies enhancement methods and their key parameters and factors favorable for prolonged CTES systems, based on their distinct impacts on the melting and solidification rates. The review reveals that incorporating nanomaterials at higher concentrations, metal foams with lower porosities, and convective flow restricting fins demonstrate higher solidification and slower melting rates, resulting in faster charging and prolonged cold retention durations. In contrast, adding fins that facilitate natural convection and embedding metal foams with higher porosities exhibit comparable melting and solidification rates. Additionally, the review includes performance limitations and life-cycle aspects of enhanced PCMs. Moreover, various techniques, including spatiotemporal PCMs, form-stable cold thermal energy storage phase change materials (FCPCMs), and double-layer insulations, significantly improve the cold retention duration of PCMs used in long-term CTES systems. It also highlights the challenges and future prospects, focusing on developing phase change CTES systems for prolonged cold storage, emphasizing performance, cost-effectiveness, scalability, and sustainability.