Energy Storage最新文献

This study explores the hydrothermal synthesis of NiCo₂O₄ and Ag-doped NiCo₂O₄ (Ag_xNi_1−xCo₂O₄, x = 0.0–0.5) electrodes as cost-effective materials for supercapacitor applications. Electrochemical analysis of all fabricated materials was conducted using a half-cell configuration, with measurements performed at various scan rates. As Ag concentration increased (for x ≤ 0.4), the specific capacitance also increased, reaching a maximum performance of 1501 F g⁻¹ for x = 0.4. This represents a 2.5-fold increase compared to its pristine counterpart. However, the specific capacitance value decreased by 21% when the Ag concentration was raised from x = 0.4 to x = 0.5. Performance decline is linked to the increment of pore size (20%) and the decrement in surface area (12%) in sample x = 0.5 compared to x = 0.4, as confirmed by BET analysis. Cyclic studies over 5000 cycles demonstrated retention capacities of 94% for x = 0 and 106% for x = 0.4. The x = 0.4 sample outperformed others, exhibiting the lowest solution-resistance (R_s = 0.5 Ω) and charge transfer resistance (R_ct = 0.9 Ω). The sample with the best performance, x = 0.4, has been chosen for fabrication of a 2-electrode system in both symmetric and asymmetric designs to evaluate device-level performance. The symmetric supercapacitor (SSC) showed specific capacitance of approximately 252 F g⁻¹ at current density of 1 A g⁻¹, maintaining 93.5% of its initial capacitance after 5000 cycles at 10 A g⁻¹. It delivered an energy density of 42 W h kg⁻¹ at a power density of 549 W kg⁻¹. Meanwhile, the asymmetric supercapacitor showed specific capacitance (178 F g⁻¹ at 1 A g⁻¹), and retaining 105% capacitance after 5000 cycles at 10 A g⁻¹, with energy and power densities of 67 W h kg⁻¹, 853 W kg⁻¹, respectively. The findings from various characterization techniques are thoroughly analyzed to draw the structure–property–performance correlations and presented in detail.

In this study, the hydrogen storage capacities of activated carbons derived from sunflower stalk wastes were enhanced by initial chemical activation using different activating agents (ZnCl₂ or KOH) at biomass ratios of 1:1, 2:1, and 3:1 (w/w), followed by carbonization at varying temperatures (600°C, 700°C, 800°C, and 900°C) based on their surface area performance. The optimization and characterization of the prepared samples were systematically conducted using BET, FTIR, DTA/TG, and SEM/EDX techniques. SEM/EDX analysis revealed a marked increase in porosity and notable alterations in the elemental composition of the activated carbon surfaces as a function of the activating agent and carbonization temperature. Hydrogen storage capacities of the optimized samples were measured as a function of pressure at both room and cryogenic temperatures. As a result of the optimization process, the samples with the highest surface areas were identified as AC-Z2-700 and AC-K2-700, with AC-Z2-700 exhibiting the highest hydrogen storage performance. Storage capacities increased with rising pressure and decreasing temperature for both samples, while the isotherm profiles varied significantly between room and cryogenic conditions. The experimental data fitted well with the Henry and Freundlich isotherms at room temperature and with the Langmuir isotherm at cryogenic temperature. Furthermore, kinetic analyses indicated that the adsorption followed a pseudo-second-order model and that the dominant mechanism was intraparticle diffusion within the pores of the activated carbon. Overall, the findings demonstrate that sunflower stalk is a promising and sustainable precursor for producing high-surface area activated carbons with competitive hydrogen storage capabilities, contributing to both clean energy applications and environmental sustainability.

Supercapacitors are increasingly adopting two-dimensional (2D) carbon-intercalated transition metal chalcogenide (TMC) composites (C_xMX_1−x) due to their adjustable surface properties, makeup, and structure. Even though they show promise, we still do not know much about how the strain in the structure and changes in electronic properties from 2D carbon intercalation affect them. In this study, we prepared (rGO/g-C₃N₄)_x-(CoSe)_1−x nanocomposites using a new one-step hydrothermal method with very low (x = 0.01) and higher (x = 0.10) amounts of carbon to see how they affect lattice strain and electrochemical performance. The results of XRD and Rietveld refinement demonstrated the purity of the materials and revealed an increase in lattice size with the addition of more rGO/g-C₃N₄. Crystallite size decreased from 12.97 nm for CoSe to 9.5 nm for the (rGO/g-C₃N₄)_0.1-(CoSe)_0.90 sample due to strain introduced by carbon intercalation. TEM analysis showed nanosheet morphologies with visible rGO and g-C₃N₄ structures. XPS confirmed the Co²⁺ and Se²⁻ oxidation states and validated the presence of C–C and C–N bonds. The (rGO/g-C₃N₄)_0.1-(CoSe)_0.90 electrode exhibited a high specific capacitance of 1102 F g⁻¹ at 1 A g⁻¹ and retained 97.1% after 2000 cycles. An asymmetric device using activated carbon (AC) achieved an energy density of 53.31 Wh kg⁻¹, a power density of 750 W kg⁻¹, and 97% capacitance retention after 5000 cycles, underscoring the material's potential for durable, high-performance.

India's lithium-ion battery (LIB) ecosystem is rapidly expanding, driven by the surge in electric vehicle (EV) adoption, renewable energy integration, and portable electronics. This review critically analyzes India's LIB market dynamics, which are projected to exceed 260 GWh annual demand by 2030, up from 3 GWh in 2020. It evaluates safety challenges, including thermal runaway, BMS failures, and temperature-induced degradation under Indian climatic and road conditions. Technological strategies such as hybrid BTMS designs, advanced chemistries (LFP, NMC), and AI-integrated BMS are discussed. The paper highlights national policies like FAME-II, PLI, and battery swapping frameworks, while assessing industrial readiness, localization efforts, and recycling gaps. Unique to this work is a comparative benchmarking of Indian battery performance, manufacturing capacity (targeted at 50 GWh by 2030), and regulatory progress. This comprehensive review provides a strategic roadmap for overcoming infrastructural, environmental, and technological barriers to support India's transition toward energy resilience and sustainable battery innovation.

The operation of Lithium-Ion Battery at high C-rates generates enormous heat resulting in higher temperatures which may affect its performance, cycle life, and safety. This necessitates the regulation on temperatures through effective thermal management. The present study evaluates a battery thermal management system (BTMS), viz. a serpentine and L-shaped mini-channel cold plates using nanofluid coolant combined with phase change material (PCM) subjected to a constant discharge of 80 A (8 C) and US06 drive schedule. A 4S4P LIB module rated 0.147 kWh, consisting of cylindrical cells, was chosen for the investigation. The thermal and electrical governing equations of the MSMD battery module were numerically solved using ANSYS Fluent solver. It is observed that a laminar flow at a Reynolds number of 1380 with the Al₂O₃ nanofluid having concentration in the range of 0.02–0.035 is effective in achieving lower battery surface temperatures and decreased pumping losses. The serpentine cold plate with the PCM effectively dissipated nearly 91% of the generated heat, but it experienced a 50% higher pressure drop compared to the L-shaped configuration. The study emphasizes that both the heat dissipation and the pressure loss in the cooling system play a vital role in the design and choice of BTM.

Materials development for energy generation and storage has been widely investigated in the present decade. In this work, carbon collected from rice bran oil burning, termed nanocarbon (NC) and its activated form (ANC), is well characterized for structure, morphology, and electrochemical properties, to assess their potential use in supercapacitor applications. The performance of the supercapacitors, fabricated using NC, ANC, and a commercial carbon (CC) as electrode material, has been evaluated on FTO-coated glass plates. The device performance has been tested in three different electrolytes, namely, 6 M KOH, 1 M H₂SO₄, and 0.5 M solution of 1-Butyl-3-methylimidazolium hexafluorophosphate in acetonitrile. The supercapacitor with ANC electrode in 6 M KOH electrolyte yielded a specific capacitance of 97.77 F g⁻¹ at 1 A g⁻¹ current density and retained 93% efficiency after 5000 cycles, quite comparable to the commercial carbon-based device. The device also showed a higher energy density of 11 Wh kg⁻¹ and power density of 900 W kg⁻¹. While using the ionic liquid electrolyte, the specific capacitance was lowered to 40.44 F g⁻¹ at 1 A g⁻¹ current density, but with a wider potential window of 2.5 V. The results confirm that carbon soot from rice bran oil burning, which is a waste form of carbon, on activation by simple air annealing could be a potentially promising electrode material for supercapacitor applications.

This review presents a comprehensive overview beginning with the introduction to MOFs as ideal candidates for gas storage. The synthesis of MOFs through various methodologies is examined in detail. Additionally, the review explores the factors that affect MOF stability, such as framework rigidity, metal–ligand bond strength, and environmental tolerance. A comprehensive section is devoted to the impact of structural parameters like pore size, surface area, and functional groups on gas storage efficiency. The applications of MOFs in CO₂ capture, as well as hydrogen and methane storage, are critically assessed, highlighting material design strategies aimed at enhancing uptake and selectivity under ambient conditions. The review wraps up with future perspectives, concentrating on scaling up production, enhancing environmental stability, and incorporating MOFs into practical storage systems. This work seeks to direct researchers toward rational design and scalable implementation of MOFs for sustainable and efficient gas storage technologies.

Graphenes are very thin layers formed by hexagonal networks of carbon atoms that possess special mechanical, electrical, and optical properties. There is a growing interest in the study and exploitation of graphene, expressed in numerous recent studies, both theoretical and practical. Here, graphenes were theoretically investigated using molecular descriptors. The complete set of 22 graphene conformers, with five cycles of six connected carbon atoms, was subjected to the study. The Zagreb index family was used in the first instance. The analysis showed that, in the case of the analyzed graphenes, the degeneracy of the Zagreb indices is very high. In addition, when the first Zagreb index is degenerate, the structures can still be discriminated by the second Zagreb index. However, when the second Zagreb index is also degenerate, the entire Zagreb index family built with expressions involving vertex degree on adjacent ones is degenerate. Thus, its use in the case of graphenes is not recommended. In general, topological descriptors have a low power of discrimination in classes of conformers. Moreover, for a pair of conformers, even the extended Hückel energy is degenerate. In this case, the resolution can be obtained with descriptors generated from molecular geometry. Furthermore, using a pool of descriptors exploring the robustness of topology and resolution of geometry significantly increases the accuracy of structure to property prediction. The SMPI (Szeged matrix property indices) family of descriptors has been used here as an alternative, and discriminated all 22 conformers adequately. A simple linear regression, explaining over 99.97% of the extended Hückel energy using one SMPI descriptor, has been found, showing thus the potential of the SMPI family in graphene discrimination in particular and materials science-related structure-based estimations and predictions in general.