Energy advances最新文献

Li-ion batteries stand out among energy storage systems due to their higher energy and power density, cycle life, and high-rate performance. Development of advanced, high-capacity anodes is essential for enhancing their performance, safety, and durability, and recently, two-dimensional materials have garnered extensive attention in this regard due to distinct properties, particularly their ability to modulate van der Waals gap through intercalation. Covalently intercalated Graphene oxide interlayer galleries with mono-Boc-ethylenediamine (GO-EnBoc) was synthesized via the ring opening of epoxide, forming an amino alcohol moiety. This creates three coordination sites for Li ion exchange on the graphene oxide nanosheets' surface. Consequently, the interlayer d-spacing expands from 8.47 Å to 13.17 Å, as anticipated. When explored as an anode, Li–GO–EnBoc shows a significant enhancement in the stable and reversible capacity of 270 mA h g⁻¹ at a current density of 25 mA g⁻¹ compared to GO (80 mA h g⁻¹), without compromising the mechanical or chemical stability. Through ¹³C, ⁷Li and ⁶Li MAS NMR, XPS, IR, Raman microscopy, and density functional theory (DFT) calculations, we confirm the positioning of Li⁺ ions at multiple sites of the interlayer gallery, which enhances the electrochemical performance. Our findings suggest that these novel systematically modulated van der Waals gap GO-engineered materials hold promise as efficient anodes for Li-ion batteries.

There is an ever-growing requirement for systems that enable both conversion and storage of solar energy in the same device, thereby reducing the need for grid electricity and fossil fuels. Although photo-supercapacitors (PSCs) potentially meet this requirement, it is essential to develop high-performance devices in which conversion and storage can be achieved on the same electrode. This study investigated two-electrode PSC systems based on three-dimensional (3D) zinc oxide (ZnO) nanoflakes/reduced graphene oxide (rGO) nanocomposites to meet the need for in situ solar energy conversion/storage. To better understand the effect of rGO and 3D ZnO nanoflakes separately, three different compositions have been studied, in which the weight percent of rGO changes from 8 to 32%. The energy density increases as the amount of rGO increases, but the composite material loses its light sensitivity above a critical value. Therefore, the electrodes containing 16% rGO exhibited higher performance than those containing 32% and 8% rGO. As a result, the (16%) rGO/ZnO-based PSC exhibited superior performance compared to the other samples, with its ability to maintain 100% of its performance at 40 000 cycles, its areal capacitance of 40 mF cm⁻² and energy density values of 22 μW h cm⁻², which were 170% higher than under dark condition measurements.

International Civil Aviation Organization member states need to develop national strategies for sustainable aviation fuel (SAF) production to reduce greenhouse gas emissions from aviation. In this work, we developed a framework to estimate the national SAF potential and applied it to a case study for canola SAF in Canada. Specifically, we answered (i) how many SAF plants can be constructed and what are their maximum name-plate capacities? (ii) which geographic locations can economically support a SAF plant? (iii) what could be the average life cycle GHG emissions of SAF supplied to major airports? Our study developed an improved framework for estimating the SAF potential for a region by incorporating detailed site selection criteria for identifying optimal locations. We found that 15.2 million metric tonnes (MT) of potentially available canola can supply about 1–1.8 billion litres of SAF by 2030 (12–21% of Canada's 2019 jet fuel consumption) across 7–11 optimal sites, after accounting for infrastructure and accepted industry/financing guidelines on feedstock utilization. Up to 20% of this potential is lost if there is a lack of coordination and plants are sited sequentially based on profitability instead of maximizing feedstock utilization. The life cycle-GHG emissions of the SAF produced in the optimal sites ranged between 20–58 g CO₂e per MJ, depending on the local farming practices and legacy land use & land management changes. Increasing the supply chain transportation connectivity and managing feedstock competition could provide access to more canola for SAF production; however, other pathways will also be required to meet the growing SAF demand in Canada.

Correction for ‘Recent trends on the application of phytochemical-based compounds as additives in the fabrication of perovskite solar cells’ by Naomy Chepngetich et al., Energy Adv., 2024, 3, 741–764, https://doi.org/10.1039/D4YA00025K.

We synthesized two derivatives of Y6, namely Y-TNF and Y-TN. Compared to Y6, these two derivatives possess fluorinated and non-fluorinated extended terminal groups, respectively. Y-TNF exhibits a red-shifted absorption compared to Y-TN, a narrower bandgap, and a better matched energy level to the donor material PM6. Hence, Y-TNF demonstrates better photovoltaic performance. The incorporation of Y-TN further enhances the photovoltaic performance of binary PM6:Y-TNF devices due to its good compatibility and intermolecular interactions with Y-TNF, resulting in improved charge transport and reduced non-radiative energy loss. The ternary organic solar cells (OSCs) offer a higher device efficiency of 16.63% with a high open-circuit voltage of 0.857 V, a high short-circuit current density of 25.84 mA cm⁻², and a high fill factor of 75.10%. The results show that incorporating a similar acceptor material as the third component is an effective strategy to enhance the performance of OSCs.

This research work aims to develop a new dual-functional electrode material suitable for both lithium-ion batteries (LIBs) and dye-sensitized solar cells (DSSCs). Nanostructured Cu₂ZnSnS₄ (CZTS) was synthesized through the solvothermal method. Structural properties analysed through the X-ray diffraction pattern (XRD) and Raman spectra reveal the formation of the CZTS with kesterite structure . The stoichiometry and the oxidation states of CZTS have been analyzed using X-ray photoelectron spectroscopy (XPS). The core level XPS spectra of Cu 2p, Zn 2p, Sn 3d, and S 2p confirm the presence of the constituent elements in the required oxidation states (Cu⁺, Zn²⁺, Sn⁴⁺, S²⁻). The surface morphology of the CZTS nanoparticles showed a nanoflake-like structure with a surface area of 34.20 m² g⁻¹. The geometrical optimization, electronic, and optical properties were calculated using DFT calculations. The semiconducting material CZTS is electrochemically active toward Li, which can be used as an alternative anode material for lithium-ion batteries offering potential improvements in cycling stability and specific capacity. The electrochemical studies of the CZTS nanoflakes exhibited a specific capacity of 1141.08 mA h g⁻¹ and 350 mA h g⁻¹ at 0.1C and 1C rates respectively. The cycling stability of CZTS at a high scan rate of 1C, and the specific capacity of 220 mA h g⁻¹ over 70 cycles with 73% coulombic efficiency, suggest it to be a promising alternative anode material in the next-generation lithium-ion batteries. The performance of CZTS as a counter electrode in dye-sensitized solar cells was also explored. The DSSC constructed with CZTS as the counter electrode showed an efficiency of 5.9%.

Research focusing on catalyst layers is critical for enhancing the performance and durability of proton exchange membrane fuel cells. In particular, the role of the ionomer is pivotal but remains poorly explored due to the difficulty to access complex electrode structures. Moreover, perfluorosulfonic acid (PFSA) polymers are usually employed in catalyst layers but their drawbacks have spurred interest in aromatic compounds, which promise improved conductivity and performance. Here we investigated the structure-to-function relationship and interactions in novel catalyst layers using non-perfluorinated sulfonic acid ionomers, e.g. multiblock poly(arylene ether sulfones) bearing perfluorosulfonic acid side chains. By combining dynamic vapor sorption, small-angle neutron scattering and synchrotron humidity-controlled infrared spectroscopy, we accessed the water uptake, nanostructures, and molecular structures in a series of catalyst layers prepared with different loadings of aromatic polymer, as well as reference compounds, e.g. pure membrane and polymer–carbon systems. Our measurements show that the water sorption mechanism in catalyst layers differs from pure ionomers due to catalyst-induced structural changes. We observed that most of the formed ionic species interact primarily with the platinum catalyst and probably locate at the particle–ionomer interface. These results emphasize the need for continued research to advance aromatic-type ionomers in fuel cell technology under realistic conditions.

In this paper we report the synthesis and characterization of a γ-Fe₂O₃/reduced graphene oxide composite anode for Na-ion batteries. The nanocomposite anode is synthesized by a facile and green method. Structural and morphological characterization highlights a small γ-Fe₂O₃ particle size and their successful embedding in the carbonaceous matrix. Electrochemical characterization reveals a high specific capacity of ≈300 mA h g⁻¹ at 1000 mA g⁻¹, while at 5 A g⁻¹ a capacity of 113 mA h g⁻¹ is retained. Cyclic voltammetry at different scan rates, impedance spectroscopy, and ex situ Raman measurements evidence a redox pseudocapacitive behavior and full reversibility of the conversion reaction. The green synthesis coupled to the high specific capacity and rate capability make the proposed γ-Fe₂O₃/rGO nanocomposite a very promising candidate anode material for sustainable Na-ion batteries.

It is essential to have an adequately thick active layer to achieve efficient performance in quantum dot intermediate band solar cells (QD-IBSC) utilizing In_xGa_1−xN with high indium concentrations. The thickness plays a crucial role in maximizing photon absorption and optimizing the overall effectiveness of the solar cell (SC). In this paper, we introduce QD-IBSC with Ga-face (0 0 0 1) applying 1 nm i-GaN interlayers, which will provide strain relaxation to the In_0.5Ga_0.5N/GaN QD layer for increasing photovoltaic performance. Normally, the coupling among QDs splits the quantized energy level and leads to the formation of minibands within the forbidden region of conventional SC. In particular, the QDs are sensitive to dot regimentation and thus affect the properties of QD-IBSC. The electronic band structure of these QDs is controlled by changing the size of the QD, interdot distances and regimentation. In this paper, optimization of the optical structure of the QD-IBSC is performed by investigating the calculation results of both the maximum number of absorbed photons and the carrier transport property through tunneling simultaneously as a function of the thickness of the i-GaN interlayers. For the calculation, the three-dimensional regimented array of In_xGa_1−xN QD is analyzed using an envelope function. This work demonstrates Ga-face n–i–p structure (n-GaN/i-GaN:In_0.5Ga_0.5N:i-GaN/p-GaN) utilizing the 20 periods of 3 nm thick In_0.5Ga_0.5N QD layers and a GaN layer of 1 nm thickness can achieve a maximum conversion efficiency of 48%.

In the present work, colloidal systems of sodium lignosulfonate (lignin) and its carbonized form (C-lignin) in H₂O and polyethylene glycol (PEG) were synthesized and used for solar-thermal conversion. PEG and H₂O play the role of a dispersant of the suspended particles as the base fluids and an environment for transferring heat. Based on the results, PEG performs better as the base fluid than water. All the synthesized microfluids (MFs) were stable at an optimum concentration of 0.2 g/60 ml. The comparative studies show that the C-lignin/PEG has the best light-to-heat conversion efficiency. The C-lignin/PEG was used at high light intensities and for several heating/cooling cycles without losing its performance in heat generation. All the calculated thermo-physical parameters indicated that C-lignin/PEG is more eligible than lignin/PEG in photo-thermal conversion. The prepared C-lignin/PEG has several advantages: green, inexpensive and simplicity of the preparation procedure, not using a dispersant, high photo-thermal durability and heat-generation efficiency, and excellent ability to generate heat from sunlight.