Advanced Energy and Sustainability Research最新文献

This study introduces two new fluorine-free ionic liquids (ILs) produced by coupling biomass-derived heterocyclic anions, i.e., tetrahydro-2H-pyran-4-carboxylate (THP) and furan-3-carboxylate (3-FuA), and tetrahydroxyphosphonium cation (P₄₄₄₄). The (P₄₄₄₄)(3-FuA) IL exhibits slightly higher thermal stability, displays a lower glass-transition temperature and significantly higher ionic conductivity than (P₄₄₄₄)(THP). This improvement arises from π-electron delocalization in the (3-FuA) anion, by dispersing the negative charge over the ring, weakening the cation–anion attractions, and thus enhancing the ion mobility. Owing to the favorable ion transport characteristics, (P₄₄₄₄)(3-FuA) performs exceptionally well as a supercapacitor electrolyte. When paired with multiwalled carbon nanotubes (MWCNT)-based electrodes, (P₄₄₄₄)(3-FuA) delivers an areal capacitance of 430 mF cm⁻² at 2 mV s⁻¹, an energy density of 86 µWh cm⁻² at 0.298 mA cm⁻², and a power density of 1492 µW cm⁻² at 0.995 mA cm⁻², while maintaining 97% Coulombic efficiency after 6 000 cycles at 60°C. In comparison, the (P₄₄₄₄)(THP) IL demonstrate a lower capacitance performance, albeit with robust long-term stability. Overall, both the ILs display enhanced capacitance with increasing temperature, underscoring their potential as fluorine-free electrolytes for supercapacitors operating under elevated thermal conditions.

We report that coating a Ni sheet electrode with a patterned mosaic of PTFE islands having uniform diameters (0.10–0.15 mm) and proximity to each other, and which cover 2% of the area of the electrode, decreases its overpotential for hydrogen production by a remarkable 0.15–0.21 V at current densities of 2–15 mA cm⁻² in 1 M KOH (PTFE = polytetrafluoroethylene). This correlates to a ≈20-fold amplification in the rate of hydrogen generation by the electrode at a fixed electrode voltage of −1.15 V (vs. Hg/HgO) relative to control bare electrodes. The effect originates in the low surface energy of PTFE, which induces newly produced hydrogen to preferentially form bubbles on the PTFE surfaces, leaving the adjacent, uncoated Ni surface free of bubbles and able to catalyse hydrogen production with high energy efficiency. Fifteen different patterns of PTFE islands, incorporating three distinct island diameters, that covered 2%–20% of the electrode surface, were prepared and systematically studied in five replicates each, on large Ni sheet electrodes. The studies demonstrate statistically significant declines in overpotentials and onset potentials for electrochemical hydrogen production. Ni electrodes are widely used in commercial alkaline water electrolysis cells to produce renewable (‘green’) hydrogen.

Cobalt-based oxides have been investigated as potential alternatives to Ir/Ru-based oxides for catalyzing the oxygen evolution reaction (OER) in acidic media. Past research, however, is mainly focused on the spinel oxide structure so far. Exploring alternative crystal structures is essential for expanding the material library and developing highly efficient OER catalysts for acidic environments. As a proof of concept, we demonstrate that Co-based perovskite oxides can drive acidic OER effectively. Appling hard/soft X-ray absorption spectroscopy (hXAS/sXAS) characterizations, we show that the La and Ce doped SrCoO₃ (denoted as LSC and CSC, respectively) have a bulk-average Co oxidation state close to 3+ and surface-dominant low-spin Co^III species. Electrochemical analysis reveals that they only show one Co redox pair, similar to CoOOH in acidic environments. The recorded Tafel slopes are around ∼65 mV dec⁻¹, comparable to the benchmarking Ir/Ru-based catalysts. The combination of the spectroscopic and electrochemical findings presented here highlights the important role of low-spin Co^III species in catalyzing OER in acidic environments and contributes to the rational design of non-noble metal OER catalysts.

Cu(In, Ga)Se₂ (CIGSe) solar cells with a tunable bandgap stand out as a promising technology for tandem applications. Addressing the environmental concerns associated with Cd-based buffers, this study investigates the suitability of zinc tin oxide (ZTO), deposited via chemical bath deposition (CBD), as a Cd-free alternative for both low-bandgap CIGSe and wide-bandgap (Ag, Cu)(In, Ga)Se₂ (ACIGSe) solar cells. Best ZTO-buffered devices exhibit competitive power conversion efficiencies (PCE) of 14% and 7% for low-bandgap and wide-bandgap absorbers, respectively. The optimal tin concentration for ZTO buffer layers vary, with 10% [Sn]/([Sn] + [Zn]) ratio (TTZ) identified as optimal for wide-gap ACIGSe and 20% TTZ for low-gap CIGSe. A performance decline beyond optimal tin concentrations could be linked to losses in open-circuit voltage. In summary, ZTO-based devices showcase promising photovoltaic performance, emphasizing ZTO's potential as a practical and nontoxic alternative, deposited by CBD, to traditional CdS for diverse CIGSe solar cell applications.

Sodium-ion batteries (SIBs) are considered a promising alternative to lithium-ion batteries due to the high availability of sodium resources. Among the various candidates for the positive electrode, layered (O3-type) NaMnO₂ has attracted considerable attention. However, understanding of its interfacial stability remains limited. Differential electrochemical mass spectrometry (DEMS) is a powerful tool for monitoring gas evolution and therefore provides valuable insights into side reactions occurring at the interface between anode/cathode and electrolyte. In this work, the gassing behavior of SIB half-cells with NaMnO₂ cathode and six representative electrolyte formulations is investigated using DEMS. The results show that electrolytes with fluoroethylene carbonate effectively suppress parasitic reactions and promote the formation of passivating interphases, resulting in improved performance and limited gas release. PC-based electrolytes appear to be more stable than EC-based electrolytes, especially in combination with NaClO₄. The use of NaPF₆ is associated with increased H₂ evolution and possible manganese dissolution, thereby impairing interfacial stability and releasing more lattice oxygen. An increase in the upper cutoff potential enhances gas release, indicating more severe (electro)chemical oxidation of the electrolyte. Overall, this study paves the way for new strategies for tailoring electrolytes to improve the cyclability and safety of SIBs.

Anode-free Li metal batteries (AFLMBs) show great potential for achieving high energy and power densities, but their practical application is hindered by inefficient Li plating and stripping on conventional Cu foil current collectors (CCs), resulting in poor cycling stability and safety risks. To address this, a novel grid CC fabricated by depositing a thin Cu layer onto a glass-grid substrate is investigated. Electrochemical tests reveal that the grid CC significantly improves Li deposition uniformity and cycling performance compared to standard Cu foil. AFLMBs employing the grid CC and a LiFePO₄ (LFP) cathode with 2.23 mAh cm⁻² loading retain 46% of their initial capacity after 100 cycles, while those with Cu foil retain only 30%. Postmortem analyzes using scanning electron microscopy, coulometric titration time analysis, and titration gas chromatography confirm that the enhanced performance arises from reduced dead Li accumulation during cycling. The 3D grid structure with high surface area promotes uniform current distribution and accommodates Li volume changes, mitigating dendrite growth and inactive Li formation. This resource-efficient and versatile design provides a promising pathway for developing advanced CC architectures for next-generation high-performance AFLMBs.

Aqueous processing of nickel-rich layered oxide active materials for positive electrodes, while attractive, possesses multiple obstacles not encountered when using state-of-the-art methods. One is found in structural changes at the active materials’ surface caused by the interaction with water. This study explores mechanism of interaction of water (H₂O) on such materials via use of deuterium oxide (D₂O) in production and comparison to a state-of-the-art reference. The materials, electrode pastes, and positive electrodes were prepared with H₂O or D₂O and characterized regarding their properties, combined with microscopy and thermal analysis. D₂O and H₂O exhibited similar behavior in most metrics. Thermal analysis indicated analogous decomposition of electrodes processed with H₂O and D₂O, with any water detected stemming from surface residues such as hydroxides. Furthermore, the D₂O-processed sample showed a diverging signal from its H₂O-processed counterpart, indicating penetration of deuterium into the layered active material's structure. The findings offer a clear mechanistic insight into the effect of aqueous processing on nickel-rich layered oxide materials and thus contribute to greater understanding of the hurdles to facilitate commercial viability for aqueously processed Ni-rich layered oxide material-based positive electrodes. Furthermore, they show the use of D₂O as a tracking agent for water in active materials.

Elongated lithium diffusion lengths, parasitic interfacial reactions, and rapid capacity fading continue to hinder the practical application of single-crystalline Ni-rich Li[Ni_xCo_yMn_1−x−y]O₂ (SC NCM) cathodes. Although existing surface modification strategies enhance electrochemical stability, high charge transfer resistance and low lithium diffusion result in poor cycling performance. In this work, a lithiophilic Ga₂O₃ surface-coated SC NCM material with 83% Ni content is synthesized for the first time via a wet chemical and postannealing route. The Ga₂O₃-coated material delivers 149.54 mAh g⁻¹ with 57.33% retention after 300 cycles at 1 C over a potential window of 3.0–4.5 V. Compared to the uncoated counterpart, the modified material exhibits a 37.50% reduction in charge transfer resistance and a 79.20% increment in lithium diffusion. Moreover, the nonfaradaic electrochemical active surface area shows only a 1.1% reduction after extended cycling, suggesting effective interfacial stabilization and possible mitigation of HF-induced surface degradation. These findings demonstrate that the surface modification of NCM materials with lithiophilic Ga-based oxides is an effective strategy to enhance Li transport, suppress interfacial side reactions, which results in much improved electrochemical performance for next-generation lithium-ion batteries.

Aqueous zinc-ion batteries (AZIBs) serve as a vital candidate technology for large-scale energy storage, and the enhancement of their wide-temperature performance is crucial for expanding application scenarios. However, in extreme environments, they are prone to constraints such as intensified electrode side reactions and electrolyte solidification, which severely limit their practical applications. This review systematically summarizes the major advances in wide-temperature AZIBs research in recent years, and systematically analyzes the influence of temperature on battery performance from three perspectives: thermodynamics, kinetics, and hydrogen bond regulation. Furthermore, it focuses on electrolyte regulation strategies and gains in-depth insights into the mechanism of Zn²⁺ solvation from strategies including high-concentration electrolytes, deep eutectic electrolytes, organic molecular electrolytes, and hydrogel electrolytes. Finally, it puts forward insights on the future challenges of AZIBs, so as to promote the development and application of high-safety energy storage systems.

Polymer-bonded Nd–Fe–B magnets, made from hard magnetic powder and a polymer binder, are essential in many high-tech applications. The growing demand in energy-conversion devices calls for a more circular and versatile approach to their production. This study presents a sustainable approach to fabricate anisotropic polymer-bonded Nd–Fe–B magnets using recycled powder from end-of-life (EOL) hot-deformed magnets. Employing laser powder bed fusion with a low CO₂ footprint polyamide 12 matrix in combination with magnetic powder enables production of complex geometries. Two methods are compared for converting EOL hot-deformed magnets into powder and the resulting performance of printed bonded magnets with these powders. Both powders have an elongated shape with the magnetic easy axis oriented perpendicular to the particle's length. Utilizing these anisotropic powders, based on a previously studied alignment mechanism, anisotropic bonded magnets are fabricated with over 60% higher magnetic performance compared to those made from EOL sintered magnet powders in 3D printing. The fabricated magnets have a remanence of 0.34 T and coercivity of 1238 kA m⁻¹. The findings demonstrate a pathway toward turning parts of the magnet market into a more circular economy by reducing reliance on primary Nd–Fe–B sources and enhancing efficiency of magnetic powder use.