EcoMat最新文献

Solid-state batteries based on versatile halide solid electrolytes with outstanding ionic conductivity, electrode compatibility, and stability are attracting significant research attention. Recent experimental studies have illustrated the outstanding performance of LaCl₃ as a solid electrolyte capable of conducting Li ions through its one-dimensional channels that can be interconnected into a three-dimensional network through the creation of La vacancies. In this work, we present a composition optimization strategy for maximizing the Li-ion conductivity in LaCl_3−xBr_x solid electrolytes based on density functional theory and ab initio molecular dynamics simulations. Our simulations show LaCl_2.5Br_0.5 to have a remarkable Li-ion conductivity of 66 mS cm⁻¹ at 300 K and the lowest activation energy of 0.10 eV, followed by LaCl_0.5Br_2.5 with values of 14 mS cm⁻¹ and 0.13 eV, respectively. Both these compositions are predicted to be easily synthesizable, have large band gaps, and are likely to be of experimental interest given their outstanding Li-ion transport properties. Our results highlight the potential for enhanced Li-ion conductivity in LaCl_3−xBr_x solid electrolytes that can be achieved through anion mixing.

The growing utilization of the Ocean Internet of Things (Ocean IoT) has a significant impact on human society. Recent advances in nanotechnology in terms of developing unprecedented structural, mechanical, electrical, chemical, and photonic properties have led to devices that are expected to promote the sustainable growth of the emerging Ocean IoT. This review provides a system-level analysis of nanotechnology-enabled sensors, actuators, energy harvesting, antifouling coatings, and environmental remediation that have been developed, with a focus on their materials, structures, and manufacturing technologies, as well as their merits and drawbacks. The challenges associated with the ecotoxicity of nanotechnology-derived pollutants in marine ecosystems are also discussed. Finally, potential future research directions are presented for this emerging field.

Perovskite solar cells (PSCs) have attracted considerable attention in the field of photovoltaics owing to their high power conversion efficiency (PCE), cost-effective production methods, and versatile applications. However, the widespread use of lead (Pb)-based materials in PSCs poses challenges related to their toxicity and environmental sustainability. This review explores recent advances in the development of Pb-free perovskite materials, such as tin (Sn)-based, germanium (Ge)-based, and other B(IV) and B(III) cation alternatives, while assessing their electronic properties, stability, and performance-enhancing strategies. Additionally, we discuss the use of green solvents and fabrication techniques to minimize their environmental impact. This review aims to guide future research toward safe, efficient, and environmentally sustainable PSC technologies, ensuring that the benefits of solar energy can be harnessed without compromising human health or the environment.

The limited energy density of the current Li-ion batteries restricts the electrification of transportation to small- and medium-scale vehicles. On the contrary, Li-O₂ batteries (LOBs), with their significantly higher theoretical energy density, can power heavy-duty transportation, if the sluggish electrode kinetics in these devices can be substantially improved. The use of solid electrocatalysts at the cathode is a viable strategy to address this challenge, but current electrocatalysts fail to provide sufficient discharge depths and cyclability, primarily due to the formation of the film-like discharge product, Li₂O₂, on catalytic sites, which obstructs charge transport and gas diffusion pathways. Here, we report that a triphase heterogeneous catalyst comprising NiCoP, NiCo₂S₄, and NiCo₂O₄, assembled into a hierarchical hollow architecture (NC-3@Ni), efficiently modulates the morphology and orientation of the discharge product, facilitating the sheet-like growth of Li₂O₂ perpendicular to the cathode surface. These modifications enable the assembled LOB to deliver a high discharge capacity of 25 162 mAh g⁻¹ at 400 mA g⁻¹, along with impressive cycling performance, achieving 270 cycles with a discharge depth of 1000 mAh g⁻¹, exceeding 1350 h of continuous operation. This promising performance is attributed to the presence of individual electrophilic and nucleophilic phases within the heterogeneous microstructure of the triphase catalyst, collectively promoting the formation of sheet-like Li₂O₂.

The development of clean energy technologies is increasingly dependent on advanced materials capable of enhancing energy storage and conversion efficiencies. Carbon nanofibers (CNFs), known for their unique fibrous morphology, high aspect ratio, high electrical conductivity and specific surface area, particularly with post-treatment, as well as their chemical robustness, have emerged as exceptional candidates for a variety of clean energy applications. This review comprehensively provides the synthesis, structural modification, and surface activity tuning of electrospun CNFs, with a focus on their utilization in energy storage devices such as lithium-metal batteries, lithium-sulfur batteries, lithium-air batteries, and supercapacitors as well as in energy conversion systems, including water splitting, fuel cells, electrochemical CO₂ reduction technologies, and solar thermal-driven water evaporation. The discussion delves into the fabrication methodologies for electrospun CNFs, highlighting the critical role of structural modifications and surface activity tuning in enhancing material performance. Recent progress in the application of CNFs-based nanomaterials for clean energy solutions is presented, demonstrating their potential to significantly advance the efficiency and sustainability of energy-related technologies. Furthermore, this review identifies existing challenges and outlines future research directions, aiming to provide readers with a comprehensive understanding of state-of-the-art CNFs fabrication techniques and their applications in the fields of energy and environmental science. This work serves as a valuable resource for researchers in materials science, nanotechnology, and environmental science, guiding the further development and deployment of CNFs for sustainable energy solutions.

Iron hexacyanoferrate (FeHCF) is a promising cathode material for sodium-ion batteries (SIBs) due to its high theoretical capacity and low cost. Nevertheless, water in FeHCF is likely to take up Na⁺ sites leading to the reductions in capacity and rate capability. Herein, an ion-exchange method is proposed to synthesize low-water potassium-sodium mixed iron hexacyanoferrate (KNaFeHCF). The ion-exchange method can preserve the lattice structure with low vacancies and K⁺ with larger ionic radii can reduce the water content in FeHCF and improve Na⁺ reaction kinetics. Compared with the NaFeHCF synthesized by co-precipitation method, the water content of optimal sample KNaFeHCF-12 h can be decreased by 21.2%. The sample exhibits excellent electrochemical performance, with a discharge capacity of 130.33 at 0.1 and 99.49 mAh g⁻¹ at 30 C. With a full-cell configuration with a hard carbon anode, the discharge capacity reaches 115.3 mAh g⁻¹ at 0.1 C. This study demonstrates a viable method for producing Prussian blue cathode materials with low water content, high specific capacity, and exceptional cycling stability.

The shift toward sustainable energy has increased the demand for efficient energy storage systems to complement renewable sources like solar and wind. While lithium-ion batteries dominate the market, challenges such as safety concerns and limited energy density drive the search for new solutions. Liquid metals (LMs) have emerged as promising materials for advanced batteries due to their unique properties, including low melting points, high electrical conductivity, tunable surface tension, and strong alloying tendency. Enabled by the unique properties of LMs, four key scientific functions of LMs in batteries are highlighted: active materials, self-healing, interface stabilization, and conductivity enhancement. These applications can improve battery performance, safety, and lifespan. This review also discusses current challenges and future opportunities for using LMs in next-generation energy storage systems.

The increasing global concerns about energy shortages and environmental pollution are driving the development of materials for clean energy conversion. Among various materials, lead halide perovskite solar cells (PSCs) have emerged as promising candidates for next-generation photovoltaic (PV) technologies. However, the use of toxic lead in high-efficiency perovskite devices raises sustainability concerns, particularly due to the risk of environmental contamination from lead leakage. Given the projected growth of the perovskite photovoltaic market, effective management of lead toxicity is essential for the safe deployment of this technology. This review explores the latest developments in lead encapsulation strategies, including both external and internal encapsulation materials, aimed at mitigating lead leakage and enhancing the safety and sustainability of perovskite photovoltaics. Additionally, it also discusses various recycling solutions necessary to establish a sustainable closed-loop lead management system. These approaches not only recycle lead but also reclaim other materials, promoting the circular use of resources and advancing the competitiveness of perovskite PV technologies.

The partial Pb²⁺ substitution with Cu⁺ ions has been thoroughly applied as an approach to produce new absorber materials with enhanced light and radiation hardness required for potential aerospace applications of perovskite solar cells. X-ray photoelectron spectroscopy revealed that Cu⁺ ions are partially integrated into the crystal lattice of MAPbI₃ on the surface of perovskite grains and induce p-doping effect, which is crucial for a range of applications. Importantly, the presence of Cu⁺ enhances photostability of perovskite films and blocks the formation of metallic lead as a photolysis product. Furthermore, we have carried out one of the first studies on the radiation hardness of complex lead halides exposed to two different stressors: γ-rays and 8.5 MeV electron beams. The obtained results demonstrate that Cu⁺ doping alters completely the radiation-induced degradation pathways of the double cation perovskite. Indeed, while Cs_0.12FA_0.88PbI₃ degrades mostly with segregation of δ-phase of FAPbI₃ forming a Cs-rich perovskite phase, the Cs_0.12FA_0.88Pb_0.99Cu_0.01I_2.99 films tend to expel δ-CsPbI₃ and produce FA-rich perovskite phase, which shows impressive tolerance to both γ-rays and high energy electrons. The beneficial effect of copper ion incorporation on the stability of lead halide perovskite solar cells under light soaking and γ-ray irradiation conditions has been shown. The discovered possibility of controlling the electronic properties and major materials degradation pathways through minor modification of their chemical composition (e.g., replacing 1% of Pb²⁺ with Cu⁺) opens up tremendous opportunities for engineering new perovskite absorber compositions with significantly improved properties for both terrestrial and aerospace applications.

The complex molecular structures of electron donor (D)–acceptor (A) polymers provide a wealth of useful hints for producing high power conversion efficiency (PCE) as hole transport materials (HTMs) in perovskite solar cells (PVSCs). Given the recent improvements in PCE, various features are focused on altering the functionalities of HTMs. In this study, a pyrazine-based acceptor is fused with two known donors benzodithiophene (BDT) and dithienobenzodithiophene (DTBDT) to synthesize two new D–A type polymers (NBD-Pyz and NDT-Pyz) to employ them as dopant-free HTM in PVSCs. The insertion of pyrazine moiety downshifted the energy levels and enhanced coplanarity for both the HTMs. NBD-Pyz can significantly lower the trap density and passivate the perovskite layer. More interestingly, the NBD-Pyz HTM performs better than NDT-Pyz, exhibiting higher hole mobility and better solubility in 2-methyl anisole (2MA) and o-xylene. Moreover, a 2MA/o-xylene cosolvent-processed dopant-free polymeric NBD-Pyz HTM-based device achieved a champion PCE of 22.9%. Unlike NDT-Pyz and Spiro-OMeTAD-based PVSCs, the unencapsulated NBD-Pyz devices were more stable, retaining almost 90% of their initial efficiency after 1000 h. In addition, excellent thermal stability was demonstrated by the resulting PVSCs without encapsulation.