Rare Metals最新文献

Zinc ion batteries (ZIBs) are promising for large-scale energy storage applications, but the technology lacks high-capacity and high-stability cathode materials. Herein, oxygen vacancy-VN/V₂O₃/C (Ov-VN/V₂O₃/C) heterostructural composite was successfully designed and synthesized as high-stability cathode to promote reversible ZIBs. Thanks to the oxygen-vacancy heterojunction features and the transformed amorphous new phase V₁₀O₂₄·12H₂O, Ov-VN/V₂O₃/C provides abundant channels and active sites for Zn²⁺ diffusion and adsorption. Thus, Ov-VN/V₂O₃/C as a cathode material for aqueous ZIBs exhibits excellent a high reversible capacity of 531 mAh g⁻¹ at 0.3 A g⁻¹, good rate performance (446 mAh g⁻¹ at a high current density of 10 A g⁻¹), and good stability (115 mAh g⁻¹ at 20 A g⁻¹ after 5000 cycles). More importantly, Ov-VN/V₂O₃/C//Zn assembled quasi-solid-state batteries also have excellent long-term cycling performance. This work not only obtains high-performance cathode materials, but also provides a new idea for the development of the synthesis of transformational new materials with the synergistic effect of vacancies (defects) and heterojunctions.

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Alkaline water electrolysis poses significant potential for large-scale industrial hydrogen generation, but is impeded by the absence of an efficient electrocatalyst capable of operating at high current densities while maintaining with minimal overpotential. Herein, we construct a mechanically stable and highly active RuSe₂/MXene heterojunction electrocatalyst. A typical SC-Ti₃C₂T_x MXene substrate was successfully prepared by supercritical CO₂ (SC-CO₂) etching, combined by subsequent DMSO intercalation treatment. Further, the RuSe₂ nanoparticles were uniformly deposited on the surface of SC-Ti₃C₂T_x. Theoretical calculations and experimental results demonstrate that fluorine-rich MXene exhibits stable binding with the active 1T phase RuSe₂. The as-prepared representative RuSe₂@SC-Ti₃C₂T_x-3 heterostructure showed exceptional alkaline hydrogen evolution performance, demonstrating an overpotential of 15 mV at 10 mA cm⁻² and a Tafel slope of 21.84 mV dec⁻¹, which presents excellent HER performance and stability at high-current-density conditions. Moreover, the overpotential under the current density of 500 mA cm⁻² is merely 182 mV, and the HER efficiency remains unaffected even after 5000 cycles and 120 h of continuous testing.

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A novel protocol is proposed for etching Ti3AlC2 MAX phase depending on the supercritical CO2 and ZnF2·4H₂O as an effective etchant to fabricate MXene with enriched F delamination. The F-rich MXene exhibits stronger interactions with the active 1T phase RuSe2, thereby significantly enhancing the electrocatalytic activity and stability under high current density.

Nickel-rich LiNi_xCo_yMn_1−x−yO₂ (NCM) cathodes, pivotal for high-energy–density lithium-ion batteries, face severe challenges from surface residual lithium compounds and hydrofluoric acid (HF)-induced degradation. These issues accelerate capacity fading, exacerbate interfacial polarization, and compromise safety. To address these issues, we proposed a scalable CeF₃/H₃BO₃ hybrid coating strategy for LiNi_0.82Co_0.12Mn_0.06O₂ cathodes. The CeF₃ nanoparticles served as a robust physical barrier, effectively scavenging HF, while the LiBO₂ layer derived from H₃BO₃ eliminated residual Li₂CO₃ through chemical conversion and established rapid Li⁺ transport pathways. Dynamic B-O bond reorganization enabled self-repair of coating defects, synergistically suppressing interfacial polarization and maintaining structural integrity. Electrochemical evaluations demonstrated that the hybrid-coated cathode achieves 94% capacity retention after 200 cycles at 1C (2.8–4.3 V), significantly outperforming the pristine NCM (56.3%). Additionally, the modified cathode exhibits enhanced air stability, with suppressed H₂O/CO₂ infiltration, and delivers 80% capacity retention after 1000 cycles in practical pouch cells. This work provides a cost-effective and industrially viable solution to simultaneously mitigate HF corrosion, residual lithium accumulation, and cathode–electrolyte interphase instability, paving the way for durable high-energy–density batteries.

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The proton ceramic electrochemical cell (PCEC), distinguished by its robust all-solid-state construction, emerges as a particularly promising contender in the realm of hydrogen production technologies. However, inadequate water-storage capability (hydration) and limited proton mobility within conventional PCEC oxygen electrodes hinder the efficiency of water splitting to oxygen, thereby restricting the broader application of PCECs. Here, we report a Ni-doped perovskite oxygen electrode Sr₂Fe_1.4Ni_0.1Mo_0.5O_6-δ (SFNM), where the incorporation of nickel can effectively amplify the concentration of oxygen vacancies while synergistically enhancing the hydration interaction between water molecules and the perovskite lattice. The enhanced hydration capacity facilitates proton-defect formation and lowers the energy barrier for proton migration. Benefiting from these synergistic enhancements, SFNM demonstrates a substantially reduced polarization resistance of approximately 0.078 Ω cm² at 700 °C under humidified conditions (pH₂O = 0.1 atm). A PCEC utilizing the SFNM electrode achieves a remarkable current density of 2.60 A cm² with an applied voltage of 1.3 V at 700 °C. Furthermore, the PCEC exhibits favorable stability over a duration of 200 h. These outstanding results emphasize the potential of Ni doping to substantially improve both the hydration efficiency and proton mobility within perovskite electrode materials, positioning them as excellent candidates for high-performance PCECs.

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Bacterial infection presents formidable challenges that frequently culminate in the malfunction of metal implants. Traditional surface treatment methods struggle to effectively achieve controllable management of bacterial infections associated with metal implants. To effectively enhance the antibacterial capabilities and preventing bacterial adhesion, electroactive materials have emerged as a groundbreaking strategy for surface modification of metal. By responding to external signals, the electroactive materials can improve antibacterial properties and resistance to bacterial adhesion on the implant surface through harnessing the electrostatic interaction of charges, ion release, oxidation of reactive oxygen species (ROS), electron transfer, and the involvement of cellular immunity. This review delves into the principles of how electroactive materials confer implants with antibacterial properties and antibacterial adhesion, while also summarizing the latest research breakthroughs in their application for surface modification. These strategies successfully strike a balance between the antibacterial and the antimicrobial performance of the implant surface. Lastly, the review examines the limitations and ongoing challenges faced by electroactive material modification technology in implant applications, and sketches out the future trajectory and potential innovative avenues in this promising field.

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Despite their high-energy conversion efficiency that has earned them the label of next-generation energy utilization devices, protonic ceramic fuel cells (PCFCs) have not yet fully fulfilled their potential in terms of low-cost integration and environmentally friendly application, which remain significant concerns that heavily influence their progress towards commercial viability. A pragmatic way of cell recycling is extremely helpful for addressing these concerns. Herein, we unveil a novel concept of reusable PCFCs, and propose a comprehensive recycling scheme for discarded PCFCs. In this research, a recycled cell with a recycled single perovskite cathode exhibited a peak power density (PPD) of 1.10 W cm⁻² at 700 °C, comparable to a pristine cell of 1.05 W cm⁻². Metal ion rearrangement and phase evolution during the recycling processes were investigated, which were demonstrated to be in high relevance to the performance of recycled cells. This research constitutes a pioneering exploration of the mechanisms underlying recycling efforts and offers valuable insights into the material recycling of solid-state functional devices used for energy conversion and storage.

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Si, as the most promising anode with high theoretical capacity for next-generation lithium-ion batteries (LIBs), is hampered in commercial application by its poor electrical conductivity and significant volume expansion. Herein, the core-shell Si@SiO_x/C@C-Ar (SSC-A) or Si@SiO_x/C@C-H₂/Ar (SSC-H) composites are purposefully designed by in situ introduction of inorganic SiO_x in pure Ar or H₂/Ar atmosphere to realize a Si-based anode for LIBs. By introducing different atmospheres, the valence states of SiO_x are regulated. The inorganic transition layer formed by the combination of SiO_x with higher average valence and asphalt-derived carbon demonstrates better performance in both stabilizing the core-shell structure and inhibiting the agglomeration of Si particles. Given these advantages, the SSC-A electrode exhibits excellent electrochemical performance (1163 mAh g⁻¹ after 400 cycles at 1 A g⁻¹), and the commercial blended graphite-SSC-A electrode reaches a specific capacity of 442 mAh g⁻¹ with 74.8% capacity retention under the same conditions. Even the SSC-A electrode without Super P maintains an ultrahigh discharge specific capacity of 803 mAh g⁻¹ with 60.6% after cycling. Importantly, the full batteries based on SSC-A without Super P achieve a discharge specific capacity of 126 mAh g⁻¹ with 28.2% capacity decay after 200 cycles, demonstrating the superior commercial application potential.

The formation and evolution process of the solid electrolyte interphase (SEI) is critical for stable cycling of the lithium metal anode (LMA). The concept of regulating SEI components with additives is widely incorporated into electrolyte design, as these additives can alter the lithium ion (Li⁺) deposition behavior on the surface of LMA. However, conventional additives are limited in their ability to produce only loose and porous SEI. In this study, we propose an organic additive of methyl methacrylate (MMA) that facilitates in-situ polymerization on the surface of LMA by generating anions or free radicals from LiTFSI. The MMA and LiNO₃ work in tandem to produce a polymer/inorganic SEI (PI–SEI) characterized by an outer layer enriched with PMMA–Li short–chain polymers and an inner layer enriched with Li₂O and Li₃N inorganics. Unlike the SEI formed by conventional additives, this PI–SEI exhibits higher stability and better Li⁺ transfer properties. The presence of short–chain polymers in PI–SEI alters the transport uniformity of Li⁺, facilitating stable cycling of Li || Li cell for over 2000 cycles with a capacity of 1 mAh cm⁻². Furthermore, these PMMA–Li can chemically adsorb lithium polysulfides (LiPSs), thereby inhibiting Li corrosion by LiPSs, and enabling the capacity of lithium–sulfur batteries to achieve 474.3 mAh g⁻¹ after 500 cycles at 0.5C. This study presents a strategy for generating SEI through the in-situ polymerization, which supports the commercial development of LMA in future liquid/solid Li metal batteries.

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Nuclear energy provides a competitive path for reduction of CO₂ with water, whereas the high-efficiency utilization of radiolytically produced active species for oriented transformation remains challenging. Herein, we report the assembling of yttrium-decorated bimetallic MOFs via one-step hydrothermal strategy, which can act as a sensitized nanoreactor for syngas production under γ-ray irradiation. The flower-shaped CuNi-MOF matrix with tunable metal centers exposed plentiful cooperative active sites for CO₂ binding, and its nanopetals enabled the well dispersion of Y₂O₃ nanoparticles on the surfaces. The introduction of high-Z element Y enhanced the secondary electron scattering and promoted the water radiolysis to produce more hydrated electrons (e_aq⁻), thus accelerating the initial CO₂ activation to CO₂^•−. Moreover, the in situ formed coupling interlayer provided a fast charge transfer channel between Y₂O₃ and the MOF framework, which facilitated the interfacial electron migration for intermediate generation and subsequent CO₂ conversion. By regulating the contents of Cu and Y₂O₃ within the nanocomposites, the affinity toward CO₂ and the product compositions could be modulated. As a result, the optimal 7CN-2Y catalyst achieved a high syngas evolution rate of 311.07 μmol g⁻¹ with a H₂/CO ratio of 2.7:1 at an absorbed dose of 4 kGy. The present study offered a feasible route for the efficient transformation of CO₂ into valuable chemicals and the design of viable catalysts for ionizing radiation.

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Excessive nitrogen emission caused by human activities has significantly disrupted the global nitrogen cycle, adversely affecting ecosystems and human health. Electrocatalytic nitrate reduction to valuable ammonia (eNRA) presents an encouraging alternative marked by mild reaction conditions, rapid reaction rates, and minimal byproduct pollution, successfully overcoming the challenges of the energy-intensive Haber–Bosch process. Recent innovations in two-dimensional (2D) electrocatalysts have emerged as a promising approach to enhance the efficiency and selectivity of this transformation. This review systematically examines the latest advancements in 2D materials, including metals, metal compounds, nonmetallic elements, and organic frameworks, highlighting their unique electronic properties and high surface area that facilitate the electrocatalytic reactions. We explore strategies to optimize these catalysts, such as doping, heterostructure, and surface functionalization, which have shown significant improvements in catalytic performance. Furthermore, the role of in situ/operando characterization techniques in understanding the reaction mechanisms is highlighted, aiming to provide both theoretical and practical insights for the research and development of 2D nano-electrocatalysts during eNRA. Additionally, future perspectives and ongoing challenges are discussed to offer insights for transitioning from experimental investigations to real-world applications.

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