Advanced Powder Materials最新文献

Sulfide all-solid-state lithium batteries (SASSLBs) with a single-crystal nickel-rich layered oxide cathode (LiNi_xCo_yMn_1-x-yO₂, x ​≥ ​0.8) are highly desirable for advanced power batteries owing to their excellent energy density and safety. Nevertheless, the cathode material's cracking issue and its severe interfacial problem with sulfide solid electrolytes have hindered the further development. This study proposes to employ surface modification engineering to produce B-NCM cathode materials coated with boride nanostructure stabilizer in situ by utilizing NCM encapsulated with residual lithium. This approach enhances the electrochemical performance of SASSLBs by effectively inhibiting electrochemical-mechanical degradation of the NCM cathode material on cycling and reducing deleterious side reactions with the solid sulfide electrolyte. The B-NCM/LPSCl/Gr SASSLBs demonstrate impressive cycling stability, retaining 84.19 ​% of its capacity after 500 cycles at 0.2 ​C, which represents a 30.13 ​% increase vs. NCM/LPSCl/Gr. It also exhibits a specific capacity of 170.4 mAh/g during its first discharge at 0.1 ​C. This work demonstrates an effective surface engineering strategy for enhancing capacity and cycle life, providing valuable insights into solving interfacial problems in SASSLBs.

Nuclear power is essential for sustainable energy infrastructure and economic development, necessitating materials for high-radiation environments that can facilitate visualization and observation. Conventional lead glass is inadequate for future requirements due to radiation-induced darkening, poor mechanical properties, and toxicity. Therefore, there is urgent to find new window materials that offer multi-ionization shielding (particularly against deep-penetrating gamma ray, γ, and neutron, n, radiations), desirable opto-mechanical properties, service stability against darkening, and non-toxicity. In this study, we report a family of transparent rare-earth pyrochlore ceramics La_xGd_2−xZr₂O₇, offering unique chemo-physical properties that are ideal for robust radiation shielding windows. Remarkably, we demonstrated the capability of maintaining high transparency under heavy-dose exposure to 1000 ​kGy ⁶⁰Co γ radiation. We observed the service stability against radiation darkening can be greatly enhanced with La-rich compositions, while Gd-rich compositions undergo shallow darkening that can be reversibly recovered under visible light. This behavior is attributed to mitigated oxygen migration from 48f to 8a in La-rich compositions, which have high pyrochlore phase stability and well-ordered atomic structures, and reversible oxygen migration between 48f and 8a in Gd-rich compositions, which remain active at room temperature. Our proposal and demonstration unlock ample opportunities in designing functional transparent ceramics as window materials for demanding applications in high-radiation environments.

Seawater electrolysis is a sustainable energy conversion technology that generates clean energy by splitting seawater into hydrogen and oxygen. However, the catalysts used in seawater electrolysis often face significant stability challenges because of the high concentration of salt ions and other impurities present in seawater. This review aims to discern the pivotal factors influencing catalyst stability in seawater electrolysis, elucidate the corrosion and electrochemical degradation mechanisms, and delve into the various strategies employed to enhance catalyst stability. These strategies encompass catalyst material selection, surface modification techniques, catalyst support materials, and catalyst design strategies. By gaining deeper insights into the obstacles and innovations concerning catalyst stability in seawater electrolysis, this review strives to expedite progress toward the commercialization and widespread adoption of this technology as a renewable and feasible approach for hydrogen production. Ultimately, the goal is to foster a cleaner and more sustainable future by enabling the efficient and enduring generation of hydrogen from seawater.

3D printing of flexible piezoelectric composites (3D-FPCs) is increasingly attracting the attention due to its unique advantage for customized smart applications. However, current research mainly focuses on the 0–3 piezoelectric composites, in which the piezoelectric ceramics are embedded in polymer matrix in the form of particles. The poor connectivity between particles much reduces the conduction of strain and charge in the composites, seriously limiting its application in actuation. In this work, a continuous lead zirconate titanate (PZT) double-layer ceramic scaffold was prepared by 3D printing and assembled with epoxy resin and interdigital electrodes together to manufacture a multifunctional device. The 3D-FPCs exhibit a free strain of 1830 ​ppm in actuating and are able to actuate a stainless-steel cantilever beam to produce a tip displacement of 5.71 ​mm. Additionally, the devices exhibit a sensitivity of 26.81V/g in sensing applications. Furthermore, 3D-FPCs are demonstrated as actuators for mobile small robots and wearable sensors for sensing joint activities.

The reported electrocaloric (EC) effect in ferroelectrics is poised for application in the next generation of solid-state refrigeration technology, exhibiting substantial developmental potential. This study introduces a novel and efficient EC effect strategy in (1–x)Pb(Lu_1/2Nb_1/2)O₃-xPbTiO₃ (PLN-xPT) ceramics for low electric-field-driven devices. Phase-field simulations provide fundamental insights into thermally induced continuous phase transitions, guiding subsequent experimental investigations. A comprehensive composition/temperature-driven phase evolution diagram is constructed, elucidating the sequential transformation from ferroelectric (FE) to antiferroelectric (AFE) and finally to paraelectric (PE) phases for x=0.10−0.18 components. Direct measurements of EC performance highlight x=0.16 as an outstanding performer, exhibiting remarkable properties, including an adiabatic temperature change (ΔT) of 3.03 ​K, EC strength (ΔT/ΔE) of 0.08 ​K ​cm kV⁻¹, and a temperature span (T_span) of 31 ​°C. The superior EC effect performance is attributed to the temperature-induced FE to AFE transition at low electric fields and diffusion phase transition behavior contributing to the wide T_span. This work provides valuable insights into developing high-performance EC effect across broad temperature ranges through the strategic design of continuous phase transitions, offering a simplified and economical approach for advancing ecofriendly and efficient solid-state cooling technologies.

Tuning the surface properties of catalysts is an effective method for accelerating water electrolysis. Herein, we propose a directional doping and interfacial coupling strategy to design two surface-functionalized Schottky junction catalysts for coordinating the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Directional doping with B/S atoms endows amphiphilic g-C₃N₄ with significant n-/p-type semiconductor properties. Further coupling with Fe₃C modulates the energy band levels of B–C₃N₄ and S–C₃N₄, thus resulting in functionalized Schottky junction catalysts with specific surface-adsorption properties. The space-charge region generated by the dual modulation induces a local “OH⁻- and H⁺-enriched” environment, thus selectively promoting the kinetic behavior of the OER/HER. Impressively, the designed B–C₃N₄@Fe₃C||S–C₃N₄@Fe₃C pair requires only a low voltage of 1.52 ​V to achieve efficient water electrolysis at 10 ​mA ​cm⁻². This work highlights the potential of functionalized Schottky junction catalysts for coordinating redox reactions in water electrolysis, thereby resolving the trade-off between catalytic activity and stability.

CoCrMoW alloys with different nitrogen (N) additions (0, 0.05, 0.1, and 0.2 ​wt%) were prepared via laser powder bed fusion (LPBF). The effects of N content on the microstructure and mechanical properties were investigated. The results indicate that the LPBFed CoCrMoW alloy with 0.1 ​wt% N addition (0.1 ​N alloy) shows the best combination of mechanical properties with a yield strength of ∼983 ​MPa and an elongation of ∼19 ​%. Both the LPBF process and the N addition impose great effects on suppressing the γ to ε martensitic transformation, resulting in a decrease in the width and amount of ε laths/stacking faults. Besides, the N addition promotes the segregation of elements Mo, W, and Si along the cellular sub-grain boundaries (CBs), forming fine and discontinuous precipitates rich in Mo, W and Si along the CBs in the 0.1 ​N alloy, but dense and continuous (Mo,W)₅Si₃ precipitates along the CBs in the 0.2 ​N alloy. The (Mo,W)₅Si₃ precipitates with a tetragonal structure were observed and characterized for the first time in the Co–Cr based alloys. The negative mixing enthalpy between the non-metallic elements N, Si and the metallic elements Mo, W, Cr, and the rapid solidification induced segregation of high melting point elements such as Mo and W along CBs during LPBF process, synergistically contribute to the chemical heterogeneity in the alloys. The pure FCC matrix, the slightly increased segregation of Mo, W, Si elements and fine precipitates along the CBs contribute to the good combination of strength and elongation of the 0.1 ​N alloy. However, though pure FCC phase was present in the 0.2 ​N alloy, the dense and continuous (Mo,W)₅Si₃ precipitates along CBs acted as nucleation sites for cracks, deteriorating the elongation of the alloy. Overall, it is possible to tune the mechanical properties of the LPBFed CoCrMoW alloy by adjusting the local chemical heterogeneity.

The development of high-energy-density Li-ion batteries is hindered by the irreversible capacity loss during the initial charge-discharge process. Therefore, pre-lithiation technology has emerged in the past few decades as a powerful method to supplement the undesired lithium loss, thereby maximizing the energy utilization of LIBs and extending their cycle life. Lithium oxalate (Li₂C₂O₄), with a high lithium content and excellent air stability, has been considered one of the most promising materials for lithium compensation. However, the sluggish electrochemical decomposition kinetics of the material severely hinders its further commercial application. Here, we introduce a recrystallization strategy combined with atomic Ni catalysts to modulate the mass transport and decomposition reaction kinetics. The decomposition potential of Li₂C₂O₄ is significantly decreased from ∼4.90V to ∼4.30V with a high compatibility with the current battery systems. In compared to the bare NCM//Li cell, the Ni/N-rGO and Li₂C₂O₄ composite (Ni-LCO) modified cell releases an extra capacity of ∼11.7 ​%. Moreover, this ratio can be magnified in the NCM//SiO_x full cell, resulting in a 30.4 ​% higher reversible capacity. Overall, this work brings the catalytic paradigm into the pre-lithiation technology, which opens another window for the development of high-energy-density battery systems.

Magnetostrictive Fe–Ga alloys have been demonstrated potentialities for numerous applications, whereas, suffering a tradeoff between large magnetostrictive strain and high sensitivity. Herein, bulk polycrystalline Fe₈₁Ga₁₉ alloys were prepared by laser-beam powder bed fusion (LPBF) and then annealed in magnetic field for manipulating the comprehensive magnetostrictive properties. Results indicate that <001> oriented grains are developed in the LPBF-prepared Fe₈₁Ga₁₉ alloys due to high temperature gradient. After magnetic field annealing (MFA), the magnetic domains within the alloys gradually transformed into well-arranged stripe domains, especially, flat and smooth 90° domains were established in the alloys annealed at 2600 ​Oe. As a result, the induced <001> orientation grains and 90° domains contributed to an improved effective magnetic anisotropy constant (57.053 ​kJ/m³), leading to an enhanced magnetostrictive strain of 92 ​ppm. Moreover, the MFA-treated alloys also displayed enhanced magnetostrictive sensitivity (0.097 ​ppm/Oe) owing to the smooth domain structures and low dislocation densities, demonstrating a fruitful strain-sensitivity synergy. In addition, good magnetostrictive dynamic response and enhanced compressive yield strength were also observed for the prepared alloys. This work demonstrates that LPBF and MFA might be an attractive strategy to resolve the tradeoff between strain and sensitivity, providing a basis for the preparation of high-performance magnetostrictive materials.