Nanoscale Soft Wetting Observed in Co/Sapphire during Pulsed Laser Irradiation

Liquid drops on deformable soft substrates exhibit quite complicated wetting behavior as compared to those on rigid solid substrates. We report on a soft wetting behavior of Co nanoparticles (NPs) on a sapphire substrate during pulsed laser-induced dewetting (PLID). Co NPs produced by PLID wetted the sapphire substrate with a contact angle near 70°, which is in contrast to typical dewetting behavior of metal thin films exhibiting contact angles greater than 90°. In addition, a nanoscale γ-Al2O3 wetting ridge about 15 nm in size and a thin amorphous Al2O3 interlayer were observed around and beneath the Co NP, respectively. The observed soft wetting behavior strongly indicates that the sapphire substrate became soft and deformable during PLID. Moreover, the soft wetting was augmented under PLID in air due to the formation of a CoO shell, resulting in a smaller contact angle near 30°

Nanoscale Soft Wetting Observed in Co/Sapphire during Pulsed Laser Irradiation

Liquid drops on deformable soft substrates exhibit quite complicated wetting behavior as compared to those on rigid solid substrates. We report on a soft wetting behavior of Co nanoparticles (NPs) on a sapphire substrate during pulsed laser-induced dewetting (PLID). Co NPs produced by PLID wetted the sapphire substrate with a contact angle near 70°, which is in contrast to typical dewetting behavior of metal thin films exhibiting contact angles greater than 90°. In addition, a nanoscale γ-Al2O3 wetting ridge about 15 nm in size and a thin amorphous Al2O3 interlayer were observed around and beneath the Co NP, respectively. The observed soft wetting behavior strongly indicates that the sapphire substrate became soft and deformable during PLID. Moreover, the soft wetting was augmented under PLID in air due to the formation of a CoO shell, resulting in a smaller contact angle near 30°

Highly Efficient Reductive Catalytic Fractionation of Lignocellulosic Biomass over Extremely Low-Loaded Pd Catalysts

The reductive catalytic fractionation (RCF) of lignocellulosic and herbaceous biomass over heterogeneous catalysts has been demonstrated to recover high-yield phenolic monomers and holocellulose-rich solids effectively, and these products could be further used to produce value-added chemicals and second-generation biofuel. Catalyst selection plays a critical role in the performance of the RCF process, and noble metal catalysts (e.g., Pt, Pd, and Ru) with a high loading of 5 wt % have been extensively used to obtain high-yield phenolic monomers and delignified holocellulose-rich solids. In this study, we demonstrated that the RCF of biomass over extremely low Pd loaded on N-doped carbon (CNx) support catalysts could produce phenolic monomers at approximately theoretical maximum yield and presented high holocellulose-rich solid recovery. When birch wood was converted over the catalyst with 0.25 wt % Pd loaded on CNx (Pd0.25/CNx) at 250 ??C and an initial H2 pressure of 3.0 MPa for 3 h, a lignin-derived phenolic monomer carbon yield and highly delignified holocellulose recovery of 52.7 C % and 84.2 wt %, respectively, were achieved. The Pd0.25/CNx catalyst contained both ultrasmall Pd nanoclusters and single Pd atoms, which were stabilized on the N-functionalized carbon support. The highly activated hydrogenolysis and double-bond saturation that occurred over the Pd0.25/CNx catalyst dominantly produced 4-n-propyl guaiacol/syringol. In contrast, 4-n-propanol guaiacol/syringol with residual ???OH groups was the major species obtained over the typical 5 wt % Pd/activated carbon catalyst. The plausible reaction pathways for the production of different types of phenolic monomers were discussed using density functional theory calculations. The excellent RCF performance of the Pd0.25/CNx catalyst was demonstrated using other types of biomass, such as oak, pine, and miscanthus. The successful use of extremely low-Pd-loaded catalysts is advantageous for implementing economically viable RCF techniques

New Cost‐Effective Halide Solid Electrolytes for All‐Solid‐State Batteries: Mechanochemically Prepared Fe 3+

Owing to the combined advantages of sulfide and oxide solid electrolytes (SEs), that is, mechanical sinterability and excellent (electro)chemical stability, recently emerging halide SEs such as Li3YCl6 are considered to be a game changer for the development of all-solid-state batteries. However, the use of expensive central metals hinders their practical applicability. Herein, a new halide superionic conductors are reported that are free of rare-earth metals: hexagonal close-packed (hcp) Li2ZrCl6 and Fe3+-substituted Li2ZrCl6, derived via a mechanochemical method. Conventional heat treatment yields cubic close-packed monoclinic Li2ZrCl6 with a low Li+ conductivity of 5.7 × 10−6 S cm−1 at 30 °C. In contrast, hcp Li2ZrCl6 with a high Li+ conductivity of 4.0 × 10−4 S cm−1 is derived via ball-milling. More importantly, the aliovalent substitution of Li2ZrCl6 with Fe3+, which is probed by complementary analyses using X-ray diffraction, pair distribution function, X-ray absorption spectroscopy, and Raman spectroscopy measurements, drastically enhances the Li+ conductivity up to ≈1 mS cm−1 for Li2.25Zr0.75Fe0.25Cl6. The superior interfacial stability when using Li2+xZr1−xFexCl6, as compared to that when using conventional Li6PS5Cl, is proved. Furthermore, an excellent electrochemical performance of the all-solid-state batteries is achieved via the combination of Li2ZrCl6 and single-crystalline LiNi0.88Co0.11Al0.01O2. © 2021 Wiley-VCH GmbH1

Unleashing the Potential of Sodium-Ion Batteries: Current State and Future Directions for Sustainable Energy Storage

Rechargeable sodium-ion batteries (SIBs) are emerging as a viable alternative to lithium-ion battery (LIB) technology, as their raw materials are economical, geographically abundant (unlike lithium), and less toxic. The matured LIB technology contributes significantly to digital civilization, from mobile electronic devices to zero electric-vehicle emissions. However, with the increasing reliance on renewable energy sources and the anticipated integration of high-energy-density batteries into the grid, concerns have arisen regarding the sustainability of lithium due to its limited availability and consequent price escalations. In this context, SIBs have gained attention as a potential energy storage alternative, benefiting from the abundance of sodium and sharing electrochemical characteristics similar to LIBs. Furthermore, high-entropy chemistry has emerged as a new paradigm, promising to enhance energy density and accelerate advancements in battery technology to meet the growing energy demands. This review uncovers the fundamentals, current progress, and the views on the future of SIB technologies, with a discussion focused on the design of novel materials. The crucial factors, such as morphology, crystal defects, and doping, that can tune electrochemistry, which should inspire young researchers in battery technology to identify and work on challenging research problems, are also reviewed

Tailoring Solution-Processable Li Argyrodites Li6+xP1-xMxS5I (M = Ge, Sn) and Their Microstructural Evolution Revealed by Cryo-TEM for All-Solid-State Batteries

Owing to their high Li+ conductivities, mechanical sinterability, and solution processability, sulfide Li argyrodites have attracted much attention as enablers in the development of high-performance all-solid-state batteries with practicability. However, solution-processable Li argyrodites have been developed only for a composition of Li6PS5X (X = Cl, Br, I) with insufficiently high Li+ conductivities (similar to 10(-4) S cm(-1)). Herein, we report the highest Li+ conductivity of 0.54 mS cm(-1) at 30 degrees C (Li6.5P0.5Ge0.5S5I) for solution-processable iodine-based Li argyrodites. A comparative investigation of three iodine-based argyrodites of unsubstituted and Ge- and Sn-substituted solution-processed Li6PS5I with varied heat-treatment temperature elucidates the effect of microstructural evolution on Li+ conductivity. Notably, local nanostructures consisting of argyrodite nanocrystallites in solution-processed Li6.5P0.5Ge0.5S5I have been directly captured by cryogenic transmission electron microscopy, which is a first for sulfide solid electrolyte materials. Specifically, the promising electrochemical performances of all-solid-state batteries at 30 degrees C employing LiCoO2 electrodes tailored by the infiltration of Li6.5P0.5Ge0.5S5I-ethanol solutions are successfully demonstrated

Synthesis of Monocarboxylic Acids via Direct CO2 Conversion over Ni-Zn Intermetallic Catalysts

The direct conversion of CO2 to methane, gasoline-to-diesel range fuels, methanol, and light olefins using sustainable hydrogen sources is considered a promising approach for mitigating global warming. Nevertheless, the direct conversion of CO2 to high value-added chemicals, such as acetic acid and propionic acid (AA and PA, respectively), has not been explored to date. Herein, we report a Ni-Zn intermetallic/Zn-rich NixZnyO catalyst that directly converted CO2 to AA and PA with an overall selectivity of 77.1% at a CO2 conversion of 13.4% at 325 degrees C. The surface restructuring of the ZnO and NiO phases during calcination and subsequent reduction led to the formation of a Ni-Zn intermetallic on the Zn-rich NixZnyO phase. Surface-adsorbed (*CHx)(n) species were formed via the reverse water gas shift reaction and subsequent CO hydrogenation. Afterward, monocarboxylic acids were produced via the direct insertion of CO2 into the (*CHx)(n) species and subsequent hydrogenation. The synthesis of monocarboxylic acid was highly stable up to 216 h on-stream over the Ni-Zn intermetallic catalyst, and the catalyst maintained its phase structure and morphology during long-term CO2 hydrogenation. The high selectivity toward monocarboxylic acids and high stability of the Ni-Zn intermetallic demonstrated its high potential for the conversion of CO2 into value-added chemicals

MoO₃@MoS₂ Core-Shell Structured Hybrid Anode Materials for Lithium-Ion Batteries

We explore a phase engineering strategy to improve the electrochemical performance of transition metal sulfides (TMSs) in anode materials for lithium-ion batteries (LIBs). A one-pot hydrothermal approach has been employed to synthesize MoS2 nanostructures. MoS2 and MoO3 phases can be readily controlled by straightforward calcination in the (200–300) °C temperature range. An optimized temperature of 250 °C yields a phase-engineered MoO3@MoS2 hybrid, while 200 and 300 °C produce single MoS2 and MoO3 phases. When tested in LIBs anode, the optimized MoO3@MoS2 hybrid outperforms the pristine MoS2 and MoO3 counterparts. With above 99% Coulombic efficiency (CE), the hybrid anode retains its capacity of 564 mAh g−1 after 100 cycles, and maintains a capacity of 278 mAh g−1 at 700 mA g−1 current density. These favorable characteristics are attributed to the formation of MoO3 passivation surface layer on MoS2 and reactive interfaces between the two phases, which facilitate the Li-ion insertion/extraction, successively improving MoO3@MoS2 anode performance

Boosting the interfacial superionic conduction of halide solid electrolytes for all-solid-state batteries

Designing highly conductive and (electro)chemical stable inorganic solid electrolytes using cost-effective materials is crucial for developing all-solid-state batteries. Here, we report halide nanocomposite solid electrolytes (HNSEs) ZrO2(-ACl)-A(2)ZrCl(6) (A = Li or Na) that demonstrate improved ionic conductivities at 30 degrees C, from 0.40 to 1.3 mS cm(-1) and from 0.011 to 0.11 mS cm(-1) for Li+ and Na+, respectively, compared to A(2)ZrCl(6), and improved compatibility with sulfide solid electrolytes. The mechanochemical method employing Li2O for the HNSEs synthesis enables the formation of nanostructured networks that promote interfacial superionic conduction. Via density functional theory calculations combined with synchrotron X-ray and Li-6 nuclear magnetic resonance measurements and analyses, we demonstrate that interfacial oxygen-substituted compounds are responsible for the boosted interfacial conduction mechanism. Compared to state-of-the-art Li2ZrCl6, the fluorinated ZrO2-2Li(2)ZrCl(5)F HNSE shows improved high-voltage stability and interfacial compatibility with Li6PS5Cl and layered lithium transition metal oxide-based positive electrodes without detrimentally affecting Li+ conductivity. We also report the assembly and testing of a Li-In||LiNi0.88Co0.11Mn0.01O2 all-solid-state lab-scale cell operating at 30 degrees C and 70 MPa and capable of delivering a specific discharge of 115 mAh g(-1) after almost 2000 cycles at 400 mA g(-1). Compositional tuning is a standard procedure to improve the ionic conductivity of inorganic superionic conductors. Here, the authors report (electro)chemical stable composite halide solid electrolytes applying a nanostructure approach that promotes interfacial superionic conductivity

Ultra-stable and tough bioinspired crack-based tactile sensor for small legged robots

Abstract For legged robots, collecting tactile information is essential for stable posture and efficient gait. However, mounting sensors on small robots weighing less than 1 kg remain challenges in terms of the sensor’s durability, flexibility, sensitivity, and size. Crack-based sensors featuring ultra-sensitivity, small-size, and flexibility could be a promising candidate, but performance degradation due to crack growing by repeated use is a stumbling block. This paper presents an ultra-stable and tough bio-inspired crack-based sensor by controlling the crack depth using silver nanowire (Ag NW) mesh as a crack stop layer. The Ag NW mesh inspired by skin collagen structure effectively mitigated crack propagation. The sensor was very thin, lightweight, sensitive, and ultra-durable that maintains its sensitivity during 200,000 cycles of 0.5% strain. We demonstrate sensor’s feasibility by implementing the tactile sensation to bio-inspired robots, and propose statistical and deep learning-based analysis methods which successfully distinguished terrain type