Manipulating amorphous and crystalline hybridization of Na3V2(PO4)3/C for enhancing sodium-ion diffusion kinetics.

Na3V2(PO4)3 (NVP) has attracted considerable attention as a promising cathode material for sodium-ion batteries (SIBs). But its insufficient electronic conductivity, limited capacities, and fragile structure hinder its extended application, particularly in scenarios involving rapid charging and prolonged cycling. A hybrid cathode material has been developed to integrate both amorphous and crystalline phases, with the objective of improving the rate performance and Na storage capacity by leveraging bi-phase coordination. Consequently, the combination of amorphous and crystalline phases enhanced the kinetics of Na-ion diffusion, resulting in a 1-2 orders of magnitude enhancement in diffusion dynamics. Furthermore, the existence of amorphous states has been demonstrated to elevate the active Na2 site content, resulting in an increased reversible capacity. This assertion is substantiated by evidence derived from solid-state nuclear magnetic resonance (ss-NMR) and electrochemical characteristics. The innovative bi-phase collaborative material provides a specific capacity of 114 mAh/g at 0.2 C, exceptional rate performance of 82 mAh/g at 10 C, and remarkable long-term cycle stability, retaining 95 mAh/g at 5 C even after 300 cycles. In conclusion, the homogeneous hybridization of amorphous and crystalline phases presents itself as a promising and effective strategy for improving Na-ion storage capacity of cathodes in SIBs.

Hot-Pressing Enhances Mechanical Strength of PEO Solid Polymer Electrolyte for All-Solid-State Sodium Metal Batteries.

Poly(ethylene oxide) (PEO)-based solid polymer electrolytes (SPEs) are widely utilized in all-solid-state sodium metal batteries (ASSSMBs) due to their excellent flexibility and safety. However, poor ionic conductivity and mechanical strength limit its development. In this work, an emerging solvent-free hot-pressing method is used to prepare mechanically robust PEO-based SPE, while sodium superionic conductors Na3 Zr2 Si2 PO12 (NZSP) and NaClO4 are introduced to improve ionic conductivity. The as-prepared electrolyte exhibits a high ionic conductivity of 4.42 × 10-4 S cm-1 and a suitable electrochemical stability window (4.5 V vs Na/Na+ ). Furthermore, the SPE enables intimate contact with the electrode. The Na||Na3 V2 (PO4 )3 @C ASSSMB delivers a high-capacity retention of 97.1% after 100 cycles at 0.5 C and 60 °C, and exhibits excellent Coulombic efficiency (CE) (close to 100%). The ASSSMB with the 20 µm thick electrolyte also demonstrates excellent cyclic stability. This study provides a promising strategy for designing stable polymer-ceramic composite electrolyte membranes through hot-pressing to realize high-energy-density sodium metal batteries.

Fractionated lignin as a polyol in polyurethane fabrication.

The main purpose of this paper was to systematically evaluate the effect of lignin, which was fractioned by green solvents into different molecular weights and used as polyol in the production of polyurethane foams (PUF). The results indicated that the foams prepared with the lower molecular weight lignin had uniform and complete pore structure and improved the mechanical strength. However, the higher molecular weight fraction lignin improved the density and thermal stability of the foam more significantly at the expense of inferior mechanical strength and pore structure deficiency. When the substitution degree of lignin in the PUF was 2 %-30 %, 99.13 % of the lowest molecular weight lignin was participated in the reaction to produce PUF, which improved the elongation at break (Eb) and tensile strength (Ts) of PUF to 834 % and 0.90 MPa, respectively. Also, thermal stability and the amount of unreacted lignin in PUF were increased at a higher substitution degree of lignin in PUF.

Intrinsic Properties Affecting the Catalytic Activity toward Oxygen Reduction Reaction of Nanostructured Transition Metal Nitrides as Catalysts for Hybrid Na-Air Batteries.

Nanostructured transition metal nitrides (TMNs) have been considered as a promising substitute for precious metal catalysts toward ORR due to their multi-electron orbitals, metallic properties, and low cost. To design TMN catalysts with high catalytic activity toward ORR, the intrinsic features of the influencing factor on the catalytic activity toward ORR of nanostructured TMNs need to be investigated. In this paper, titanium nitride (TiN), zirconium nitride (ZrN), and hafnium nitride (HfN) nanoparticles (NPs) are highly efficient and synthesized in one step by the direct current arc plasma. TiN, ZrN, and HfN NPs with an oxidation layer are applied as the catalysts of hybrid sodium-air batteries (HSABs). The effect of the composition and structural attributes of TMNs on ORR catalysis is defined as follows: (i) composition effect. With the increase in the oxygen content, the catalytic ORR capability of TMNs decreases progressively due to the reduction in oxygen adsorption capacity; (ii) structure effect. The redistribution of the density of states (DOS) of ZrN indicates higher ORR activity than TiN and HfN. HSABs with ZrN exhibit an excellent cyclic stability up to 137 cycles (about 140 h), an outstanding rate performance, and a specific capacity of 2817 mAh·g-1 at 1.0 mA·cm-2.

Glucopyranose from Pleurotus geesteranus prevent alcoholic liver diseases by regulating Nrf2/HO-1-TLR4/NF-κB signalling pathways and gut microbiota.

This study investigated the effects of PGPs (Pleurotus geesteranus polysaccharides), a glucopyranose isolated from the mycelium of Pleurotus geesteranus and characterized with the main chain of →4)-α-D-Glcp-(1→, on the prevention against alcohol liver diseases (ALD), with the aim of providing a theoretical basis for the application of P. geesteranus as prebiotic agents in preventing and treating gut dysbiosis and alcohol-related metabolic disorders in individuals with ALD. The results showed that PGP treatment reduced oxidative stress by up-regulating the Nrf2/HO-1 signalling pathways, and decreased the pro-inflammatory factors by down-regulating TLR4/NF-κB signalling pathways. Furthermore, we validated effects of PGPs on balancing the gut-liver axis by maintaining the integrity of the intestinal epithelial barrier of decreasing intestinal permeability, increasing intestinal tight-junction protein and mucin expression and elevating the abundance of short-chain fatty acids (SCFAs) producers in the intestine by regulating the microbiota composition.

Multiscale Investigation into Chemically Stable NASICON Solid Electrolyte in Acidic Solutions.

Natrium superionic conductor (NASICON) solid electrolyte has been attracting wide attention due to its high ionic conductivity, low cost, and environmental friendliness. In this work, the chemical stability of the NASICON solid electrolyte with the composition of Na3Zr2Si2PO12 was evaluated in acidic solutions with different pH values, and the corrosion mechanism of the NASICON solid electrolyte was revealed at the multiscale level. Variations in bulk impedance, grain boundary impedance, and surface crack impedance with immersion time were determined by an AC impedance method. Comprehensive studies upon scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) etching, X-ray diffraction (XRD), and Raman spectroscopy, the morphological transformation, degradation limit depth, Cl- penetration effect, and proton exchange between H3O+ and Na+ were examined ranging from macro- and meso- to microscales, respectively. With the decrease of the pH of the solution, the exchange rate between H3O+ and Na+ protons increases. The lack of Na+ within the crystallographic lattice leads to the shrinkage of phosphorus-oxygen tetrahedra, which is the main reason for the decrease of unit cell volume, grain refinement, and surface cracks gradually. This work features multiscale characterizations of crystal structure, grain boundaries, surface morphology changes, and Na+ transport, which deepens our physicochemical understanding of solid electrolytes with high chemical stability.

Plasma tailored reactive nitrogen species in MOF derived carbon materials for hybrid sodium-air batteries.

The rational design of efficient and durable electrocatalysts to accelerate sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics is highly desirable for enhancing the efficiency of fuel cells and metal-air batteries. Here, we demonstrated a low-temperature plasma strategy at atmospheric pressure for enhancing the catalytic activity of metal-organic framework derived N-doped carbon nanotubes (MOF-NCNTs) by changing the relative contents of Co-Nx sites, Co-Co bonds and pyridinic-N. The increase of pyridinic-N/pyrrolic-N ratio improves the ORR performance, while unsaturated Co-Nx sites and strong Co-Co bonds promote the OER performance. The relative contents of pyridinic-N, Co-Nx sites, and Co-Co bonds in MOF-NCNTs can be readily tailored by varying the plasma treatment time. The MOF-NCNTs treated with N2 plasma for 4 min (MOF-NCNTs-N2-4) exhibited improved ORR (ηonset: 0.91 V) and OER (η10: 0.44 V) activities compared to MOF-NCNTs because of the higher ratio of pyridinic-N to pyrrolic-N and higher relative contents of Co-Nx sites and Co-Co bonds. The hybrid sodium-air batteries (HSABs) assembled with MOF-NCNTs-N2-4 catalyst display a low overpotential of 0.35 V and excellent round trip efficiency of 88.9% at 0.1 mA cm-2. Besides, they also exhibited great cycling stability with an average discharge voltage of 2.75 V and an outstanding round trip efficiency of 84% after 150 cycles.

Rapid iodine capture from radioactive wastewater by green and low-cost biomass waste derived porous silicon-carbon composite.

The effective and safe capture and storage of radioactive iodine (129I or 131I) are of significant importance during nuclear waste storage and nuclear energy generation. Herein, a porous silicon-carbon (pSi-C) composite derived from paper mill sludge (PMS) is synthesized and used for rapid iodine capture. The influences of the activator type, the impregnation ratio of the paper mill sludge to the activator, carbonization temperature, and carbonization time on the properties of the pSi-C composite are investigated. The pSi-C composite produced in the presence of ZnCl2 as the activator and at an impregnation ratio of 1 : 1, a carbonization temperature of 550 °C, and a carbonization time of 90 min has a surface area of 762.13 m2 g-1. The as-synthesized pSi-C composite exhibits promising iodine capture performance in terms of superior iodine adsorption capacity (q t ) of around 250 mg g-1 and rapid equilibrium adsorption with in 15 min. The devised method is environmentally friendly and inexpensive and can easily be employed for the large-scale production of porous silicon-activated carbon composites with excellent iodine capture and storage from iodine-contaminated water.

Challenges and perspectives of NASICON-type solid electrolytes for all-solid-state lithium batteries.

NASICON-type (lithium super ionic conductor) solid electrolyte is of great interest because of its high ionic conductivity, wide potential window, and good chemical stability. In this paper, the key problems and challenges of NASICON-type solid electrolyte are described from the aspects of ionic conductivity, electrode interface, and electrochemical stability. Firstly, the migration mechanism of lithium ion is analyzed from the three-dimensional structure of NASICON-type solid electrolyte, and progress in the research of conductivity and stability is summarized. Then, the effective methods to reduce interface impedance and improve the cycle stability of all-solid-state lithium batteries (ASSLBs) with NASICON-type solid electrolyte are introduced. Finally, solutions to improve the conductivity of electrolytes and deal with electrode/electrolyte interface problems are summarized, and the development prospects of ASSLBs are discussed.