RESUMO
The uneven formation of lithium dendrites during electroplating/stripping leads to a decrease in the utilization of active lithium, resulting in poor cycling stability and posing safety hazards to the battery. Herein, introducing a 3D continuously interconnected zirconium-based metal-organic framework (MOF808) network into a polyethylene oxide polymer matrix establishes a synergistic mechanism for lithium dendrite inhibition. The 3D MOF808 network maintains its large pore structure, facilitating increased lithium salt accommodation, and expands anion adsorption at unsaturated metal sites through its diverse large-space cage structure, thereby promoting the flow of Li+. Infrared-Raman and synchrotron small-angle X-ray scattering results demonstrate that the transport behavior of lithium salt ion clusters at the MOF/polymer interface verifies the increased local Li+ flux concentration, thereby raising the mobility number of Li+ to 0.42 and ensuring uniform Li+ flux distribution, leading to dendrite-free and homogeneous Li+ deposition. Furthermore, nanoindentation tests reveal that the high modulus and elastic recovery of MOF-based polymer electrolytes contribute to forming a robust, dendrite-resistant interface. Consequently, in symmetric battery systems, the system exhibits minimal overpotential, merely 35 mV, while maintaining stable cycling for over 1800 h, achieving low-overpotential lithium deposition. Moreover, it retains redox stability under high voltages up to 5.3 V.
RESUMO
Atomic-scale interface engineering is a prominent strategy to address the large volume expansions and sluggish redox kinetics for reinforcing K-storage. Here, to accelerate charge transport and lower the activation energy, dual carbon-modified interfacial regions are synthesized with high lattice-matching degree, which is formed from a CoSe2 /FeSe2 heterostructure coated onto hollow carbon fibers. State-of-the-art characterization techniques and theoretical analysis, including ex-situ soft X-ray absorption spectroscopy, synchrotron X-ray tomography, ultrasonic transmission mapping, and density functional theory, are conducted to probe local atomic structure evolution, mechanical degradation mechanisms, and ion/electron migration pathways. The results suggest that the heterostructure composed of the same crystal system and space group can sharply regulate the redox kinetics of transition metal selenium and dual carbon-modified approach can tailor physicochemical degradation. Overall, this work presents the design of a stable heterojunction synergistic superior hollow carbon substrate, inspiring a pathway of interface engineering strategy toward high-performance electrode.
RESUMO
N-Oxide zwitterionic polyethyleneimine (ZPEI), a new kind of aqueous phase monomer synthesized by commercially branched polyethyleneimine (PEI) via oxidation reaction, was prepared for fabrication of thin-film composite (TFC) polyamide membranes via interfacial polymerization. The main factors, including the monomer concentration and immersion time of the aqueous phase and organic phase, were investigated. Compared with PEI-TFC membranes, the obtained optimal defect-free ZPEI-TFC membranes exhibited a lower roughness (3.3 ± 0.3 nm), a better surface hydrophilicity, and a smaller pore size (238 Da of MWCO). The positively charged ZPEI-TFC membranes (isoelectric point at pH 8.05) showed higher rejections toward both divalent cationic (MgCl2, 93.0%) and anionic (Na2SO4, 96.1%) salts with a water permeation flux of up to 81.0 L·m-2·h-1 at 6 bar, which surpassed currently reported membranes. More importantly, mainly owing to N-oxide zwitterion with strong hydration capability, ZPEI-TFC membranes displayed a high flux recovery ratio (97.0%) toward a model protein contaminant (bovine serum albumin), indicating good anti-fouling properties. Therefore, the novel N-oxide zwitterion functionalized positively charged nanofiltration membranes provide an alternative for water desalination and sewage reclamation.
Assuntos
Nylons , Óxidos , Nylons/química , Polietilenoimina , Membranas Artificiais , Água/químicaRESUMO
Owing to abundant polar groups and good lithiophilicity, protein materials regain interest for application in lithium metal batteries (LMBs). Current proteins with an α-conformation for modifying lithium (Li) anodes possess typically poor mechanical properties, and there is therefore a significant need for advanced protein materials. Herein, a lysozyme-modified layer is coated onto the poly(vinylidene fluoride) electrospun mat for high mechanical strength and uniform Li-ion flux. The lysozyme membrane can regulate Li+ deposition behavior due to complete ß-sheet configuration, high lithiophilicity sulfhydryl groups, and columnar nanopores. As a result, the lysozyme-modified Li metal anode exhibits a high stability performance of Li-Li symmetric cells (2800 h) and Li-LiFePO4 full cell (1450 cycles). Our strategy pushes the protein with ß-sheet configuration toward the applications of next-generation LMBs.
Assuntos
Lítio , Muramidase , Peptídeos beta-AmiloidesRESUMO
In order to solve the problems of poor mechanical property, non-antibacterial and low flux of calcium alginate (CaAlg) membrane, silver nanoparticles (AgNPs) were synthesized with bovine serum albumin (BSA) and carboxymethyl chitosan (CMCS) for improving CaAlg membrane in this paper. Meanwhile, the dispersion property of silver nanoparticles and the mechanical property, thermal stability, antibacterial property and filtration efficiency of the composite membrane were explored. The results illustrated CMCS observably strengthened the mechanical property and thermal stability of the composite membrane, and AgNPs endowed the composite membrane with excellent antibacterial property. The flux of the BSA/CMCS/AgNPs/CaAlg composite membrane was raised compared to CaAlg membrane. Finally, the viscose fiber/polyethylene terephthalate fiber (VF-PET) nonwoven fabric was introduced as the support layer to further improve the filtration flux and mechanical property of the composite membrane. VF-PET/BSA/CMCS/AgNPs/CaAlg membrane had a rejection rate of over 99.0 % for dye molecules and <9.0 % for salt ions, while the flux maintained 38.5 L·m-2·h-1. Furthermore, VF-PET/BSA/CMCS/AgNPs/CaAlg membrane also had excellent separation effect on actual dye wastewater. The separation of dye and salt by the membrane mainly depended on the screening mechanism of membrane pore size, rather than adsorption. The composite membrane had an outstanding performance on the separation of dye molecules and inorganic salt ions.