Anisotropically Hybridized Porous Crystalline Li-S Battery Separators.

Anisotropically hybridized porous crystalline Li-S battery separators based on porous crystalline materials that can meet the multiple functionalities of both anodic and cathodic sides are much desired for Li-S battery yet still challenging in directional design. Here, an anisotropically hybridized separator (CPM) based on an ionic liquid-modified porphyrin-based covalent-organic framework (COF-366-OH-IL) and catalytically active metal-organic framework (Ni3 (HITP)2 ) that can integrate the lithium-polysulfides (LiPSs) adsorption/catalytic conversion and ion-conduction sites together to directionally meet the requirements of electrodes is reported. Remarkably, the-obtained separator exhibits an exceptional high Li+ transference-number (tLi+  = 0.8), ultralow polarization-voltage (<30 mV), high initial specific-capacity (921.38 mAh g-1 at 1 C), and stable cycling-performance, much superior to polypropylene and monolayer-modified separators. Moreover, theoretical calculations confirm the anisotropic effect of CPM on the anodic side (e.g., Li+ transfer, LiPSs adsorption, and anode-protection) and cathodic side (e.g., LiPSs adsorption/catalysis). This work might provide a new perspective for separator exploration.

Cu2+1O/Ag Heterostructure for Boosting the Electrocatalytic Nitrate Reduction to Ammonia Performance.

Electrocatalytic nitrate reduction reaction (ENO3RR) is an alternative, sustainable, and environmentally friendly value-added NH3 synthesis method under ambient conditions relative to the traditional Haber-Bosch process; however, its low NH3 yield, low Faradaic efficiency (FE), low selectivity, and low conversion rate severely restrict the development. In this work, a Cu2+1O/Ag-CC heterostructured electrocatalyst was successfully fabricated by constructing a heterogeneous interface between Cu2+1O and Ag for selective electrochemical nitrate-to-ammonia conversion. The construction of the heterogeneous interface effectively promotes the synergistic effect of the catalytically active components Cu2+1O and Ag, which enhances the material conductivity, accelerates the interfacial electron transfer, and exposes more active sites, thus improving the performance of ENO3RR. Such Cu2+1O/Ag-CC manifests a high NH3 yield of 2.2 mg h-1 cm-2 and a notable ammonia FE of 85.03% at the optimal applied potential of -0.74 V vs RHE in a relatively low concentration of 0.01 M NO3--containing 0.1 M KOH. Moreover, it shows excellent electrochemical stability during the cycle tests. Our study not only provides an efficient catalyst for ammonia electro-synthesis from ENO3RR but also an effective strategy for the construction of ENO3RR electrocatalysts for electrocatalytic applications.

Synergistic Manipulation of Hydrogen Evolution and Zinc Ion Flux in Metal-Covalent Organic Frameworks for Dendrite-free Zn-based Aqueous Batteries.

Zn-based aqueous batteries have attracted much attention because of their high theoretical-capacity, safety, and low-cost, yet the H2 -evolution, qualification or inhibition mechanism investigations that are closely related to the dendrite-growth are rare and challenging. Herein, a series of zincophilic metal-covalent organic frameworks (e.g., Zn-AAn-COF, Zn-DAAQ-COF, and Zn-DAA-COF) have been explored as model-platforms to manipulate the H2 -evolution and Zn2+ flux. Best of them, Zn-AAn-COF based cell only produces 0.002 mmol h-1 cm-2 H2 , which is >2 orders of magnitude lower than bare Zn. Noteworthy, it affords high stability for 3000 cycles (overpotential, <79.1 mV) at 20 mA cm-2 in symmetric-cell and enhanced cycling-stability up to 6000 cycles at 2000 mA g-1 in the assembled full-battery. Besides, mechanistic characterizations show that Zn-AAn-COF can enhance the energy-barrier of H2 -evolution and homogenize the ion-distribution or electric-filed to achieve high performance.

A solvent-free processed low-temperature tolerant adhesive.

Ultra-low temperature resistant adhesive is highly desired yet scarce for material adhesion for the potential usage in Arctic/Antarctic or outer space exploration. Here we develop a solvent-free processed low-temperature tolerant adhesive with excellent adhesion strength and organic solvent stability, wide tolerable temperature range (i.e. -196 to 55 °C), long-lasting adhesion effect ( > 60 days, -196 °C) that exceeds the classic commercial hot melt adhesives. Furthermore, combine experimental results with theoretical calculations, the strong interaction energy between polyoxometalate and polymer is the main factor for the low-temperature tolerant adhesive, possessing enhanced cohesion strength, suppressed polymer crystallization and volumetric contraction. Notably, manufacturing at scale can be easily achieved by the facile scale-up solvent-free processing, showing much potential towards practical application in Arctic/Antarctic or planetary exploration.

Porous crystalline conjugated macrocyclic materials and their energy storage applications.

Porous crystalline conjugated macrocyclic materials (CMMs) possess high porosity, tunable structure/function and efficient charge transport ability owing to their planar macrocyclic conjugated π-electron system, which make them promising candidates for applications in energy storage. In this review, we thoroughly summarize the timely development of porous crystalline CMMs in energy storage related fields. Specifically, we summarize and discuss their structures and properties. In addition, their energy storage applications, such as lithium ion batteries, lithium sulfur batteries, sodium ion batteries, potassium ion batteries, Li-CO2 batteries, Li-O2 batteries, Zn-air batteries, supercapacitors and triboelectric nanogenerators, are also discussed. Finally, we present the existing challenges and future prospects. We hope this review will inspire the development of advanced energy storage materials based on porous crystalline CMMs.

Influences of Friedel's Salt Produced by CaO-Activated Titanium-Extracted Tailing Slag on Chloride Binding.

Titanium-extracted tailing slag (TETS) has high activity, but the content of chloride ions is high. To effectively bind the chloride ions, CaO was used to activate the TETS, and the solidified cementitious material of CaO-activated TETS was prepared. The effects of CaO content and curing age on the strength of solidified samples, chloride binding capacity, and chloride binding mechanism were studied. By means of XRD, FTIR, SEM, and EDS, the hydration reaction products, microstructure, morphology, and micro-components of the solidified sample were characterized. The results show that the chloride ions can be effectively bound by using CaO to activate TETS with higher mechanical strength. When the CaO content is 10 wt%, the strength of the 28-day-cured body can reach more than 20 MPa, the chloride ion binding amount is 38.93 mg/g, and the chloride binding rate is as high as 68%. The new product phases of the solidified sample are mainly Friedel's salt (FS) and calcite, in which the amount of FS production and the degree of crystal development are affected by the CaO content and curing age. The chloride binding ions in the solidified sample are mainly the chemical binding by FS. The FS diffraction peak strength increases with the increase of CaO content and curing age, but the calcite diffraction peak strength is less affected by them. FS mainly accumulates and grows in the pores of the solidified sample. It can optimize the pore structure of the solidified sample and improve the strength of the solidified sample while binding chloride ions. The results can provide useful information for the resource utilization of chlorine-containing TETS, the improvement of durability of Marine concrete, and the application of sea sand in concrete.

In Situ Interweaved High Sulfur Loading Li-S Cathode by Catalytically Active Metalloporphyrin Based Organic Polymer Binders.

The elaborate design of powerful Li-S binders with extended-functions like polysulfides adsorption/catalysis and Li+ hopping/transferring in addition to robust adhesion-property has remained a challenge. Here, an in situ cathode-interweaving strategy based on metalloporphyrin based covalent-bonding organic polymer (M-COP, M = Mn, Ni, and Zn) binders is reported for the first time. Thus-produced functional binders possess excellent mechanical-strengths, polysulfides adsorption/catalysis, and Li+ hopping/transferring ability. Specifically, the modulus of Mn-COP can reach up to ≈54.60 GPa (≈40 times higher than poly(vinylidene fluoride)) and the relative cell delivers a high initial-capacity (1027 mAh g-1 , 1 C and 913 mAh g-1 , 2 C), and excellent cycling-stability for >1000 cycles even at 4 C. The utilization-rate of sulfur can reach up to 81.8% and the electrodes based on these powerful binders can be easily scale-up fabricated (≈20 cm in a batch-experiment). Noteworthy, Mn-COP based cell delivers excellent capacities at a high sulfur-loading (8.6 mg cm-2 ) and low E/S ratio (5.8 µL mg-1 ). In addition, theoretical calculations reveal the vital roles of metalloporphyrin and thiourea-groups in enhancing the battery-performance.