Fatigue-Resistant Interfacial Layer for Safe Lithium Metal Batteries.

The plating/stripping of Li dendrites can fracture the static solid electrolyte interphase (SEI) and cause significant dynamic volume variations in the Li anode, which give rise to poor cyclability and severe safety hazards. Herein, a tough polymer with a slide-ring structure was designed as a self-adaptive interfacial layer for Li anodes. The slide-ring polymer with a dynamically crosslinked network moves freely while maintaining its toughness and fracture resistance, which allows it can to dissipate the tension induced by Li dendrites on the interphase layer. Moreover, the slide-ring polymer is highly stretchable, elastic, and displays an ultrafast self-healing ability, which allows even pulverized Li to remain coalesced without disintegrating upon consecutive cycling. The Li anodes demonstrate greatly improved suppression of Li dendrite formation, as evidenced by the high critical current density (6 mA cm-2 ) and stable cycling for the full cells with high-areal capacity LiFePO4 , high-voltage NCM, and S cathodes.

Building a Self-Adaptive Protective Layer on Ni-Rich Layered Cathodes to Enhance the Cycle Stability of Lithium-Ion Batteries.

Layered Ni-rich lithium transition metal oxides are promising battery cathodes due to their high specific capacity, but their poor cycling stability due to intergranular cracks in secondary particles restricts their practical applications. Surface engineering is an effective strategy for improving a cathode's cycling stability, but most reported surface coatings cannot adapt to the dynamic volume changes of cathodes. Herein, a self-adaptive polymer (polyrotaxane-co-poly(acrylic acid)) interfacial layer is built on LiNi0.6 Co0.2 Mn0.2 O2 . The polymer layer with a slide-ring structure exhibits high toughness and can withstand the stress caused by particle volume changes, which can prevent the cracking of particles. In addition, the slide-ring polymer acts as a physicochemical barrier that suppresses surface side reactions and alleviates the dissolution of transition metallic ions, which ensures stable cycling performance. Thus, the as-prepared cathode shows significantly improved long-term cycling stability in situations in which cracks may easily occur, especially under high-rate, high-voltage, and high-temperature conditions.

Preparation of mesoporous Cs-POM@MOF-199@MCM-41 under two different synthetic methods for a highly oxidesulfurization of dibenzothiophene.

Two different synthetic methods, the direct method and the substitution method, were used to synthesize the Cs-POM@MOF-199@MCM-41 (Cs-PMM), in which the modified heteropolyacid with cesium salt has been encapsulated into the pores with the mixture of MOF and MCM-41. The structural properties of the as-prepared catalysts were characterized using various analytical techniques: powder X-ray diffraction, FT-IR, SEM, TEM, XPS and BET, confirming that the Cs-POM active species retained its Keggin structure after immobilization. The substitution method of Cs-PMM exhibited more excellent catalytic performance for oxidative desulfurization of dibenzothiophene in the presence of oxygen. Under optimal conditions, the DBT conversion rate reached up to 99.6% and could be recycled 10 times without significant loss of catalytic activity, which is mainly attributed to the slow leaching of the active heteropolyacid species from the strong fixed effect of the mixture porous materials.

Photocatalytic oxidation desulfurization of model diesel over phthalocyanine/La0.8Ce0.2NiO3.

A series highly efficient and stable metallophthalocyanine/La0.8Ce0.2NiO3 (ML/LCNO) photocatalysts were prepared by a facile sol-gel and immersion method. The as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), TEM, N2 adsorption-desorption, and UV-Vis. The results revealed that LCNO calcined at 700°C possessed a perovskite structure with porous, and phthalocyanine not only adsorbed on the surface but also loaded in the pores of the LCNO oxide. The photocatalytic activities of the samples were evaluated by the photocatalytic oxidation of dibenzothiophene (DBT) under simulated sunlight irradiation. It was found that either macrocyclic structure or center metal of phthalocyanine had great influences on the photocatalytic activity of ML/LCNO. The oxidative reactivity of the different macrocycles was found in the order of MPc/LCNO>MTAP/LCNO>MPTpz/LCNO; which of different center metals was CoL/LCNO>FeL/LCNO>MnL/LCNO>NiL/LCNO>CuL/LCNO. The catalysts were reused several times with a slight decrease in activity. Furthermore, this kinetics of photocatalytic oxidation of DBT indicated that the reaction was a pseudo-first-order reaction.

Assembly of a series of MOFs based on the 2-(m-methoxyphenyl)imidazole dicarboxylate ligand.

The coordination features of an imidazole dicarboxylate ligand, 2-(3-methoxyphenyl)-1H-imidazole-4,5-dicarboxylic acid (m-H(3)MOPhIDC) has been explored. Consequently, seven coordination polymers, namely [Sr(m-HMOPhIDC)(H(2)O)](n) (1), [Sr(m-H(2)MOPhIDC)(2)](n) (2), [Cd(3)(m-H(2)MOPhIDC)(2)(m-HMOPhIDC)(2)(H(2)O)(2)](n) (3), [Cu(m-HMOPhIDC)(phen)](n) (phen = 1,10-phenanthroline) (4), [Cd(2)(m-HMOPhIDC)(2)(phen)(2)](n) (5) [Cd(2)(m-HMOPhIDC)(2)(2,2'-bipy)(2)](n) (2,2'-bipy = 2,2'-bipyridine) (6) and [Co(m-HMOPhIDC)(H(2)O)(2)](n) (7) have been hydro(solvo)thermally synthesized by fine control over synthetic conditions, and structurally characterized. X-ray single-crystal analyses reveal that these polymers indicate rich structural chemistry ranging from one-dimensional (4-7), two-dimensional (1 and 3) to three-dimensional (2) structures, and the m-H(3)MOPhIDC ligand in these polymers can be singly deprotonated or doubly deprotonated, and coordinates to metal ions by various modes. The thermal and fluorescence properties of the complexes 1-7 have been determined as well.