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Electric results: The rate capability can be improved in lithium ion batteries (LIBs) by reducing the dimensions of the active material; however, the LIBs would then have insufficient electrode density. To overcome this problem, carbon-coated single-crystal LiMn(2) O(4) nanoparticle clusters were synthesized as a cathode material for LIBs; this material can be densely packed on the current collector.  相似文献   

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Herein we report a new class of low-melting ionic liquids (IL) that consist of N,N,N-trialkylammonioundecahydrododecaborates(1-) as the anion and a range of cations. The cations include the common cations of conventional ILs such as tetraalkylammonium, N-alkylpyridinium, and N-methyl-N'-alkylimidazolium. In addition, their salts with lithium, potassium, and proton cations also exist as ILs. Pulse radiolysis studies indicate that the anions do not react with solvated electrons.  相似文献   

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One of the major impediments to using electroorganic synthesis is the need for large amounts of a supporting electrolyte to ensure the passage of charge. Frequently this causes separation and waste problems. To address these issues, a polymeric ionic liquid–Super P carbon black composite has been formulated. The system enables electrolyses to be performed without adding an additional supporting electrolyte, and its efficient recovery and reuse. In addition, the ability of the composite to modify the electrode surface in situ leads to improved kinetics. A practical consequence is that one can decrease catalyst loading without sacrificing efficiency.  相似文献   

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Compositing amorphous TiO2 with nitrogen‐doped carbon through Ti? N bonding to form an amorphous TiO2/N‐doped carbon hybrid (denoted a‐TiO2/C? N) has been achieved by a two‐step hydrothermal–calcining method with hydrazine hydrate as an inhibitor and nitrogen source. The resultant a‐TiO2/C? N hybrid has a surface area as high as 108 m2 g?1 and, when used as an anode material, exhibits a capacity as high as 290.0 mA h g?1 at a current rate of 1 C and a reversible capacity over 156 mA h g?1 at a current rate of 10 C after 100 cycles; these results are better than those found in most reports on crystalline TiO2. This superior electrochemical performance could be ascribed to a combined effect of several factors, including the amorphous nature, porous structure, high surface area, and N‐doped carbon.  相似文献   

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Much attention has recently been focused on the synthesis and application of graphene analogues of layered nanomaterials owing to their better electrochemical performance than the bulk counterparts. We synthesized graphene analogue of 3D MoS2 hierarchical nanoarchitectures through a facile hydrothermal route. The graphene‐like MoS2 nanosheets are uniformly dispersed in an amorphous carbon matrix produced in situ by hydrothermal carbonization. The interlaminar distance between the MoS2 nanosheets is about 1.38 nm, which is far larger than that of bulk MoS2 (0.62 nm). Such a layered architecture is especially beneficial for the intercalation and deintercalation of Li+. When tested as a lithium‐storage anode material, the graphene‐like MoS2 hierarchical nanoarchitectures exhibit high specific capacity, superior rate capability, and enhanced cycling performance. This material shows a high reversible capacity of 813.5 mAh g?1 at a current density of 1000 mA g?1 after 100 cycles and a specific capacity as high as 600 mAh g?1 could be retained even at a current density of 4000 mA g?1. The results further demonstrate that constructing 3D graphene‐like hierarchical nanoarchitectures can effectively improve the electrochemical performance of electrode materials.  相似文献   

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Nanoporous MnO frameworks with highly dispersed Co nanoparticles were produced from MnCO3 precursors prepared in a gel matrix. The MnO frameworks that contain 20 mol % Co exhibited excellent cycle performance as an anode material for Li‐ion batteries. The solid–electrolyte interphase (SEI) formed in the frameworks through the electrochemical reaction mediates the active materials, such as MnO, Mn, and Li2O, during the conversion reaction in the charge–discharge cycle. The Co nanoparticles and SEI provide the electron and Li‐ion conductive networks, respectively. The ternary nanocomposites of the MnO framework, metallic Co nanoparticles, and embedded SEI are categorized as durable anode materials for Li‐ion batteries.  相似文献   

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Of the various beyond‐lithium‐ion batteries, lithium–sulfur (Li‐S) batteries were recently reported as possibly being the closest to market. However, its theoretically high energy density makes it potentially hazardous under conditions of abuse. Therefore, addressing the safety issues of Li‐S cells is necessary before they can be used in practical applications. Here, we report a concept to build a safe and highly efficient Li‐S battery with a flame‐inhibiting electrolyte and a sulfur‐based composite cathode. The flame retardant not only makes the carbonates nonflammable but also dramatically enhances the electrochemical performance of the sulfur‐based composite cathode, without an apparent capacity decline over 750 cycles, and with a capacity greater than 800 mA h?1 g?1(sulfur) at a rate of 10 C.  相似文献   

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Three‐dimensional (3D) reticular SnO2 thin films deposited on copper and stainless steel substrates were prepared by the electrostatic spray deposition (ESD) technique. The 3D reticular SnO2 film exhibit a high reversible capacity near 300 mAh g?1 up to the 50th cycle.  相似文献   

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脲醛树脂-zro2复合微球;染料配体;固相萃取剂  相似文献   

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Cyclic naphthalene diimides (cNDIs), with a ferrocene moiety (cFNDs) and different linker lengths between the ferrocene and cNDI moieties, were designed and synthesized as redox-active, tetraplex-DNA ligands. Intramolecular stacking was observed between ferrocene and the NDI planes, which could affect the binding properties for G-quadruplexes. Interestingly, the circular dichroism spectrum of one of these compounds clearly shows new Cotton effects around 320–380 and 240 nm, which can be considered a direct evidence of intramolecular stacking of ferrocene and the NDI. Regarding recognition of hybrid G-quadruplexes, the less rigid structures (longer linkers) show higher binding affinity (106 m −1 order of magnitude). All new compounds show higher selectivity for G4 during electrochemical detection than noncyclic FND derivatives, which further identifies the redox-active potentiality of the cFNDs. Two of the three compounds tested even show preferential inhibition of cell growth in cancer cells over normal cells in a low concentration range, highlighting the potential for bioapplications of these cFNDs.  相似文献   

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