The electrochemical behavior of lithium incorporated in aluminum electrode in LiTFSI/KTf （lithium bis （trifluoromethylsulfonyl） amide/CF3SO3K） molten salt electrolyte was studied by a variety of electrochemical te...The electrochemical behavior of lithium incorporated in aluminum electrode in LiTFSI/KTf （lithium bis （trifluoromethylsulfonyl） amide/CF3SO3K） molten salt electrolyte was studied by a variety of electrochemical techniques including cyclic voltammetry, chronopotentiometry and chronoamperometry. The reduction reaction is found involving a nucleation process on the aluminum electrode. The results of chronopotentiometry indicate that the process of lithium incorporation in aluminum is smooth and uniform. The galvanostatic cycle experiments show that the coulombic efficiency is very low in the first cycle, which is mainly due to the ＂retention capacity＂ of Li-Al alloys. This characteristic is testified by the results of XRD and SEM. The results of chronoamperometry indicate that the incorporation of lithium into aluminum for the formation of a-phase Li-Al alloy is limited by its diffusion rate, with a measured diffusion coefficient of 1.8× 10^-10 cm2/s.展开更多
Nano-crystalline tungsten carbide thin films were fabricated on graphite substrates by plasma enhanced chemical vapour deposition in H2 and Ar atmosphere, using WF 6 and CH4 as precursors.The crystal phase, structure ...Nano-crystalline tungsten carbide thin films were fabricated on graphite substrates by plasma enhanced chemical vapour deposition in H2 and Ar atmosphere, using WF 6 and CH4 as precursors.The crystal phase, structure and chemical components of the films were characterized with X-ray diffraction （XRD）, scanning electron microscopy （SEM） and energy-dispersive spectrometer （EDS）,respectively.The results showed that the film prepared at CH4/WF6 concentration ratio of 20,working pressure of 100Pa and temperature of 800℃ were composed of sphere particles with a diameter of 20—35 nm Electrochemical investigations show that the electrochemical surface area of electrode of the film was large.The electrode of the film exhibited higher electro-catalytic activity in the reaction of methanol oxidation,and its catalytic properties were similar to those of Pt or Pt group catalysts.The constant current of the film catalyst was 123.6 mA·cm -2 in the mixture solution of H2SO4 and CH3OH at the concentration of 0.5 mol·L -1 and 2.0 mol·L -1 respectively at 70 ℃, and its constant potential was only 0.306 V（ vs .SCE）.展开更多
基金Project (70510011) supported by Scientific Research Starting Foundation of Jiaxing University,ChinaProject (84209001B3) supported by Open Fund of Key Laboratory of Clean Chemical Process of Jiaxing,China
文摘The electrochemical behavior of lithium incorporated in aluminum electrode in LiTFSI/KTf （lithium bis （trifluoromethylsulfonyl） amide/CF3SO3K） molten salt electrolyte was studied by a variety of electrochemical techniques including cyclic voltammetry, chronopotentiometry and chronoamperometry. The reduction reaction is found involving a nucleation process on the aluminum electrode. The results of chronopotentiometry indicate that the process of lithium incorporation in aluminum is smooth and uniform. The galvanostatic cycle experiments show that the coulombic efficiency is very low in the first cycle, which is mainly due to the ＂retention capacity＂ of Li-Al alloys. This characteristic is testified by the results of XRD and SEM. The results of chronoamperometry indicate that the incorporation of lithium into aluminum for the formation of a-phase Li-Al alloy is limited by its diffusion rate, with a measured diffusion coefficient of 1.8× 10^-10 cm2/s.
文摘Nano-crystalline tungsten carbide thin films were fabricated on graphite substrates by plasma enhanced chemical vapour deposition in H2 and Ar atmosphere, using WF 6 and CH4 as precursors.The crystal phase, structure and chemical components of the films were characterized with X-ray diffraction （XRD）, scanning electron microscopy （SEM） and energy-dispersive spectrometer （EDS）,respectively.The results showed that the film prepared at CH4/WF6 concentration ratio of 20,working pressure of 100Pa and temperature of 800℃ were composed of sphere particles with a diameter of 20—35 nm Electrochemical investigations show that the electrochemical surface area of electrode of the film was large.The electrode of the film exhibited higher electro-catalytic activity in the reaction of methanol oxidation,and its catalytic properties were similar to those of Pt or Pt group catalysts.The constant current of the film catalyst was 123.6 mA·cm -2 in the mixture solution of H2SO4 and CH3OH at the concentration of 0.5 mol·L -1 and 2.0 mol·L -1 respectively at 70 ℃, and its constant potential was only 0.306 V（ vs .SCE）.
