Synthesis and Crystal Structure of Tetra(diisopropyl-amido-N)ytterbium Mono(tetrahydrofuran-O)lithium

The reaction of anhydrous YbCl3 with LiNPri2 in 1:3 molar ratio gave the homo- leptic lanthanide amide ate complex Yb(C6H14N)4Li(C4H8O). The crystal structure was determined by X-ray diffraction and the following crystallographic data were obtained: C28H64N4OYbLi, Mg = 652.82, monoclinic, P21/c (#14), a = 15.239(3), b = 21.502(6), c = 21.288(4) ? b = 93.18(2), V = 6964(2) 3, Z = 8, Dc = 1.245 g/cm3, F(000) = 2728 and m(MoKa) = 27.08 cm-1. The final R and Rw are 0.044 and 0.053 for 6765 observed reflections with I > 3.00s(I), respectively. The ytterbium atom is bonded to two terminal amide ligands with the normal YbN distances of 2.171(6) and 2.174(7) ? and two bridging amide ligands with the YbN bonds about 0.1 ?longer than those of the formers, forming a distorted tetrahedral geometry.

Strong coordination interaction in amorphous Sn-Ti-ethylene glycol compound for stable Li-ion storage

Sn has been considered one of the most promising metallic anode materials for lithium-ion batteries(LIBs)because of its high specific capacity.Herein,we report a novel amorphous tin-titanium-ethylene glycol(Sn-Ti-EG)bimetal organic compound as an anode for LIBs.The Sn-Ti-EG electrode exhibits exceptional cyclic stability with high Li-ion storage capacity.Even after 700 cycles at a current density of 1.0 A g−1,the anode maintains a capacity of 345 mAh g−1.The unique bimetal organic structure of the Sn-Ti-EG anode and the strong coordination interaction between Sn/Ti and O within the framework effectively suppress the aggrega-tion of Sn atoms,eliminating the usual pulverization of bulk Sn through volume expansion.Furthermore,the Sn M-edge of the X-ray absorption near-edge structure spectra obtained using soft X-ray absorption spec-troscopy signifies the conversion of Sn2+ions into Sn0 during the initial lithiation process,which is reversible upon delithiation.These findings reveal that Sn is one of the most active components that account for the excellent electrochemical performance of the Sn-Ti-EG electrode,whereas Ti has no practical contribution to the capacity of the electrode.The reversible formation of organic functional groups on the solid electrolyte interphase is also partly responsible for its cyclic stability.

HCWCI/Carbon Steel Bimetal Liner by Liquid-Liquid Compound Lost Foam Casting

Impact, friction and corrosion from the grinding balls and the grinding medium during the mineral processing result in liner breakage. Liner, made from Hadfield steel or alloyed steel, could not have served in wet grinding environment for more than ten months. Composite liner, made from HCWCI (high Cr white cast iron) and carbon steel, has been developed successfully with liquid-liquid composing process based on LFC (lost foam casting). The microstructure of composite was analyzed with optical microscope, SEM (scanning electron microscope)/EDX energy-dispersive X-ray and XRD (X-ray diffraction). According to micrograph, the combination region of two metals was staggered like dogtooth, no mixtures occurred between two liquid metals, and its interface presented excellent metallurgical bonding state. The results of mechanical property test show that, the hardness of HRC, the fracture toughness, and the bending strength are more than 61, 16.5 J/cm2 and 1 600 MPa, respectively. Comparison between liners made from bimetal composite and alloyed steel has also been investigated in industrial hematite ball mill. The results of eight months test in wet grinding environment prove that the service life of bimetal composite liner is three times as long as that of one made from alloyed steel.

Experimental and Simulation Studies on Fabricating GCr15/40Cr Bimetallic Compound Rollers Using Electroslag Surfacing with Liquid Metal Method

Electroslag surfacing with liquid metal （ESSLM） is an excellent method for producing high quality bimetallic compound rollers. The quality of each compound roller is primarily determined by the metallurgical quality of the combined interface. A GCrl5/40Cr compound roller is produced using an ESSLM non-consumable electrode electro- slag heating method. The temperature and electric fields produced by the ESSLM system are calculated. As the roller core moves downward in the mold, it passes through five sections., the preheating section, the rapid heating section, the temperature homogenizing section, the bimetal fusing section and the cooling section which listed from the top to bottom of the mold, respectively. The temperature distribution and the degree of the surface temperature fluctuation in the roller core are different for each section. Near the combined interface, four layers are found from the roller core to the cladding layer= the remelting layer, the fusion layer, the interface solidification layer and the chilling layer, re spectively. Among these, the fusion and interface solidification layers are the key transition zones that greatly influ- ence the combination quality. The surface temperature of the roller core prior to cladding is mainly determined by the drawing velocity, and the thickness of the transition layer increases as the drawing velocity decreases. A transition layer that is too thick or too thin will reduce the mechanical properties at the combined interface. Therefore, the drawing velocity should be limited to a moderate range to produce a satisfactory bimetallic Compound roller.

Bimetallic CoNiSe_(2)/C nanosphere anodes derived from Ni-Co-metal-organic framework precursor towards higher lithium storage capacity

Through uncomplicated carbonation process,a carbon-embedded CoNiSe_(2)/C nanosphere was synthesized from Ni-Co-MOF (metal-organic framework) precursor whose controllable structure and synergistic effect of bimetallic Ni/Co brought CoNiSe_(2)/C anodes with high specific surface area (172.79 m^(2)/g) and outstanding electrochemical performance.CoNiSe_(2)/C anodes obtained reversible discharge capacities of850.9 mAh/g at 0.1 A/g after cycling for 100 cycles.In addition,CoNiSe_(2)/C exhibits excellent cycle stability and reversibility in the rate test at a current density of 0.1–2.0 A/g.When the current density returns to 0.5 A/g for 150 cycles,its discharge ratio the capacity is 330.8 m Ah/g.Electrochemical impedance spectroscopy (EIS) tests suggested that CoNiSe_(2)/C anodes had a lower charge transfer impedance of 130.02Ωafter 30 cycles.In-situ X-ray diffraction (XRD) tests confirmed the alloying mechanism of CoNiSe_(2)/C which realized higher lithium storage capacity.This work affords substantial evidence for the extension of bimetallic selenides in secondary batteries,promoting the development of bimetallic selenides in anode materials for LIBs.