An oxalate cathode for lithium ion batteries with combined cationic and polyanionic redox

Authors acknowledge financial support from the National Natural Science Foundation of China (51822210), the Australian Research Council (ARC) for its support through Discover Project (DP 140100193),Shenzhen Peacock Plan (KQJSCX20170331161244761), the Program for Guangdong Innovative and Entrepreneurial Teams (No. 2017ZT07C341), and the Development and Reform Commission of Shenzhen Municipality for the development of the “Low-Dimensional Materials and Devices” discipline.The growing demand for advanced lithium-ion batteries calls for the continued development of high-performance positive electrode materials. Polyoxyanion compounds are receiving considerable interest as alternative cathodes to conventional oxides due to their advantages in cost, safety and environmental friendliness. However, polyanionic cathodes reported so far rely heavily upon transition-metal redox reactions for lithium transfer. Here we show a polyanionic insertion material, Li2Fe(C2O4)2, in which in addition to iron redox activity, the oxalate group itself also shows redox behavior enabling reversible charge/discharge and high capacity without gas evolution. The current study gives oxalate a role as a family of cathode materials and suggests a direction for the identification and design of electrode materials with polyanionic frameworks.Publisher PDFPeer reviewe

Hydrothermal Synthesis of Delafossite-Type Oxides

The syntheses of copper and silver delafossite-type oxides from their constituent binary metal oxides, oxide hydroxides and hydroxides, by low temperature (<210 °C) and low pressure (<20 atm) hydrothermal reactions are described. Particular emphasis is placed on how the acid-base character of a constituent oxide determines its solubility and therefore whether a particular delafossite-type oxide can be synthesized, a strategy utilized by geologists and mineralogists to understand the conditions necessary for the synthesis of various minerals. Thus, the geochemical and corrosion science literature are shown to be useful in understanding the reaction conditions required for the syntheses of delafossite-type oxides and the relationship between reactant metal oxide acid-base character, solubility, aqueous speciation, and product formation. Manipulation of the key parameters, temperature, pressure, pH, and reactant solubility, results in broad families of phase-pure delafossite-type oxides in moderate to high yields for copper, CuBO2 (B) Al, Sc, Cr, Mn, Fe, Co, Ga, and Rh), and silver, AgBO2 (B ) Al, Sc, Fe, Co, Ni, Ga, Rh, In, and Tl)

Hexagonally ordered Ni nanocone array; controlling the aspect ratio

Hexagonally ordered Ni nanocones and films possessing a cone geometry were produced using anodization and metal plating techniques. The conical porous anodic alumina (PAA) film was produced using a process of repeated applications of anodization and pore-widening steps, applying the two steps alternately. The structures on the PAA films were a hexagonally ordered array with an interval of 100 nm. An intended height of 100–500 nm of the conical pores were produced by tuning the fabrication conditions of the PAA film. The Ni nanocones were produced by electroless deposition onto the conical PAA film. The Ni films with a nanocone topography were produced by detaching the deposited layer. These nanostructures were produced using wet-process techniques of anodization, electroless and electrochemical deposition

Fabrication of ordered Ni nanocones using a porous anodic alumina template

Hexagonally ordered Ni nanocones have been produced using an electroless Ni deposition technique on a porous anodic alumina (PAA) template, where the pores are of a cone shape. The conical PAA film was found to exhibit hexagonal order with a period of 100 nm. The aspect ratio (cone height vs. the diameter of the base of the cone) of the conical pores on the PAA film was found to be one. The Ni nanocones and the surface morphology of the nano-conical film exhibit the same periodic structure of the template. A significant advantage of the fabrication process employed in this work is that it utilizes existing techniques. (C) 2008 Elsevier B.V. All rights reserved

BEHAVIOUR OF WELDED PART OF Ti-Ni SHAPE MEMORY ALLOY

Thin wires of Ti-Ni shape memory alloy are welded without fusion or cast zone by the resistance butt welding. The weld current is fed to the butt welded parts with little offset during the time shorter than that in the forging process. The tensile strength of the welded part is attained over 80 percents of that of the base metal. For checking the shape memory effect, the recovery from bending deformation for the welded parts is tested in comparison with that for the base metal, and the residual strain after the recovery is experimentally related to the ratio of latent heat of martenstic transformation to that of reverse transformation, measured by the differential scanning caloriemeter

Interaction between Uneven Cavity Length and Shaft Vibration at the Inception of Synchronous Rotating Cavitation

Asymmetric cavitation is known as one type of the sources of cavitation induced vibration in turbomachinery. Cavity lengths are unequal on each blade under condition of synchronous rotating cavitation, which causes synchronous shaft vibration. To investigate the relationship of the cavity length, fluid force, and shaft vibration in a cavitating inducer with three blades, we observed the unevenness of cavity length at the inception of synchronous rotating cavitation. The fluid force generated by the unevenness of the cavity length was found to grow exponentially, and the amplitude of shaft vibration was observed to increase exponentially. These experimental results indicate that the synchronous shaft vibration due to synchronous rotating cavitation is like selfexcited vibrations arising from the coupling between cavitation instability and rotordynamics

The expression of Fn14 via mechanical stress-activated JNK contributes to apoptosis induction in osteoblasts

10.1074/jbc.M113.536300Journal of Biological Chemistry289106438-6450JBCH