Pan American Materials Congress: Materials for Green Energy: Battery Technologies for Green Energy
Sponsored by: Third Pan American Materials Congress Organizing Committee
Program Organizers: Ramalinga Viswanathan Mangalaraja, University of Concepcion; Hector Calderon, ESFM-IPN; Julie Schoenung, University of California, Irvine; Roberto Arce, SAM - Soc. Argentina de Materiales

Wednesday 10:10 AM
March 1, 2017
Room: Marina G
Location: Marriott Marquis Hotel

Session Chair: Hector Calderon, ESFM-IPN

10:10 AM  
A Novel Air Electrode Using Core-Shell Particles for Metal Hydride/Air Rechargeable Battery: Hideyuki Sano1; Masatsugu Morimitsu1; 1Doshisha University
    This work aimed to develop the novel air electrode for metal hydride/air rechargeable battery. The improvement in mass energy density of the battery needs to reduce the weight of the air electrode, because the air electrode of metal hydride/air battery has no limitation on discharge capacity, which is quite different from lithium/air secondary battery producing solid discharge product in the air electrode. The air electrode of the metal hydride/air battery is also required to have a high durability for oxygen evolution in concentrated KOH solutions. This paper shows the preparation and performance of the novel air electrode using core-shell particles as the conducting material, in which the core is a low density oxide and the shell is an anti-corrosive alloy for alkaline solutions. The oxygen evolution and reduction performance of the air electrode and the cell performance using the air electrode are also reported.

10:30 AM  
Effect of Mo6+ Substitution on Microstructure and Lithium Ionic Conductivity of Garnet-Type Li7La3Zr2O12 Solid Electrolytes by Field Assisted Sintering Technology: Fei Chen1; Junyang Li1; Yanhua Zhang1; Dunjie Yang1; Qiang Shen1; Lianmeng Zhang1; 1Wuhan University of Technology
    Solid-state batteries with non-flammable inorganic solid electrolytes are one candidate to replace the currently-used liquid electrolyte. Garnet structure Li7La3Zr2O12, known as LLZO, with high mechanical, chemical, and electrochemical stability has been developed recently. In this study, Mo6+ doped Li6.5La3Zr1.75Mo0.25O12 (LLZM) solid electrolytes are successfully prepared via field assisted sintering technology (FAST). The effect of sintering temperature on the microstructure and lithium ionic conductivity is investigated. The results show that pure cubic phase LLZM can be obtained at a range of temperatures from 1050 to 1150 oC for no more than 10 min. For the sample sintered at 1150 oC, a maximum relative density of 95% with a total ionic conductivity as high as 1.310-4 Scm-1 are obtained at room temperature. The ionic conductivity is ascribed to both the smaller ionic size of Mo6+ (0.62) to Zr4+ (0.72) and the higher valence of Mo6+ to Zr4+ which reduces the Li+ concentration.

10:50 AM  
Development of Air Electrodes Using Different Types of Carbon Materials for Metal Hydride/Air Secondary Battery: Yusuke Ujino1; Masatsugu Morimitsu1; 1Doshisha University
    This paper presents the preparation procedure and conditions of the air electrode for metal hydride/air secondary battery, which has been developing for high energy density applications such as electric vehicles and solar power energy storage. The prepared air electrodes used different types of carbon as the conducting material with bi-functional catalyst for oxygen evolution and reduction, Bi2Ru2O7-z, and PTFE. The air electrode’s performance was examined with a three-electrode cell with 6 mol/L KOH solutions. The carbon material and preparation conditions affected the internal structure of the air electrode, and this caused a large difference in the polarization behaviors of the air electrode. The SEM and EDX analysis of the air electrode was also performed to show the internal and surface structure.

11:10 AM  
Study of the Influence on the Thermodynamic Properties of Replacing V by Zr in Alloys for Hydrogen Storage: Daniela Bellon Monsalve1; 1Universidad de Santander
    In this paper is studied the influence of replacing proportionally V for Zr, in the stoichiometric ratio of alloys for hydrogen storage by type Zr2-xFeVx (x = 0.0, 0.1, 0.2). Samples were melted in an arc furnace with controlled argon atmosphere. The thermodynamic properties were studied by measuring isothermal absorption / desorption. In order to verify the influence of the synthesis processes on the kinetic properties, measurements of absorption and desorption at different temperatures were performed. The material characterization has been carried out by X-ray diffraction, scanning electron microscopy and differential scanning calorimetry. The results show that the absorption and desorption kinetics is less than 5 minutes, approaching the parameters set by the DOE; however, it is evidenced that the absorption capacity decreases.

11:30 AM  
Cycle Performance of Air Electrode and Metal Hydride/Air Secondary Battery: Tsukasa Gejo1; Kenji Kawaguchi1; Masatsugu Morimitsu1; 1Doshisha University
    A metal hydride/air secondary battery works with water production during discharge and water decomposition during charge, so that the water management is one of the key issues to achieve a high cycleability. Especially, the air electrode needs to give active sites for oxygen reduction and evolution, which occur at the three-phase boundary consisted of the bi-functional oxygen catalyst, the concentrated alkaline solution, and air. The open pore for oxygen diffusion is maintained for charge-discharge cycling, and the optimization of the internal structure of the air electrode is quite important to give a high cycle performance. In this study, the cycle performance of the MH electrode, the air electrode, and the battery was examined, and the optimum structure of the air electrode concerning the water management was discussed with the detail analysis of the internal structure of the air electrode.