Research And Application Of Rechargeable Air Electrode

Purpose of this paper is to study the electrochemical performance of chargeable air electrode, using silver oxide as catalyst; to research its application in metal hydride- air batteries.Study the effect of thickness ratio between the catalyst layer and air electrode on the electrochemical performance of air electrode. In three-electrode system to test their electrochemical properties,5.1mol.L-1potassium hydroxide aqueous as electrolyte、air electrodes as working electrode、zinc rod as the reference electrode、nickel wire as the electrode.Study the effect of adding different proportions of PTFE on performance of air electrode during preparation of catalyst layer; the effect of partial graphite replacement activated carbon on air electrode and its influence on electrochemical performance of metal hydride-air batteries.Using XRD analysis the state of the silver ions in air electrode reactions. The cyclic voltammeter curve and charge-discharge steady-state polarization of air electrode are tested; Study the reaction mechanism of oxygen reduction and oxygen release with silver as catalyst. Scanning Electron microscopic can observe the distribution of silver, charcoal, graphite and PTFE in catalyst layer, can observe the micro-structure of diffusion layer.The MH-Air battery was assembled by as-prepared air electrode and the metal hydride electrode, testing the electrochemical performance, analyzing the main factors to effect battery performance.Silver oxide added in the air electrode was completely decomposed as silver during the heat treatment, while the silver played a catalytic role in the air electrodes;The air electrode has the best electrochemical performance with a certain thickness which provided an excellent method for scaled up production; The air electrode has batter cycling performance with 25% weight ratio of PTFE; The discharge voltage of air electrode is on the rise with adding amounts of graphite increased,but which has some negative effects on cycling performance. According to these investigations, active material shedding,electrolyte evaporation,gas overflows and battery package were the main factors to effect MH-Air battery performance.