Oxidation rate of Fe and electrochemical performance of Fe–air solid oxide rechargeable battery using LaGaO3 based oxide ion conductor

Abstract

Effects of oxidation rate of Fe powder in Fe-air solid oxide rechargeable battery on discharge potential and capacity were studied. From the measurement of P O 2 in Fe set chamber and AC impedance for electrode reaction, oxidation rate of Fe, i.e., formation rate of H 2 , was an important parameter for discharge performance of Fe-air solid oxide battery. Slow oxidation rate of Fe, namely, low current density, shows high discharge potential, however, caused sintering of Fe powder resulting in the decreased discharge capacity and so decreased usage efficiency of Fe powder. On the other hand, larger capacity (1145 mAh g Fe 21), which is close to the theoretical capacity, can be achieved at higher discharge rate of 30 mA cm 22 at 873 K. Therefore, higher current density seems to be suitable for larger discharge capacity.Concentration overpotential is negligibly small at initial stage of discharge, however, with discharge period, diffusion overpotential became significantly enlarged caused by the slow oxidation rate of Fe. Sintering of Fe powder was observed after discharge at 5 mA cm 22 by SEM and TEM observations and so fast oxidation rate at larger current density can be assigned to bulk oxidation of Fe powder with small particle size sustained during discharge. Experimental sectionSchematic view of the experimental setup used in this study is shown in our previous report. 15 Electrolyte support planar type

A Multi-Physics Model for Solid Oxide Iron-Air Redox Flow Battery: Simulation of Discharge Behavior at High Current Density

“…[5][6][7][8][9][10][11][12][13][14][15][16][17][18] Although the operating temperature, geometries and configurations for the flow battery systems reported in the literature vary to some degree, our multi-physics model presented here is developed for a close-loop tubular battery reactor working at 800…”

“…r 2 = −r 1 [17] where c 1 and c 2 are the molar concentrations of hydrogen and steam, and k and k −1 (in units of 1/s) are respectively the rate constants for the forward and reverse reactions. For species i, the volumetric mass source terms,R i , is the molar reaction rate scaled by the Molar mass, M i :…”

“…[1][2][3][4] Recently, a distinct group of solid oxide redox flow batteries targeted at stationary energy storage was developed based on the technologies of reversible solid oxide fuel cell (RSOFC) and H 2 chemical looping. [5][6][7][8][9][10][11][12][13][14][15][16][17] The nature of this type of metal-air battery is the use of solid O 2− conducting electrolyte. The uniqueness of this new battery is manifested by the fact that the electrical energy conveyed by RSOFC can be reversibly converted into chemical energy by a physically separated metal-metal oxide (Me-MeO x ) redox couple.…”

Understanding the High-Temperature Solid-Oxide Iron-Air Redox Battery Operated with an Oxygen Shuttle Mechanism: A Computational Study

“…Since the first demonstration of oxide-ion-chemistry based anodesupported tubular Solid-Oxide Iron-Air Redox Battery (SOIARB) in 2011, 1 significant progress has been made experimentally in the areas of materials identification, 2-5 new metal-air chemistries 1,6-14 and performance optimization. [15][16][17][18][19][20] In contrast, theoretical understanding of the operating oxygen shuttle mechanisms of the new battery lags behind. In the open literature, only Ohmoti et al 21,22 and Guo et al 23 have reported multiphysics models for the battery.…”

Heat Balance in a Planar Solid Oxide Iron-Air Redox Battery: A Computational Analysis

“…The advantages of SOMARB include double electron transfer (O 2− ), energy storage in a chemical bed separated from the electrode, fast charging and discharging rate, use of earth-abundant element such as iron for energy storage, scalability and operational safety. Since its debut in 2011, 1 significant progress has been made in the areas of electrochemical performance optimization, [2][3][4][5][6][7][8][9][10][11][12] new metal-air chemistries [13][14][15][16][17][18][19][20] and multiphysics modeling of electrochemistry, mass transport and chemical redox kinetics that govern the electrical behaviors of the battery. [21][22][23] However, these studies were all performed isothermally with a focus on evaluating the factors that can affect the electrochemical performance of the battery.…”