Modeling of reaction kinetics and transport in the positive porous electrode in a sodium-iron chloride battery
Journal of Power Sources, cilt.203, ss.211-221, 2012 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 203
- Basım Tarihi: 2012
- Doi Numarası: 10.1016/j.jpowsour.2011.11.007
- Dergi Adı: Journal of Power Sources
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Sayfa Sayıları: ss.211-221
- Anahtar Kelimeler: Iron chloride solubility, Iron/iron chloride porous electrode, Mathematical modeling, Reaction kinetics, Sodium-iron chloride battery, Transport
- Boğaziçi Üniversitesi Adresli: Hayır
Özet
A one-dimensional mathematical model of the positive electrode of a sodium-iron chloride battery for an isothermal, constant-current discharge-charge cycle is presented. Macroscopic theory of porous electrodes and concentrated solution theory are used in the model to describe the transport processes. The change in the solubility of FeCl 2 with position and time within the cell is included in the model by defining an equilibrium constant that is a function of the NaCl:NaAlCl 4 molar ratio. The concentrated solution theory for a three-ion system with common cation is extended to account for a diffusive flux of a sparingly soluble ferrous complex. It is seen that this flux is important, especially at moderate depths of discharge. The effect of the assumed solubility constant K sp,FeCl on the battery performance is characterized. When K sp,FeCl is higher than 10 6, its variation does not change the short-time behavior of the system appreciably. Simulations suggest that the iron accumulates near the sodium tetrachloroaluminate reservoir during discharge. When charging, the net movement is reversed. As a result of continuous cycling, simulations predict that iron is depleted at this boundary. For instance, at the end of the fifth cycle, the iron amount decreases by ∼1% near the reservoir. © 2011 Elsevier B.V. All rights reserved.