When a chemical reaction is driven by an external voltage, or when an electric current is the spontaneous result of such a reaction, the description and control of the process belongs to the field of electrochemical engineering. Reactions can be used in electrochemical systems such as fuel cells and batteries, industrial electrolysis like electroplating, and galvanic corrosion.

Modeling of electrochemical systems in its simplest form involves the coupling of material balances with a charge balance, where the material balances incorporate a source term that depends on the system’s electric potential. Yet, most electrochemical systems also involve other transport phenomena such as fluid flow and heat transfer.

Current Density Distribution in a Solid Oxide Fuel Cell

The animation shows the mass fraction of oxygen at the cathode (top) and hydrogen at the anode (bottom) in a solid oxide fuel cell (SOFC), as well as the cell voltage as a function of the oxygen's feed concentration.