Modelization of a Bipolar Electrochemical Reactor

Abstract

We explain the principles of a software able to compute electrical potentials and currents in electrochemical plane systems, composed of electrodes, electrolytes, and insulators. At interfaces electrodes-electrolytes, the relationship between the potential jump and the crossing current is modeled by any nondecreasing function (called generalized Butler-Volmer function, Eqn. 1.2). This takes in account the thermodynamical barriers, oxydations, reductions, and diffusion limitations.The conductivity of the different environments can be constant or variable. We give three formulations of the problem to solve (Eqns. 2 and 3), then (Eqn. 4), we show the finite element discretization. This yields to a nonlinear equations system that we discuss. Furthermore, we describe an original method to determine floating potentials of electrodes (Eqn. 8). Examples are choosen to show the possibilities of softwares and methods. These examples are relatively simple, but we are able to compute more complex configurations.