Dynamics of a Non-equilibrium Electrochemical System

Irreversible phenomena are much more stubborn. However even they tend to enter the general order. 

1 Coupling in Electrochemical Systems Electrochemical Decomposition of Mixed Conductor 

As was shown in Chap. 4, the behaviour of real electrochemical systems on long timescales cannot often be predicted from short-term observations. In terms of the approach considered in 1.6, this happens because of the onset of positive feedbacks destabilising the stationary state of the system. Several possible reasons exist for this event to take place. Among them, most significant, however very rarely considered, is the coupling between the electrochemical processes at separate electrodes. To understand how it works, we shall first consider the process of electrochemical decomposition of an electrolyte with mixed ion-electron conductivity. 

As follows from the previous chapters, a complex interface Metal/MIEC/Electrolyte (MIEC = mixed ion-electron conductor) appears in many processes related to the electrochemistry of polyvalent metals. The model of MIEC in terms of the concept of polyfunctional conductor (PFC) can be a useful approach to deal with the mechanisms of the processes in such systems. The qualitative classification of EPS has been given based on this approach. Further on, we are going to demonstrate that this concept is useful for quantitative (or at least, semi-quantitative) modelling of macrokinetics (dynamics) of the processes in highly non-equilibrium systems. Before doing this, it is worthwhile to outline some basic ideas related to the MIEC. These considerations will also show some restrictions and approximations that are commonly applied in electrochemical practice and which are no longer valid in such kind of systems. 

Andriiko et al., Many-electron Electrochemical Processes, Monographs in Electrochemistry, DOI 10.1007/978-3-642-35770-l 5, Springer-Veriag Berlin Heidelberg 2013 

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