Phase contact structures mechanical stresses

In solid-state systems it is often advantageous to have some of the electrolyte material mixed in with the reactant. There are two general advantages that result from doing this. One is that the contact area between the electrolyte phase and the electrode phase (the electrochemical interface) is greatly increased. The other is that the presence of the electrolyte material changes the thermal expansion characteristics of the electrode structure so as to be closer to that of the pure electrolyte. By doing so, the stresses that arise as the result of a difference in the expansion coefficients of the two adjacent phases that can use mechanical separation of the interface are reduced. 

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