Abstract

A dense, substantially gas-tight electrically conductive interconnection layer is formed on an air electrode structure of an electrochemical cell by (A) providing an air electrode surface; (B) forming on a selected portion of the electrode surface, a layer of doped LaCrO3 particles doped with an element or elements selected from Ca, Sr, Ba, Mg, Co, Ni, Al and mixtures thereof by thermal spraying doped LaCrO3 particles, either by plasma arc spraying or flame spraying; (C) depositing a mixture of CaO and Cr2 O3 on the surface of the thermally sprayed layer; and (D) heating the doped LaCrO3 layer coated with CaO and Cr2 O3 surface deposit at from about 1000° C. to 1200° C. to substantially close the pores, at least at a surface, of the thermally sprayed doped LaCrO3 layer. The result is a dense, substantially gas-tight, highly doped, electrically conductive interconnection material bonded to the electrode surface. A solid electrolyte layer can be applied to the nonselected portion of the air electrode. A fuel electrode can be applied to the solid electrolyte, to form an electrochemical cell, for example for generation of electrical power.