Improvement by heating of the electronic conductivity of cobalt spinel phases, electrochemically synthesized in various electrolytes

In “Co3O4” type spinel phases synthesized by eleectrooxidation, the nature of the alkaline electrolyte allows to monitor the amounts of hydrogen and lithium, inserted in spinel framework and therefore the electronic conductivity. Whatever the initial synthesis electrolyte, a moderate thermal treatment of the materials induces a significant increase of the electronic conductivity, due to a structural reorganization (illustrated by the evolution of the cell parameter) and an increase of the Co4+/Co3+ ratio in the octahedral framework.