The electrochemistry of polymers is reviewed, in comparison with solid
or liquid electrolytes. It is shown that the coordination chemistry l
eading to the formation of conductive complexes is very general with s
pecific interactions (e.g. transition metal-nitrogen). While the trans
ference numbers are still the subject of controversies, a coordination
chemistry akin to that of water for PEO or ammonia with PEI exists. A
lso, the possibility of redox conduction, through microphase separatio
n leads to mixed conductivity (ions + electrons).