Conductive composites

The invention relates to formulations comprising: (i) a first active material; (ii) a second active material; and (iii) a metal-coordination complex, wherein the first active material and the second active material have at least one surface property which is different, one from the other. Such formulations are more homogenous than those formed without the metal-coordination complex and can be used to form composite materials, such as those forming part of a conductive interface, having advantageous properties and providing for improvement in functionality of the conductive interface.