From conducting polymers to electroactive hybrid materials

Electron or hole conductivity in conjugated polymers provided their initial thrust, but conductive polymers also display interesting electrochemical properties which constitute the base for their application in different types of electro-ionic devices. A further step in the development of functional materials based on conductive polymers is provided by the design of hybrid materials. In hybrid organic-inorganic materials based on conductive polymers, the electroactivity of molecular doping species or other inorganic components is added to that of the polymers themselves, leading to a whole new spectrum of hybrid materials that allow for the harnessing and control of the electrochemical properties of molecular species and put them to work in the development of all sorts of functional materials and devices, from sensors or catalysts to rechargeable lithium batteries, supercapacitors or photoelectrochemical devices. In this chapter we present several examples of this type of functional materials, their synthesis, properties and applications. We will present a general overview of this field and will discuss in some detail the design of insertion electrodes based on conducting polymers and hybrid organic-inorganic materials based on them, analyzing their peculiar ion-inserting mechanisms and their possible application in energy storage devices.