Graphenal polymers: 3D carbon-rich polymers as energy materials with electronic and ionic transport pathways

Abstract

Graphene and its derivatives have attracted increasing attention during the last decade as efficient materials for the storage and conversion of energy. In most cases, however, these graphene materials possess large numbers of structural defects such as cavities, heteroatoms and functional groups, making them quite different from the precisely-defined "single carbon layer of graphite" observed for graphene. These materials also differ considerably in terms of their electrochemical properties because of their variable structures, which are strongly influenced by the methods used during their preparation. Structural analyses have indicated that these materials consist of graphene subunits, which are interconnected by organic linkers with properties lying between those of graphene and polymers, which we have defined as "graphenal polymers". The thermal crosslinking reactions of porous polymer networks fabricated from small organic molecules using a bottom-up strategy also result in graphene-like subunits, which are covalently interconnected by polymeric fractions. These materials cover a series of transitional intermediates belonging to the "graphenal polymers" family, where polymers and graphene sit at opposite ends of family spectrum. Moreover, the special structures and properties of these materials make them ideal electrode materials for the storage and conversion of energy via electronic and ionic transport pathways, allowing for a deeper evaluation of the structure-property relationships of different electrode materials.