3D Hierarchical Porous Graphene-Based Energy Materials: Synthesis, Functionalization, and Application in Energy Storage and Conversion

The rational development of effective energy materials is crucial to the sustainable growth of society. Here, 3D hierarchical porous graphene (hpG)-based materials with micro-, meso-, and macroporous features have recently attracted extensive research efforts due to unique porosities, controllable synthesis, versatile functionalization, favorable mass/electron transport, and superior performances in which corresponding electrochemical performances are strongly dependent on the nature of the building blocks and structural hierarchy of the assemblies. In this review, recent achievements in the controllable synthesis, versatile functionalization, and device application of 3D hpG-based energy materials will be summarized, including controllable and facile synthesis through chemical vapor deposition on 3D porous templates, post-assembly/treatment of graphene oxide nanosheets, and templated polymerization. In addition, graphene material functionalization through heteroatom doping, spatially confined decoration of active nanoparticles, and surface hybridization of graphene-analogous components to enhance electrochemical properties will be discussed. Furthermore, applications of 3D hpG materials in various electrochemical energy storage and conversion systems will be summarized, including lithium-ion batteries, lithium-sulfur batteries, lithium metal anodes, oxygen reduction reaction, oxygen evolution reaction, hydrogen evolution reaction, and nitrogen reduction reaction. Overall, this review will comprehensively present the property advantages, design principles and synthesis strategies of 3D hpG-based energy materials and provide guidance in the development of various 2D graphene-analogous materials and nanomaterials for advanced electrochemical energy storage and conversion systems.Graphical Abstract