Vertically Aligned Graphene Nanosheet Arrays: Synthesis, Properties and Applications in Electrochemical Energy Conversion and Storage

In the pursuit of better electrode kinetics and mass transportation for electrochemical energy applications, 3D graphene-based electrodes have been receiving increasing research interest. Distinguished from other kinds of 3D graphene structures, the well-developed, vertically aligned graphene nanosheet arrays (VAGNAs) could be grown on a variety of substrates by plasma-enhanced chemical vapor deposition (PECVD), forming a 3D interconnected structure with intimate contact with substrates and largely exposed edges, and easily accessible open surfaces of the graphene nanosheets. Ascribing to the combined superior inherent properties of graphene and the special structure configuration, e.g., large surface area, excellent electron transfer capability, outstanding mechanical strength, great chemical and thermal stabilities, and enhanced electrochemical activity, VAGNAs have demonstrated promising applications in supercapacitors, batteries, and fuel cell catalysts. This progress report provides a brief review on the nucleation and growth of VAGNAs, their growth mechanism and properties, and highlights the recent important progress in their electrochemical energy conversion and storage applications, in the views of their pros and cons in comparison with other 3D graphene-based structures. Challenges and perspectives for future advance are discussed in the end.