Storage dynamics of ions on graphene

Carbon has been widely utilized as electrode in electrochemical energy storage, relying on the interaction between ions and electrode. The performance of a carbon electrode is determined by a variety of factors including the structural features of carbon material and the behavior of ions adsorbed on the carbon surface in the specific environment. As the fundamental unit of graphitic carbons, graphene has been employed as a model to understand the energy storage mechanism of carbon materials through various experimental and computational methods, ex-situ or in-situ. In this article, we provide a succinct overview of the state-of-the-art proceedings on the ion storage mechanism on graphene. Topics include the structure engineering of carbons, electric gating effect of ions, ion dynamics on the interface or in the confined space, and specifically lithium-ion storage/reaction on graphene. Our aim is to facilitate the understanding of electrochemistry on carbon electrodes. The ion dynamics on graphene is summarized through five aspects, including structural modulation of graphene materials, electrostatic and ionic gating effect, ion adsorption at graphene-electrolyte interface, ion dynamics in confined space, and charge transfer between lithium ions and graphene. image