Lithium-ion storage behavior of ZIFs polyhedral carbons with topological structure

Abstract Polyhedral carbons from zeolitic imidazolate frameworks (ZIFs) have been studied as anode materials for lithium-ion batteries, because their topological feature enabled ideal research objects. However, the similarities and differences of lithium-ion storage behavior between ZIFs polyhedral carbons have not been systematically studied. Here we synthesized four kinds of ZIF-8 polyhedral carbons, including cubes (ZIF-8/C-C), small rhombicuboctahedrons (ZIF-8/C-R1), large rhombicuboctahedrons (ZIF-8/C-R2) and dodecahedrons (ZIF-8/C-D), and well-studied their storage behavior. The as-made ZIF-8/C-R2 with 24 vertexes and 48 edges exhibited superior electrochemical performance (657 mAh g−1 at 0.1 A g−1) compared to other ZIF-8/C polyhedrons with less vertexes and edges. In situ TEM was employed to observe the lithiation process of various ZIF-8/C polyhedrons, showing that the solid electrolyte interface films were initiated to form at the vertex sites followed by the edges, which indicates that it is reasonable to design advanced polyhedral electrode materials with abundant vertexes and edges by applying Euler's formula.