Constructing Heterointerface of Metal Atomic Layer and Amorphous Anode Material for High-Capacity and Fast Lithium Storage.

Interfacial engineering plays an important role in tuning the intrinsic property of electrode materials for energy applications such as lithium-ion batteries (LIBs), which however is rarely realized to amorphous electrode materials, despite a set of characteristics of amorphous materials desirable for LIBs. Here, Au atomic cluster layer-interfaced amorphous porous CoSnO nanocubes were fabricated by galvanic replacement and employed as a superior LIB anode, showing high reversible capacity (1615 mAh g at 0.2 A g), good rate capability (1059 mAh g with a 61.3% capacity retention upon the dramatic current variation from 0.1 to 5 A g), and excellent cycling stability. The amorphous nature, interconnected mesopores, and especially the thin Au atomic cluster layer on the surface/pore walls of CoSnO nanocubes can not only improve electron transport and ion diffusion in the electrode and electrolyte but also release the volume strain. Most significantly, density functional theory calculations reveal that the CoSnO∥Au heterointerface can induce the atomic polarization of CoSnO and lower Li ion diffusion barriers in CoSnO near the heterointerface, endowing it with a significantly enhanced theoretical lithium storage capacity and outstanding rate capability. This study provides a model of a heterointerface for amorphous materials with desired properties for high-performance LIBs and future energy applications.