Graphene oxide wrapped Fe2O3 as a durable anode material for high-performance lithium-ion batteries

Abstract

Ferric oxide has demonstrated as a promising anode candidate for lithium ion batteries (LIBs) due to large charge storage capacity, but its high cost, low Coulombic efficiency, and unstable solid-electrolyte interphase remain to be a technical challenge. Here, we report a flexible interleaved hybrid in which Fe2O3 nanoparticles were encapsulated by graphene oxide layers (Fe2O3/GO) using facile freeze-drying approach as anode for LIBs. Within this flexible interleaved structure, GO layers act as flexible but mechanically strong buffer to accommodate volume expansion and reduce associated stress in Fe2O3 nanoparticles, thereby maintaining mechanical integrity and increasing the cycling life of batteries. With the synergistic effects from Fe2O3 and GO, this hybrid not only promotes fast mass transfer and shortens the diffusion path of the Li ions but also forms a stable solid electrolyte interface, contributing improved Coulombic efficiency in the first few cycles. The Fe2O3/GO hybrid as anode for LIBs exhibited a reversible specific capacity of ca. 890 mAh g−1 after 50 cycles at 1 C (1005 mA g−1) and 405 mAh g−1 after 1000 cycles at 10 C rate. Furthermore, a full-cell battery with a LiFePO4 cathode also showed high Coulombic efficiency and good capacity retention capability. Mechanical properties and impedance spectroscopy tests were performed to confirm the mechanism in superior rate and electrochemical stability. The conclusions are considered to be very useful for design of Li batteries with improved mechanical performance.