Graphene caging core-shell Si@Cu nanoparticles anchored on graphene sheets for lithium-ion battery anode with enhanced reversible capacity and cyclic performance

With the large-scale practical application of electric vehicles and mobile devices, more and more attention has been focused on the research of high specific capacity lithium-ion batteries (LiBs) anode materials . Novel graphene caging core-shell Si@Cu nanoparticles anchored on graphene sheets (Si@Cu@rGO) anode was prepared by deposition-precipitation and one-step thermal reduction methods. During the preparation, CuC 2 O 4 and graphene oxide are simultaneously reduced and coated on silicon nanoparticles . Introduced copper can enhance charge transfer kinetics of the electrode and suppress the tight cluster of Si nanoparticles . Besides, the graphene nanocage outside Si@Cu nanoparticle restricts polarization and pulverization of silicon inside itself. Graphene provides not only buffering space for core-shell Si@Cu nanoparticles to expand but also a conductive network to enhance the electronic conductivity and flexibility of the electrode. Therefore, the synergism of copper shells and graphene sheets improved electrochemical performance . The Si@Cu@rGO composites exhibited the reversible capacity of 2095.2 mAh g −1 at 200 mA g −1 after 50 cycles, showing extraordinary electrochemical performance. This outstanding Si@Cu@rGO anode becomes an ideal candidate for superior silicon-based lithium-ion battery applications.