Doping Graphene into Monodispersed Fe3O4 Microspheres with Droplet Microfluidics for Enhanced Electrochemical Performance in Lithium‐Ion Batteries

Abstract

AbstractGraphene‐doped Fe3O4 monodispersed microspheres are fabricated utilizing a droplet microfluidic technology. The electrochemical performance of the Fe3O4 microspheres as anode material for Li‐ion batteries is enhanced by doping trace graphene in the droplet reactor. The discharge capacity remains 550 mAh/g at 0.1 C after 190 cycles, which is 2 times higher than that of the graphene doped Fe3O4 samples prepared by the traditional precipitation method, and 5 times higher than that of pure Fe3O4 after 100 cycles. The uniform droplet reactor in form of a droplet microfluidic chip might provide a homogeneous microscopic condition for in‐situ electrostatic co‐assembly of the positive‐charged Fe colloids and the negative‐charged graphene oxide sheets to shape a homogeneous solid framework, resulting in homogeneously doping trace graphene into the Fe3O4 microspheres.