Self-propagating fabrication of SiO _x @rGO film with superior cycling stability and rate performance as anode for lithium-ion batteries

Abstract With high theoretical capacity and suitable operating potential, SiO _x is regarded as one of the most promising anode materials for high-energy density lithium-ion batteries (LIBs), but it suffers from large volume change during charge/discharge and low electronic conductivity, leading to poor cycling stability and rate capability. To overcome these problems, a SiO _x @ reduced graphene oxide (rGO) film with porous structure is prepared through vacuum filtration and self-propagation reduction method, which can be directly used as a free-standing anode for LIBs. The self-propagation process of graphene oxide to graphene can be completed rapidly within 1 s, and endows the film with developed pores due to the instantaneous release of substantial gases. The porous structure is beneficial for exposing massive active sites, facilitating fast ion transport and buffering the volume change of the SiO _x during charge/discharge. Moreover, the rGO sheets construct a conductive framework for rapid electron transfer in the film. As a result, the SiO _x @rGO film exhibits high lithium storage capacity (1189.7 mAh g ⁻¹ at 0.1 A g ⁻¹ ), excellent cycling stability (81.1% capacity retention after 100 cycles) and good rate capability (349.2 mAh g ⁻¹ at 3.2 A g ⁻¹ ). This study not only provides a high-performance film anode material for LIBs, but also develops a simple and efficient method for constructing porous film electrodes for various energy storage devices.