Reduced Graphene Oxide-Supported SrV 4 O 9 Microflowers with Enhanced Electrochemical Performance for Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) have received considerable attention in recent years. Anode material is one of the key factors that determine SIBs' electrochemical performance. Current commercial hard carbon anode shows poor rate performance, which greatly limits applications of SIBs. In this study, a novel vanadium-based material, SrV 4 O 9 , was proposed as an anode for SIBs, and its Na + storage properties were studied for the first time. To enhance the electrical conductivity of SrV 4 O 9 material, a microflower structure was designed and reduced graphene oxide (rGO) was introduced as a host to support SrV 4 O 9 microflowers. The microflower structure effectively reduced electron diffusion distance, thus enhancing the electrical conductivity of the SrV 4 O 9 material. The rGO showed excellent flexibility and electrical conductivity, which effectively improved the cycling life and rate performance of the SrV 4 O 9 composite material. As a result, the SrV 4 O 9 @rGO composite showed excellent electrochemical performance (a stable capacity of 273.4 mAh g -1 after 200 cycles at 0.2 A g -1 and a high capacity of 120.4 mAh g -1 at 10.0 A g -1 ), indicating that SrV 4 O 9 @rGO composite can be an ideal anode material for SIBs.