A reduced graphene oxide-encapsulated phosphorus/carbon composite as a promising anode material for high-performance sodium-ion batteries

As a promising anode for sodium ion batteries, phosphorus has captured remarkable interest due to its highest sodium-storage capacity. However, phosphorus suffers from huge volume expansion during discharging and its typical low conductive nature. So, herein, we have realized a phosphorus/carbon composite encapsulated by reduced graphene oxide (P/C@rGO) through a simple spray drying process combined with in situ oxidation of the P/C composite. The rGO coating layer alleviates the volume expansion of phosphorus and improves its electrical conductivity. In addition, a small amount of phosphate species in P/C@rGO enables strong interaction between rGO nanosheets and P/C particles, finally promoting sodium ion transfer and cycling stability. As a result, P/C@rGO shows a high reversible capacity of 2445 mA h g_p⁻¹ and maintains 95% of its initial capacity even after 100 cycles.