Significant enhancement of the cycling performance and rate capability of the P/C composite via chemical bonding (P–C)

Abstract

Among anode materials for sodium ion batteries, red phosphorus is a very promising one due to its abundant reserves, low-cost and high theoretical capacity of 2600 mA h g⁻¹. However, its huge volume expansion on sodiation (∼490%) and poor conductivity leads to dramatic capacity decay, restraining its practical application. To improve the electrochemical performance, here, we prepared a red phosphorus and graphene nanoplate composite using cheap red P and natural graphite as the starting materials via a simple and scalable ball-milling method. The phosphorus–carbon bond formed during the milling process improves the electrical connectivity between P particles and graphene nanoplates, consequently stabilizing the structure of the composite to achieve high cycling performance and rate capability. As a result, the red phosphorus and graphene nanoplate composite delivered a high reversible capacity of 1146 mA h g⁻¹ (calculated on the basis of the composite mass) at a current density of 100 mA g⁻¹ and an excellent cycling stability of 200 cycles with 92.5% capacity retention.