High P Doped Hollow Carbon Spheres for Rapid Sodium Storage and Ultra-Long Cycling Life

Abstract

The poor performance of carbon anode materials represents a significant obstacle impeding the development and application of sodium-ion batteries (SIBs) performance. Phosphorus-doped carbon materials have attracted much attention as anodes due to their extensive interlayer spacing and robust adsorption capacity of Na+. Herein, we utilize the vapor-condensation method to conduct doping utilizing the diffusion of red phosphorus from the core to the periphery of the carbon spheres and thus obtained phosphorus-doped hollow carbon spheres (PHCs) with a phosphorus atom incorporation concentration of 5.02 at%. High phosphorus doping can potentially enlarge the interlayer spacing of carbon accelerating the transmission of Na+. In addition, the formation of P-C bonds enhances the adsorption energy of Na+. It introduces more active sites for storing more sodium which helps to achieve high capacity and excellent rate performance. In particular, phosphorus-doped hollow carbon spheres exhibit an extraordinary performance of 147 mA h g-1 at 10 A g-1, accompanied by remarkable cycling durability under ultrahigh current densities. It is noteworthy that after 9200 cycles at a current density of 10 A g-1, the specific capacity of the battery remains consistently at 139 mA h g-1, highlighting the material's significant potential for long-term, high-performance SIBs.

Keywords: High phosphorus-doped, Hollow carbon spheres, Anodes, Sodium-ion batteries