Nanoporous Red Phosphorus on Reduced Graphene Oxide as Superior Anode for Sodium-Ion Batteries

As a potential alternative to lithium-ion batteries, sodium-ion batteries (SIBs) have attracted more and more attention due to the lower cost of sodium than lithium. Red phosphorus (RP) is an especially promising anode for SIBs with the highest theoretical capacity of 2596 mAh g^-1, which faces the challenges of large volume change and low conductivity. Herein, we develop a nanoporous RP on reduced graphene oxide (NPRP@RGO) as a high-performance anode for SIBs through boiling. Its nanoporous structure could accommodate the volume change and minimize the ion diffusion length, and the high electronic conductive network built on RGO sheets facilitates the fast electron and ion transportation. As a result, NPRP@RGO exhibits a superhigh capacity (1249.7 mAh g_composite^-1 after 150 cycles at 173.26 mA g_composite^-1), superior rate capability (656.9 mAh g_composite^-1 at 3465.28 mA g_composite^-1), and ultralong cycle life at 5.12 A g_RP^-1 for RP-based electrodes (775.3 mAh g_RP^-1 after 1500 cycles). The successful synthesis of NPRP@RGO marks a significant enhanced performance for RP-based SIB anodes, providing a scalable synthesis route for nanoporous structures.