Boosting Potassium Storage Kinetics, Stability, and Volumetric Performance of Honeycomb-Like Porous Red Phosphorus via In Situ Embedding Self-Growing Conductive Nano-Metal Networks

Large volume expansion and sluggish reaction kinetics of low-conductivity red phosphorus (RP) anodes hinder its practical application in potassium-ion batteries (PIBs). Here, a self-limited growth strategy to fabricate Bi (Sb) nanoparticles is demonstrated, as electrochemically active and conductive coating, in situ embedded into honeycomb-like porous red phosphorus (HPRP) to form HPRP@Bi (HPRP@Sb) composites, greatly improving the potassium-storage kinetics, stability and volumetric performance of HPRP. Here, Bi nanoparticles are converted into amorphous Bi during cycling, which are uniformly coated on the porous HPRP skeleton to form 3D conductive Bi networks. Theoretical calculations verify that introducing amorphous Bi significantly decreases K+ diffusion barrier in composites, and greatly enhancing their electrical conductivity and interfacial ion transport between HPRP and Bi, thereby accelerating their potassium storage kinetics and stability. Whereas the robust porous structure and inward expansion mechanism of HPRP effectively buffer their volume expansion of RP and Bi. Therefore, HPRP@Bi anode delivers high gravimetric and volumetric capacity (465.6 mAh g(-1), 745 mAh cm(-3)) and stable long lifespan with 200 cycles at 0.05 A g(-1) in PIBs. This work demonstrates a new approach to promote ion storage kinetics and stability of RP via integrating the synergy of high-conductivity active metal and high-capacity porous RP.