A review on phosphorus and metal phosphides as anodes for sodium‐ion batteries

Abstract Sodium‐ion batteries (SIBs) are promising electrochemical energy storage systems as lithium‐ion batteries by virtue of their similar chemical properties and natural abundance and availability. However, the ionic radius of Na + is larger than that of Li + , leading to challenges in its insertion/extraction at anode side. As a class of anode materials, phosphorus allotropes (PAs, red, and black) and metal phosphides (MPs) have shown great prospects because of high theoretical gravimetric/volumetric capacity, high carrier mobility, and suitable redox potential. In this review, recent developments in the studies of PAs and MPs with particular emphasis on understanding sodium storage mechanisms, developing novel synthesis strategies, and performance validations have been manifested valuable solutions to address these challenges. We begin with the introduction and classification of the macroscopic sodiation mechanisms of PAs and MPs, and the various fabrication strategies of PAs and MPs are comprehensively summarized in second section. The third section thoroughly reviews the progresses on PAs and MPs‐based advanced materials for their application in SIBs. Finally, we also discuss the significant challenges and outline a roadmap for future research directions.