Red‐Phosphorus‐Based Anode Materials for Sodium‐Ion Batteries: Challenges and Progress

The shortage of lithium resources is widely recognized as a key factor that affects the further development of lithium‐ion batteries (LIBs). The sodium (Na) has abundant resources in the earth's crust and its physicochemical properties are similar to Li, which ensure that sodium‐ion batteries (SIBs) are considered as a substitute for LIBs in certain fields. Unfortunately, the lower energy density of SIBs limits its application range. Therefore, studying high specific capacity anode materials to improve the energy density of batteries is an important direction of SIBs. Red‐phosphorus (P)‐based anode materials are ideal candidates for high energy density SIBs because of their high theoretical specific capacity and suitable working voltage. However, the red‐P‐based anode materials for SIBs meet intractable challenges in terms of the poor electrical conductivity and huge volume changes during cycling, resulting in inferior electrochemical performances. In this article, the research progress of red‐P‐based anode material for SIBs in recent years, including the red‐P/carbon composite, element‐doped composite, metal phosphide, and stable interface design, is reviewed. Herein, the decisive role is highlighted that composite design with highly conductive carbon materials plays in addressing the challenges associated with red‐P‐based anodes and a perspective on their development direction is given.