Phosphorus: An Anode of Choice for Sodium-Ion Batteries

Phosphorus (P) offers a high theoretical capacity of 2596 mAh g–1 and thus has been intensively pursued as one of the most promising anodes for sodium-ion batteries. However, sodium storage in P anodes is facing significant technical challenges in terms of poor conductivity, large volume swelling, and an unstable solid–electrolyte interphase. These challenges need to be well mitigated before P material can be deployed in full batteries. In this Perspective, we summarize the latest research progress in the development of P anodes. We focus on the design principle and criteria of efficient P anodes and materials strategies that mainly leverage the knowledge accumulated for the lithium anode of silicon. We also highlight the decisive role that theoretical simulation and in situ techniques play in addressing these difficulties associated with P materials.