Limitations and Strategies toward High-Performance Red Phosphorus Materials for Li/Na-Ion Batteries

Phosphorus, particularly the red phosphorus (RP) allotrope, has been extensively studied as an anode material in both lithium-ion batteries (LIBs) and emerging sodium-ion batteries (SIBs). RP is featured with high theoretical capacity (2,596 mA h g⁻¹), suitable low redox potential (~0.7/0.4 V for LIBs/SIBs), abundant resources, and environmental friendliness. Despite its promises, the inherent poor electrical conductivity of RP (~10⁻¹⁴ S cm⁻¹) and significant volume changes during charge/discharge processes (>300%) compromise its cycling stability. In order to address these issues, various countermeasures have been proposed, focusing on the incorporation of materials that provide high conductivity and mechanical strength in composite-type anodes. In addition, the interfacial instability, oxidation, and safety concerns and the low mass ratio of active material in the electrode need to be addressed. Herein, this review summarizes the up-to-date development in RP materials, outlines the challenges, and presents corresponding countermeasures aimed to enhance the electrochemical performance. It covers aspects such as the structural design of RP, the choice of the additive materials and electrolytes, rational electrode construction, etc. The review also discusses the future prospects of RP for LIBs/SIBs and aims to provide a different perspective on the challenges that must be overcome to fully exploit the potential of RP and meet commercial application requirements.