Simultaneous Catalytic Acceleration of White Phosphorus Polymerization and Red Phosphorus Potassiation for High‐Performance Potassium‐Ion Batteries

Abstract

AbstractRed phosphorus (P) as an anode material of potassium‐ion batteries possesses ultra‐high theoretical specific capacity (1154 mAh g−1). However, owing to residual white P during the preparation and sluggish kinetics of K‐P alloying limit its practical application. Seeking an efficient catalyst to address the above problems is crucial for the secure preparation of red P anode with high performance. Herein, through the analysis of the activation energies in white P polymerization, it is revealed that the highest occupied molecular orbital energy of I2 (−7.40 eV) is in proximity to P4 (−7.25 eV), and the lowest unoccupied molecular orbital energy of I2 molecule (−4.20 eV) is lower than that of other common non‐metallic molecules (N2, S8, Se8, F2, Cl2, Br2). The introduction of I2 can thus promote the breaking of the P─P bond and accelerate the polymerization of white P molecules. Besides, the ab initio molecular dynamics simulations show that I2 can enhance the kinetics of P‐K alloying. The as‐obtained red P/C composites with I2 deliver excellent cycling stability (358 mAh g−1 after 1200 cycles at 1 A g−1). This study establishes catalysis as a promising pathway to tackle the challenges of P anode for alkali metal ion batteries.