Simultaneous Catalytic Acceleration of White Phosphorus Polymerization And Red Phosphorus Potassiation for High-Performance Potassium-Ion Batteries.

Red phosphorus (P) as an anode material of potassium-ion batteries (KIBs) 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 above problems is crucial for 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 (HOMO) energy of I 2 (-7.40 eV) is in proximity to P 4 (-7.25 eV), and the lowest unoccupied molecular orbital (LUMO) energy of I 2 molecule (-4.20 eV) is lower than that of other common non-metallic molecules (N 2 , S 8 , Se 8 , F 2 , Cl 2 , Br 2 ). The introduction of I 2 can thus promote the breaking of P-P bond and accelerate the polymerization of white P molecules. Besides, the ab initio molecular dynamics (AIMD) simulations show the I 2 can enhance the kinetics of P-K alloying. The as-obtained red P/C composites with I 2 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. This article is protected by copyright. All rights reserved.