Fast-Charging Phosphorus Anodes Enabled by Fluorinated Weakly Solvated Electrolytes for Stable and High-Rate Lithium...

Phosphorus-based anodes hold promise for energy storage due to their high theoretical capacity and favorable lithiation potential. However, their practical application is hindered by sluggish reaction kinetics and irreversible capacity loss, primarily attributed to multiphase lithiation/delithiation reactions and the dissolution of lithium polyphosphide intermediates. Herein, a universal design principle of weakly solvated electrolytes (WSEs) tailored for phosphorus-based anodes is proposed. Combined with a high dielectric constant, and significant dipole moment, a fluorinated cosolvent is incorporated into a WSE to effectively suppress the dissolutions of lithium polyphosphides, enhance interfacial stability, and accelerate reaction kinetics. With this electrolyte, a phosphorus-based anode achieves a remarkable capacity of 2615.2 mAh g⁻¹ at 1C, maintaining 91.7% capacity retention over 1000 cycles. Even at a high rate of 4 C, it delivers 2210.7 mAh g⁻¹ with an exceptional retention of 96.7% after 1500 cycles. Furthermore, at 0 °C, the anode sustains a capacity of 2016.7 mAh g⁻¹, with 97% retention after 300 cycles at 1C. This study provides a novel electrolyte design strategy to regulate the solvation sheath, paving the way for high-rate, long-cycle phosphorus-based anodes suitable for fast-charging applications.