Reconstructing the inner/outer interphases in phosphorus/carbon anodes toward fast and durable potassium storage via...

As a commercially viable anode for cost-effective potassium-ion batteries in large-scale energy storage, the low-cost and high-capacity phosphorus/carbon composites still confront destructive volume changes and sluggish reaction kinetics for insulating phosphorus with aggressive/persistent interface reactions on active electrodes upon harsh potassiation/depotassiation. To ameliorate structural/interfacial stability and accelerate slothful reaction kinetics, the electrically conductive and electrochemically reactive chalcogen substances were uniformly deposited on unstable phosphorus/carbon composites through a facile vacuum heat treatment. In addition to partially buffering the detrimental volume variations of phosphorus without changing the intrinsic attributes of phosphorus/carbon composites, the highly conductive and chemically active Te material could not only construct the abundant but continuous electron transport pathways among insulative active materials in electrodes, but also regulate the configuration of inner Helmholtz plane via preferentially absorbing anions and enable the formations of inorganics-rich solid electrolyte interphases on anode. Consequently, the optimal Te-modified P/C anodes could present a large first charging capacity of 634 mAh g^-1 with a 69.3 % coulombic efficiency at 400 mA g^-1 and a highly reversible capacity of 145 mAh g^-1 with a 38.1 % capacity retention rate at 1600 mA g^-1 over 300 cycles. Even cycled at 8000 mA g^-1, an outstanding rate capability of 295 mAh g^-1 can be realized for P/C@Te anode, due to concurrent reconstructions of inner/outer interphases in anode through a homogeneously distributed Te coating. This innovative research on simultaneously manipulating the multifunctional interphases of phosphorus/carbon anodes would enlighten the novel surfaces modifications of large-capacity and high-rate anode materials for high-performance PIBs.