Self-healing High-performance Phosphorus Composite Anode Enabled by in-situ Preformed Intermediate Lithium Sulfides
The poor electrical conductivity and contrast volumetric changes hinder the practical application of red phosphorus despite of its high theoretical capacity of 2596 mAh g-1. A simple approach for this challenge via anchoring solvable lithium-sulfur intermediate compounds on the surface of red phosphorus and configuring efficient interface is proposed here. Sulfur is strategically incorporated with phosphorous by P-S bonding to construct phosphorous-sulfur/carbon composite with high conductive interface. The solvable Li-S intermediates formed during the electrochemical lithiation process could be anchored on the surface of phosphorous by capillary action to heal the cracks/defects of phosphorous caused by volumetric expansion. The calculations based on first principles demonstrates that the strategic introduction of sulfur enables the band overlaps near Fermi level, which facilitates high efficient electron-transferring on their interface and thus improves the overall electrochemical properties of the constructed composite . Therefore, the phosphorus-sulfur/carbon composite delivers a high initial charge capacity of 1808.2 mAh g-1 at a current density of 200mA g-1 and maintains a reversible capacity of 935.3 mAh g-1 with a high coulombic efficiency of approximately 99.4% after 200 cycles.