Understanding of the capacity Contribution of carbon in phosphorus-carbon composites for high-performance anodes in lithium ion batteries

Phosphorus has recently received extensive attention as a promising anode for lithium ion batteries （LIBs） due to its high theoretical capacity of 2,596 mAh·g^-1. To develop high-performance phosphorus anodes for LIBs, carbon materials have been hybridized with phosphorus （P-C） to improve dispersion and con- ductivity. However, the specific capacity, rate capability, and cycling stability of P-C anodes are still less than satisfactory for practical applications. Furthermore, the exact effects of the carbon support on the electrochemical performance of the P-C anodes are not fully understood. Herein, a series of xP-yC anode materials for LIBs were prepared by a simple and efficient ball-milling method. 6P-4C and 3P-7C were found to be optimum mass ratios of x/y, and delivered initial discharge capacities of 1,803.5 and 1,585.3-mAh·g^-1, respectively, at 0.1 C in the voltage range 0.02-2 V, with an initial capacity retention of 68.3% over 200 cycles （more than 4 months cycling life） and 40.8% over 450 cycles. The excellent electrochemical performance of the 6P-4C and 3P-7C samples was attributed to a synergistic effect from both the adsorbed P and carbon.