P-doped Porous Carbon As The Phosphorus Host Material And The Study Of Lithium Storage Performance Of The Composite

Red phosphorus（RP）is a promising anode material for use in lithium-ion batteries owing to its superior theoretical specific capacity(2596 m A h g^-1)and suitable lithiation potential（～0.7 V vs Li⁺/Li）.However,the inherent poor electrical conductivity of RP(～10^-14 S cm^-1)and the volume expansion（～300%）generated during lithiation lead to low utilization rates of RP and poor cycling stability of corresponding batteries,which greatly limit the practical application of RP.In order to solve these two major problems,combining RP with carbon materials becomes an effective solution.Porous carbon materials stand out among many carbon materials because of their unique structural controllability and large specific surface area.However,its non-polar surface is difficult to achieve high loading of active materials,which leads to the limitation of battery capacity and application performance.Therefore,tuning the morphology and interfacial properties of the porous carbon matrix to achieve high RP loading is essential for enhancing the electrochemical performance of phosphorus/carbon composites.In this work,porous carbon with phosphorus doping（P-PC）was prepared by a simple and convenient in situ synthesis method,and then RP was compounded with P-PC by an evaporation-condensation method（the resulting complexes were denoted as RP@P-PC）.The phosphorus dopant substantially enhanced the interfacial properties of the carbon matrix as a high RP loading of up to 60.7 wt%was realized,the size of the incorporated RP particles was reduced to the nanoscale,and the distribution of the RP nanoparticles was uniform.These features,along with the porous structures of the P-PC matrix,effectively enhanced the Li storage performance of the RP@P-PC composite.In half-cells assembled by using lithium foil as counter electrode,the RP@P-PC electrode had a specific capacity of 1848 m A h g^-1 at 0.1 A g^-1,and1022 m A h g^-1 after 800 cycles at 2.0 A g^-1,corresponding to a capacity decay of only 0.048%per cycle.Even at a high current density of 10.0 A g^-1,the RP@P-PC electrode still exhibited excellent rate performance with a reversible capacity of 1111 m A h g^-1.In addition,the full cell was assembled with Li Fe PO₄（LFP）as the cathode and the RP@P-PC as the anode.The LFP//RP@P-PC full cell still exhibited excellent cycling stability with a capacity retention rate of 80.0%after 100 cycles at 0.5 A g^-1.