Red Phosphorus-Based Materials As Anode for Na-Ion Batteries K-Ion Batteries

Abstract

Recently, sodium ion batteries (NIBs) and potassium-ion battery (KIBs) have been attracted much attention since sodium and potassium resource is natural abundant, environmental friendly and showing similar chemical properties with lithium ion batteries. The red P anode for Na-ion and K-ion batteries has attracted great attention recently due to the high theoretical capacity, but the poor intrinsic electronic conductivity and large volume expansion restrains its widespread applications. The intrinsic low electronic conductivity of red P leads to the poor electronic kinetics, large polarization and further low active material utilization. In addition, the large volume expansion (~400%) during Na insertion/extraction in red P leads to pulverization of red P and loose contact between the red P and the current collector, resulting in the severe capacity fading. Herein, we successfully encapsulate the red P into the carbon-based material (such as MOF-derived carbon, N-doped carbon, carbon-nanofibers) via the vaporization-condensation method.1, 2 Superior cycling stability (high capacity retention of about 93% at 2 A g-1 after 100 cycles) and excellent rate performance (502 mAh g-1 at 10 A g-1) could be obtained for the P/C electrode. The superior electrochemical performance could be ascribed to the successful incorporation of red P into the unique carbon matrix with large surface area and pore volume, interconnected porous structure, excellent electronic conductivity and superior structural stability.The porous carbon matrix with abundant micro/meso pores, large pore volume could effectively facilitate the infiltration of the electrolyte, and accommodate large volume expansion of red P during electrochemical process. The excellent conductivity of the carbon could ensure the essential electrical contact to the insulating red P, leading to excellent sodium storage performances. The rational design of the unique red P/ carbon structure could be served as a model for other anode material with poor intrinsic electronic conductivity and large volume expansion.