Synthesis of porous bowl-like LiFePO4/C composite with ultrahigh rate capability

Abstract

Well-crystallized olivine-structure LiFePO4/C composite was synthesized by a wet milling-assisted spray drying using cheap Fe3O4 as iron source. The composite exhibited bowl-like secondary particles that are mainly constructed of numerous carbon coated nanoparticles. Such a composite possesses a porous structure with an average pore size of 8.14 nm and a high BET surface area of 50.57 m2 g-1. Electrochemical tests revealed that the cathode material exhibited a high rate capability (84 mA h g-1 at 90 C) and good cycle stability (93% capacity retention over 500 cycles at 10 C). That is because the uniform carbon coating increased the electronic conductivity, while, large specific surface area, porous structure, and nano-sized particles greatly favored the electrolyte accessibility and rapid Li+ transport.