Enhanced rate performance of the mortar-like LiFePO4/C composites combined with the evenly coated of carbon aerogel

Abstract

Mortar-like LiFePO4/C composites are synthesized by a ball milling-spray drying-carbothermal reduction method using polyethylene glycol (PEG) as the organic carbon source, dispersant, and reductive agent, while the carbon aerogel as the excellent conductive network. PEG enables the carbon aerogel to uniformly coat the primary particles, which restricts the overgrowth of primary particles' during the synthesis process. While the carbon aerogel provides a three-dimensional conductive network, and its porous structure can absorb more electrolyte. Moreover, the mortar-like secondary particles could further increase the specific surface of LiFePO4/C composites. The high speed of electron transfer and lithium-ion transportation can be achieved simultaneously for the Mortar-like LiFePO4/C composites. All these factors contribute to the outstanding rate performance (163.4 mAh g-1 at 0.2 C and 115.4 mAh g-1 at 15 C) and considerable cycling stability (99.3% of capacity retention after 300 cycles at 5 C/5 C). The Mortar-like LiFePO4/C composites combined with the evenly coated carbon aerogel are promising cathode materials for rechargeable lithium-ion power batteries.