Alternative route for LiFePO4 synthesis: Carbothermal reduction combined with microwave-assisted solid-state reaction

摘要

LiFePO4 was synthesized via a microwave-assisted solid-state reaction. The precursors LiOH center dot H2O, FePO4 center dot 4H(2)O, glucose, and graphite were first subjected to carbothermal reduction at 200 degrees C during 3 h and subsequently calcined under microwave irradiation at 800 W for very short times varying from 1 to 5 min. The products obtained at different microwave calcination times were systematically investigated through thermal (TGA-DTG and DSC), structural (XRD), morphological (SEM), and electrochemical (cyclic voltammetry) analyses. The best results were attained for the product obtained at the microwave calcination time of 3 min: smallest particle size (majority in the range of 100-150 nm), crystallographic pattern of LiFePO4 and some by-products, and voltammetric profile characteristic of LiFePO4. Thus, the here-presented synthesis methodology implies a significant reduction in processing time while yielding LiFePO4 nanoparticles with good electrochemical activity for the Li ion intercalation process. (C) 2016 Elsevier Ltd. All rights reserved.