9-13 July 2012
First principle stability study of FePO4 and LiFePO4 polymorphs
Presented by Mr. NDANDULENI LESLEY LETHOLE on 10 Jul 2012 from 14:30 to 14:50
Type: Oral Presentation
Track: Track A - Division for Condensed Matter Physics and Materials
Lithium iron phosphate, LiFePO<sub>4</sub> has been under intense study as a future cathode material for lithium ion batteries, due to its good thermal stability, competitive electrochemical properties, high safety, low cost, and long life cycle; and it has been recently commercialized in power tool applications. The electrochemical charge/discharge potential profile of Li/LiFePO<sub>4</sub> cells is very flat and located at 3.45V vs. Li/Li+, moreover, its theoretical capacity is relatively high (170 mAh/g). We use first principle calculations to investigate the structural, electronic and mechanical properties of FePO<sub>4</sub> and LiFePO<sub>4</sub> employing the pseudo-potential plane-wave within the local density approximation. We also determine the effect of lithiation on FePO<sub>4</sub> polymorphs. Our results show that β-FePO<sub>4</sub> and HP-FePO<sub>4</sub> shows stability over α-FePO<sub>4</sub>, while lithiation stabilises FePO<sub>4</sub> polymorphs.
PHUTI NGOEPE, PHUTI.NGOEPE@L.AC.ZA, UNIVERSITY OF LIMPOPO