Characterization of LiFePO₄/C Cathode for Lithium Ion Batteries

Abstract

LiFePO 4 /C was synthesized from a mixture of different precursors of Li, Fe, and C by solid-state reaction. The initial mixture obtained was heated in different calcination conditions under inert atmosphere. The precursor of LiFePO 4 doped with carbon was studied using different techniques such as thermal analysis, chemical and physical characterizations, and M€ osbauer spectroscopy. A calculation of the crystallinity of the final product with two different methods is also presented. The chemical analysis techniques used were IRTF, XRD, and SEM. This characterization confirmed that we obtained a well-crystallized LiFePO4/ C in all the operating conditions tested. The SEM showed aggregation and sintering during the calcination process, which were confirmed by the particle-size distribution measurements and by the physical characterizations. M€ osbauer spectroscopy was used to determine the quantity of Fe(II) and Fe(III) contained in the final product. Our calcination conditions did not significantly modify the quantity of the two oxidation states.

A facile synthesis and characterization of LiFePO4/C using simple binary reactants with oxalic acid by polyol technique and other high temperature methods

“…The Fe/P ratio is equal to 1 and O/Fe, O/P equal to 4. The precursor formation of LiFePO 4 is in good agreement with the report of Lyczko et al [37].…”

Enhanced rate performance of multiwalled carbon nanotube encrusted olivine type composite cathode material using polyol technique

“…The Energy dispersive X-ray spectra of both samples (Fig. 3 (c, d) demonstrate the Fe/P ratio is equal to 1; Also, O/Fe and O/P equal to 4 that are calculated by observed atomic weight percentage of the prepared material, which is in good agreement with the report of Lyczko et al [46]. It is clearly seen from the spectra that the carbon content is increased upon encrusting the multi-walled carbon nanotube on LiFePO 4 /C sample.…”

Degradation mechanisms in Li-ion batteries: a state-of-the-art review

“…The interdependent nature of the various degradation mechanisms in Li‐ion batteries makes the study of the degradation mechanisms challenging and often requires the employment of novel in‐situ and ex‐situ characterization techniques to elucidate the degradation mechanisms at the nanoscale. The most important characterization techniques for understanding the degradation mechanism in Li‐ion batteries are in‐situ and ex‐situ transmission electron microscopy (TEM) , in‐situ atomic force microscopy (AFM) , ex‐situ X‐ray diffraction (XRD), Raman spectroscopy, X‐ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) . The better understanding of the degradation mechanism would lead to prolonged cycle life, development of improved materials as well as help in identifying the optimal control strategies to limit degradation.…”