Structure and electrochemical properties of vanadium doped for lithium iron phosphate cathode

LiFePO4 and vanadium doped LiFePO4 were successfully prepared by sol- gel method. The concentrations of vanadium were varied by 0.01, 0.03, 0.05, 0.10, 0.15, and 0.2 wt %. Both doped and pure LiFePO4 were calcined at 400 and 600°C. XRD results showed that by changing the dopant concentration and cal...

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Main Author:	Che Raimi, Nur Isarah
Format:	Thesis
Language:	English
Published:	2014
Subjects:	TK Electrical engineering Electronics Nuclear engineering
Online Access:	http://eprints.utm.my/id/eprint/48627/1/NurIsarahCheRaimiMFS2014.pdf
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spelling	my-utm-ep.486272020-03-04T06:18:42Z Structure and electrochemical properties of vanadium doped for lithium iron phosphate cathode 2014 Che Raimi, Nur Isarah TK Electrical engineering. Electronics Nuclear engineering LiFePO4 and vanadium doped LiFePO4 were successfully prepared by sol- gel method. The concentrations of vanadium were varied by 0.01, 0.03, 0.05, 0.10, 0.15, and 0.2 wt %. Both doped and pure LiFePO4 were calcined at 400 and 600°C. XRD results showed that by changing the dopant concentration and calcination temperature, the crystallinity changed. As the concentration of dopant increased the size of crystallite size become larger. The peaks pattern shows orthorhombic structure for LiVFePO4 upon incorporation of vanadium, and changed to hematite at low calcination temperature. As the calcination temperature increase the size of particle become larger while smaller particle were obtained at low temperature. FESEM analysis showed that at low temperature, smaller particles tend to agglomerate. Agglomeration of several grains produced larger particles which might be due aggregation of very small crystal grains during calcinations. Upon addition of vanadium to LiFePO4, larger particles size was obtained. Similar ionic radius of vanadium with iron may cause the expansion of crystal lattice, resulting in larger particle size. EDX analysis confirmed the existence of each element in the samples except for Li which cannot be detected as the atomic number is less than five. In charge/discharge electrochemical test, the obtained discharge capacities were far from the theoretical value and not suitable for commercialization of lithium ion batteries. Poor performance of the prepared samples may be due to the formation of solid electrolyte interface layer and cracking causes the loss of lithium and active materials from the sample. 2014 Thesis http://eprints.utm.my/id/eprint/48627/ http://eprints.utm.my/id/eprint/48627/1/NurIsarahCheRaimiMFS2014.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:80445?queryType=vitalDismax&query=Structure+and+electrochemical+properties+of+vanadium+doped+for+lithium+iron+phosphate+cathode&public=true masters Universiti Teknologi Malaysia, Faculty of Science Faculty of Science
institution	Universiti Teknologi Malaysia
collection	UTM Institutional Repository
language	English
topic	TK Electrical engineering Electronics Nuclear engineering
spellingShingle	TK Electrical engineering Electronics Nuclear engineering Che Raimi, Nur Isarah Structure and electrochemical properties of vanadium doped for lithium iron phosphate cathode
description	LiFePO4 and vanadium doped LiFePO4 were successfully prepared by sol- gel method. The concentrations of vanadium were varied by 0.01, 0.03, 0.05, 0.10, 0.15, and 0.2 wt %. Both doped and pure LiFePO4 were calcined at 400 and 600°C. XRD results showed that by changing the dopant concentration and calcination temperature, the crystallinity changed. As the concentration of dopant increased the size of crystallite size become larger. The peaks pattern shows orthorhombic structure for LiVFePO4 upon incorporation of vanadium, and changed to hematite at low calcination temperature. As the calcination temperature increase the size of particle become larger while smaller particle were obtained at low temperature. FESEM analysis showed that at low temperature, smaller particles tend to agglomerate. Agglomeration of several grains produced larger particles which might be due aggregation of very small crystal grains during calcinations. Upon addition of vanadium to LiFePO4, larger particles size was obtained. Similar ionic radius of vanadium with iron may cause the expansion of crystal lattice, resulting in larger particle size. EDX analysis confirmed the existence of each element in the samples except for Li which cannot be detected as the atomic number is less than five. In charge/discharge electrochemical test, the obtained discharge capacities were far from the theoretical value and not suitable for commercialization of lithium ion batteries. Poor performance of the prepared samples may be due to the formation of solid electrolyte interface layer and cracking causes the loss of lithium and active materials from the sample.
format	Thesis
qualification_level	Master's degree
author	Che Raimi, Nur Isarah
author_facet	Che Raimi, Nur Isarah
author_sort	Che Raimi, Nur Isarah
title	Structure and electrochemical properties of vanadium doped for lithium iron phosphate cathode
title_short	Structure and electrochemical properties of vanadium doped for lithium iron phosphate cathode
title_full	Structure and electrochemical properties of vanadium doped for lithium iron phosphate cathode
title_fullStr	Structure and electrochemical properties of vanadium doped for lithium iron phosphate cathode
title_full_unstemmed	Structure and electrochemical properties of vanadium doped for lithium iron phosphate cathode
title_sort	structure and electrochemical properties of vanadium doped for lithium iron phosphate cathode
granting_institution	Universiti Teknologi Malaysia, Faculty of Science
granting_department	Faculty of Science
publishDate	2014
url	http://eprints.utm.my/id/eprint/48627/1/NurIsarahCheRaimiMFS2014.pdf
_version_	1747817436613181440

Structure and electrochemical properties of vanadium doped for lithium iron phosphate cathode

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