28 June 2015 to 3 July 2015
Africa/Johannesburg timezone
SAIP2015 Proceeding published on 17 July 2016

Armorphization and Recrystallization of spinel LiMn<sub>2</sub>O<sub>4</sub> nano-architectures

1 Jul 2015, 09:40
20m
Oral Presentation Track A - Division for Physics of Condensed Matter and Materials DPCMM

Speaker

Ms Raesibe Sylvia Ledwaba (University of Limpopo)

Please indicate whether<br>this abstract may be<br>published online<br>(Yes / No)

no

Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?

yes

Apply to be<br> considered for a student <br> &nbsp; award (Yes / No)?

yes

Abstract content <br> &nbsp; (Max 300 words)<br><a href="http://events.saip.org.za/getFile.py/access?resId=0&materialId=0&confId=34" target="_blank">Formatting &<br>Special chars</a>

Spinel LiMn2O4 has attracted attention as a potential cathode material for use in advanced lithium ion batteries. The current study focused on the effects of high temperatures on the spinel system: the 3D framework sustainability, structural transformation and impacts of melting temperature on the lithium ion diffusion. Furthermore, understanding these materials will facilitate in the implementation of armorphization and recrystallization technique for spinel nano-architectures. Molecular dynamics simulations were carried out at various temperatures. The melting points and transformations are clearly visible on the RDF plots and structural snapshots of the supercells at different temperatures. LiMn2O4 indicated a diffusion rate that increased rapidly above 1500K, just before melting (~1700 K) and reached its maximum diffusion at 2.756x10E-7 cm2.s-1 before it decreased. Simulated armorphization and recrystallization was carried out on the system. The nanoparticle started armorphizing into a nanosphere around 150 ps during the simulation and nucleated after 1500ps with the assistance of a crystalline seed in the centre of the armorphised nanoparticle. Recrystalization was complete after 6 ns, the latent heat of crystallization is therefore reflected in the energy difference between the first (0–1.5 ns) and second (6 ns –15ns) energy trace.

Level for award<br>&nbsp;(Hons, MSc, <br> &nbsp; PhD, N/A)?

M.Sc.

Main supervisor (name and email)<br>and his / her institution

Prof. Phuti Ngoepe

Primary author

Ms Raesibe Sylvia Ledwaba (University of Limpopo)

Co-authors

Dr Dean Christopher Sayle (University of Kent) Prof. Phuti Esrom Ngoepe (University of Limpopo)

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