SAIP2016

Phase Stability Study of Nickel Doped Spinel LiMn₂ O₄ Using Cluster Expansion Method

5 Jul 2016, 16:10

1h 50m

Kramer Law building

Board: A.049

Poster Presentation Track A - Division for Physics of Condensed Matter and Materials Poster Session (1)

Speaker

Mr kemeridge Tumelo Malatji (University of Limpopo)

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

Prof R.R Maphanga
rapela.maphanga@ul.ac.za
University of Limpopo, Materials Modelling Centre

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

No

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

No

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>

One of the challenges for improving the performance of lithium-ion batteries to meet increasingly demanding requirements for energy storage is the development of suitable cathode materials. Spinel-structured LiMn₂ O₄(LMO) is a desirable cathode material for Li-ion batteries, due to its low cost, abundance and high power capability. However, LMO suffers from limited cycle life that is triggered by manganese dissolution into the electrolyte during electrochemical cycling. Doping in battery materials tends to improve the efficiency in maintaining electrochemical capacity over a large number of cycles without sacrificing initial reversible capacity at room temperature. In this paper, Universal Cluster Expansion (UNCLE) code implemented in cluster expansion formalism is used to investigate nickel doped LMO phase stabilities. The method determines stable multi-component crystal structures and rank metastable structures by enthalpy of formation, while maintaining the predictive power and accuracy of first-principles density functional methods. Complex configurations of nickel doped LMO systems with various concentrations are determined at different temperatures by means of Monte Carlo random sampling. The ground state phase diagram generated various structures with different concentrations and symmetries. The findings predict that nickel doped LMO with 50:50 concentration of manganese and nickel is the most stable phase.

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

PhD

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

No