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Phase Diagram App and Reaction Calculator

Phase Diagram App and Reaction Calculator. Shyue Ping Ong Research Associate, MIT. Stability - The most important material property. Can a material even exist? Under what conditions? How can I make it? To what does it decompose into?. Phase Diagram App. Reaction Calculator.

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Phase Diagram App and Reaction Calculator

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  1. Phase Diagram App and Reaction Calculator Shyue Ping Ong Research Associate, MIT

  2. Stability - The most important material property Can a material even exist? Under what conditions? How can I make it? To what does it decompose into? PhaseDiagramApp ReactionCalculator

  3. PhaseDiagramApp Make 2-4 component phase diagrams from Materials Project data Supports both closed and open systems

  4. Phase Diagram Construction From VASP calculations Fixed S. P. Ong, L. Wang, B. Kang and GCeder. Li-Fe-P-O2 Phase Diagram from First Principles Calculations. Chemistry of Materials, 2008, 20(5), 1798-1807.

  5. Some subtleties 1A. Jain, G. Hautier, S. Ong, C. Moore, C. Fischer, K. Persson, & G. Ceder. Formation enthalpies by mixing GGA and GGA + U calculations. Physical Review B, 2011, 84(4), 045115. Uses both GGA/GGA+U data where appropriate; mixing scheme to ensure compatibility between GGA and GGA+U run1 Found to have very good results, particularly in systems which contain both insulator and metallic phases

  6. Interpreting phase diagrams B C Edecomp A Edecomp = 0  Stable Phase Edecomp > 0  Unstable Phase Edecomp = ΔH ( C -> A + B) Phase diagram tells us that a compound C has an equilibrium decomposition of A + B. Edecomp : Reaction energy for the decomposition reaction to the predicted equilibrium phases.

  7. How accurate are the calculated phase diagrams? S. P. Ong, L. Wang, B. Kang and GCeder. Li-Fe-P-O2 Phase Diagram from First Principles Calculations. Chemistry of Materials, 2008, 20(5), 1798-1807.

  8. Real-world application glass forming region LiFe0.9P0.95O4-δ.

  9. Nano material with glassy second phase gives very high power density inexpensive nanoparticles Full charge/discharge in 15 minutes Full charge/discharge in 75 seconds 5nm Kayyar, Qian & Luo, Appl. Phys. Lett. 95: 221905 (2009) B. Kang, G. Ceder, Nature, Vol. 458, 190-193 (2009)

  10. Thermal Stability of Olivine Cathodes • Higher voltage olivines, LiCoPO4 (4.8V) and LiNiPO4 (> 5V), have even worse predicted thermal stability than LiMnPO4! • Delithiated CoPO4 and NiPO4 are both predicted to be unstable at room temperature and evolves 0.25 mol of O2per mol of charged cathode (c.c.) S. P. Ong, A. Jain, G. Hautier, B.W. Kang, G. Ceder. Thermal stabilities of delithiated olivine MPO4 (M=Fe, Mn) cathodes investigated using first principles calculations. Electrochemistry Communications, 2010, 12(3), 427-430.

  11. Stability of Li10GeP2S12superionic conductor N. Kamaya, et al. Nature materials, 2011 10(9), 682-686. Li-Ge-P-S phase diagrams at constant uLi • Demonstrated that the observed electrochemical stability of LGPS is likely the result of passivating layers. Y. Mo, Y., S. P. Ong, & G. Ceder. First Principles Study of the Li 10 GeP 2 S 12 Lithium Super Ionic Conductor Material. Chemistry of Materials, 2012, 24(1), 15-17. doi:10.1021/cm203303y uLi = 0eV (bulk Li metal) uLi = -2.5eV Li10GeP2S12 (LGPS) is a recently discovered superionic conductor with highest reported Li-conductivity ever.1 Claimed to be stabled over a voltage rage of >5V

  12. Demo • Simple example • Fe-O phase diagram. • Li-Fe-P-O phase diagram • Grand canonical PD examples • Li-Fe-P-O uO phase diagram • Li-Fe-F uLi phase diagram • Link with Conversion Voltages.

  13. ReactionCalculator Calculate reaction enthalpies Compare with experimental data (NIST and Kubaschewski Tables) where available

  14. How accurate are we?

  15. Binary oxide -> Ternary oxide Reactions

  16. Limitations Works really well for pure solid state reactions, i.e. crystal -> crystal Works reasonably well for crystal + gas reactions where the gas reactions have been properly fitted (e.g., O2, F2, etc.) Results are not good for reactions involving liquids + non-fitted gases, e.g. H2O

  17. Demo • Show best result reaction • MgO + Al2O3 -> MgAl2O4 • Li2O + Al2O3 -> LiAlO2 • Show fitted reactions • Fe3O4 + O2 -> Fe2O3 • Show example of terrible reaction • H2 + O2 -> H2O (maybe some other example)

  18. More on computational battery design:MRS Symposium O Moscone West, Level 2, Room 2024 • Tuesday • 10:45AM (A. Jain) • Wednesday • 1:30 PM (G. Ceder) • 2:00 PM (K. Persson) • 3:30 PM (G. Hautier) • 3:45 PM (S.P. Ong) • others…

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