1 / 18

DFG Priority Programme SPP 1473, WeNDeLIB :

DFG Priority Programme SPP 1473, WeNDeLIB : Thermodynamics and Kinetics for Stabilization of Conversion-Type Electrodes for LIB Based on Nano 3d Transition Metal Oxides. Thermodynamic Description of the Li-Cu-O System for Conversion Type Electrode Materials for Lithium Ion Batteries.

alyssa
Download Presentation

DFG Priority Programme SPP 1473, WeNDeLIB :

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. DFG Priority Programme SPP 1473, WeNDeLIB: Thermodynamics and Kinetics for Stabilization of Conversion-Type Electrodes for LIB Based on Nano 3d Transition Metal Oxides Thermodynamic Description of the Li-Cu-O System for Conversion Type Electrode Materials for Lithium Ion Batteries M. Lepple, D.M. Cupid, P. Franke, C. Ziebert, H.J. Seifert

  2. ElectrochemicalConversionMechanism • Electrochemicalconversionmechanism • X = O, N, F, S, P • More than 1 Faraday charge per molecanbetransferred • High theoreticalcapacity • Conversionmechanismdoes not need a stablecrystallographicstructurefreedom in material selection • Bad cyclingstability J. Cabana, et al. Adv. Mater.22, E170-E192 (2010). MSE Congress 2012 Maren Lepple

  3. Material System: Li-Cu-Fe-O • Fe-oxides • High theoretical capacity • Cu-oxides • Cycling stability • Mixedtransitionmetalcompounds • Show an overallperformancesimilarto simple oxides • Potentialisdominatedbymetalcontent adjustment of batteryperformance Theoretical capacity: CuFe2O4: 896 mAh g-1 Theoretical capacity: CuO: 674 mAh g-1 Cu2O: 375 mAh g-1 Theoretical capacity: Fe2O3: 1007 mAh g-1 Fe3O4: 926 mAh g-1 MSE Congress 2012 Maren Lepple

  4. Motivation forThermodynamicDescriptions • Overall drivingforceacross a electrochemicalcellisdeterminedbythechange in thestandard Gibbs freeenergy • Thermodynamiccalculationsbased on the CALPHAD method (Coupling of thermochemistry and phasediagram) • Predictbatteryperformance (OCV, capacity) • Database developmentforthe Li-Cu-Fe-O System: • The Cu-Fe-O ternarysystemassessed byKhvan et al., Journal of Phase Equilibria and Diffusion, 2011, 32:498-511 • First calculatedphasediagrams in the Li-Cu-O systemaddressed in presentwork MSE Congress 2012 Maren Lepple

  5. Li-Cu-O System at 298.15 K 298.15 K Investigatedbycoulometrictitration N.A. Godshall, Solid State Ionics 1986, 18&19:788-793 MSE Congress 2012 Maren Lepple

  6. Li-Cu-O System at 298.15 K 298.15 K Is the LiCu2O2phasestable? S. Patat et al., Solid State Ionics 1991, 46:325-329 MSE Congress 2012 Maren Lepple

  7. Database Developement Li-Cu-O System Li-O: K. Chang, B. Hallstedt, CALPHAD, 2011, 35:160-164 Cu-O: B. Hallstedt, L.J. Gauckler CALPHAD, 2003, 27:177-191 Li-Cu: N. Saunders, I. Ansara (Ed), Cost 507 Report,1994,168–169 Extrapolation frombinaryassessments MSE Congress 2012 Maren Lepple

  8. Database Development Li-Cu-O System Formation based on thecompounds in thethree-phasefield All phases in thethree-phase equilibriumareconsideredas pure substances LiCuO: 298.15 K Li2CuO2: MSE Congress 2012 Maren Lepple

  9. Database Development Li-Cu-O System 298.15 K Ternarycompoundsincluded MSE Congress 2012 Maren Lepple

  10. Titration Curves • Equilibrium cellvoltageas a function of lithiumcontentatthecathodealongselectedcompositionpaths MSE Congress 2012 Maren Lepple

  11. Description ofTemperatureDependence • Stoichiometricphase (AB) • a, csolutioncalorimetry, cpmeasurements • b,clow T cpmeasurements (0 – 298.15 K), ab initio • ccpmeasurements • Phase stability • DTA/TGA GHSERA: Gibbs freeenergyofcomponent A withreferencetothestandardenthalpyoftheelementat 298.15 K a, b, c,…: Variables MSE Congress 2012 Maren Lepple

  12. Experimental Investigations • Sample preparation via solid statereaction • Li2CuO2 • LiCu2O2 • Sample characterization • XRD • Thermal analysis • Specificheatcapacitywith DSC • Phase stabilityof LiCu2O2 in argonandairwithsimultaneous DTA/TGA Includeresults in database XRD MSE Congress 2012 Maren Lepple

  13. HeatCapacity • Li2CuO2: • -10 – 400°C, HR=10 K/min • LiCu2O2: • -10 – 200°C, HR=10 K/min MSE Congress 2012 Maren Lepple

  14. Phase Stabilityof LiCu2O2 • Simultaneous DTA/TG (Setaram) • 200-900°C, HR=10 K/min, 3 cycles • In argon • Reversible phasetransformationat 705 °C • Slightmassloss due toreductionof Cu+2 Cu+1athightemperatures • In air • Irreversible phasetransformationaccompaniedwithmassgainΔTG during 1st cycle Maren Lepple MSE Congress 2012

  15. Phase Stabilityof LiCu2O2 • Simultaneous DTA/TG (Setaram) • 200-900°C, HR=10 K/min, 3 cycles • In argon • Reversible phasetransformationat 705 °C • Slightmassloss due toreductionof Cu+2 Cu+1athightemperatures • In air • Irreversible phasetransformationaccompaniedwithmassgainΔTG during 1st cycle • Reversible phasetransformations in 2nd and 3rd cycles Maren Lepple MSE Congress 2012

  16. Conclusionsand Outlook MSE Congress 2012 Maren Lepple

  17. Acknowledgment • This work is supported by the priority programme SPP 1473 WeNDeLIB of the German Science Foundation (DFG) in the project SE 647/14-1. • Thanksto Robert Adam (TU Freiberg) Thank you for your kind attention! MSE Congress 2012 Maren Lepple

  18. OCV vs. Experimental Results Potential plateauofCuOand Cu2O: ~1.4 V S.J. Hibble, Solid State Ionics 1990, 39:289-295 MSE Congress 2012 Maren Lepple

More Related