In-operando XAS analysis of Li-ion and Li-sulphur batteries Iztok Ar - PowerPoint PPT Presentation

In-operando XAS analysis of Li-ion and Li-sulphur batteries Iztok Ar č on 1,2 Robert Dominko 3,4 , Giuliana Aquilanti 5 , Manu Patel 3,4 , Lorenzo Stievano 5 1 University of Nova Gorica, Vipavska 13, POB 301, Nova Gorica, Slovenia 2 J. Stefan Institute, Jamova 39, P. P. 3000, Ljubljana, Slovenia 3 National institute of Chemistry, P.O.B. 660, SI-1001 Ljubljana, Slovenia 4 Center of excelence Low carbon technologies, Ljubljana, Slovenia 5 Elettra Sincrotrone Trieste, Italia 6 Univeriste Montpellier II, 2 Place Eugene Bataillon–CC 1502, 34095 Montpellier (France) XAS Joint ICTP – IAEA School on novel experimental methodologies fro SR aaplications in nano-science 19. 11. 2014 Iztok Ar č on and environmental monitoring

Motivation for in-operando XAS analysis on Li-ion batteries • Searching for new cathode materials for high energy Li-ion batteries with fully reversible lithium extraction that can deliver high battery capacitiy. • Some candidates Li 2 VTiO 4 , Li 2 FeTiO 4 and Li 2 (Fe x Mn x-1 )SiO 4 • Exploiting the reversable oxidation potential of Fe 2+ /Fe 3+ , Mn 2+ /Mn 3+ / Mn 4+ and V 2+ /V 3+ /V 4+ redox couples without collapse of the structure.  Theoretical specific capacity ~ 166 mAh/g ( 332 mAh/g if both Li equivalents are extracted);  Thermal stable cathode materials;  Cheap and environmental acceptable cathode materials; XAS 19. 11. 2014 www.ung.si/~arcon/xas Iztok Ar č on

Aim of in-operando XAS on Li-ion batteries  The feasibility and reliability of in situ XANES and EXAFS analysis as a tool to monitor gradual changes of oxidation state and local structure of transition-metal cations during lithium exchange, i.e. during charging and discharging of the Li-ion battery.  Provide the information on the dynamics of the battery operation on the atomic level and clarify the role of transition-metal cations (Fe, Mn, V) in the electrochemical activity of the material. Determine the degree of reversibility of the process in one or several cycles. R. Dominko, I. Ar č on, et al., Journal of Power Sources 189 (2009) 51–58 XAS 19. 11. 2014 www.ung.si/~arcon/xas Iztok Ar č on

Some basic facts about the Li 2 (Fe 0.8 Mn 0.2 )SiO 4 meterial XRD data : Advantages :  Monoclinic crystal structure with P121/n1 space  high capacity (200 mAh/g at a C/50 cycling rate) group. a = 8.245 Å, b = 5.018 Å and c = 8.246 Å  good thermal stability  The structure is composed of MnO 4 , FeO 4 , Moesbauer data on Fe valence in as synthesized SiO 4 and LiO 4 tetrahedra. Li 2 Fe 0.8 Mn 0.2 SiO 4 : •80% Fe 2+ (tetrahedral iron in crystal structure)  The crystal structure contains empty octahedral •20% Fe 3+ (tetrahedral iron in crystal structure) interstitial cavities that form empty channels, which enables transport of Li + ions. 4.5 4.0 3.5 + U / V vs. Li/Li 3.0 2.5 2.0 1.5 1.0 0.0 0.2 0.4 0.6 0.8 1.0 x in Li 2-x Fe 0.8 Mn 0.2 SiO 4 Charge / discharge curves in the first cycle at C/15 current density at 60 oC. Exchanged of 1 mol Li. R. Dominko, M. Bele, M. Gaberš č ek, A. Meden, M. Remškar, and XAS J. Jamnik, Electrochem. Commun. 8 , 217 (2006). 19. 11. 2014 www.ung.si/~arcon/xas Iztok Ar č on

In situ battery In operando XAS experiment charge / discharge owen – 60 o C Half-battery sealed in triplex foil: 3.5 Fe K-edge ELETTRA, XAFS beamline, April 2009 XANES 3.0 2.5 Mn K-edge XANES • Li 2 FeTiO 4 charging (411min), discharging (192 min) at RT 2.0  d with C/10 current density in time intervals of 25 min. 1.5 Fe EXAFS • Li 2 Fe 0.8 Mn 0.2 SiO 4 : In situ charging ( 908 min), discharging (852 min) 1.0 Mn EXAFS at 60 o C with C/15 current density in time intervals of 50 min 0.5 • XAFS beamline at ELETTRA and C beamline in HASYLAB at DESY, 0.0 Hamburg. A Si(111) double crystal monochromator with about 1 eV 6400 6800 7200 7600 8000 energy resolution at Fe k-edge (7112 eV) was used. Exact energy E (ev) calibration with simultaneous absorption measurements on a 5 mm thick Fe and Mn XANES and EXAFS spectra were V, Fe or Mn metal foil. Absolute energy reproducibility of the measured spectra was  0.05 eV. XAS measured in time intervals of of 55 min. 19. 11. 2014 www.ung.si/~arcon/xas Iztok Ar č on

Li 2-x Fe 0.8 Mn 0.2 SiO 4 battery discharging battery charging 1.6 1.6 Fe oxidation Fe reduction 1.4 1.4 as synth. 1.2 1.2 as synth. 3+ 22% Fe Normalised absorption 3+ Normalised absorption 19.5% Fe 1.0 1.0 0.8 0.8 end of reduction st cycle) (1 0.6 3+ 0.6 27% Fe st cycle) 0.4 start of reduction (1 st cycle) 0.4 end of oxidation (1 3+ 86% Fe 3+ 86% Fe 0.2 0.2 0.0 0.0 7110 7115 7120 7125 7130 7135 7140 7145 7110 7115 7120 7125 7130 7135 7140 7145 E (eV) E (eV) R. Dominko et al., Journal of The Electrochemical Society, 157 12 A1309-A1316 2010 XAS 19. 11. 2014 www.ung.si/~arcon/xas Iztok Ar č on

Li 2-x Fe 0.8 Mn 0.2 SiO 4 battery charging battery discharging Mn oxidation Mn reduction 1.6 1.6 1.4 1.4 as synth. as synth. 2+ 1.2 100% Mn 1.2 2+ 100% Mn Normalised absorption Normalised absorption 1.0 1.0 0.8 0.8 end of reduction st cycle) (1 0.6 0.6 3+ 11% Mn 0.4 st cycle) 0.4 end of oxidation (1 st cycle) start of reduction (1 3+ 37% Mn 3+ 37% Mn 0.2 0.2 0.0 0.0 6535 6540 6545 6550 6555 6560 6565 6535 6540 6545 6550 6555 6560 6565 E (eV) E (eV) R. Dominko et al., Journal of The Electrochemical Society, 157 12 A1309-A1316 2010 XAS 19. 11. 2014 www.ung.si/~arcon/xas Iztok Ar č on

Linear combination fit Li 2-x Fe 0.8 Mn 0.2 SiO 4 of XANES spectra of intermediate states with the spectra of the starting and the most charged state. 1.5 4 Li 2-x Fe 0.8 Mn 0.2 SiO 4 3+ 34% Fe Li 2-x Fe 0.8 Mn 0.2 SiO 4 Normalised absorption ch. 141 min Experiment 3+ 22% Fe Fit 1.0 3+ 27% Fe 3 Li 2-x Fe 0.8 Mn 0.2 SiO 4 -sint (81%) 3+ 34% Fe 0.5 Normalised absorption 3+ 35% Fe as-sint. 3+ 56% Fe Li 2-x Fe 0.8 Mn 0.2 SiO 4 (19%) dis. 841 min 0.0 ch. 908 min 3+ 58% Fe 7100 7110 7120 7130 7140 7150 7160 2 E (eV) ch. 141 min 3+ 1.5 75% Fe Li 2-x Fe 0.8 Mn 0.2 SiO 4 3+ 56% Fe dis. 694 min 3+ 74% Fe Normalised absorption ch. 336 min Experiment ch. 336 min 3+ 86% Fe 1.0 Fit dis. 351 min 1 Li 2-x Fe 0.8 Mn 0.2 SiO 4 (53%) ch. 908 min ch. 537 min 0.5 dis. 204 min Li 2-x Fe 0.8 Mn 0.2 SiO 4 -sint (47%) ch. 908 min 0 0.0 7100 7110 7120 7130 7140 7150 7160 7100 7110 7120 7130 7140 7150 E (eV) E (eV) R. Dominko et al., Journal of The Electrochemical Society, 157 12 A1309- XAS A1316 2010 19. 11. 2014 www.ung.si/~arcon/xas Iztok Ar č on

Linear combination fit Li 2-x Fe 0.8 Mn 0.2 SiO 4 of XANES spectra of intermediate states with the spectra of the starting and the most charged state. 1.5 Li 2-x Fe 0.8 Mn 0.2 SiO 4 3+ 27% Fe 4 Normalised absorption dis. 841 min Li 2-x Fe 0.8 Mn 0.2 SiO 4 Experiment 1.0 Fit 3+ 22% Fe 3+ 27% Fe Li 2-x Fe 0.8 Mn 0.2 SiO 4 -sint (92%) 3 3+ 34% Fe 0.5 Normalised absorption 3+ 35% Fe Li 2-x Fe 0.8 Mn 0.2 SiO 4 (8%) as-sint. ch. 908 min 3+ 56% Fe dis. 841 min 0.0 3+ 58% Fe 7100 7110 7120 7130 7140 7150 7160 2 E (eV) ch. 141 min 3+ 75% Fe 1.5 dis. 694 min 3+ Li 2-x Fe 0.8 Mn 0.2 SiO 4 74% Fe 3+ 74% Fe Normalised absorption dis. 204 min ch. 336 min 3+ 86% Fe Experiment dis. 351 min Fit 1.0 1 ch. 537 min Li 2-x Fe 0.8 Mn 0.2 SiO 4 (81%) dis. 204 min ch. 908 min 0.5 ch. 908 min 0 7100 7110 7120 7130 7140 7150 Li 2-x Fe 0.8 Mn 0.2 SiO 4 -sint (19%) 0.0 E (eV) 7100 7110 7120 7130 7140 7150 7160 XAS E (eV) 19. 11. 2014 www.ung.si/~arcon/xas Iztok Ar č on R. Dominko et al., Journal of The Electroch. Society, 157 12 A1309-A1316 2010

Linear combination fit with XANES spectra of “as-sint.” and “ch. 908 min” Li 2-x Fe 0.8 Mn 0.2 SiO 4 1.5 Li 2-x Fe 0.8 Mn 0.2 SiO 4 3+ 35% Fe Normalised absorption dis. 694 min Experiment 4 1.0 Fit Li 2-x Fe 0.8 Mn 0.2 SiO 4 3+ 22% Fe Li 2-x Fe 0.8 Mn 0.2 SiO 4 -sint (79%) 3+ 27% Fe 0.5 3 3+ 34% Fe Li 2-x Fe 0.8 Mn 0.2 SiO 4 (21%) Normalised absorption 3+ 35% Fe ch. 908 min 0.0 as-sint. 7100 7110 7120 7130 7140 7150 7160 3+ 56% Fe E (eV) dis. 841 min 3+ 58% Fe Linear combination fit with XANES spectra of 2 ch. 141 min 3+ 75% Fe “dis. 841 min ” and “ch. 908 min” dis. 694 min 3+ 74% Fe 1.5 Li 2-x Fe 0.8 Mn 0.2 SiO 4 3+ 35% Fe ch. 336 min Normalised absorption dis. 694 min 3+ 86% Fe dis. 351 min Experiment 1 Fit 1.0 ch. 537 min dis. 204 min Li 2-x Fe 0.8 Mn 0.2 SiO 4 (86%) dis. 841 min 0.5 ch. 908 min 0 7100 7110 7120 7130 7140 7150 Li 2-x Fe 0.8 Mn 0.2 SiO 4 (14%) 0.0 ch. 908 min E (eV) 7100 7110 7120 7130 7140 7150 7160 XAS E (eV) 19. 11. 2014 www.ung.si/~arcon/xas Iztok Ar č on R. Dominko et al., Journal of The Electroch. Society, 157 12 A1309-A1316 2010