Binder, J.R.

Geßwein, H.

Glatthaar, S.

Lieser, G.

Schroeder, M.

Winkler, V.

Binder, J. R.

KITopen

KIT – Universität des Landes Baden-Württemberg und nationales Forschungszentrum in der Helmholtz-Gemeinschaft www.kit.edu Institute for Applied Materials - Material Process Technology New synthesis of lithium transition metal fluorides and their use as positive electrode materials in Li-ion batteries In-situ und ex-situ characterization Theory Final evaluation Synthesis Characterization Elektrochemical characterization G. Lieser, V. Winkler, S. Glatthaar, H. Geßwein, M. Schroeder, J.R. Binder, IAM-WPT 2 - 1972  Watanabe et al.: Patent registration for metal fluorides “High Energy Density Battery“ - 1997  Arai et al.  “Cathode performance and voltage estimation of metal trihalides“  - 2000  Koyama et al. theoretical study about LiCaCoF6 and LiCdCoF6 “New Fluoride Cathodes for Rechargeable Lithium Batteries“ - 2009  Gocheva et al.   “Electrochemical Properties of Trirutile Li2TiF6…“ - 2009 - 2012 Li3FeF6 (4) (Gonzalo et al. Madrid) and LiFeFeF6 (2)    - 2012  Basa et al. “Facile synthesis of Li3VF6: A new electrochemically active…”  - 2009 - 2012 At least 7 patents claim for these materials as positive electrodes   Historical development 27.08.2013 Dipl.-Chem. Georg Lieser IAM-WPT 3 Which lithium transition metal fluorides exist? LixMFy      ternary fluorides (e.g. Li3FeF6) LixM1M2Fy quarternary fluorides (e.g. LiCdCoF6)   More then 100 compounds are known  27.08.2013 Dipl.-Chem. Georg Lieser IAM-WPT 4 What do we expect for a lithium transition metal fluoride as positive electrode? Intercalation: „The host structre is retained“ 27.08.2013 G. Amatucci, N. Pereira, Journal of Fluorine Chemistry, 128, (2007), 243–262 Dipl.-Chem. Georg Lieser LiyMOx LiyMFx High voltage stable ? Electronic conducitivity Li ion conductivity Flameability Cycle stability Toxicity ? Conversion: „The host structure is rebuild“ IAM-WPT 5 • Solid state reaction    LiF(s)  T  3 LiF + FeF3∆  Li3FeF6 • Wet chemical   HF(fl)  T+ C FeCl3 + 6 HF + 1.5 Li2CO3 Li3FeF6 + 3 HCl + 1.5 H2O + 1.5 CO2 • Gas phase fluorination  F2(g) T+ O C LiCl + CaF2 + Co NH3 6 Cl3100bar F2+500°CLiCaCoF6 + ⋯ • High energy ball milling  LiF(s) T LiF + FeF2 + FeF3 LiFeFeF6    Dipl.-Chem. Georg Lieser Synthesis of lithium transition metal fluorides 27.08.2013 IAM-WPT 6 TFA – Route: An easy sol-gel process Synthesis can be applied to many lithium transition metal fluorides e.g. Li3CrF6, Li3VF6 H2O C=O C-O C-F COOH Dipl.-Chem. Georg Lieser 27.08.2013 IAM-WPT 7 Pyrolytic decomposition of the precursor 275°C Li3FeF6 TG-FTIR spectra of the exhaust fume  TG-DSC Dipl.-Chem. Georg Lieser CO2, CO, CF3COOH, (CF3CO)2O  and CF4 in traces Formation of HF can be detected at higher temperature 27.08.2013 IAM-WPT 8 Monoclinic Li3FeF6          Oxides and organic redisdues are below detectable limit Formation of binary fluorides (FeF3; LiF) is a crucial problem         Dipl.-Chem. Georg Lieser S.G.: C/2c 27.08.2013 IAM-WPT 9 Preparation of a positive electrode No electrochemical Performance Li3FeF6 + C + Binder + NMP (N-Methyl-2-pyrrolidon)  Literature: 1. Small particles (nanoscale)     2. A good contact with a well conductive agent   Dipl.-Chem. Georg Lieser 27.08.2013 IAM-WPT 10 Dipl. chem. Georg Lieser Li3FeF6 + C + Binder (72/25/3) Reduceing the particle size 1 eq. Li (140 mAh/g)  128 mAh/g (91%) 7 mAh/g (5 %) 27.08.2013 IAM-WPT 11 Li2FeF6−Li (charge)Li3FeF6+Li (discharge)Li4FeF6 Which redox couple is involved? Dipl.-Chem. Georg Lieser Quantum-chemical calculations :   Too high for common electrolyte systems ! > 6 V (1)  3.0  V Discharge behavior of the 1st and 2nd  cycle is different ! Part of future investigations Li3FeF6+LiLi4FeF6 Li3FeF6−LiLi2FeF6 27.08.2013 (1) J. Kohl et. al, Journal of Materials Chemistry, 22, (2012), 15819–15827 IAM-WPT 12 Long term cycle ability (C/20)   (theoretical capacity 140 mAh/g)     Rate performance test Electrochemcial behavior Dipl. chem. Georg Lieser Even at C/1 50% of the theoretical capacity 91 % of the  theoretical capacity 27.08.2013 IAM-WPT 13 X-ray photoelectron spectroscopy Dipl.-Chem. Georg Lieser The redox couple Fe3+/Fe2+ can be confirmed Li3FeF6±𝐿𝑖𝐿𝑖4FeF6 27.08.2013 IAM-WPT 14 Summary Synthesis of Li3FeF6 without high toxic chemicals Further processing is required to increase the electrochemcial performance Theoretic capacity was nearly reached Intercalation and deintercalation of Lithium is reversible Even at high discharge rates a good capacity can be obtained  Future work: Investigations on new cathode materials e.g. Li3CrF6     Lithium transition metal fluorides are suitable as positive electrode  in lithium ion batteries. Dipl.-Chem. Georg Lieser 27.08.2013 Financial support from: 

New synthesis of lithium transition metal fluorides and their use as positive electrode materials in Li-ion batteries

KIT – Universität des Landes Baden-Württemberg und nationales Forschungszentrum in der Helmholtz-Gemeinschaft www.kit.edu Institute for Applied Materials - Material Process Technology New synthesis of lithium transition metal fluorides and their use as positive electrode materials in Li-ion batteries In-situ und ex-situ characterization Theory Final evaluation Synthesis Characterization Elektrochemical characterization G. Lieser, V. Winkler, S. Glatthaar, H. Geßwein, M. Schroeder, J.R. Binder, IAM-WPT 2 - 1972  Watanabe et al.: Patent registration for metal fluorides “High Energy Density Battery“ - 1997  Arai et al.  “Cathode performance and voltage estimation of metal trihalides“  - 2000  Koyama et al. theoretical study about LiCaCoF6 and LiCdCoF6 “New Fluoride Cathodes for Rechargeable Lithium Batteries“ - 2009  Gocheva et al.  “Electrochemical Properties of Trirutile Li2TiF6…“ - 2009 - 2012 Li3FeF6 (4) und LiFeFeF6 (2) - 2012  Basa et al. “Facile synthesis of Li3VF6: A new electrochemically active…”  - 2009 - 2012 At least 7 patents claim for these materials as positive electrodes   Historical development 16.05.2013 Dipl.-Chem. Georg Lieser IAM-WPT 3 Which lithium transition metal fluorides exist ? LixMFy      ternary fluorides (e.g. Li3FeF6) LixM1M2Fy quarternary fluorides (e.g. LiCdCoF6)   More then 100 compounds are known  16.05.2013 Dipl.-Chem. Georg Lieser IAM-WPT 4 What do we expect for a lithium transition metal fluoride as positive electrode ? Intercalation: „The host structre is retained“ 16.05.2013 G. Amatucci, N. Pereira, Journal of Fluorine Chemistry, 128, (2007), 243–262 Dipl.-Chem. Georg Lieser LiyMOx LiyMFx High voltage stable ? Electronic conducitivity Li ion conductivity Flameability Cycle stability Toxicity ? Conversion: „The host structure is rebuild“ IAM-WPT 5 • Solid state reaction    LiF(s)  T  3 LiF + FeF3∆  Li3FeF6 • Wet chemical   HF(fl)  T+ C FeCl3 + 6 HF + 1.5 Li2CO3 Li3FeF6 + 3 HCl + 1.5 H2O + 1.5 CO2 • Gas phase fluorination  F2(g) T+ O C LiCl + CaF2 + Co NH3 6 Cl3100bar F2+500°CLiCaCoF6 + ⋯ • High energy ball milling  LiF(s) T LiF + FeF2 + FeF3 LiFeFeF6    Dipl.-Chem. Georg Lieser Synthesis of lithium transition metal fluorides 16.05.2013 IAM-WPT 6 TFA – Route: An easy sol-gel process Synthesis can be applied to many lithium transition metal fluorides e.g. Li3CrF6, Li3VF6 H2O C=O C-O C-F COOH Dipl.-Chem. Georg Lieser 16.05.2013 IAM-WPT 7 Pyrolytic decomposition of the precursor 275°C Li3FeF6 TG-FTIR spectra of the exhaust fume  TG-DSC Dipl.-Chem. Georg Lieser CO2, CO, CF3COOH, (CF3CO)2O  and CF4 in traces Formation of HF can be detected at higher temperature 16.05.2013 IAM-WPT 8 Monoclinic Li3FeF6          Oxides and organic redisdues are below detectable limit Formation of binary fluorides (FeF3; LiF) is a crucial problem         Dipl.-Chem. Georg Lieser S.G.: C/2c 16.05.2013 IAM-WPT 9 Preparation of a positive electrode No electrochemical Performance Li3FeF6 + C + Binder + NMP (N-Methyl-2-pyrrolidon)  Literature: 1. Small particles (nanoscale)     2. A good contact with a well conductive agent   Dipl.-Chem. Georg Lieser 16.05.2013 IAM-WPT 10 Dipl. chem. Georg Lieser Li3FeF6 + C + Binder (72/25/3) Reduceing the particle size 1 eq. Li (140 mAh/g)  128 mAh/g (91%) 7 mAh/g (5 %) 16.05.2013 IAM-WPT 11 Li2FeF6−Li (charge)Li3FeF6+Li (discharge)Li4FeF6 Which redox couple is involved ? Dipl.-Chem. Georg Lieser Quantum-chemical calculations :   Too high for common electrolyte systems ! > 6 V (1)  3.0  V Discharge behavior of the 1st and 2nd  cycle is different ! Part of future investigations Li3FeF6+LiLi4FeF6 Li3FeF6−LiLi2FeF6 16.05.2013 (1) J. Kohl et. al, Journal of Materials Chemistry, 22, (2012), 15819–15827 IAM-WPT 12 Long term cycle ability (C/20)   (theoretical capacity 140 mAh/g)     Rate performance test Electrochemcial behavior Dipl. chem. Georg Lieser Even at C/1 50% of the theoretical capacity 91 % of the  theoretical capacity 16.05.2013 IAM-WPT 13 X-ray photoelectron spectroscopy Dipl.-Chem. Georg Lieser The redox couple Fe3+/Fe2+ can be confirmed Li3FeF6±𝐿𝑖𝐿𝑖4FeF6 16.05.2013 IAM-WPT 14 Summary Synthesis of Li3FeF6 without high toxic chemicals Further processing is required to increase the electrochemcial performance Theoretic capacity was nearly reached Intercalation and deintercalation of Lithium is reversible Even at high discharge rates a good capacity can be obtained  Future work: In-situ and ex-situ investigations with different analytical methods (XRD, EXAFS, NMR, Mößbauer)     Lithium transition metal fluorides are suitable as positive electrode  in lithium ion batteries. Dipl.-Chem. Georg Lieser 16.05.2013 Financial support from: 

https://publikationen.bibliothek.kit.edu/230091419/3816284

New synthesis of lithium transition metal fluorides and their use as positive electrode materials in Li-ion batteries

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