Sodium insertion properties of titanates and related materials as negative electrodes for Na-ion batteries

Transcription

1 International Symposium on Electrical Fatigue in Functional Materials September 2014, Sellin, Rügen Island Sodium insertion properties of titanates and related materials as negative electrodes for Na-ion batteries J. C. Pérez-Flores 1, F. García-Alvarado 1, C. Baehtz 2, M. Hoelzel 3, and A. Kuhn 1 1 Universidad San Pablo CEU, Dept. Chemistry and Biochemistry, Boadilla del Monte (Madrid-Spain) 2 HZDR Dresden-Rossendorf, ESRF (Grenoble-France) 3 FRM II, Technische Universität München, Garching (München-Germany) Session: Batteries I September 15 th,

2 Outline Introduction Li-ion vs. Na-ion batteries Hexatitanate Na 2 Ti 6 O 13 Hollandite TiO 2 Summary 2

3 Volumetric density Introduction Gravimetric density Nexergy ( See for example: Xue-Ping Gao and Han-Xi Yang, Energy Environ. Sci., 2010,3,

4 Advantages of sodium Inexhaustible resources Earth crust Na: ppm Li: 20 ppm Sea water Na: ppm Li: 0.18 ppm Low cost Na 2 CO 3 : 0.11 $/kg ; Li 2 CO $/kg High standard reduction potential ( 2.7 vs NHE) No alloying with Al Sodium based technologies already existing Intercalation chemistry similar to Li abundance_crust/group_1.html M.S Whittingham, Prog. Solid State Chem., 1978, 12, 41. C. Delmas, Solid State Ionics, 1981, 3/4, 165. K.M. Abraham, Solid State Ionics, 1982, 7, 199. T.R. Jow, L.W. Shacklette, M. Maxfield, D. Vernick. J. Electrochem. Soc., 1987, 134, M.M. Doeff et al. Electrochimica Acta, 1990, 40, D.A. Stevens et al. J. Electrochem. Soc. 2000, 147, J. Barker et al. US Patent 2002/ But: - Size +59% (r Li + = 73 pm ; r Na + = 116 pm) - Diffusion coefficient - Solubility of salts 4

5 Electrochemical intercalation into W 18 O 49 Li intercalation Na intercalation A. Martínez de la Cruz et al, J. Mater Chem A. Martínez de la Cruz et al, J. Solid State Chem. 2000

6 Na-ion battery materials Na 4 Fe(CN) 6, PBs WoK January 2014 Ti-oxides Updated from P. Senguttuvan et al., Chem. Mater. 23, 2011, Total results Na-ion battery : 259 ; Anode: 84 ; TiO 2 : 7 6

7 Ti-based oxides: potential new negatives Abundance Low cost of TM Non toxic, environmentally benign Safe in LiB Ti 4+ /Ti 3+ : 1.5V High capacities in LiB ~170 Ah/kg High structural stability ( zero strain ) In LIB: Spinel Li 4 Ti 5 O 12 (LTO) 170 mah/g Ramsdellite Li 2 Ti 3 O mah/g 7

8 New Materials: Na 2 Ti 6 O 13 S.G. C2/m Na: 4i (x,0,z): 100% Å pseudocubic NaO 8 S. Andersson, A. D. Wadsley, Acta Cryst. 15 (1962) Rich ion-exchange chemistry: Na 2 Ti 6 O 13 LiNO 3, 325 C, 180 C Li 2 Ti 6 O 13 H 2 Ti 6 O 13 W. A. England, et al. J. Solid State Chem 49 (1983) J. C. Pérez-Flores et al., RSC Advances 2 (2012)

9 Structural characterization of A 2 Ti 6 O 13 DRX ED SXRD H 2 Ti 6 O 13 H 2 Ti 6 O 13 = Å Li 2 Ti 6 O 13 Li 2 Ti 6 O 13 Na 2 Ti 6 O 13 Na 2 Ti 6 O 13 C2/m Na 2 Ti 6 O 13 Li 2 Ti 6 O 13 H 2 Ti 6 O 13 a (Å) (4) (7) (3) b (Å) (8) (1) (1) c (Å) (2) (2) (2) ( ) (3) (2) (2) V (Å 3 ) (2) (3) (2) J.C. Pérez-Flores et al., Phys. Chem. Chem. Phys., 2012, 14, ; J. C. Pérez-Flores et al., RSC Advances 2, 2012,

10 x/a x/a O Ti Locating the channel ions with NPD rv li2ti6o13 liofilización + intercambio marzo 2010 Difference Fourier synthesis maps using the [Ti 6 O 2 13 ] skeleton x z/c 1.0 rv h2ti6o Na 2 Ti 6 O 13 Li 2 Ti 6 O 13 H 2 Ti 6 O 13 x y=0 y=0.5 y=0.5 z z z x z/c Na-T Li-T H-T R wp % R B % J. C. Pérez-Flores et al., Dalton Trans., 2012, 41,

11 MAS-NMR spectroscopy using 23 Na, 7 Li y 1 H 23 Na C Q 0 7 Li 1 H 0 C Q

12 Lithium insertion in Na 2 Ti 6 O 13 Na 2 Ti 6 O 13 2 reversible Li Capacity: 100 mah/g 2-phase 2-phase R. Dominko et al., Electrochem. Comm. 8 (2006) ; R. Dominko et al. J. Power Sources 174 (2007) ; J. C. Pérez-Flores et al., Phys. Chem. Chem. Phys. (2012) Chemical lithiation: Na 2 Ti 6 O 13 + x C 4 H 9 Li Li x Na 2 Ti 6 O 13 + x/2 C 8 H 18 Li1: 2c (½ ½ ½) Occ. 100% Li1: 2c (½ ½ ½) NPD + 1 Li + 1 Li Li2: 4i (x 0 z) Occ. 50% Na 2 Ti 6 O 13 Li 1.0 Na 2 Ti 6 O 13 Li 2.0 Na 2 Ti 6 O 13 12

13 Sodium insertion in Na 2 Ti 6 O 13 1 reversible Na Capacity: ~ 50 mah/g A. Kuhn et al. (to be submitted) > 5000 cycles Proposed as promising negative electrode material for Na-ion battery A. Rudola et al., Chem. Comm. 49, 2013,

14 Structural characterization of Na 2+x Ti 6 O 13 Ex situ XRD: no significant change Discharged Charged In situ SXRD: little change in lattice parameters Volume change: little 1.3% 14

15 E/V vs. Li + /Li Home-made in situ cell for synchrotron facilities Separator Lithium ( ) Active material (+) Positive case Beam Negative case E Window Na2Ti6O13 ex situ Na2Ti6O13 in situ Li/Na 2 Ti 6 O 13 «Shedding light on the lithium insertion mechanism in A 2 Ti 6 O 13 electrode materials for Li ion batteries using in situ synchrotron diffraction operated in commercial coin cells» SPD Beamline BM20 HZDR ESRF, Grenoble (Project CH-3634). 15

16 Location of sodium channel atoms in Na 2+x Ti 6 O 13 using SXRD Difference Fourier synthesis maps using the [Ti 6 O 13 2 ] skeleton + 1 Na E=0.8 V Na 2 Ti 6 O 13 Na 3 Ti 6 O 13 J. C. Pérez-Flores et al., Dalton Trans., 2012, 41, A. Kuhn et al., (to be submitted) 16

17 + Na + (E=0.8 V) Na 2 Ti 6 O 13 Structural Na: 4i (x,0,z) Na-Na Na 4 Ti 5 O 12 (h.t.): 2.86 Å Å Na 2+x Ti 6 O 13 Inserted Na: 2d (½ 0 ½) occ 100% Na-Na Å instead of Å 17

18 Hollandite TiO 2 Up to 7 known polymorphs of TiO 2 anatase rutile TiO 2 -B TiO 2 -H Y. Xu et al., Chem. Commun. 49, 2013, (A-NC) J.P. Huang et al., RSC Adv., 2013, 3, (B-NT) TiO 2 (H): topotactic oxidation - K + -extraction from K 0.2 TiO 2 (H) bronze 1.) K 2 CO TiO 2 + H 2 10 K 0.2 TiO 2 (H) + H 2 O + CO 2 2.) K 0.2 TiO 2 (H) Ox TiO 2 (H) K Ox Ox=H 2 O 2 (H + ) M. Latroche et al., J. Solid State Chem. 81, 1989,

19 Lithium insertion in TiO 2 (H) 0.5 Li / Ti Capacity: 170 mah/g Coul. efficiency > 99% A. Kuhn et al., Int. J. Inorg. Mat. 1, 1999, A. Kuhn et al., J. Power Sources 81-82, 1999, L.D. Noailles, J. Power Sources 81-82, 1999, Theoretical capacity 1Li (or Na)/f.u. : 335 mah/g 19

20 Sodium insertion in TiO 2 (H) 10 mv/2h V 65:30:5 1M NaClO 4 in PC C/70 1 st 2 nd Rev: 0.25 Na / Ti Rev Capacity: 85 mah/g J.C. Pérez et al., J. Mater. Chem. A, 2014,2, C-related, SEI processes: 0.64 V. vanishes after second cycle Na insertion related processes: 1.23 and 0.47 from second cycle on 20

21 Ex situ XRD study of Na insertion in TiO 2 (H) I4/m I2/m I4/m Discharged state: - Splitting of (110) and (020) - Broadening of peaks J.C. Pérez et al., J. Mater. Chem. A, 2014,2,

22 Structural characterization of Na x TiO 2 (H) In situ SXRD Closely related phases: Volume change only 1.1%! 1) Little angular shifts from ocv to ca. 1 V: single phase region 2) Broadening of peaks from 1 to 0.75 V : two very related phases 3) Below 0.55 V. Solid solution of the monoclinic phase. 22

23 x/a x/a x/a x/a Locating the channel ions in TiO 2 (H) rv na2ti8o Ti2 O4 O2 Li Ti2 Na Ti2 TiO 2 (H) skeleton y=0 y= z/c z/c O2 O4 Ti z/c Li 0.5 TiO 2 (H) Na 0.25 TiO 2 (H) NPD SXRD z/c 23

24 TiO 2 (H) Na 0.25 TiO 2 (H) Li 0.5 TiO 2 (H) d(na-na) is very short O3 Li occ. :100 % Na occ. 50% Recall: 2.721Å in Na 3 Ti 6 O 13 O4 O2 O1 Na Å O3 Li 24

25 Voltage (V, vs. Na + /Na) Summary Capacity (mah/g) Coul. Efficiency (%) Cycling Safety Hard carbon Good Poor Na 2 Ti 3 O 7 2, ? Moderate Moderate Li 4 Ti 5 O Good Good Na 2 Ti 6 O 13 5, High Good Good/moderate NaTi 3 O 6 (OH) xh 2 O Low Moderate TiO 2 -NT ? Moderate Good TiO 2 -A-NC ? Good TiO 2 -B-NT Moderate Good TiO 2 -H Moderate Good/moderate 1 S. Komaba et al., Adv. Funct. Mater. 21, 2011, P. Senguttuvan et al., Chem. Mater. 23, 2011, A. Rudola et al., J. Mater. Chem. A, 2013, 1, Y Sun et al., Nature Comm. 4:1870, 2013, A. Rudola et al., Chem. Comm. 49, 2013, H. Nakayama et al. ECS PRiME Meeting, Honolulu, M. Shirpour et al. Energy Environ. Sci., 2013, 6, H. Xiong et al., J. Phys. Chem. Lett. 2, 2011, Y. Xu et al., Chem. Commun. 49, 2013, J.P. Huang et al., RSC Adv., 2013, 3, J.C. Pérez et al., J. Mater. Chem. A, 2014,2,

26 Summary Na 2 Ti 6 O 13 and TiO 2 (H) have interesting structures for dual Li- and Nainsertion chemistry Na 2 Ti 6 O 13 reversibly inserts 1 Na: 50 mah/g. Improvement of electrode performance is not expected, because of structural space limitations. TiO 2 (H) reversibly inserts 0.25 Na: 85 mah/g. Optimization of electrode (binder, carbon) is important to improve performance. General optimization of cell performance is required: fading, rate capability 26

27 Financial Support is kindly acknowledged: Project S-2009/PPQ/1626 Project MAT C06-01 Thank you for your attention!! 27