Laboratoire de Réactivité et Chimie des Solides Université de Picardie Jules Verne, Amiens, FRANCE
Investigation of Li+ insertion/extraction mechanisms in polyanion-based positive electrodes for Li batteries C. Masquelier
Ch arg e
-
Di
sc
ha
rg
e
Time
+ 4V
2V (311)
(121)
Be
(002)
(221)
Neutrons for Energy, Delft September 17th, 2012
(202)
Li-Ion Battery : Basic Principles
Electrode Positive
e e e -
Li+
Li+
Li+
Tension
e -
Electrode Négative
Electrolyte
Li+
Li+
Li+
Li+
LiCoO2
EC / DMC LiPF6
Capacité
C Graphite
Q
Energy : ∑ (Voltage * Capacity)
One cell : ~3.7 V, 3Ah (AAA)
Amiens
Discharge of a battery : Transformation of chemical energy into electric energy Energy
Li, Carbon
Oxidation à l’électrode negative
-
Li
e-
Li + + e –
E
Reduction à l’électrode positive
N(e)
+ LixMO2 LixFePO4
M n+ + e –
M (n-1)+
The associated structural transformations should be, preferably, REVERSIBLE The Crystal structure of the positive electrode material plays a MAJOR ROLE Amiens
Li-Ion Battery : Figures of Merit Capacity (Ah.kg-1) Capacity (Ah.L-1) Higher S afety
Higher Energy
Energy Density (Wh.kg-1 ; Wh.L-1) Number of Cycles
Higher Rat e
Operating Voltage (V)
Lower Cost
Raw Materials Production Process
Foresight ?
Amiens
The positive attributes of POLYANION-based positive electrode materials.. Tuning the value of a given redox potential (Fe3+/Fe2+ for instance)
2.8 eV
Consequently, the position in Energy of the antibonding states is strongly modified
Li
3.6 eV 3.0 eV
Through the inductive effect of a given polyanion which affects strongly the covalency of the Fe-O bonds (Goodenough, 1988)
e EF
eLiFeO2 Li3Fe2(PO4)3 Fe2(WO4)3
Sulfates have highest operating potentials vs. Li
Fe2(SO4)3
N(e)
A.K. Padhi, K. S. Nanjundaswamy, C. Masquelier, S. Okada, and J. B. Goodenough, J. Electrochem. Soc. 144 [5], 1609-1614 (1997). A.K. Padhi, K. S. Nanjundaswamy, C. Masquelier, J. B. Goodenough, J. Electrochem. Soc. 144 [8], 2581-2588 (1997) C. Masquelier, A. K. Padhi, K. S. Nanjundaswamy and J. B. Goodenough, J. Solid State Chem., 135, 228-234 (1998)
The NASICON Framework as a solid electrolyte NaZr2(PO4)3
Na4Zr2(SiO4)3
Na1+xZr2(P1-x/3Six/3O4)3 c
a
1 site M1
3 sites M2
(PO4)3-
(SiO4)4-
b Max Conductivity for x = 2
The NASICON Framework as an insertion electrode…. 0 V2(SO4)3 Fe2(SO4)3 TiNb(PO4)3
1
2
2.6 V
3
x (Li)
Li2V2(SO4)3
3.6 V
5
4
Li2Fe2(SO4)3
2.5 et 2.2 et 1.5 V
LiTi2(PO4)3
2.5 V
Li3TiNb(PO4)3 Li3Ti2(PO4)3
Li2FeTi(PO4)3
2.8 et 2.5 V
Li3Fe2(PO4)3 LiV2(PO4)3
3.8 V
Li3V2(PO4)3
Li4FeTi(PO4)3 2.8 V 1.7 V
Li5Fe2(PO4)3 Li5V2(PO4)3
Neutrons at the rescue….. Amiens
Phosphates
Fluorophosphates
Silicates
Lix(M,M’)yPO4
LiVPO4F
Li2FeSiO4
LiFe2/3 1/3PO4 + 1/6 Fe2O3
LiFePO4 3
Temperature/ ˚C
4
[010]Pnma
3
290 288
2 286 1
284 282
Pmnb (γII)
200
300
400
Pmnb (γII) : LFS FeO4
[010] P21/n (γs) [10-1]
530 °C
P21/n (γs) : LFS
[001]
280 100
[100]
875 °C
0 0
LiO4
[001]
Mass variation (%)
Lattice volume ( Å )
292
Pmn21 (β)
500
[100] Pmn21: LFS
Temperature (°C)
PhDs S. Hamelet & R. Amisse
PhD J.M. Ateba Mba
PhD C. Sirisopanaporn
with
with
with
C. GREY, R. DOMINKO
L. CROGUENNEC
R. DOMINKO, R. ARMSTRONG
P1-84, P3-140
P2-194
P1-128, P1-87
J. Mater. Chem. 2009 Chem. Mater. 2011
Chem. Mater. 2012 JES 2012
Dalton Trans. 2010 JACS 2011, Chem. Mater. 2011
SiO4
Amiens
FIRST PART Highly defective Li Fey PO4
227 nm
800 nm
60 nm
45 nm 45 nm
9
A typical example of a two-phase reaction LiFeIIPO4 - x e- - x Li+
4,4
160 150 140 FePO 4
ox red
130 120 110 100
90
x FeIIIPO4 + (1-x) LiFePO4 80
70
60
50
40
30
20
10
0
4,2
+
Potentiel vs. Li /Li (V)
4,0 3,8
Extraction of Li+
3,6 3,4 3,2
3,42 V vs Li°
3,0 2,8 2,6 2,4
LiFePO4
2,2 2,0 0,0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1,0
x dans LixFePO4 Amiens
In Situ X-Ray Diffraction during battery operation Co K Radiation, Réflexion - geometry, PSD counter Within a Be-capped cell
Amiens
Two-phase reaction
FePO4
V 6 % V
LiFePO4 18
20
22
24
26
28
30
32
Diffraction Angle, 2(°), CoK radiation Amiens
Downsizing LiFePO4 particles and cristallites (direct precipitation in H2O)
Mechanical or magnetic stirring
H3PO4 ; FeSO4.7H2O ; DMSO LiOH.H2O
pH~7
108°C, patm 500 nm Thermometer
50 nm
C. Delacourt, P. Poizot, C. Masquelier, CNRS-UMICORE Patent, WO Patent WO2007 / 00251 C. Delacourt, P. Poizot, C. Masquelier, ECS Letters. 9, A352 (2006)
Amiens
Intensity (arb. units)
Plot 4multi file Downsizing LiFePO particles and cristallites (direct precipitation in H2O)
« nano » LFP 40 nm
25000
200 Pnma 20000
15000 10nm
« micro » LFP 2 m
10000
200 5000
Pnma
0
20
25
30
35
40
45
50
10nm
55
2theta WinPLOTR-2006 Version: 0.40b
Amiens
Significant deviations from usual crystallographic data are systematically spotted …. Pnma
a
b
c
V
Sample
1 hour
10,297(6)
5,961(3)
4,701(7)
288,6(1)
C
12 hours
10,323(6)
5,983(5)
4,702(3)
290,6(1)
B
Standard
10,337(1)
6,0112(2)
4,6950(2)
291,7(1)
A
FeO6
LiO6
PO4 LiO6 10.337 Å
a
6.011 Å
b Amiens
Rietveld refinement of X-Ray and neutron diffraction data Defects (site exchanges + vacancies) present a (Å) = 10.3007(7) b (Å) = 5.9673(3) c (Å) = 4.7038(1) V (Å3) = 289.13(1)
(Li0.79Fe0.06
13 nm
.9
.9
.8
.8
.7
.7
.6
.6
.5
.5
.4
.4
.3
.3
.2
.2
.1
.1
0
0.1]M2PO4
41 nm
1
z /c
y/ b
1
Intensity (arb. units)
0.15)M1[Fe0.9
0 0
.1 .2 .3 .4 .5 .6 .7 .8 .9
x/a
1
0
.1 .2 .3 .4 .5 .6 .7 .8 .9
1
y/b
2 (º), Co K Amiens
Neutron diffraction + aberration-corrected STEM clearly identifies Fe atoms on Li positions for LiFePO4 prepared at « low » temperature (600°C)
Electrochemistry: Complete change of behaviour !!! 160 150 140 130 120 110 100 90
80
70
60
50
40
30
20
10
0
4,4 4,2
+
Potentiel vs. Li /Li (V)
4,0
Microsize stoichiometric particles : 2-phase plateau
3,8 3,6 3,4 3,2 3,0 2,8
« nano » non-stoichiometric particles : 1-phase (solid solution)
2,6 2,4 2,2 2,0 0,0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1,0
x dans LixFePO4 P. Gibot, M. Casas-Cabanas, L. Laffont, S. Levasseur, P. Carlach, S. Hamelet, J.M. Tarascon, C. Masquelier, Nature Materials, 7, 741-747, 2008
Amiens
In Situ X-Ray Diffraction : Solid Solution at RT !!! 80
(211)
(020)
(301)
(311)
(121)
(a)
70
S40
Vi = 291.7 Å3
Vi = 289.1 Å3
60
Discharge
50 40 30 20 Charge
10 0 2.8
3
3.2
3.4
3.6
Voltage vs. Li (Volt)
30
32
34
36
2 (º), Cu K
P. Gibot, M. Casas-Cabanas, L. Laffont, S. Levasseur, P. Carlach, S. Hamelet, J.M. Tarascon, C. Masquelier, Nature Materials, 7, 741-747, 2008
38
« LiFePO4 » behaves in air with much surprise
6
« micro » LFP
µm-LFP (Air) nm-LFP (Air) nm-LFP (Ar)
Mass Variation (%)
5 4
« nano » LFP ~ 40 nm
3 2 +4.45 %
1 0 -1 0
100
200
300
400
500
600
700
Temperature (°C) S. Hamelet et al., J. Mater. Chem., 19, 3979-3991, 2009 Amiens
Especially « nano » powders….., as soon as ~140°C
295
« micro » LFP 1 µm
290 3
V (Å )
What is going on ? « nano » LFP ~ 40 nm 100nm
285
280
0
100
200 300 400 500 Temperature (°C)
600
700
Amiens
Common belief 3 Li FeII PO4 + O2
Li3 FeIII2 (PO4)3 + ½ Fe2O3 « Anti - NaSICON »
Amiens
Common belief 3 Li FeII PO4 + O2
Li3 FeIII2 (PO4)3 + ½ Fe2O3 « Anti - NaSICON »
More surprising Li FeII PO4 + O2
Li FeIII0.67 □ 0.33 PO4 + 1/6 Fe2O3 « Olivine » 400°C
Pristine a)
227 nm
800 nm
60 nm
45 nm 45 nm
500nm
Selected Mossbauer spectra (among many !!) -3
-2
-1
0
1
2
3
1
Defective « nano » LixFeyPO4
0.98
0.96 0.94 0.92
Absorption
1 0.99 0.98 0.97 0.96 0.95 0.94 1 0.99 0.98 0.97 0.96 0.95 0.94 1 0.99 0.98 0.97 0.96 0.95 0.94 1 0.99 0.98 0.97 0.96 0.95 0.94 -12
Measured Spectrum Calculated fit Fe(III)-1 (08.3%) Fe(III)-2 (01.6%) Fe(II) (90.0%)
Thermal expansion
RT BRT
Defective « nano » LixFeyPO4 Measured Spectrum Calculated fit Fe(III)-1 (02.9%) Fe(III)-2 (58.3%) Fe2O3 (17.5%) Fe(II) (21.5%)
220°C B220
Measured Spectrum Calculated fit Fe(III)-1 (38.3%) Fe(III)-2 (31.4%) Fe2O3 (30.3%)
Redistribution of Fe within M1 and M2 sites
Very highly defective olivine + Fe2O3 ~ Li0.97Fe0.67PO4
400°C B400
Measured Spectrum Calculated fit Li3Fe2(PO4)3(57.8%) Fe2O3 (42.2%)
-4
Extrusion of Fe to yield Fe2O3 as soon as 140°C
Fully oxidized & highly defective LixFeyPO4 + Fe2O3
270°C B270
Measured Spectrum Calculated fit Fe(III)-1 (43.4%) Fe(III)-2 (23.4%) Fe2O3 (33.2%)
-8
Volume contraction
700°C B700 0
V (mm.s-1)
4
8
12
Mixture of Fe2O3 & Li3Fe2(PO4)3
A Closer look at XRD Data …..
Amiens
Sample annealed at 400°C (a = 10.02 Å ; b = 5.85 Å ; c = 4.73 Å ; Pnma)
WDICVOL04 solution (Automatic generated PCR file)
CE
Many peaks are not indexed… 300000
2.68Å
(020) 2.92Å
3.29Å
200000
4.13Å
8.78Å
4.39Å
250000
150000
100000
50000
0
-50000 10 10
15 15
20 25 30 35 40 20 25 30 35 40 2theta Diffraction angle 2θ(°) – λKα Co
45 45
50 50 WinPLOTR-2006 Version:
Amiens
(020)Supercell
Sample annealed at 400°C (a = 10.02 Å ; b = 17.56 Å ; c = 4.73 Å ; Pnma)
10
15 15
20 20
25 30 35 40 45 45 25 30 35 40 Diffraction angle 2θ(°) – λKα Co
50 50
55 55
60
WinPLOTR
Amiens
Sample annealed at 400°C (a = 10.02 Å ; b = 17.56 Å ; c = 4.73 Å ; Pnma) Pristine
Sample annealed at 400°C
Li Fe0.67 □ 0.33 PO4 shows long range ordering along [010] !! S. Hamelet , M. Casas-Cabanas, C. Davoisne, L. Dupont, J.M. Tarascon, C. Masquelier, Chem. Mater., 23, 32-38 (2011)
A Parallel with Fayalite to Laihunite Transformation (OLIVINE-type structure) Known as well as a natural « chemical weathering » process
Amiens
A Parallel with Fayalite to Laihunite Transformation (OLIVINE-type structure)
Triphylite
Fayalite
Li Fe2+ PO4
Fe2+ Fe2+ SiO4
M1
M1
M2 z=0
z = 0.5
M2
z=0
b c
a
M1 site
M2 site
Amiens
A Parallel with Fayalite to Laihunite Transformation (OLIVINE-type structure)
Triphylite
Fayalite
Li Fe2+ PO4
Fe2+ Fe2+ SiO4
M1
M1
M2 z=0
z = 0.5
M2
z=0
2+
3+
Li Fe0.67 □ 0.33 PO4
3+
Fe0.5 Fe □0.5 SiO4
b c
a
M1 site
M2 site
Amiens
A Parallel with Fayalite to Laihunite Transformation (OLIVINE-type structure) b a
c
Triphylite
Fayalite
Li Fe2+ PO4 M1
M2
3+
Fe2+ Fe2+ SiO4
b
M1 site c
a
M1
2+
Li Fe0.67 □ 0.33 PO4
M2 site
M1 site
M2
3+
Fe0.5 Fe □0.5 SiO4
M2 site
Vacant site (occupied with 67% Fe)
b c
a
M1 site
site partly occ. M2 site M1Vacant
Amiens
What about the Electrochemistry ?
C/5 No C-coating
S. Hamelet et al., J. Mater. Chem., 19, 3979-3991 (2009)
Amiens
Sample Air-annealed at 200°C Tension (V vs. Li+/Li0)
4.5 2
4 3.5
6
1
5 3
3 2.5 2 1.5
4 0
5
10
15
20
25
30
35
Temps (h)
35000
30000
6
Temps (h)
25000 30
20000 24 5
15000 18 4
10000 12
3
5000 06 2 0 0 1
15 15
20 20
25 25
30 30
35 35
40 40
Angle de diffraction 2θ(°) – λKα (Co)
45 45
34 50 50 WinPLOTR-2006
Versi
a (Å)
6.05 6 5.95 5.9 4.74 4.73 4.72 4.71 4.7
V(Å3)
10.25 10.2 10.15 10.1 10.05
b(Å)
4.5 4 3.5 3 2.5 2 1.5 0
c(Å)
VOLTAGE
Anisotropic and non-continuous variations of lattice parameters
295 290 285 280 275 0
Sample annealed at 270°C
5
5
10
10
15
15
20
20
25
25
30
30
Temps (h) S. Hamelet & C. Masquelier, submitted, 2012
Amiens
Amiens
SECOND PART
OPERANDO X-Ray (Synchrotron) Diffraction and Absorption out of equilibrium
Typically : 1 pattern recorded on the Image Plate for 10 seconds, every 3 minutes
Amiens
LRCS In-Situ Cell
A reliable in situ cell tested and tested again (very highly reproducible data)
Amiens
3
2
4
4.2
+
Tension (V vs.Li /Li)
4.0 3.8 3.6 3.4 3.2
BAT n°1 BAT n°2 BAT n°3 BAT n°4
3.0 2.8 2.6
C-coated LiFePO4 C rate
1
2.4 0.0
0.2
0.4 0.6 x dans LixFePO4
0.8
1.0
J. B. Leriche et al., J. Electrochem. Soc., 157(5), A606-A610 (2010)
Transmission Réflexion
Operando X-ray diffraction : Li / Electrolyte / LiFePO4 GOAL : Measure electrodes OUT OF EQUILIBRIUM
Amiens
One XRD pattern (recorded within 10 sec.) every 3 min., Wavelength : = 0.727 Å
C/2 rate 8 6
38
4.0 038
Charge
+
2
3.5
Décharge 10
20
0 -2
3.0 00 LiFePO4
FePO4
Current(mA)
Voltage(V vs.Li /Li)
4
-4
LiFePO4
-6
2.5
035 030 025 020 015 010 005 000
-8 0
2 t(h)
Intercalation plateau associated with a two-phase reaction : classical
39
Operando X-ray diffraction : Li / Electrolyte / LiFePO4 #01 LiFePO4
#20
#30
1 Rapport des intensités normalisées
a)
Amiens
0.8 0.6 0.4
(200) C/2 (301) C/2 (200) C/10 (301) C/10
0.2 0 0
0.2
0.4
0.6
x dans Li FePO x
0.8
1
4
#40 -« delay » whatever the diffraction peak observed
FePO4
8
9
10 11 12 13 14 θ °) Diffraction angle (22θ(°) Angle de diffraction
15
- Dépend on cycling rate
Same (apparently !!) « delay » reported in the litterature
Amiens
H.H. Chang, C.C. Chang, H.C. Wu, M.H. Yang, H.S. Sheu, N.L. Wu, Elec. Comm, 10, 2008, 335 Y. Kao, M. Tang, N. Meethong, J. Bai, W. C. Carter, Y.M. Chiang, Chem. Mater., 2010, 22, 5845-5855 J. Liu, M. Kunz, K. Chen, N. Tamura, T. J. Richardson, J. Phys. Chem. Lett., 2010, 1, 2120-2123
OUR finding: no amorphous phase formed
Amiens
The pristine LiFePO4 phase disappears at the same rate than the FePO4 forms (independent refinements…)
I/Imax (200)
1 LiFePO4
0.8 0.6
I/Imax (200)LFP I/Imax (200)FP
0.4 0.2 FePO4
0 0
0.2
0.4 0.6 x dans Li FePO x
0.8
1 42
4
What is at the origin of the apparent delay ? Micro X-Ray Fluorescence gives the clue….
Amiens
Absorption normalisée (u.a.)
Fluorescence
1.6 1.4
Absorption
4
FePO
4
1.2 1 0.8 0.6 0.4 0.2 0 7110
LRCS In-Situ Cell
LiFePO
7115
7120 7125 7130 Energie (eV)
7135
7140
43
13.0
17.0
16.0
15.0
3
x10
14.0
13.0
12.0
18.0
-6000
-0.2
-0.3
14.0
13.0
12.0
-0.2
-0.3
-3000 -2000
-0.5
-1000 0
0
-0.6
-1000
-0.6
0
-3000 -2000
-0.5
Amiens
3
-0.4
-1000
-3000 -2000 -1000
15.0
-0.1
-5000
-0.1
-0.4
0
16.0
0.0
-4000
-6000 -5000 -4000
-6000 -4000
-5000
0.0
17.0
-7000
18.0
-6000
12.0
-5000
13.0
-4000
x10
14.0
-3000
3
15.0
-2000
16.0
-7000
17.0
-7000
-7000
x10 18.0
What is at the origin of the apparent delay ? Micro X-Ray Fluorescence gives the clue…. 18.0
17.0
x10 16.0
15.0
3
14.0
13.0
12.0
0.0
0.0
-0.1
-0.1
-0.2
-0.2
-0.3
-0.3
-0.4
-0.4
-0.5
-0.5
-0.6
-0.6
4.5 12.0
Fe2+ 0.0
4
Charge
-0.1
-0.2
3.5
-0.3
3 -0.4
-0.5
LiFePO4 stœchiométrique 68% Mat. Act. 1C-1D
2.5
-0.6
Fe3+
2 0
0.2
0.4
44
0.6
0.8
1
18.0
17.0
16.0
15.0
14.0
13.0
12.0
18.0
13.0
12.0
-6000 -5000
-0.2
-0.3
-0.2
-0.3
-0.4 -3000
-0.5
-2000
-0.5
-1000
-1000
-1000
0
0
-0.6
0
-0.6
-1000
-3000
14.0
0
-2000
15.0
-0.1
-4000
-6000 -5000 -4000
-6000 -5000 -4000
-0.1
-0.4 -3000
16.0
0.0
0.0
-2000
17.0
-7000
12.0
-6000
13.0
x10 18.0
-5000
14.0
3
-4000
15.0
x10
-3000
16.0
3
-2000
17.0
x10
-7000
18.0
3
-7000
-7000
x10
Amiens
17.0
16.0
3
15.0
-7000
4.5
0.0
-0.1
-0.1
-0.2
-0.2
-0.3
-0.3
-0.4
-0.4
-0.5
-0.5
-0.6
-0.6
3
14.0
13.0
12.0
-6000 -5000
-0.1
-0.2
-0.3
-3000
-0.5
-2000
3.5 3
Discharge
-0.4
LiFePO4 stœchiométric 68% Mat. Act. 1C-1D
2.5
-0.6
Fe3+
15.0
-0.4
-0.3
-0.5
16.0
-4000
4
-0.1
-0.2
17.0
0.0
Fe2+ 0.0
12.0
2 0
0.2
-0.6
-1000
12.0
13.0
0.0
x10 18.0
14.0
0
0
What is at the origin of the apparent delay ? Micro X-Ray Fluorescence gives the clue….
45
0.4
0.6
0.8
1
Inverse delay non homogeneity between charge & discharge 17.0
16.0
15.0
3
14.0 x10
18.0
17.0
16.0
15.0
13.0
x10 14.0
13.0
12.0
0.0
Fe2+
-0.2
16.0
15.0
-0.3
-0.2
-0.3
-0.4 -3000
-0.5
-2000
-0.4
-0.5
-0.6
-1000
-1000
12.0
-0.6
-1000
0
Fe3+
0
-3000 -2000
-3000
-0.6
13.0
-0.1
-0.4
-0.5
14.0
0.0
-4000
-0.3
-4000
-4000
17.0
-5000
-0.1
-0.2
18.0
3
-6000
-0.1
-5000
-5000
-6000
-6000
0.0
-2000
Amiens
12.0
3
-7000
18.0
-7000
-7000
x10
4.5 4 Charge
Discharge
+
Voltage (V vs. Li /Li°)
0
Fe3+
3.5 3 Fe2+
Fe3+ at Center
Fe2+ at Center
Fe2+
2.5 2 -1
-0.5
0 x in Li FePO x
4
0.5
1
Transmission XRD illuminates only limited central area, « delayed » because submitted to smaller internal pressure
Amiens
#01
#20
#30
Transmission -7000
x10
18.0
17.0
16.0
15.0
3
14.0
13.0
12.0
-6000
0.0
-5000
-0.1
-4000
-0.3
-0.4 -3000
#40
-0.2
-2000
-0.5
-1000
-0.6
0
#20
8
9
10 11 12 13 14 Diffraction angle (2 θ °)
15
Réflexion
47
What about highly defective LiFeyPO4 ? Amiens
C/5, no C-coating
What about highly defective LiFeyPO4 ? Amiens
13.0
12.0
18.0
0.2
-0.2
-0.4
16.0
15.0
14.0
13.0
12.0
18.0
0.4
0.3
14.0
13.0
12.0
0.3
0.2
0.1
0.0
-0.1
-0.1
-0.2
-0.2
0.1
0.0
0.0
-2000 -1000
-1000
-0.2
-1000
3
0.3
0.1
-2000
-2000
-2000
x10
15.0
0.4
0.2
-0.6
16.0
0.4
0.2
-0.1
-1000
17.0
-5000
0.0
17.0
-7000
14.0
-6000
15.0
-4000
-5000 -4000 -3000
16.0
Fe2+
3
-3000
-5000 -4000 -3000
17.0
-7000
18.0
x10
-6000
12.0
3
-5000
13.0
x10
-4000
14.0
-7000
15.0
-6000
16.0
-7000
17.0
-6000
18.0
Fe3+
3
-3000
x10
4.5
x10 17.0
16.0
15.0
14.0
13.0
12.0
-7000
18.0
3
0.4
-6000
4
-5000 -4000
3
0.2
0.1
-3000
3.5
0.3
0.0
-2000
-0.1
-0.2
2
-1000
2.5 LiFe1-yPO4 annealed 200°C 68% Mat. Act. 1C-1D
1.5 0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
1.6
49
What about highly defective LiFeyPO4 ? Amiens
Fe3+
C/5 rate (vs. Li°)
Fe2+
SOLID SOLUTION behaviour No « DELAY » HOMOGENEOUS It re-equilibrates ITSELF even at very high rates (5C)
50
THIRD PART TAVORITES A M XO4 B
Tavorite LiFeIIIPO4(OH)
LiVIIIPO4F
An ideal new candidate for Li-ion batteries ? High Voltage ……. 2 e- per Vanadium…… Amiens
The TAVORITE «family» A M XO4 B
M4+
O2-
A = Li, Na ; M = Fe, V, Ti, Mn ; X = P, S ; B = F, OH, O Ti (d0, d1)
V (d1, d2)
LiTiPO4O 1
LiVPO4O 2-4
OHM3+
HVPO4.(OH) (VPO4.H2O)
OHF-
LiTiPO4F 8
Li1
LiVPO4F 4,8-10
Mn (d4)
Fe (d5)
LiMnPO4.(OH) 5
LiFePO4.(OH) 6
HMnPO4.(OH) (MnPO4.H2O)
HFePO4.(OH) 7 (FePO4.H2O) LiFePO4F 8,11
1. Patoux, Masquelier - Chem. Mater. 2002 2. Allen, Jia, Chinnasamy, Mukerjee, Abraham - J. Electrochem. Soc. 2011 3. Saravanan, Lee, Kuezma, Vittal, Balaya - J. Mater. Chem. 2011 4. Ateba Mba, Masquelier, Suard, Croguennec - Chem. Mater. 2012 5. Yang, Hirayama, Yonemura, Kanno - J. Solid State Chem. 2012 6. Marx, Croguennec, Carlier, Wattiaux, Le Cras, Suard, Delmas - Dalton Transactions 2010 7. Marx, Croguennec, Carlier, Bourgeois, Kubiak, Le Cras, Delmas - Chem. Mater. 2010 8. Recham, Chotard, Jumas, Laffont, Armand, Tarascon - Chem. Mater. 2010 8. Huang, Faulkner, Barker, Saïdi - J. Power Sources 2009 9. Ellis, Ramesh, Davis, Goward, Nazar - Chem. Mater. 2011 10. Ateba Mba, Croguennec, Basir; Barker; Masquelier - J. Electrochem. Soc. 2012 11. Ramesh, Lee, Ellis, Nazar - Electrochem. Solid-State Lett. 2010
Li2
Triclinic P-1
Synthesis of homeothypic LiVPO4O and LiVPO4F Amiens
VLiVPO O= 2VLiVPO F 4
LiVIVPO4O
a = 6.7320(1) Å; = 89.843(1) ° b = 7.1942(1) Å; b = 91.272(1) ° c = 7.9204(1) Å; g = 116.886(4) ° V = 343.13(1) Å3; V/Z = 85.78 Å3
LiVIIIPO4F
a = 5.1708(3) Å; = 107.595(3) ° b = 5.3083(3) Å; b = 107.969(2) ° c = 7.2631(4) Å; g = 98.388(2) ° V = 174.36(2) Å3; V/Z = 87.18 Å3
4
Crystal structure of LiVPO4O and LiVPO4F (Neutron Diffraction at ILL)
LiVIIIPO4F
Very regular V-F distances V(1)-F-V(2) angle in LiVPO4F : 132.5°
LiVIVPO4O
Alternatively long and short V-O distances V(1)-O(6)-V(2) and V(2)-O(5)-V(1) angles in LiVPO4O :138.6° and 137.1° respectively
Electrochemistry LiVIIIPO4F LiVIVPO4O IV
V
V PO4F
V PO4O
VIV/VIII
VV/VIV III
LiV PO4F
IV
LiV PO4O
Amiens
Electrochemistry LiVIIIPO4F LiVIVPO4O IV
V
V PO4F
V PO4O
VIV/VIII
VV/VIV IV
III
LiV PO4O
LiV PO4F
III
IV
LiV PO4F
LiV PO4O
VIII/VII VIV/VIII II
Li2V PO4F
III
Li2V PO4O
Amiens
Electrochemistry LiVIVPO4O
LiVIIIPO4F IV
V
V PO4F
V PO4O
VIV/VIII
VV/VIV IV
III
LiV PO4O
LiV PO4F
III
IV
LiV PO4F
LiV PO4O
VIII/VII VIV/VIII II
Li2V PO4F
III
Li2V PO4O
9 key compositions VIVPO4F Li2/3VIV,IIIPO4F LiVIIIPO4F Li2VIIPO4F LixVIV,VPO4O (???) LiVIVPO4O Li3/2VIV,IIIPO4O Li7/4VIV,IIIPO4O Li2VIIIPO4O HUGE difference between the V3+/4+ redox couples in LiVPO4F (4,25 V) and LiVPO4O (~2,2 V)
Intermediate compositions spotted * In-situ cell
In Situ investigation of LiVPO4F Amiens
V3+/4+ V ~ 2.45 V
LiVIIIPO4F
V2+/3+
In Situ investigation of LiVPO4F Amiens
In Situ investigation of LiVPO4F Discharge
LiVPO4F
Charge
Amiens
Li2VPO4F
1
1
71
71
In Situ investigation of LiVPO4F Charge
LiVPO4F
Intermediate composition observed in charge and not in discharge Reversibility of the process
LiVPO4F Li0.67VPO4F
Charge
VPO4F
Discharge
In Situ investigation of LiVPO4F
Intermediate composition observed in charge and not in discharge Reversibility of the process
Charge
Charge
LiVPO4F
LiVPO4F Li0.67VPO4F Li0.67VPO4F VPO4F
VPO4F
Discharge
Intermediate composition observed in charge and not in discharge Reversibility of the process
Discharge Charge
Charge
LiVPO4F
LiVPO4F Li0.67VPO4F Li0.67VPO4F VPO4F
VPO4F
Discharge
VPO4F LiVPO4F
In Situ investigation of LiVPO4F
FOURTH PART Li2MSiO4 (M = Fe, Mn) : two-electrons systems ??
Amiens
Polymorphism in Li2FeSiO4 Amiens
b900
LFS900-γII
25 µm
b200
LFS700-γS
a900 a200
5 µm
LFS900; Pmnb [1,3] a=6.2853(5) b=10.6592(8) c=5.0367(4) Å
LFS200-βII
LFS700; P21/n [2,3] a= 8.2278(1), b=5.0204(6), c= 8.2295(1) Å, β=99.22
100 nm 15
20
25
30
35
40
45
LFS200; Pmn21 a=6.2709(8), b= 5.3382(7), c= 4.9651(7) Å
[1] C. Sirisopanaporn, A. Boulineau, D. Hanzel, R. Dominko, A. R. Armstrong, P. G. Bruce, C. Masquelier, Inorg. Chem., 2010, 49, 7446 [2] S. I. Nishimura, S. Hayase, R. Kanno, M. Yashima, N. Nakayama, A. Yamada, J. Am. Chem. Soc., 2008, 130, 13212. [3] A. Boulineau, C. Sirisopanaporn, R. Dominko, A. R. Armstrong, P. G. Bruce, C. Masquelier, Dalton Trans. 2010, 39, 6310
Amiens
Structures of LFS900 and LFS200 from Neutron data measured at ISIS with A.R. Armstrong LFS200 (βII)
LFS900 (γII)
60
22 20
50
Neutron counts
18
40
obs calc
30 20 10
16 14 12
obs calc
10 8 6 4 2
0
0 0.5
1.0
1.5
2.0
2.5
3.0
0.5
d-spacing / Å 8 4 0 -4 -8
1.0
1.5
2.0
2.5
3.0
d-spacing / Å diff/esd
diff/esd
Neutron counts
Polymorphism in Li2FeSiO4
12 8 4 0 -4 -8
Amiens
Polymorphism in Li2FeSiO4 Amiens
Temperature/ ˚C LiO4
[001] Pmnb (γII)
[100]
Pmnb (γII) : LFS
875 °C
FeO4
[010] P21/n (γs) [10-1]
530 °C
P21/n (γs) : LFS
SiO4
[001]
Pmn21 (β)
[100] Pmn21: LFS
Phase transitions confirmed by DSC and T-controlled neutron diffraction (ISIS)
Polymorphism in Li2FeSiO4 Amiens
LFS@700 (cooled from 900°C and quenched)
31-1
LFS@700 (heated from 400°C and quenched)
31-1
30-1
30-1 -210
020
[ 103 ]mon. [ 120 ]orth.
020
[ 103 ]mon.
Depending on the annealing “history”, presence of intergrowths and/or cation Mixing Spotted by electron diffraction and confirmed through neutron diffraction
Amiens
Lithium environment investigated through NMR Amiens
Each corner of Li-O4 Td connected to 1 Li-O4 , 1 Si-O4 and 1 Fe-O4 Td in all polymorphs LFS@ 200: βII
LFS@ 900: γII
LFS@ 700: γS Li1: shared edge with FeO4 Li2: shared edge with LiO4
All corner sharing
Fe Li
Li2
Li1
shared edge with FeO4
Fe Li
Li1
-7 ppm -72 ppm
-55 ppm -30 ppm
G. Mali, C. Sirisopanaporn, C. Masquelier, D. Hanzel and R. Dominko, Chem. Mater., 2011, DOI:10.1021/cm103193a
Iron environment investigated through Mossbauer Amiens
LFS@ 200: βII
LFS@ 700: γS
All corner sharing
LFS@ 900: γII
1 LiO4 shared edge
LFS200
LFS700
2 LiO4 shared edges
LFS900
Av. FeO bond length 2.076(3) Å
>
2.032(1) Å
>
2.026(1) Å
Degree of Distortion of FeO4
2.3*10-4
<
9.9*10-4
<
12.8*10-4
Inductive effect spotted (first time) in silicates Amiens
Weaker Fe-O bonds Higher voltage for Fe2+ /Fe3+ vs. Li+/Li0 LFS@ 900: γII
LFS@ 700: γS
Fe-O av. = 2.026(1) Å Si-O av. = 1.631(6) Å
Fe-O av. = 2.032(1) Å Si-O av. = 1.632(4) Å
PITT 10 mVmin-1 I < 0.005C
Fe-O av. = 2.076(3) Å Si-O av. = 1.637(1) Å
3.4
g (2.90 V) gS (2.97 V)
+
0
U (V vs. Li /Li )
-1
-dx/dV (V )
LFS200 (3.13 V) LFS700 (3.10 V) LFS900 (3.06 V)
LFS@ 200: βII
1st oxidation
3.2
b (3.10 V)
3.0 2.8
2.4
2.6
2.8 3.0 3.2 + Potential (V vs Li/Li )
3.4
3.6
1.2
1.4
1.6
1.8
2.0
x in LixFeSiO4
C. Sirisopanaporn, C. Masquelier, P. G. Bruce, A. R. Armstrong and R.Dominko, J. Am. Chem. Soc, 2011, 133, 1263.
Conclusions First priorities for electric vehicle applications of Li-Ion batteries :
SAFETY ; Life-time ; Cost ; Power, Energy
Amiens
Conclusions
Amiens
First priorities for electric vehicle applications of Li-Ion batteries :
SAFETY ; Life-time ; Cost ; Power, Energy At first sight, LiFePO4 looked like a pretty « simple » and straightforward crystal chemistry !! It came out from academia (UT Austin, USA)…. and is now considered as the material of choice….. The Tavorite structure (may be also the Triplite) is a serious next contender
Conclusions
Amiens
First priorities for electric vehicle applications of Li-Ion batteries :
SAFETY ; Life-time ; Cost ; Power, Energy At first sight, LiFePO4 looked like a pretty « simple » and straightforward crystal chemistry !! It came out from academia (UT Austin, USA)…. and is now considered as the material of choice….. The Tavorite structure (may be also the Triplite) is a serious next contender Diffraction (Synchrotron XRD, Neutrons) is an essential tool for the search of materials for Li batteries NEW Materials, … Materials stoichiometries, defects, charge ordering, … Magnetic ordering at low T (super-super exchange interactions)
Mechanisms of Li+ insertion/extraction (reversibility, kinetics, …)
Special thanks to….
M. Casas Cabanas
S. Hamelet
J. M. Atebamba
Amiens
C. Sirisopanaporn
R. Dominko (NIC), L. Croguennec (ICMCB)
Silicates and Fluorophosphates
E. Suard J. Rodriguez-Carvajal (ILL)
Neutron diffraction
R. A. Armstrong and P. Bruce (St Andrews)
Silicates
C. Grey and J. Cabana (STONY BROOK)
« Defect » project (NMR)
G. Ouvrard (IMN Nantes) & S. Belin (SOLEIL)
« Synchrotron » project
M. Morcrette & J.B. Leriche (LRCS Amiens)
« Synchrotron » project
and
and
for financial support
