designing new polymeric electrolytes for lithium – ion battery applications
TRANSCRIPT
DeDesigning new signing new polymeric electrolytes polymeric electrolytes
for for Lithium Lithium – Ion – Ion Battery ApplicationsBattery Applications
Alistore ERI | www.alistore.eu
OutlineOutline
• Polymer electrolytes advantages and drawbacksPolymer electrolytes advantages and drawbacks
• Composite polymeric electrolytes: fillers and anion receptorsComposite polymeric electrolytes: fillers and anion receptors
• Role of salt anionsRole of salt anions
• New types of imidazole saltsNew types of imidazole salts
• ConclusionsConclusions
Copyrights Marek Marcinek
Li+
PEO
Polymer Electrolytes Polymer Electrolytes
• Electrodonor polymersElectrodonor polymers• O,N,S (sufficient donor ability for O,N,S (sufficient donor ability for
complexation)complexation)• Sufficient distance between sitesSufficient distance between sites• AmorphousAmorphous• Polyethers - good candidatesPolyethers - good candidates• Low Tg (flexibility)Low Tg (flexibility)
General classification General classification Polymer ComplexesPolymer ComplexesPolymer GelsPolymer GelsPolyelectrolytes (Single Ion Conductors)Polyelectrolytes (Single Ion Conductors)
•nonvolatility,•no decomposition at the electrodes,•no possibility of leaks,•use of metallic lithium in secondary cells (lithium dendrites growing on
the electrode surface would be stopped by the non-porous and solid electrolyte),
•lowering the cell price (PEO is cheaper than organic carbonates; it could be used as a binder for electrodes to improve the compatibility of consecutive layers; moreover fabrication of such a cell would be easier –cost),
•strengthening of cells thanks to the all-solid-state construction,•shape flexibility,•lowering the cell weight – non-volatile, all-solid-state cells don’t need
heavy steel casing,•improved shock resistance,•better overheat and overcharge allowance,•improved safety!!!
Solid Polymer Electrolytes AdvantagesSolid Polymer Electrolytes Advantages
low cationic transference number (close to 0.1-0.3) of most conventional P(EO)-LiX polymer electrolytes,
forming of highly resistive layers at the anode-electrolyte interface,
high degree of crystallinity of PEO based electrolytes,
conductivity at ambient temperature not high enough for application in batteries.
Limitations of polymeric Limitations of polymeric electrolyteselectrolytes
Three component systems:Three component systems:
Composite electrolytes
polymer
Lithium salt
filler able to impact ion-ion and ion-polymer interaction
PEO-DME - (Mw=500) dicapped with methyl groups(Mw=500) dicapped with methyl groups
LiClOLiClO44, LiNTFSi, LiCF, LiNTFSi, LiCF33SOSO33, LiI, LiBF, LiI, LiBF44
•Ceramic fillers•TriphenylboraneTriphenylborane•CalixareneCalixarene•Calix[6]pyrolleCalix[6]pyrolle
ConductivityConductivity
PEGME-LiClO4
PEGME-LiClO4 -Al2O3neutral
PEGME-LiClO4 -Al2O3basidic
PEGME-LiClO4 -Al2O3acidic c / mol kg-1
10-5 10-4 10-3 10-2 10-1 100
log
/ S
cm
-1
-7
-6
-5
-4
-3
Viscosity as a function of salt Viscosity as a function of salt concentrationconcentration
c / mol kg-1
10-6 10-5 10-4 10-3 10-2 10-1 100 101
/ P
a s
0.1
1
10
100
PEGME-LiClO4
PEGME-LiClO4 -Al2O3neutral
PEGME-LiClO4 -Al2O3basidic
PEGME-LiClO4 -Al2O3acidic
…and temperature
temperatura/ oC
0 20 40 60 80 100
lepk
oϾ/
Pa
s0,1
1
10
100
PEGME-LiClO4 3 mol kg -1
PEGME-LiClO4-Al2O3 kw. 3 mol kg -1
PEGME-LiClO4-Al2O3 oboj. 3 mol kg -1
PEGME-LiClO4-Al2O3 zas. 3 mol kg -1
PEODME-LiClO4 3 mol kg -1
PEODME-LiClO4-Al2O3 kw. 3 mol kg -1
PEODME-LiClO4-Al2O3 oboj. 3 mol kg -1
PEODME-LiClO4 4 mol kg -1
PEODME-LiClO4-Al2O3 oboj. 4 mol kg -1
Fuoss-KrausFuoss-Kraus
PEGME-LiClO4
PEGME-LiClO4 -Al2O3 neutral
PEGME-LiClO4 -Al2O3 basidic
PEGME-LiClO4 -Al2O3 acidic
c / mol kg-1
10-6 10-5 10-4 10-3 10-2 10-1 100 101
% p
ar j
onow
ych
0
20
40
60
80
100
0
20
40
60
80
100
1e-4 1e-3 1e-2 1e-1 1e+015
20
25
30
35
C / mol * kg-1
T /
oC
% of free ions in PEO-DME neutral system as a function of temperature
0 %20 %40 %60 %80 %100 % 0
20
40
60
80
100
1e-5
1e-4
1e-31e-2
1e-11e+0
15
20
25
30
35
% o
f ion
pai
rs
% of ion pairs in PEO-DME neutral system as a function of temperature
0 %20 %40 %60 %80 %100 %
0
20
40
60
80
100
1e-4 1e-3 1e-2 1e-1 1e+015
20
25
30
35
% of ions triplets in PEO-DME neutral system as a function of temperature
0 %20 %40 %60 %80 %100 %
Changes of the interface resistance in time
Lithium transference numbers for (PEO)20LiClO4 based composite electrolytes containing 10% by weight of inorganic filler additivesType of the electrolyte
Type of the filler Temperature/oC Lithium transference number
(PEO)20LiClO4 Filler free sample 40 0.31
(PEO)20LiClO4 Al2O3 40 0.61
(PEO)20LiClO4 Al2O3 (1% ASG) 40 0.66
(PEO)20LiClO4 Al2O3 (4% ASG) 40 0.72
(PEO)20LiClO4 Al2O3 (8% ASG) 40 0.77
(PEO)20LiBF4 0 70 0.32
(PEO)20LiBF4 Surface modified ZrO2 70 0.81
PEO-based electrolytes transference numberPEO-based electrolytes transference number
CC7272HH9696NN44OO66
MW=1113.56 gr/moleMW=1113.56 gr/mole
Calixarene 1
CC7272HH9494NN66OO1010
MW=1203.55 gr/moleMW=1203.55 gr/mole
Calixarene 2
CC6868HH104104NN44OO66
MW=1073.58 gr/moleMW=1073.58 gr/mole
Calixarene 3
Calix[6]pyrrole
CC7272HH6666NN66
MW= MW= 1014.52 1014.52 gr/molegr/mole
Supramolecular compoundsSupramolecular compounds
Polymer Type Temp (o
C)t+
LiI:PEO7 55 0.51
LiI:PEO7 75 0.56
LiI:PEO7 90 0.51
LiI:P(EO)7 (Calix.2) 0.3 75 0.74
LiI:P(EO)7 (Calix.2) 0.3 90 0.69
LiI:P(EO)7 (Calix.1) 0.3 75 0.35
LiI:P(EO)7 (Calix.1) 0.3 90 0.24
LiI:P(EO)7 (Calix.3) 0.3 75 0.70
LiI:P(EO)7 (Calix.3) 0.3 90 0.33
LiI:PEO20 55 0.35
LiI:P(EO)20 (Calix.2) 1 50 1
LiI:P(EO)20 (Calix.2) 1 75 0.93
LiI:P(EO)20 (Calix.2) 1 90 0.80
LiI:P(EO)20 (Calix.2) 0.3 50 0.51
LiI:P(EO)20 (Calix.1) 0.3 55 0.48
LiI:P(EO)20 (Calix.1) 1 55 0.45
LiI:P(EO)100 90 0.14
LiI:P(EO)100(Calix.1)0.25 90 0.15
LiI:P(EO)100(Calix.1)0.5 90 0.18
Experiment time - 60 minutes, applied voltage 0.01Volt.
Lithium transferrence numbers Lithium transferrence numbers tt++ for for LiI:PEOLiI:PEO77 and and LiI:PEOLiI:PEO2020
Conductivity of the system P(EO)10(LiI)1(Calixarene)x
2,6 2,8 3,0 3,2 3,4 3,6 3,810-11
10-10
10-9
10-8
10-7
10-6
10-5
10-4
10-3 Calixarene 1
tota
l / S
cm -
1
1000T -1 / K -1
x = 0 x = 0.1 x = 0.2 x = 0.4 x = 0.6 x = 0.8
110 100 90 80 70 60 50 40 30 20 10 0
t / °C
Temperature dependence of the bulk conductivity and interphase resistance RSEI of
the LiTf:P(EO)20 and LiTf:P(EO)20(C6P)0.5 Electrolytes
RSEI
Bulk conductivity
Lithium transference numbers for PEO-LiX-Calix-6-pyrrole electrolytes
Type of the electrolyte
Molar fraction of calix-6-pyrrole
Temperature/oC Lithium transference
number
(PEO)20LiI 0 70 0.25
(PEO)20LiI 0.125 70 0.56
(PEO)20LiI 0.25 70 0.75
(PEO)20LiI 0.5 70 0.78
(PEO)20LiBF4 0 70 0.32
(PEO)20LiBF4 0.125 70 0.78
(PEO)20LiBF4 0.25 70 0.81
(PEO)20LiBF4 0.5 70 0.85
(PEO)20LiCF3SO3 0 75 0.45
(PEO)20LiCF3SO3 0.5 70 0.76
Self-diffusion coefficients D and t+ at 363 K
Dpolymer10-8 cm2/s
D-
10-8 cm2/s
D+
10-8 cm2/s
t+
PEO-LiBF4-calixpyrrole
6.51 27.5 24.6 0.47
PEO-LiBF4 3.37 36.1 20.0 0.36
How does it (probably) work?
O OO
O
O
ClO4- Li+
Li+ClO4
-
ClO4-
Li+
Calix
CalixCalix
O
KI>Kcal>KT KI>KT>Kcal Kcal>KI>KT
KI-ion pairs formation constantKT-ionic tiplets formationKcal-calix-anion complex constant
Ion pairs (KA) and Ionic Triplets (KT) formation constans calculated for PEO-LiX (X=I-, CF3SO3
-) electrolytes
SaltKA KT
LiI 3,87x104 130
LiCF3SO3 3,18x104 72
LiBF4 1.75x105 77.69Kcal6-anion=27x103
Cyclic voltammograms of LiTf:PEO20 membranes with and without C6P and SiO2 additives at (a)75˚C and (b)90˚C over potential range
of 0-5.0V using SS/PE/SS cell configurationH. Mazor, D. Golodnitsky, E. Peled, W. Wieczorek, B. Scrosati, J.Power Sources, 178 (2008) 736-743
PEO-based electrolytes additives stabilityPEO-based electrolytes additives stability
Inhibition of crystallization
New Types of Ceramic Composites New Types of Ceramic Composites 1/2 – Concept and Structure 1/2 – Concept and Structure
New Types of Ceramic Composites New Types of Ceramic Composites 2/2 – Preliminary/First!!! 2/2 – Preliminary/First!!!
Electrochemical Testing Electrochemical Testing
Anions:
• are an important part of SEI build-upat +/- electrodes
• Control transport numbers t+ /t-
• Control dissociation and conductivity
• Control aluminium corrosion
AsF6-
BF4-
PF6- SbF6
-
ClO4-
Classics…Classics…
Tendency to decompose according to equilibrium:LiBF4 BF3 + <LiF>
LiPF6 PF5 + <LiF>Fast reaction above 80°C
Destruction of electrolyte and interfaces
Explosive ! Toxic !
Conceptual approach to anion design
“N, C” are favorable:
Weak interactions Li—N but easy oxidation
“O” is not a favorable building block:
Strong Li—O interactions ion pairing, ≠ ClO4-, BOB-
If O present, F or CnF2n+1 is required
Stability Domains
Li4Ti5PO12
LiV3O8
LiMnPO4
LiFePO4
LiCoPO4
Li metal
LiMO2 mixed oxides
Graphite
Fluorinated anions
Non fluorinated anions
Diagonally Diagonally OOpposed pposed IInterests?nterests?
+ -
Enhance the activity of anions (SN)
Li+
Organic chemistry Electrochemistry
Maximize the conductivity
Ionic processes +-
-
- I- = 2,2 Å design of polyatomic
anions
Hückel anions…
X = N, C-CN, CRF, S(O)RF
See P. Johansson et alPhysical Chemistry Chemical Physics, volume 6, issue 5, (2004).
Aromaticity 4n + 2 « » electrons
pKA = 10-60 pKA = 10-20
Gain of > 1 eV by resonance
LiDCTA
NN
N
CNNC
-
DCTA
Stable to 3.8 V (La Sapienza, KZ) inexpensive
NH2H2N
CNNC
ON
O-
NC CN
NN
N--2H2O
Gives quite fluid ILs N
NC CN
NN
N-
Most Stable Lithium Imidazole Configurations
LiTDI LiPDI
B3LYP/6-311+G(d)Scheers et al. 2009
1.88 Å 1.87 Å
1.92 Å
1.93 Å
LiTDI < LiPDI < LiDCTA < LiTFSI < LiPF6
Gas Phase Ion Pair Dissociation Energies
Ion pair (g) Li+ (g) + Anion- (g)
MP2/6-31G(d)
LiTDI LiPDI LiDCTA LiTFSI LiPF6 Scheers et al. 2009
LiTDI (2-trifluoromethyl-4,5-LiTDI (2-trifluoromethyl-4,5-dicyanoimidazole lithium salt)dicyanoimidazole lithium salt)
C
CN
C
N-
CF3
C
C
N
N
Li+
d io x a n e / T
+ L i2 C O 3 / w a te r
C NH2
NH2CN
N O
C
O
C
O
CF3
CF3
+
- Easy, low‑demanding, inexpensive, one‑step, high yield syntheses;
- Salts are pure, stable in air atmosphere, non‑hygroscopic, stable up to 250°C, easy to handle;
New saltsNew salts
- NN
CF3
N N
- NN
C2F5
N N
- NN
n-C3F7
N N
-
N
NN
N
CF3
Li+
Li+
Li+
Li+
LiTDI LiPDI LiHDI
LiTPI
Conductivity in PEO
2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.51E-8
1E-7
1E-6
1E-5
1E-4
1E-3
0.01
cond
uctiv
ity / -1
cm-1
1000/T / K-1
DCTA PDI TDI
SS / PEO20LiX / SS
cooling scan
LiDCTALiPDILiTDI
N
NN
NC CN
Li+
2.4 2.6 2.8 3.0 3.2 3.4 3.61E-8
1E-7
1E-6
1E-5
1E-4
1E-3
0.01
T/°C2139,460,184
C
ondu
cibi
lità
/ S
cm-1
x: 10%
1000T-1 / K-1
111,5
x: 0%
PEO20LiCF3SO3+ ZrO2SACasting
PEO20LiDCTAHot-Pressing
2.4 2.6 2.8 3.0 3.2 3.4 3.61E-8
1E-7
1E-6
1E-5
1E-4
1E-3
0.0121
T / °C39,460,184111,5
Cond
ucib
ilità
/ Sc
m-1
1000T-1 / K-1
PEO20
LiBOB
PEO20
LiBF4
PEO20LiBOB/ LiBF4
Hot-Pressing
2.4 2.6 2.8 3.0 3.2 3.4 3.61E-8
1E-7
1E-6
1E-5
1E-4
1E-3
0.0121
T / °C39,460,184111,5
Con
duci
bilit
à / S
cm-1
1000T-1 / K-1
PEO20
LiDCTA
PEO20
LiBF4
2.6 2.8 3.0 3.21E-6
1E-5
1E-4
1E-3
0.01
Conduct
ivity
S
/ cm
1000 / T K-1
PEO 20
A
PEO 20
B
PEO20LiTDIPEO20LiPDI
Hot-PressingPEO20LiTDIPEO20LiPDI
3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5
0.00
0.05
0.10
0.15
0.20
curr
ent /
mA
/cm
2
Potential / V
DCTA PDI TDI
Li / PEO20LiX / Super P
Anodic breakdown voltage vs. Li
P(EO)20LiDCTA 3.6V
P(EO)20LiPDI 4.0V
P(EO)20LiTDI 4.0V
Anodic stability
LiDCTALiPDILiTDI
0 40 80 120 160 2000
-20
-40
-60
-80
-100
Zim
m /
Ohm
Zreal / Ohm
2h 4.5h 7h 1d 2d 5d 7d 12d
0 40 80 120 160 2000
-20
-40
-60
-80
-100
Zim
m /
Ohm
Zreal / Ohm
2h 4.5h 7h 1d 2d 5d 7d 12d
0 40 80 120 160 2000
-20
-40
-60
-80
-100
Zim
m /
Ohm
Zreal / Ohm
2h 4.5h 7h 1d 2d 5d 7d 12d
LiPDI
LiTDILiDCTA
Li / PEO20LiX / Li
Interphase resistance - PEO
0 3 6 9 12 150
40
80
120
160
200
240
resi
stan
ce /
Ohm
time / d
PDIa PDIb TDIa TDIb DCTAa DCTAb
Interphase resistance - PEOLi / PEO20LiX / Li
LiPDIaLiPDIbLiTDIaLiTDIbLiDCTAaLiDCTAb
Cycling behaviour
Rate capability (PEO)
% o
f ca
paci
ty a
t C
/20
Rate capability (PEO)
% o
f ca
paci
ty a
t C
/20
Research team working on new saltsResearch team working on new salts
Presentation of research teamworking on new lithium salts:
Warsaw University of Technology: - L. NiedzickiL. Niedzicki, J. Syzdek J. Syzdek and W. WieczorekW. Wieczorek – characterization of salts and low molecular weight polyether electrolytes- J. PrejznerJ. Prejzner, P. SzczecińskiP. Szczeciński, M. BukowskaM. Bukowska - synthesis of new salts- A. Błażejczyk, M. KalitaA. Błażejczyk, M. Kalita – synthesis of anion receptors- Z. ŻukowskaZ. Żukowska M. Marcinek M. Marcinek – spectroscopic studies
Universite de Picardie Jules Verne, Laboratoire de Reactivite et de Chimie des Solides- S. GrugeonS. Grugeon, S. LaruelleS. Laruelle - characterization of solid polymeric electrolytes, studies of electrochemical stability and battery performance- and M. ArmandM. Armand – development of new salt systems
Faculty of Chemistry, University of Rome, “ La Sapienza- S. PaneroS. Panero, P. RealeP. Reale and B. ScrosatiB. Scrosati, - characterization of solid polymeric electrolytes; conductivity, transference numbers and electrochemical stability
Department of Applied Physics, Chalmers University of Technology, - J. ScheersJ. Scheers, P. JohanssonP. Johansson, P. JacobssonP. Jacobsson – modeling and spectroscopic studies