Post on 15-Jan-2016
Development of Novel Development of Novel Lithium Salts for Lithium Salts for
Battery ApplicationsBattery Applications
1. Introduction – searching for new salts for lithium batteries
2. Synthesis and characterization of novel family of organic covalent lithium salts
3. Properties of polymer and liquid electrolytes containing newly developed salts:
• conductivity • lithium transference number• formation of ionic aggregates• electrochemical stability • performance in lithium batteries
4. Conclusions
Outline of the presentation
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 décompose 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
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 Å1.87 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
LiHDI-PEO ConductivityLiHDI-PEO Conductivity
1:25 Ea=76.4 kJ∙mol-1 1:50 Ea=121.8 kJ∙mol-1
-8
-7
-6
-5
-4
-3
2,9 3 3,1 3,2 3,3 3,4 3,5
1000·T-1 / K-1
log(
σ / S
·cm
-1)
1:25 Li/O1:50 Li/O
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
LiLiTDI-PEGDME500 ConductivityTDI-PEGDME500 Conductivity
-6
-5,5
-5
-4,5
-4
-3,5
-3
-2,5
2,9 3 3,1 3,2 3,3 3,4 3,5 3,6
1000·T-1 / K-1
log(
σ / S
·cm
-1)
2M1M0.33M0.1M0.033M0.01M
Transference numbers in Transference numbers in PEGDME 500PEGDME 500
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
-1 0 1 2 3 4 5
-log(c / mol·dm-3)
t +
LiTDI
LiPDI
LiHDI
Cation transference number vs. Cation transference number vs. Ionic conductivity (PEGDME 500)Ionic conductivity (PEGDME 500)
Salt Ionic Conductivity
at 1 mol·dm-3 / mS·cm-1
Transference Number at
1 mol·dm-3
LiTPI 0.05 0.61
LiHDI 0.20 0.21
LiPDI 0.26 0.21
LiTDI 0.28 0.17
LiTDI-PEGDME500LiTDI-PEGDME500Stability vs. Lithium against timeStability vs. Lithium against time
0
200
400
600
800
0 200 400 600 800t / h
R /
Ω·c
m-1
1. sample2. sample3. sample
LiLiTDI-PC ConductivityTDI-PC Conductivity
-5
-4,5
-4
-3,5
-3
-2,5
2,9 3 3,1 3,2 3,3 3,4 3,5 3,6
1000·T-1 / K-1
log(
σ / S
·cm
-1)
1M0.25M0.1M0.033M0.01M0.0033M0.001M
LiLiHDI-PC ConductivityHDI-PC Conductivity
-5,5
-5
-4,5
-4
-3,5
-3
-2,5
2,9 3 3,1 3,2 3,3 3,4 3,5 3,6
1000·T-1 / K-1
log(
σ / S
·cm
-1)
1M0.33M0.1M0.033M0.01M0.0033M0.001M0.00033M
LiLiTDI-PC Molar ConductivityTDI-PC Molar Conductivity
0
10
20
30
40
50
0 0,2 0,4 0,6 0,8 1
c0.5 / mol0.5·dm-1.5
Λ /
S·c
m2 ·m
ol-1
20°C40°C60°C
LiLiHDI-PC Molar ConductivityHDI-PC Molar Conductivity
0
2
4
6
8
10
12
0 0,2 0,4 0,6 0,8 1
c0.5 / mol0.5·dm-1.5
Λ /
S·c
m2 ·m
ol-1
20°C40°C60°C
LiTDI-PC Fuoss-Kraus formalismLiTDI-PC Fuoss-Kraus formalism association estimation association estimation
0
20
40
60
80
100
0 1 2 3 4 5
-log(c) / mol·dm-3
% o
f io
ns /
ion
pair
s / t
ripl
ets.
ion pairstriplets"free" ions
LiLiHDI-PC Fuoss-Kraus formalismHDI-PC Fuoss-Kraus formalism association estimation association estimation
0
20
40
60
80
100
0 1 2 3 4 5
-log(c) / mol·dm-3
% o
f io
ns /
ion
pair
s / t
ripl
ets.
"free" ionsion pairstriplets
Transference NumberTransference Numberss in PC in PC
0,0
0,1
0,2
0,3
0,4
0,5
0 1 2 3 4 5
-log(c / mol·dm-3)
t +
LiTDILiPDILiHDI
Salts-PC Stability vs. LithiumSalts-PC Stability vs. Lithium
-0,1
-0,08
-0,06
-0,04
-0,02
0
0,02
0,04
0,06
0,08
0,1
0 1 2 3 4 5
E / V vs. Li
j / m
A·c
m-2
LiTDILiPDILiHDI
LiTDI LiTDI Conductivity in EC:DMCConductivity in EC:DMC
-4
-3,5
-3
-2,5
-2
-1,5
2,9 3 3,1 3,2 3,3 3,4 3,5 3,6
1000·T-1 / K-1
log(
σ / S
·cm
-1)
1M0.33M0.1M0.033M0.01M
Conductivities (20°C)
Ragone Signature
Anodic limit (Pt, EC-DMC)
Anodic limit (Al, EC-DMC)
Charge profile 4.3 V cut-off, Al collector
Cycling LiMn2O4 4.3 V (EC-DMC)
Swagelok cell , Al plunger
New imidazole-derived saltsNew imidazole-derived salts• 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;• 20°C ionic conductivity exceeds:
10‑3 S∙cm-1 in PC, 10‑4 S∙cm‑1 in PEGDME50010‑6 S∙cm‑1 in PEO (10‑4 S∙cm‑1 at 40°C)6 mS∙cm‑1 in EC:DMC
• T+ at ionic conductivity maximum reaches:0.45 in PC, 0.40 in EC-DMC, 0.25 in PEGDME500 (but overall max 0.62);
• Stable over time against Li;• Stable up to 4.4 V vs. Li against metallic lithium anode;• Stable up to 5.0 V vs. Li against aluminum;• Much smaller association rate than commercially available salts;
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 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- - Z. ŻukowskaZ. Żukowska – 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
For inquiries about For inquiries about buying LiTDIbuying LiTDI
(lithium 4,5-dicyano-2-(lithium 4,5-dicyano-2-(trifluoromethyl)imidazolate)(trifluoromethyl)imidazolate)
please contact:please contact:Leszek NiedzickiLeszek Niedzicki
asalm@ch.pw.edu.plasalm@ch.pw.edu.pl
- NN
CF3
N N
Li+
LiTDI