Ionic Liquid Electrolyte Development

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    Ionic Liquid-based Electrolytes for Next Generation Batteries

    Stefano PasseriniUniversity of Muenster, Institute of Physical Chemistry, Corrensstr. 28/30 Muenster

    Germany

    Beyond Lithium Ion, June 5, 2012

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    Muenster

    ElectrochemicalEnergy

    Technology

    Research Groups:

    Prof. Martin Winter

    Prof. Stefano Passerini

    Young Researcher Groups:

    Dr. Alexandra Lex-Balducci (2009 -)

    Dr. Andrea Balducci (2009 -)

    Dr. Jie Li (2012 -)

    50 Ph.D. Students

    30 Scientists with Ph.D.

    10 Bachelor Students

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    Ionic Conductivity in IL-based Materials for

    Energy Storage

    Liquid electrolytes

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    Ionic Conductivity in IL-based Materials for

    Energy StoragePolymer electrolytes

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    Li Ion Batteries Initiated a Technical Revolution....

    and might be ready for more

    20051990 by SonyMarket Introduction

    medium

    0.7Bio (2008) 7Bio (2008)Market Size

    LEV, Power ToolsConsumer

    Applications

    ModerateMinimalChances for

    Newcomers

    Realization hasto be proven

    Very large

    Stationary Elec.

    Storage

    Depends on

    starting position

    100 10.0000.1 10.001 0.1Typ. Battery-Size

    (kWh)

    2012/15(mostly HEV)

    large

    25Bio (2020)

    Automotive

    HEV & EV

    (Very) Good

    1 100

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    Conductivity

    Vapor pressure

    Environment - friendly

    Film forming ability (SEI)

    Electrochemical stability window

    Temperature range of use

    Electrolyte System

    State of the art:

    Organic solvent-based electrolytes

    LiPF6, EC, DEC, additives

    Key-role of Electrolyte in Li-Ion Batteries

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    Separator

    SEI

    Neg.

    CurrentCollector(Cu) P

    os.CurrentCollector(Al)

    Anode CathodeElectrolyte

    Li-Ion cells: Role of the SEI film

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    However ..

    Safety of present Li-ion cells is still an open issue

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    LixC6 + LiyMOz C6 + Li(y+x)MOz

    Cu Graphite SEI org. Electro lyte Film Cathode Al

    Li+

    X-

    "Full" "Empty"

    Or

    " Empty"

    LixC6 Li+ Li+ LiyMOz

    Towards Safer Batteries:

    What do we learn from LIBs?

    Key Step Forward: Replacement of volatile, flammable and

    electrochemically unstable electrolyte components

    Room temperature molten salts (Ionic Liquids)

    PYR14FSI

    Ionic Liquid-based

    Electrolyte

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    butyl conformations found in

    various crystal structures

    well-know flexibility of the TFSI- anion

    between 2 low-energy conformations

    Ion Conformational Changes

    Weak interactions due to large cation and anion

    delocalization and low tendency to crystallize due toflexibility (anion) and dissymmetry (cation)

    Ionic Liquids Low Temperature Melting Salts

    Salts, or mixtures of salts (composed solely of ions), which are liquidat low temperatures (< 100C) often below RT

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    0 sec

    ORGANIC ELECTROLYTE IONIC LIQUID ELECTROLYTE

    0 sec

    2 sec

    3 sec

    Flammability: Organic electrolyte vs. Ionic

    Liquids

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    Ionic Liquids (IL, RTIL, RTMS, etc.)

    Properties

    Wide electrochemical window

    Wide liquid range

    Very low volatility at ambient

    pressure

    Good thermal stability

    High ionicity

    Co-salts for

    solid-state

    polymer electrolytes

    Solvents for

    liquid electrolytes

    Thousands of possible ILs available

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    PYR13TFSI ionicliquidImpurities: < 100 ppm

    Water: < 10 ppm

    Clear, uncolored

    G.B Appetecchi et al., JES 153(9) (2006) A1685.

    Synthesis of Ionic Liquids

    N

    I-

    +N

    I+ethyl acetate

    filtration

    N

    TFSI-

    +

    LiTFSI aq.

    phase separ.

    purification

    AC & Al2O3

    Li = lithium

    PYR1A = N-alkyl-N-methylpyrrolidinium

    TFSI = bis(trifluoromethanesulfonyl)imide, (CF3SO2)2N-

    FSI = bis(fluorosulfonyl)imide, (FSO2)2N-

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    Boosting PerformanceCombining Ionic Liquids

    PYR13FSI (m.p. -10C) - PYR14TFSI (m.p. -5C)

    Mixtures have much lower

    melting temperatures than

    constituent Ionic Liquids

    due to additional ion

    mismatching

    Castiglione et al. JPC B113, 10750 (2009), Zhou et al. JPC C 114, 6201 (2010), Kunze et al. JPC C 114, 12364 (2010)

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    Are ionic liquids capable of dissolving Li salts?

    PYR13TFSI - LiTFSI

    Yes, but only at low Li concentration because new crystalline phases are

    formed for high Li contentHendersonetal.Chem.Mater.16,2881(2004)

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    Aggregation of Pyr1NTFSI ILs (NMR, Raman)

    N+

    CH3

    CH3

    N+

    CH3CH3 Pyr13

    +

    Pyr18+

    Pyr14+

    Pyr15+

    Pyr16+

    Pyr17

    +

    N-

    S S

    CF3 CF3

    OO

    OO

    TFSI

    polar&

    chargedregion

    nonpolar

    region

    chargecompensation

    Pyr

    TFSI

    TFSI

    TFSI

    TFSI

    variation of sidechain length

    Pyr1[2O1]+

    TFSI

    variation of sidechain type

    Pyr1[2O2]+

    nonpolarsidechains polarsidechains

    N-

    S S

    CF3 CF3

    OO

    OO

    N+

    CH3

    CH3

    N+

    CH3

    CH3

    N-

    S S

    CF3 CF3

    OO

    OO

    TFSI

    Li+

    Effect of Li+

    cation

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    Local Motion in Ionic Liquids:

    NMR characterization (Two Step Model)

    s >> 1:

    R1 only influenced by fast bond rotationsin the molecule that take place during the

    time f not influenced by aggregation of

    molecules

    R2 is largely influenced by the slowreorientations and experiences the

    molecular aggregation

    2 22 2 2 222

    11 1

    fs

    s f

    J S S

    23cos 12

    S

    22 2

    2 1

    9

    20s

    R R R S

    Wennerstrm,H.,etal.J.Am.Chem.Soc.101,68606864(1979)

    spectraldensity:

    fcharacterizes the fast internalmotions (bond rotations)

    s describes rotational tumbling

    of the molecule

    spinlattice and spinspin relaxation of a

    surfactant are sensitive to fast local

    motions and slow motions, respectively

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    0

    2

    4

    6

    8

    10

    12

    +LiTFSI+LiTFSI+LiTFSI

    Pyr14

    TFSI Pyr15

    TFSI Pyr16

    TFSI

    R(

    2H

    )/s-1

    Pyr(x)TFSI

    R1

    R2

    R

    Pyr13

    TFSI

    +LiTFSI

    0.00

    0.05

    0.10

    R/

    NMR measurements: T1 and T2 vs x (in Pyr1xTFSI)

    Typical behavior of micelles indicating the formation of aggregates

    Aggregation in Pyr1xTFSI

    R1 independent on chain length

    fast local motions not influenced

    R2 dependent on chain length

    slow local motions influenced

    two different linear dependences different aggregation

    mechanisms

    In presence of Li+ R differs from 0

    already for propyl chain

    Li forces cation aggregation

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    Pyr15TFSI

    Aggregation type?

    Pyr14TFSI

    increaseofthe

    numberof

    cations

    inanaggregate

    increaseofthe

    numberof

    cations

    inanaggregate

    Pyr13TFSI Pyr16TFSIPyr18TFSI

    increaseofaggregatesize

    dueto

    increasing

    chainlength

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    Raman measurements

    The aggregation isconfirmed by the shift of

    characteristic Raman peaks

    Aggregation in Pyr1xTFSI

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    Cation aggregation: Li+ --- TFSI- ion-pairing

    nin Li TFSI n

    increase of anions,

    which surround the Li+

    @ 742 cm-1 expansion and

    contraction of the whole TFSI-anion

    @ 748 cm-1 damped TFSI-anion

    expansion and contraction due to

    Li+ clustering

    increase of mode @ 748 cm-1 with

    increasing side chain length

    more anions are clustering the Li-

    cation when more Pyr-cations

    cluster with themselves

    M. Kunze, et al., Adv. En. Mat. (2011) 1,1

    LiTFSI LiTFSI

    Li---TFSI

    Li---TFSI

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    PYR+1x aggregate formation in presence of Li+

    increase of the

    number of cationsinanaggregate

    increaseofthe

    numberof

    cations

    inanaggregate

    increaseofaggregatesize

    dueto

    increasing

    chainlength

    Pyr13TFSI Pyr14TFSI Pyr15TFSI Pyr16TFSIPyr18TFSI

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    Paillard et al., JES 156, A891(2009) Zhou et al. JPC C 114, 6201 (2010)

    Sub-ambient temperature

    melting electrolytes

    The electrolytic mixture

    0.85 PY14FSI - 0.15 LiFSI

    melts below -40C

    The electrolytic mixtures with

    x> 0.15 show only glasstransition below -60C

    x LiFSI (1-x) PYR14FSI

    Tailored electrolyte: Li salt in PYR14FSI

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    High ionic conductivity at

    sub-ambient temperaturesWide Electrochemical Stability

    Window (ESW)

    LiFSI PYR14FSI mixtures for electrolytes

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    ANODE: Li4Ti5O12 (LTO)

    CATHODE: LiFePO4 (LFP)

    BINDER: CMC

    ELECTROLYTE: 0.1LiTFSI 0.9 PYR14FSI

    ILLIBATT Prototype

    Active material loading: 0.6 0.8 mAh/cm2

    Total Capacity: 0.7 0.8 Ah

    Stack (12 layers) of bipolar electrodes

    Ionic Liquid-based Lithium-ion Batteries

    ELECTROLYTEELECTRODES PROTOTYPESTACK OF ELECTRODES

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    Li-Ion cells (LFP-LTO) with Ionic Liquid-based Electrolytes

    Very promising

    cycling performance

    LTO/ 0.9PYR14FSI 0.1LiTFSI / LFP

    Pouch Cell, glass fiber, 20CCMC binder aqueous slurries Al collectors

    Appetecchi G. B, et al.J. POWER SOURCES 196, 6703-6709, 2011

    Vacuum test

    1- Two identical vacuum sealed cells differing only for the electrolyte

    2- The cells are placed under the same vacuum level

    ORGANIC ELECTROLYTE IONIC LIQUID

    Operation under

    vacuum

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    Aluminum in PYR14TFSI - LiTFSI electrolytes

    0 40 80 120

    0,00

    0,05

    0,10

    0,15

    0,20

    0,25

    0,30

    j/mAcm

    -2

    t/min

    PC-LiTFSI

    80wt% PYR14

    TFSI + 20wt% PC + LiTFSI

    PYR14

    TFSI -LiTFSI

    0 200 400 600

    0,00

    0,01

    0,02

    0,03

    0,04

    0,05

    j/mAcm

    -2

    t/min

    PC-LiTFSI

    80wt% PYR14

    TFSI + 20wt% PC + LiTFSI

    PYR14

    TFSI -LiTFSI

    (80%PYR14TFSI-20%PC)-LiTFSI PYR14TFSI-LiTFSIPC-LiTFSI

    Chronopotentiometry at 4.6 V vs. Li/Li

    Al corrosion suppressed with TFSI-based electrolytes1 R.-S. Khnel,et al, J. Power Sources, in press (2012)

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    HighVoltageElectrodes:ILvs [email protected]

    Very high capacity after long-term cycling

    High coulombic efficiency (pract. 100%)

    Li / Electrolyte / Li[Li0.2Mn0.56Ni0.16Co0.08]O2Pouch Cell @ 40C and C/2

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    High-Energy (Next-Generation) Battery Technologies

    >500 Wh/kg RevolutionaryTechnology-

    Change

    Pb-acid 3000 kgNi-MH 1200 kg

    Super- Battery < 200kg

    Li-ion Batteries

    Year

    Present 2017

    170 Wh/kg*

    250 Wh/kg*Estimated

    limit of

    Lithium-Ion

    Technology

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    "4V"

    Li-Ion

    Oxide

    Cathodes

    Li-Element batteries

    1

    2

    3

    4

    5

    6

    250 500 750 1000 1250 1500 1750 40003750

    Potentia

    lvs.

    Li/Li+

    0

    0

    Capacity / Ah kg -1

    Li

    metal

    O2 (Li2O)

    F2

    S

    O2 (Li2O2)

    Lithium-Element

    Battery Cathodes

    Theor. Energy: 3000-5000 Wh/kg

    4 Li + O2 2 Li2O E = 2.91

    V

    2 Li + O2 Li2O2 E = 3.10V

    Combustion Energy of Gasoline

    Theor. Energy: 13500 Wh/kg

    Practical Energy: 2700 - 3000 Wh/kg

    C8H18 + 25/2 O2 8 CO2 + 9 H2O

    CO2

    CO2 + H2O

    Gasoline

    Li2O

    Li2O2

    Li

    13500

    3750

    3000

    11700

    5200

    3500

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    Anode

    (Li/LixSi)

    Li+ ion

    conducting

    electrolyte

    -

    Li+Li

    Li2O/Li2O2

    AirLi+

    V I

    Oxygen

    harvesting

    Lithium-electrolyte

    interface

    KEY ISSUES OPEN

    Oxygen Redox

    reaction

    Target:

    500Wh/Kg & 200W/kg at the

    battery pack

    Li-Air batteries: Splitt ing the Issues

    O2

    Participant organisation name Country

    Westfaelische Wilhelms-Universitaet Muenster (WWU) DE

    Tel Aviv University (TAU) IL

    Consejo Superior de Investigaciones Cientificas (CSIC) ES

    Kiev National University of Technology and Design (KNUTD) UKR

    University of Bologna (UNIBO) IT

    University of Southampton (SOTON) UK

    SAES Getters S.p.A. (SAES) ITChemetall DE

    AVL List GmbH (AVL) AT

    Volkswagen (VW) DE

    European Research Services GmbH (ERS) DE

    EU Project LABOHRFP7-2010-GC-ELECTROCHEMICAL STORAGE265971

    Conventional electrolytes based on carbonates and ethers have beenruled out because of insufficient stability for ORR

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    FFO

    O

    O

    O

    SSN

    -

    F

    F

    FF

    F

    FO

    O

    O

    OSS

    N-

    FF

    F

    F

    F

    F

    F FF

    FF

    F

    O

    O

    O

    OSS

    N-

    F

    F

    FF

    F

    F

    F

    FF

    F

    O

    O

    O

    O

    SSN

    -

    CH3CH3

    N+

    CH3OCH3

    N+

    4 anions vs. 2 cations

    FSI BETI

    TFSI IM14

    PYR14+

    PYR12O1+

    Investigated ILs for Li-Air cells

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    0 50 100 150 200

    -20

    -15

    -10

    -5

    05

    10

    15

    20

    Stripping on Nio

    Plating on NioC

    ellOvervoltage(mV)

    Cycle Number

    0.25mAcm-2

    at 20oC

    -20

    -15

    -10

    -5

    0

    5

    10

    15

    20

    190th

    100th

    150th

    50th

    1st

    0.25mAcm-2

    at 20oCC

    ellOvervoltage(mV)

    Cycle

    0 5 10 15 20 250

    5

    10

    15

    20

    25

    -jZ''(cm

    Z'(cm2)

    After 180 cycles

    Li plating/stripping from IL-based electrolytes

    Li / 0.1LiTFSI-0.9PYR14FSI/Ni (20C, 0.25 mAcm-2, sealed cell)

    Very promising cycle performance

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    Li plating/stripping from IL-based electrolytes

    Li / 0.1LiTFSI-0.9PYR14FSI/Ni (20C, various current rates,sealedcell)

    Limited rate performance

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    Li plating/stripping from IL-based electrolytes

    Li / 0.1LiTFSI-0.9PYR12O1TFSI/Li (60C sealed cell)

    Open challenge: 1 mAcm-2

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    Effect of (dry) air on Lithium plating/stripping

    Li+

    Li / IL / Ni

    Li+

    Li / IL / Ni

    e- e- 10h plating at 0.1 mA cm-2

    Cycles of 1h stripping / 1h plating

    0.1 mA cm-2, Vcut-off= 0.5V

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    Pyr12O1 FSI: LiTFSI 9:1 (open dry air)

    Good cycling performance even in presence of air

    PYR14 is more stable than PYR12O1 in dry air

    Pyr12O1FSI: LiTFSI 9:1

    20C

    37 cyclesEff = 86.4%

    Pyr14FSI: LiTFSI 9:1

    20C

    59 cycles

    91.5%

    Lithium Metal Polymer Batteries (LMPBs)

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    Lithium Metal Polymer Batteries (LMPBs)

    10-2 Scm-1

    10-3 Scm-1

    10-6 Scm-1

    10-7 Scm-1

    Organic Liquid Electrolytes

    Room T

    conductivity

    10-4 Scm-1

    Polymer + LiX

    10-5 Scm-1- no liquid compounds

    - high safety

    - high energy density

    - very good processabil ity

    but . poor RT conductivity

    Incorporation of ILs has resulted in high ionic conductivity SPEs

    Polymer + LiTFSI

    large

    anion X-

    IL

    Polymer + LiX+ Ionic Liquid*

    J.-H. Shin, et al.. Electrochem. Comm. 2003, 5, 1016. Ionic liquids to the rescue? Overcoming the ionic conductivity limitations of polymer electrolytes.

    PEO LiX IL electrolytes: SPEs

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    PEO-LiX-IL electrolytes: SPEs

    Poly(ethylene oxide)

    PEO, n ~ 91.000Molecular weight ~ 4 Mio.

    Composition is given as:Molar ratio of P(EO) : Li salt : IL

    [ 20 : 2 : 4 ]

    Li TFSI PYR14TFSI Benzophenone

    Good adhesiveness

    Excellent mechanical properties

    PEO-LiX-IL electrolytes: conductivity and

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    PEO LiX IL electrolytes: conductivity and

    stability

    Laminated, vacuum

    sealed Li/SPE/Ni cells

    wide ESW

    High ionic conductivity

    Excellent mechanical, chemical

    and electrochemical stabilities

    high chemical stability

    Laminated, vacuum

    sealed Li/SPE/Li

    cells

    PEO : LiTFSI : PYR14TFSI = 20:2:4 (mol)

    Lithium metal electrode operation appears

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    Lithium and

    electro lyte layers Bipolar cathode Cell stack

    Vacuum Sealed Cell

    Lithium metal electrode operation appears

    feasible in IL-based electrolyte

    Li/ IL-based electrolyte/ LFP1Ah prototype

    B tt t t PEO IL LiX l t l t (RT t t )

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    Li / P(EO)10LiTFSI-PYR14TFSI / LiFePO4

    Very large capacity increase due to IL incorporation > 100 mAhg-1 at 20C

    Theoretical capacity (170 mAhg-1) at 30C

    Battery tests: PEO-IL-LiX electrolyte (RT tests)

    PEO-LiX-IL electrolytes

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    PEO LiX IL electrolytes

    How do ILs enhance Li+ conduction?

    TFSI-

    Li+

    PEO host

    Li+

    Li+

    TFSI-

    PYR+

    PYR+

    TFSI-

    PEO-LiX electrolyte: Li+ is strongly

    coordinated by PEO host

    PEO-LiX-IL electrolyte:solid ternary system composed by a polymerhost (PEO) and two salts (LiTFSI and

    PYR14TFSI)

    very weak interactions between PYR14+ andTFSI- [1]

    no interaction between PYR14+ and PEO host(Raman & NMR) [2,3]

    strong interactions between Li+ and TFSI-(in excess)

    the strength of the Li--PEO

    coordination lowered

    the lithium mobility (Li+ conduction)

    is promoted

    1M. Castriota, T. Caruso, R. G. Agostino, E. Cazzanelli, W. A. Henderson, and S. Passerini,J. Phys. Chem. A 109 (2005) 922I. Nicotera, C. Oliviero, W. A. Henderson, G. B. Appetecchi, and S. PasseriniJ. Phys. Chem. B 109 (2005) 22814.

    M. Joost et al Electrochim. Acta in ress 2012

    PEO-LiX-IL electrolytes: Li interface (40C)

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    y ( )

    Impedance is localized at the Li/SPE interface

    R1 R2

    CPE1

    CPE2

    R3

    W1 C1

    R1 = bulk electrolyte resistance

    R2 = Li/SPE interface 1CPE1 = Li/SPE interface 1

    R3 = Li/SPE interface 2

    CPE2 = Li/SPE interface 2

    W1 = Warburg impedance

    C1 = electrode limit capacitance0 150

    ___ Raw Data

    ___ Fit

    Z

    -jZ

    Li / P(EO)20(LiTFSI)2(PYR14TFSI)n / Li

    Transport properties by DC tests

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    p p p y

    How much current can be flown through the SPE?

    Lithium

    SPE

    Galvanostatic and

    Potentiostatic

    experiments

    Capacity of Li foil (Chemetall):

    50 m * 1 cm = 5mm 10.32 mAh/cm

    T t ti b l t ti t t (30 C)

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    Transport properties by galvanostatic tests (30C)

    IL containing electrolytes perform well at 30C

    Dendrites due to

    inhomogeneity of

    ionic conduction

    Li / P(EO)20(LiTFSI)2(PYR14TFSI)n / Li

    Transport properties by potentiostatic tests (30 C)

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    Transport properties by potentiostatic tests (30C)

    Good agreement between galvanostatic and potentiostatic results

    Li / P(EO)20(LiTFSI)2(PYR14TFSI)4 / Li

    0.05 mAcm-2 @ 0.2 V

    Transport properties by DC tests

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    p p p y

    Complete stripping of 50 m of lithium (ca. 10 mAh cm-2)

    Li / P(EO)20(LiTFSI)2(PYR14TFSI)n / Li

    bottom

    lithium

    SPE,

    slightly

    oxydised

    Left overedge of top

    lithium

    Area of

    stripped

    lithium

    Lithium

    SPE

    Transport properties by DC tests

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    Opened cell after full lithium plating

    Li / P(EO)20(LiTFSI)2(PYR14TFSI)n / Li

    Open cell

    SPE

    Plated lithium

    Transport properties by DC tests

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    SEM of fresh lithium, plated lithium and SPE

    Li / P(EO)20(LiTFSI)2(PYR14TFSI)n / Li

    fresh lithium plated lithium SPE on stripped lithium

    Conclusions

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    Ionic Liquid mixtures with lithium salts as such and in

    presence of polymers show very promising performance

    as Li-ion conductors.

    IL-based electrolytes:

    easy to recycle (low volatility)

    wide storage temperature rangelow flammability components

    high temperature operation capability (>60C)

    IL-based electrolytes appear promising for safe, high

    energy and moderate power applications (such as full EV

    and stationary storage).

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    Acknowledgements

    German and NRW funding agencies

    The European Commission for the financial support of the projects:

    ILLIBATT (Ionic Liquid based LIthium BATTeries)

    LABOHR (Lithium Air Batteries with split Oxygen Harvesting and Reduction processes)

    GREEN LION (Advanced Manufacturing Processes for Low Cost GREENerLi-IONBatteries)

    All members of WWU-MEET and ENEA battery groups

    Back up

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    p

    Methods

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    Methods

    relaxation measurements

    1) spin-lattice-relaxation time T1:inversion recovery

    2) spin-spin-relaxation time T2:

    CPMG-sequence

    diffusion measurements:

    pulsed gradient stimulated echo

    sequence

    d1

    180y90x

    erstes

    Echo

    180y

    zweites

    Echo

    usw.

    first

    ECHO

    second

    ECHO

    d1

    d1

    180x 90x

    90x

    gg

    markaspin

    positionbythe

    precessionphase

    readthespin

    positionafter

    time

    z1 z2

    g:gradientstrength

    :gradientduration

    :diffusiontime

    :evolutiontime

    z1

    andz2:spinpositionbeforeandafterthegradients

    90x 90x

    local motion macroscopic motion

    Is the Li+ --- TFSI- ion-pairing avoidable?

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    N+

    CH3

    CH3

    Is the Li --- TFSI ion-pairing avoidable?

    Pyr+14

    Pyr+1(2O1)

    Cation aggregation in ILs with polar side chains

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    for systems with Li salt R does

    not change

    aggregation of cations w/ polar

    group

    cations do not aggregate when

    a lithium salt is dissolved

    pure IL IL with Li salt

    N+

    CH3

    CH3

    R2 dependent on chain length in pure systems

    slow local motions influenced

    R1 independent on chain length in pure systems

    fast local motions not influenced

    R changes with chain length

    anisotropical arrangement

    PYR+1A Li+TFSI- interactions

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    Raman

    Addition of oxygen into side

    chain reduces the number of

    TFSI anions in cluster.

    Addition of oxygen into side

    chain reduces the number of

    TFSI anions in cluster.

    Pyr14

    TFSI

    Pyr15

    TFSI

    free TFSI-

    Li+ ---

    TFSI-

    Pyr1(2O1)T

    FSI

    Pyr1(2O2)T

    FS

    I

    Diffusion coefficient

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    diffusion of Li+ slower than those of

    Pyr1A+ and TFSI-

    coordination clusters hindered in

    motion

    difference of diffusion coefficientslarger for polar side chain than for

    non-polar side chain

    mobility of lithium ions not

    enhanced by coordination of

    pyrrolidinium cation

    M. Kunze, et al., JPC C (2011)

    N

    +

    CH3

    CH3

    Tailored Ionic Liquid for Lithium Batteries

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    Purity > 99.5%

    H2O < 1ppm

    Td:

    175C

    RT: > 3 mS/cm

    C: 1 mS/cm

    ESW: > 5.0 V

    PYR14FSI

    Tm: -

    18C

    Paillard et al., JES 156, A891(2009), Kunze et al. JPC A 114, 1776 (2010)

    Pyr+14 Li+TFSI- interactions

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    y 14

    NMR-chemical shift

    NMR features of oxygen

    neighbours are strongly affected as

    a result of the Li --- IL Cation

    interactions

    Red:pure

    IL

    Black:ILwith salt

    ILLIBATT Project achievements

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    ILLIBATT Project achievements

    7Page 7Page 9

    Demonstrated feasibility of Ionic Liquid-based batteries at the pre-

    industrial scale

    ILLIBATT has been selected together with other most successfulprojects within the FP5 and FP6 calls

    Materials for a sustainable chemistry

    European Commission, Research Directorate-General

    Directorate G-Industrial Technologies-Value-added Materials

    ILLIBATT Cells:

    Do not contain volatile components

    Halides are present only in the easy-to-

    recycle electrolyte

    All binders are halide-free

    Battery tests: PEO-IL-LiX electrolyte (near RT tests)

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    Large capacities (140 mAhg-1) up to medium rates (C/5)

    Moderate capacities (50-75 mAhg-1) even at high rates (2C-1C)

    > 90% of initial capacity is delivered upon about 200 cycles

    Li / P(EO)10LiTFSI-PYR14TFSI / LiFePO4

    PEO-LiX-IL electrolytes: Li interface

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    Excellent lithium plating/stripping performance

    Lowered interface resistance

    PEO : LiTFSI : PYR14TFSI = 20:2:4 (mol)

    Lithium

    electrodes

    SPE

    Plated Li SPEDepleted Li