Electrolytes For Lithium Batteries And Fuel Cells
Electrolytes for lithium batteries and fuel cellsCenter for Nanomaterials Design and Assemblyhttp://www.pa.msu.edu/ duxbury/CND/CND.htmlJanuary 24th : Jim McCusker (Chemistry - MSU), "Photochemical control of chargetransfer complexes for improved solar cells"January 31st : Keith Promislow (Mathematics - MSU), "The role of nanomorphology inproton conduction through polymer electrolytes"February 7th : Greg Baker (Chemistry - MSU), "Materials for Fuel Cells"February 14th : Don Morelli (Materials Science - MSU), "Introduction to high ZTthermoelectric materials and their applications"February 21st : Special Energy Seminar : Wolfgang Bauer (Physics, MSU) Is bio-gasgeneration a cost-effective option for the Michigan energy economy?February 28th : Phillip Duxbury (Physics - MSU) "Theoretical and practical limits onsolar conversion efficiency : Why use nanostructured materials?"
Organic (ion-conducting) membranes in energy applicationssupercapacitorsFuel cellsCO2 sequestrationsolar cellsLi ion batteriesCH4CO2
Rechargeable BatteriesHigh reactivitywith solvents usedfor electrolytes only polyethersare compatiblewith Li metalTarascon, J. M.; Armand, M., 2001, 414, (6861), 359-367
"Rocking Chair" batteries (Lithium Ion Cells)applications: laptops, cellphones, power tools,Tarascon, J. M.; Armand, M., 2001, 414, (6861), 359-367
Making batteries is as simple as baking .Tarascon, J. M.; Armand, M., 2001, 414, (6861), 359-367
Properties of real lithium batteriesDOE Workshop on Basic Research Needs For Electrical Energy Storage, tml
Advanced batteriesC-Li(x)LiCoO2(Sony)Li LiMn2O4(Bellcore/Telcordia)Li AnodeCathodeA prototype Lithium-IonPolymer Battery at NASAGlenn Research Center.LiFePO4(A123 systems)OH3COOCH3dimethyl carbonateCurrent technology: liquid electrolyte or gel electrolyte (liquid dispersed in aPVDF gel, allows flat packaging, rather than metal cans). Li PF6 or similar salt mixtures (usually) of ethylene carbonate, dimethylcarbonate, diethyl carbonateOOOdiethyl carbonateOOOethylene carbonate
Flambeau de laptop . over charging leads to dendrite formation excessive dendrite growth leads to a short a short leads to heat, venting, fire, .LiMn2O4Li(1-x)CoO2C-Li(x)liquid or polymer electrolyte(flammable! organic -conferenceLithium dendritesX-W Zhang, Y. Li, S. A. Khan, P. S. Fedkiw, J.Electrochem. Soc., 2004, 151, A1257-A1263.
The moral of the story .". the theoretical specific energy ofa lithium thionyl chloride battery is onthe order of 1420 Wh/L, which iscomparable to the theoretical specificenergy of TNT at 1922 Wh/L."
The moral of the story .". the theoretical specific energy ofa lithium thionyl chloride battery is onthe order of 1420 Wh/L, which iscomparable to the theoretical specificenergy of TNT at 1922 Wh/L."C-Li(x)Li Li(1-x)CoO2Li AnodeCathodepassivating layers (SEI)most organic solvents are inherentlyunstable to high oxidation and reductionpotentials at cathode and anode, smallmolecule easily transported to electrodesSolvent Electrode Interface: ionic conductor, electrical insulator mechanically robust through repeatedcycling inhibit dendrite formation
BASIC RESEARCH NEEDS FOR ELECTRICAL ENERGY STORAGE(DOE Workshop, 2007, uggestspolymer-based,ionic liquid, orother solutions
BASIC RESEARCH NEEDS FOR ELECTRICAL ENERGY STORAGE(DOE Workshop, 2007, http://www.sc.doe.gov/bes/reports/abstracts.html)a partial wish list .inherent safetystable, reproducible passivating layersinfinite cyclinghigh capacitylow temperature performancecould be solved via immobile (polymer) electrolytesinherent kinetic stabilitysuggestspolymer-based,ionic liquid, orother solutions
Ion-conduction in polyethers# of charge carriersmobilityOOOσ n q µOOOLi Ocharge/carrierOOOOOOOτ1.E-02CH2CH2 OOOn1.E-03OTmσ (S/cm)OOOO1.E-04O1.E-05OOOOLi OOOOOO1.E-06 dissolves Li salts well1.E-07 ion mobility correlated withsegmental motion of the PEO chain1.E-082.42.62.83.01000/T (1/K)3.23.4 crystallinity limits the conductivitybelow 60 C
Typical Approaches to Enhance ConductivityStructures designed to limit crystallinity “blocky” polymers branched copolymers network polymers1.E-02Additives designed to limit crystallinityTmσ (S/cm) polymer blends1.E-031.E-041.E-051.E-06 polymer-filler composites1.E-071.E-082.42.62.83.03.23.41000/T (1/K)Limited success (10-4-10-5 S/cm @ room temperature, vs. 10-1 -10-5S/cm for liquids
Idealized ion transportM ions diffusing in a uniformpotential - weak coupling limitVsVhighest mobilityion hopping: - strong couplingschaperone approach(a compromise)screening layerM
classifying electrolytes systems by function (mechanical, σ)"coupled" systems"de-coupled" systemsσ and E derived from asingle materialσ and E derived fromseparate componentsinorganic oxides and glassesPEO/salt complexeslow molar mass electrolytes inert separatorcomposite systems inert fillers electrolytebicontinuous block copolymers
classifying electrolytes systems by function (mechanical, σ)"coupled" systems"de-coupled" systemsσ and E derived from asingle materialσ and E derived fromseparate componentsinorganic oxides and glassesvacancy-based diffusion,thermally activated (high T)low molar mass electrolytes inert separatorcomposite systems inert fillers electrolytebicontinuous block copolymersPEO/salt complexestransport coupled tochain mobility
classifying electrolytes systems by function (mechanical, σ"coupled" systems"de-coupled" systemsσ and E derived from asingle materialσ and E derived fromseparate componentsinorganic oxides and glassesPEO/salt complexesadvantages for manufactureproviding the morphology can becontrolled.- but will the electrolyte be a liquid(high σ, but safety issues) or apolymer (low σ)low molar mass electrolytes inert separatorcurrent technology has safetyissues, stuck with "canned" batteriesto be displaced by ionic liquids?composite systems inert fillers electrolytebicontinuous block copolymers*high molecular weight and cross-linked polymers are kinetically stable - notransport to the electrode surface
Bicontinuous phase approach to electrolytes conducting phase, high σ network structure, mechanical stabilityhydrophobicIon conductingmatrix (hydrophilic)
Bicontinuous phase approach to electrolytes conducting phase, high σ network structure, mechanical stabilityhydrophobicClClSi ClClflameSiO2(H2O)Ion conducting matrix(hydrophilic)250 nmApplications: thickening agents for paints, coatings,cosmetics, . moisture control in powders irregularly shaped particles 20-100 nm in diameter SiOH surface groups aggregate in liquids and form gelsn
Thickening & StaticperiodShearingrest3-D aggregatesDriving force:agglomeratednetworkTimephase separationH-bonding (SiOH surfaces)van der Waals (alkyl-terminated)Staticperiod
low molecular weight PEO/Li saltprovides good conductivity both properties can be optimizedindependently to give highly conductiveelectrolytes that can easily be processed.CH3O CH2CH2O CH3nPEGDME-500LiClO4Elastic Modulus, G' (Pa)Strategy: fumed silica provides reversible structureformationσ298K10610-3105G'104PEG-DM, Li Imide10305101520Fumed Silica (R805) weight %PEGDME-500LiClO4PEGDME 500hydrophobic fumedsilica (R805)LiClO4 or Li imidetemporarysilica networkcross-linkedsilica network10-425RT Conductivity σ298Κ (S/cm)Particle-based Li conductors
Preparation of Modified SilicasOHOHROOHOHOHOHOHOHOO SiSiROORO OHOOO SiROOSiROORCH2OOOH1:1O4:1silicaCCCH3
Photocuring of Composites110Hg lamp10090TeflonSSelectrodeconductivity cellcross-sectionConversion, %electrolyte80706050C C4030C O2010 Irradiate with mediumpressure Hg lamp at 30 C Follow loss of C C andshift of C O00510152025Irradiation Time, (min)30
Conductivities Before and After Curing1.0E-021.0E-02BMA before UVBMA after UVMMA before UVPEO-5001.0E-031.0E-042.75OMA after UVConductivity (S/cm)Conductivity (S/cm)OMA before UVMMA after UV1.0E-031.0E-042.953.151000/T (K)3.352.752.953.153.351000/T (K) Difference in initial conductivities reflect solubility of monomer Same final σ implies no polymer in electrolyte phase
Effect of Added Monomer: a viscosity effect1.00E-03before UVPEGDME-500, crosslinkable fumed silica LiClO4σ (S/cm)after UVConductivity of compositesrelated to mis-match insolubility parameters.octylSupports phase ty parameter(δPEO - δ methacrylate)
Single-ion Conductors Prepared from SulfonimidesImmobilized on Fumed Silica NanoparticlesTransference numbert the fraction of current carried by a charge speciesFor common binary salts:LiClO4,LiN(SO2CF3)2 (LiTFSI), .t 0.2-0.4i t i i (tPolarization – decreased cell performance t ) 1solution: immobilize anionsX-Li X--XLi Li Li X-XX-XX--XX-X-- XX-X-XX-anions part of a rigidsolid (low σ)X-X-Design issues: singlecomponent, but mustoptimize transportand tether ions at thesame time
Composite electrolytes: 2-component solutions to electrolyte designlow molecularweight PEOhydrophobic particlesImproved mechanicalpropertiesLi X-σ unchangedNetwork formationX X X X XXXXXXXIon-exchanged clays3-d network structure, high tLi For an overview see:Electrochimica Acta 2003 48, 2071-2077XXXXXX“massive” relative to Li ,µ 0hydrophilic particlesdispersed in PEO
ApproachesParticles with a monolayer of anions tethered to the surfacemonolayerof anionsσ n q µParticles with polymer tethers decorated with multiple anions/chain(increased carrier concentration, easily 10X)anions bound topolymers grownfrom the surface
Synthetic route to tethered Li imides1) potassium phtalimide, DMF, 80%triethyl amineOHOTsCHCl3, TsClNH22) H2NNH2.H2O, EtOH, 60 C3) HCl, EtOH, reflux, 52%98%Ts p-toluene sulfonyl(CF3SO2)2OEt3N, CH2Cl258%NHTf(EtO)3SiH(EtO)3SiPt(0), benzeneNHTfTf trifluoromethane sulfonyl1) diethyl amine(EtO)3SiOHOHOH2) nBuLi, tolueneFumed SilicaHNOSCF3OLi OO SiOOSCF3O-N
Conductivity dataData for PEO/LiClO4/hydrophobic fumed silica Li concentrations:–40 wt% O:Li 250–35 wt% O:Li 310–30 wt% O:Li 390–19 wt% O:Li 710At 10 & 15 wt % - σ 10-8 S/cm(few charge carriers)At 40 and 50 wt% - poor ionic conductivitydiscontinuous polymer matrix
Connectivity issuesLow weight loading1E-4Li Li 1E-5Li Li Li σ (S/cm)1E-6nanoparticlesPEO1E-7Li 1E-81E-915Poorconnectivity2025303540A200-C5NTfLi weight fraction (%)Li Li Li Li Li High weight loadingnon-continuous conducting phase
Interim conclusions σ 10-8 S/cm for 10, 15 and 50 wt% particles in PEGDME500/.– For 10, and 15 wt%, low lithium concentrations.(O/Li 1000)– For 50 wt%, discontinuity of the polymer phase. Weak dependence on temperaturemonolayerof anionsNeed more charge carriers!anions bound topolymers grownfrom the surfaceParticles with polymer tethers decorated with multiple anions/chainhave increased carrier concentrations, easily a 10X increase.
Growth of polymer tethers from particle surfaces Increase number of anions on silica nano-particlesSiOOHClSiClClOHOHSiOHCuCl2, dNbipyOClSiSiOOClClnn1. SO3OHOH- SO3 Li2. MeLiSiSiOOClnClnSO3- Li
Thermal gravimetric analysis of modified nanoparticles100Cleaving chains fromsurface with HF wouldgive molecular weight.80weight %Weight loss data can beanalyzed to estimate thenumber of functionalgroups on the surface.6040particles after sulfonationparticles after surface initiated polymerizationparticles with initiator monolayer2001002003004005000temperature ( C )2.3 mmol/g (titration)600700
Li conductivity of nanoparticles in PEG-DME 350-420 wt% particles (2.3 mmol/g)10 wt% particles (2.3 mmol/g)26 wt% A200 (0.23 mmol/g)10 fold increase in conductivity-5log σ 10-5 even for aryl sulfonates-6single layer ofimmobilized anions-72.82.93.03.11000/T3.23.33.4
BASIC RESEARCH NEEDS FOR ELECTRICAL ENERGY STORAGE(DOE Workshop, 2007, ross-Cutting Science: technology challengesLiquid electrolytes Provide the needed high conductivity for electrochemical capacitorsbut can have safety and containment issues. Have voltage windows that limit the device performance range. Contain electrolyte impurities that lead to degradation in performance.Electrolytes can be the weak link limiting innovations in electrodematerials, and associated power and power density.Need new electrolytes with high ionic conductivity, low fluidity, easilypurified.Low nucleophilicity and electrophilicity - unreactive in both electrontransfer and acid-base chemistry.
BASIC RESEARCH NEEDS FOR ELECTRICAL ENERGY STORAGE(DOE Workshop, 2007, ross-Cutting Science: technology challenges"Solid" electrolytes Difficult to combine the electrolyte and electrode separator functions ina single material. Modeling provides a recipe for high conductivity - polymers with lowglass transition temperatures - but low Tg polymers have poormechanical properties. Two-phase materials provide a partial solution - favorable mechanicalproperties, but with the electrochemical characteristics and problems oflow molecular weight liquid electrolytes ( electrolyte decomposition,flammability, .).New approaches to electrolyte design are needed that go beyondincremental improvements.
Cross-Cutting Science: Electrolytes for Energy Storage Establish design rules that define the relationship between electrolytestructure and performance, including ion mobility, electrochemicalstability new concepts for electrolytes. Precisely define the double layer and interaction of electrolyte andsolvent at electrode surfaces. Create self healing/self regulatingelectrolytes for the electrode/electrolyte interface. Expand the range of weakly coordinating anions (BARF, carboranes,dicationic ionic liquids, ions linked by electronically conductingsegments ) to broaden the spectrum of electrolytes available forbatteries and capacitors. Investigate electrochemical phenomena in molten salts establishelectrolytes with high conductivities, stabilities, and wide potentialwindows. Establish the thermodynamic properties of electrolytes.
Cross-Cutting Science: basic-science challenges, opportunitiesSolid electrolytes Nanoparticle composites that exploit the interstitialspace in ensembles of high surface areananoparticles and provide conductive channels forion transport. Design smart materials that respond that moderatetemperature excursions within batteries, polymerlayers that selectively remove lithium dendrites, orrestore conductive pathways in compositeelectrode structures - potentially dramaticimprovement in device reliability, lifetime, andVsafety.cathode"dendrite mower"anodeM M
Fuel Cellshttp://www.epa.gov
Fuel cell issuesCosts. Platinum (1 mg/cm²) and membrane costs. Nafion membranes are 400/m²!Water management (in PEMFCs).too little water: dry membranes, increased resistance,failure by cracking, creating a gas "short circuit" wherehydrogen and oxygen combine directly, generating heat thatdamages the fuel cell.too much water: electrodes flood, preventing the reactantsfrom reaching the catalyst.Fuel and oxygen flow control.Temperature management.Limited carbon monoxide tolerance of the anode.Advantages of high temperature operation: Reduce CO poisoning effect on electrode catalyst. Enhance reaction kinetic at higher temperature. Simplify water management.
Nafion, the prototype PEMCF2 CF2aCF CF2b nOCF2 CF O(CF2)2 SO3HCF3Ionic clusterchannelPerfluorinated polyethylenebackbone affords chemical andmechanical stability; sulfonicgroups attached on side chainsprovides mobile protons whenhydrated. Chemically stable Mechanically stable High conductivityLimitations: Cost. 400/m2 Poor high temperatureperformance (80-90 C) Low conductivity at lowhumidity or high temperature CH3OH permeabilityHickner, M. A.; Pivoar, B. S.; Fuel Cells, 2005, 5, 213-229Hickner, M. A.; Pivoar, B. S.; Fuel Cells 2005, 5, 213.Hsu, W. Y.; Gierke, T. D.; J. Membr. Sci. 1983, 13, 307. Mauritz, K. A.; Moore, R. B.; Chem. Rev. 2004, 104, 4535.
"Diat tubes"CF2 CF2aCF CF2b nOCF2 CF O(CF2)2 SO3HCF3AFM image of Nafion at RT,30% relative humidity1 µm x 1µmNafion "tube" structure inferred from scattering dataHO3SSO3HH OSO3HSO3HHHO3SHH OSO3HHO3SO HH HO3SSO3Hend viewRubatat, L.; Gebel, G.; Diat, O., Macromolecules 2004, 37, (20), 7772-7783.
Commercial alternatives to NafionSulfonated ESI (Dais-Analytic)*CH2 CHxCH2 CH2Commercial Dow Insight product,*30-60% sulfonation1-x n85 C max temp(Tm of polyethylene crystallites)SO3HPolybenzimidazole (Celanese Ventures) with Honda, PlugPowerHNNNNHn150-190 C maximum, CO tolerantPolybenzimidazole ( PBI )Sulfonated PEEK (Vitrex/Ballard)OHO3S*OOPBI soaked with 11M H3PO4 showedconductivity of 0.02 S/cm at 130 C, 0.3atmosphere water vapor pressure.*n
Nafion model from neutron scatteringHydrophobic polymerHydrophilic networkThe bicontinuous phase structure is an analog of the cluster-network model (Nafion)Schmidt-Rohr, K.; Chen, Q., Nat. Mater. 2008, 7, 75-83.
More Nafion alternativesYang, Y. S.; Shi, Z. Q.; Holdcroft, S., Macromolecules 2004, 37, (5), 1678-1681.ONOONONOHO3SOOSO3HxONafion’s bicontinuous structureONOOyFaure S, Cornet N, Gebel G, Mercier R, Pineri M, Silicon B. Proceedings of Second International Symposium on NewMaterials for Fuel Cell and Modern Battery Systems, Montreal, Canada, July 6-10, 1997. P. 818.Random incorporation of sulfonic acid groups causes uncontrolled swelling in H2ODistribution as blocks (a la Nafion) controls swelling
Particle in polymer approachhydrophobic silicahydrophobic matrix(mechanical stability)hydrophilic silica(ion conducting)invertIon conducting matrixHydrophobic particles (alkyl terminated)dispersed in a hydrophilic ion-conductingelectrolyte.Hydrophilic particles (sulfonic acidterminated) dispersed in a hydrophobicmatrix (PVDF).Network formation enhances mechanicalproperties with insignificant effects onconductivityDimensionally stable hydrophobicpolymer provides mechanical stabilityand is uninvolved in transportKhan, A. S.; Baker, G. L.; Colson, S.; Chem. Mater, 1994, 6, 2359-2363
Particles with polystyrene brushesComposite membranes made from poly(styrene sulfonic acid) grown fromnano-sized silica surface and PVDF:SiSiO2OCln PVDFSO3HNano sized particle provides high surface areaHomogeneous membranes, comparable conductivity compared to Nafion.de-coupled mechanical properties from proton transportEasy solution to swelling issues.
Membrane fabrication Particles in DMFMixtures were cast on glass slide anddried at 50 oCPVDF in DMFCombined mixture, stirredovernight at room temperatureCast membrane
Particle content vs conductivity1Nafion 117 measuredunder the same conditions:0.08 S/cmConductivity (S/cm)0.10.010.001The conductivity data suggesta percolation threshold at 20% particle content.0.00010.00001010203040Particle content ( wt%)5060Need to push the particlecontent to lower loadingswhile maintaining conductivity.Measurements taken at room temperature, 100% relative humidity
Membrane conductivity vs. temperatureCompatible with high temperatures1.450%Still need to push the particlecontent to lower loadings40%1.230%σ (S/cm)150% particles0.80.60.440% particles0.230% particles08090100110120130140Temperature 0CMembranes were soaked with 8M H3PO4,measurements were taken under 0.3 atmosphere pressure humidity
AcknowledgementsQin YuanFadi AsfourPing LiuMica StoweJun HouSaad Khan & Peter Fedkiw (NC State)Financial SupportDepartment of Energy, Basic Energy SciencesMSU IRGP (Keith Promislow)
Advanced batteries A prototype Lithium-Ion Polymer Battery at NASA Glenn Research Center. LiCoO 2 (Sony) C-Li (x) Anode Cathode Li Li LiMn 2O 4 (Bellcore/Telcordia) Current technology: liquid electrolyte or gel electrolyte (liquid dispersed in a PVDF gel, allows flat packaging, rather than metal cans). Li PF 6 or similar salt
Lithium Batteries There are two types of lithium batteries: Primary batteries, non -rechargeable that use lithium metal; often in an AA, 9V, or coin cell format. Secondary batteries, rechargeable lithium - polymer cells use an electrolyte and thin porous membrane that allows Li-ions to pass between the anode and cathode; come in
automotive batteries SAE J2464 for automotive rechargeable batteries (RESS systems) IEC 60086-4 Safety of lithium batteries UL 1642 for lithium ion batteries UN/DOT 38.3 for testing lithium ion batteries IEC 61960 for portable lithium cells and batteries IEC 62133 for p
automotive batteries SAE J2464 for automotive rechargeable batteries (RESS systems) IEC 60086-4 Safety of lithium batteries UL 1642 for lithium ion batteries UN/DOT 38.3 for testing lithium ion batteries IEC 61960 for portable lithium cells and batteries IEC 62133 for p
IEC 60086-4 Safety standards for primary lithium batteries IEC 61960 Safety standards for secondary lithium cells and batteries IEC 62281 General guidelines for the safety of lithium cells and batteries during transport UN/DOT 38.3 Standards for shipping lithium batteries, either alone or as part of a device
1. Are all lithium-ion batteries created equal? — NO 2. Are all chemistries the same? — NO 3. Are all batteries using the same lithium-ion chemistry the same? — NO 4. Do all lithium-ion batteries have similar cycle life, like Flooded Lead Acid (FLA)? — NO 5. Can I use any lithium-ion battery in my equipment? — NO 6.
14-100508-000 Assy. Lithium Battery, 30 Ahr 14-100508-900 Assy. Lithium Battery, preown 30 Ahr 14-100957-002 Assy. Lithium Battery, w/ jumper 48 Ahr 14-100957-004 Assy. Lithium Battery, w/ jumper 30 Ahr 14-100957-904 Assy. Lithium Battery, preown 30 Ahr 14-860202-002 Pkg. Envoy, Lithium, with ACDC 115V 14-860202-004 Pkg. Envoy w/ Lithium .
State of the art in reuse and recycling of lithium-ion batteries - a research review Preface Less than 5 per cent of the lithium-ion batteries in the world are recycled. The few processes that are available are highly inefficient and the costs to recycle lithium is three times as high as mining virgin lithium. With the rapid growth in e-
Extinguishing Agents for Lithium-ion Batteries 05 -23 13 2 Background Growth in Lithium Battery Use -The number of lithium-ion batteries made in the world grew from about 800 million in 2002 to about 4.4 billion in 2012. Fire Risk -Many lithium ion cells have been known to overheat and create a potentially dangerous situation.
