锂电池测试研究

1、Using Synchrotron Based in situ X-ray Techniques and Transmission Electron Microscopy to Study Electrode Materials for Lithium BatteriesX. Q. Yang, K. W. Nam, X.J. Wang, Y.N. Zhou, H. S. Lee, O. Haas, L. Wu, and Y. ZhuBrookhaven National Lab. Upton, NY11973, USAK. Y. Chung and B. W. ChoBattery Resea

2、rch Center, Korea Institute of Science and Technology, Seoul 130-650, KoreaHong Li, Xuejie Huang and Liquan Chen Institute of Physics, Chinese Academy of Sciences, Beijing, ChinaTo be presented at the 4th Southern China Li-ion Battery Top Forum CLTF2009Shenzhen, China, May 25th, 2009Combining in sit

3、u synchrotron XAS and XRD techniques to do diagnostic studiesof battery materials and components at or near operating conditionsIn situ cellMonochromaticX-raysIOITIRefIonization DetectorsReference metal foilIn situ cellMonochromaticX-raysIOITIRefIonization DetectorsReference metal foilPosition sensi

4、tive detector (PSD)In situ cellIncident X-raysDiffraction patternPosition sensitive detector (PSD)In situ cellIncident X-raysDiffraction patternXAS setupXAS setupXRD setupXRD setupMylar sheetBolt holesX-raywindowGasketSeparatorCu currentcollectorAl currentcollectorActivematerialLi foilIn situ cellIn

5、 situ cellMylar sheetBolt holesX-raywindowGasketSeparatorCu currentcollectorAl currentcollectorActivematerialLi foilIn situ cellIn situ cellX19A & X18B (XAS) and X14A & X18A (XRD) at National Synchrotron Light Source (NSLS)2335.536.036.537.0Phase 22(121)(311)Phase 3Phase135.536.036.537.037.52 (=1.54

6、)T(121)T(311)H(121)H(311)C-LiFePO4C-LiMn1/4Fe1/4Co1/4Ni1/4PO4Two phasereactionNo significant solid solution regionExistence of solid solution regionsAppearance of Intermediate phaseIn situ XRD of C-LiFe1/4Mn1/4Co1/4Ni1/4PO4during first chargeComparison with pure C-LiFePO445In situ XAS of C-LiFe1/4Mn

7、1/4Co1/4Ni1/4PO4during first charge0204060801001201401601803.54.04.55.0Capacity ( mAh g-1 )Voltage ( V vs. Li/Li+ )(III)(II)(I)26 mAh g-160 mAh g-1in situ XASK. W. Nam, X. Q. Yang et al, Electrochemistry Communication, in press (2009).71107120713071400.00.51.01.52.06540655065600.00.51.01.52.07710772

8、077300.0832083308340835083600.00.51.0Normalized intensity (a. u.) Before charge 8 mAhg-1 17 mAhg-1 26 mAhg-1 35 mAhg-1 53 mAhg-1 70 mAhg-1 88 mAh g-1 168 mAh g-1Fe K-edge Before charge 22 mAhg-1 31 mAhg-1 40 mAhg-1 48 mAhg-1 57 mAhg-1 75 mAhg-1 93 mAh g-1 163 mAh g-1Mn K-edgeEnergy ( eV ) B

9、efore charge 22 mAhg-1 41 mAhg-1 60 mAhg-1 70 mAhg-1 79 mAhg-1 99 mAhg-1 137 mAh g-1 166 mAh g-1Co K-edge Before charge 36 mAhg-1 65 mAhg-1 93 mAhg-1 126 mAhg-1 142 mAhg-1 151 mAhg-1 171 mAh g-1 180 mAh g-1Ni K-edgeEdge shift toward higher energy position increase in oxidation state Three voltage pl

10、ateaus at 3.6, 4.2 and 4.7 V Redox reactions of Fe2+/Fe3+, Mn2+/Mn3+and Co2+/Co3+. Voltage plateau over 4.9V Mostly electrolyte decomposition. Electronic structural changes following the lithium extraction quite well to balance the electrical neutrality.Cut-off voltage: 5.0 V, C/7 rate6Thermal stabi

11、lity study of layered cathode materials (safety related issue)When x= 0.5 (50% of SOC) in LixMO2Li0.5M(3.5+)O2(layered, R-3m) Li0.5M(3.5+)1.0O2(disordered spinel, Fd3m) ; no oxygen lossLi0.5M(3.5+)1.0O2(disordered spinel, Fd3m) Li0.5M(2.5+)1.0O1.5(rock salt, Fm3m) + 0.25 O2 ; oxygen release!When x=

12、0.33 (67% of SOC) in LixMO2Li0.33M(3.67+)O2(layered, R-3m) Li0.33M(3.21+)1.0O1.77(disordered spinel, Fd3m) + 0.115 O2; oxygen release!Li0.33M(3.21+)1.0O1.77(disordered spinel, Fd3m) Li0.33M(2.33+)1.0O1.33(rock salt, Fm3m) + 0.22 O2 ; oxygen release!More charged state, more thermally unstable. Releas

13、ed oxygen causes safety problems (e.g., thermal runaway) by reacting with flammable electrolytes.Layered LiMO2Spinel-type LiM2O4Rocksalt MOOxygenreleaseOxygenreleaseLayered LiMO2Spinel-type LiM2O4Rocksalt MOLayered LiMO2Spinel-type LiM2O4Rocksalt MOOxygenreleaseOxygenreleaseTemperature induced struc

14、tural changes of charged layered cathode materials Transitionmetal layerlithiumlayer7Thermal stability of Li0.33NiO2with electrolyte (as a reference)203040506070 2 ( =1.54 )(113)(110)(108)(107)(105)(104)(102)(101)(003)R-3mFd3mFm3m(111)(200)(220)Metallic Ni210oC25oC450oC- Li0.33NiO2 A good road map f

15、or the structural changes of nickel-based cathode materials during heating. Layered structureDisordered spinel structureRocksalt structureMetallic nickelOxygenreleaseOxygenreleaseOxygenreleaseHeating up to 450oC Li0.33NiO2goes through a whole series of phase transitions (i.e., thermal decomposition)

16、 when heated from 25 to 450 oC.8Thermal stability of charged Li0.33Ni0.8Co0.15Al0.05O2(Gen2) with electrolyte203040506070200oC2 ( =1.54 )280oC240oCFd3mFm3mR-3m(113)(110)(108)(107)(105)(104)(102)(101)graphite(003)(220)(200)(111)25oC450oC10203040At 285 C(220) spinel(440)10203040At 285 C(220) spinel(44

17、0)layeredDisordered spinelRocksalt Much better thermal stability than Li0.33NiO2. Narrow temperature range (20 oC) for the disordered spinelregion. (boxed region)Heating up to 450oC9Thermal stability of charged Li0.33Ni1/3Co1/3Mn1/3O2(Gen3) with electrolyte203040506070(a)(220)(200)(111)Fm3m600oC(113

18、)(110)(108)(107)(105)(104)(102)(101)R-3m236oCFd3m441oC304oC2 ( =1.54 )graphite25oC(003)metalic phase Much wider temperature range (140 oC) for the disordered spinelregion. (boxed region) due to the existence of two different types ofspinel structures. much better thermal stability!Heating up to 600o

19、CK. W. Nam et al, Journal of Power Sources, in press (2009).layered2 types of disordered spinelRocksalt8a tetrahedral site: Mostly lithium8a tetrahedral site: Mostly transition metalM3O4typeLiM2O4type10Comparison of thermal stability of charged layered cathodes with electrolyte203040506070 2 ( =1.54

20、 )(113)(110)(108)(107)(105)(104)(102)(101)(003)R-3mFd3mFm3m(111)(200)(220)Metallic Ni210oC25oC450oC2030405060702 ( =1.54 )280oCFd3mFm3mR-3m(113)(110)(108)(107)(105)(104)(102)(101)(003)(220)(200)(111)25oC450oC203040506070(220)(200)(111)Fm3m600oC(113)(110)(108)(107)(105)(104)(102)(101)R-3m236oCFd3m441

21、oC304oC2 ( =1.54 )25oC(003)metalic phaseLi0.33NiO2Li0.33Ni0.8Co0.15Al0.05O2Li0.33Ni1/3Co1/3Mn1/3O2 G3 cathode shows the best thermal stability due to the large spinel stabilized temperature region. why? Solution: Soft & Hard X-ray absorption spectroscopy !11 Excellent thermal stability of Mn4+ions i

22、n the charged Li0.33Ni1/3Co1/3Mn1/3O2cathode. likely due to the high preference of octahedral coordination of Mn4+ions.Mn K-edge XANES and EXAFS of charged Li0.33Ni1/3Co1/3Mn1/3O2(Gen3) during heating65406550656065700.01.6Normalized intensity (a. u.)Energy ( eV ) 25oC 100oC 150oC 200oC 250o

23、C 300oC 350oC 400oC 450oC 500oCG3 (Li1-xNi1/3Co1/3Mn1/3O2)0510152025303540451234560102030FT magnitude ( a. u. )G3_Mn500 oC450 oC400 oC300 oC200 oC25 oCBefore charge NiO CoO Co3O4Interatomic distance ( A )XANES : Oxidation stateEXAFS : local atomic structureMn-OMn-M No reduction of Mn ions during hea

24、ting.In depth analysis of better thermal stability of G3 cathode using XAS Preserving local structure around Mn during heating.12Co & NiK-edge XANES of charged Li0.33Ni0.8Co0.15Al0.05O2(Gen2) and Li0.33Ni1/3Co1/3Mn1/3O2(Gen3) during heating83308340835083600.01.68325833083358340Normalized in

25、tensity (a. u.)Energy ( eV ) Before charge 25oC 100oC 150oC 200oC 250oC 300oC 350oC 400oC 450oC 500oCGen2 (Li1-xNi0.8Co0.15Al0.05O2)83308340835083608325833083358340Energy ( eV ) Before charge 25oC 100oC 150oC 200oC 250oC 300oC 350oC 400oC 450oC 500oCGen3 (Li1-xNi1/3Co1/3Mn1/3O2)77107720773077400.00.

26、770577107715Normalized intensity (a. u.)Energy ( eV ) Before charge 25oC 100oC 150oC 200oC 250oC 300oC 350oC 400oC 450oC 500oCGen2 (Li1-xNi0.8Co0.15Al0.05O2)7710772077307740770577107715Energy ( eV ) Before charge 25oC 100oC 150oC 200oC 250oC 300oC 350oC 400oC 450oC 500oCGen3 (Li1-xNi1/3Co1

27、/3Mn1/3O2)Co K-edgeNi K-edge Much slower reduction in oxidation state of Co ions in Gen3 than Gen2 during heating. Better thermal stability of Co ions in Gen3 is likely due to the stabilization of Co3O4type-spinel phase prevent further thermal decomposition to CoO type-rock salt phase. New observati

28、on of the Co3O4type-spinel phase formation in Gen 2 which was not detected in TR-XRD during heating. (Pre-edge region in Gen2) Much slower reduction in oxidation state of Ni ions in Gen3 than Gen2 during heating. Better thermal stability of Ni ions in Gen3 is likely due to the combined effects of th

29、e stabilization of spinel type-phase and excellent thermal stability of Mn ions near Ni ions.13CoK-edge EXAFS of charged Li0.33Ni0.8Co0.15Al0.05O2(Gen2) andLi0.33Ni1/3Co1/3Mn1/3O2(Gen3) during heating123456010203001020304050 NiO CoO Co3O4Interatomic distance ( A )Gen2500 oC450 oC400 oC350 oC300 oC25

30、0 oC200 oC25 oCFT magnitude ( a. u. )Before chargeMOMOCo3O4010203040501234560102030Gen3500 oC450 oC400 oC350 oC300 oC250 oC200 oC25 oCBefore chargeMOMOCo3O4 NiO CoO Co3O4Interatomic distance ( A )Co-OCo-MCo-OCo-MReferenceoxidesReferenceoxides123456010203001020304050 NiO CoO Co3O4Interatomic distance

31、 ( A )Gen2500 oC450 oC400 oC350 oC300 oC250 oC200 oC25 oCFT magnitude ( a. u. )Before chargeMOMOCo3O4010203040501234560102030Gen3500 oC450 oC400 oC350 oC300 oC250 oC200 oC25 oCBefore chargeMOMOCo3O4 NiO CoO Co3O4Interatomic distance ( A )Co-OCo-MCo-OCo-MReferenceoxidesReferenceoxides Gen2 shows ther

32、mal decomposition to MO type-rock salt phase in local structure around Co at above 400oC, while Gen3 clearly shows the formation of M3O4type-spinel phase in local structure around Co whichprevent further thermal decomposition to MO type-rock salt phase. Co K-edge EXAFS clearly supports the better th

33、ermal stability of Gen3 than Gen2 due to the stabilization ofspinel-type phase in Gen3.14NiK-edge EXAFS of charged Li0.33Ni0.8Co0.15Al0.05O2(Gen2) and Li0.33Ni1/3Co1/3Mn1/3O2(Gen3) during heating12345601020300102030405060 NiO CoO Co3O4Interatomic distance ( A )NiO500 oC450 oC400 oC350 oC300 oC250 oC

34、200 oC25 oCFT magnitude ( a. u. )Before chargeGen2NiO010203040501234560102030Gen3500 oC450 oC400 oC350 oC300 oC250 oC200 oC25 oCBefore chargeNiONiOM3O4 NiO CoO Co3O4Interatomic distance ( A )Ni-ONi-MNi-ONi-MReferenceoxidesReferenceoxides12345601020300102030405060 NiO CoO Co3O4Interatomic distance (

35、A )NiO500 oC450 oC400 oC350 oC300 oC250 oC200 oC25 oCFT magnitude ( a. u. )Before chargeGen2NiO010203040501234560102030Gen3500 oC450 oC400 oC350 oC300 oC250 oC200 oC25 oCBefore chargeNiONiOM3O4 NiO CoO Co3O4Interatomic distance ( A )Ni-ONi-MNi-ONi-MReferenceoxidesReferenceoxidesGen3 shows much slowe

36、r thermal decomposition to MO type-rock salt phase in local structure around Nicompared to Gen2. Ni K-edge EXAFS clearly supports the better thermal stability of Gen3 than Gen2 due to the combinedeffects of the stabilization of spinel-type phase (likely Co3O4) and excellent thermal stability of Mnin

37、 Gen3.15850860870880FY: Bulk300 oC200 oCRT Energy / eV100 oCThermal Abuse: Element-selective technique (Soft X-ray absorption) Ni L-edge XAS for Li0.33Co1/3Ni1/3Mn1/3O2cathode Clear observation of the reduction of Ni4+ions at the surface. The surface of the electrode is decomposed at much earlier te

38、mperature than the bulk.850860870880 Energy / eV300 oC200 oCRT100 oCPEY: Surface16US DOE Energy StorageR&D Program StructureDevelop full battery systems with industry. (Minimum 50% industry cost share)Investigate cell behavior to understand and overcome performance barriers of Li-ion battery technol

39、ogy. (DOE National Laboratories) Develop novel materials (cathode, anode, electrolyte) that promise increased power and energy. (DOE National Labs and Universities)Focused Fundamental ResearchApplied ResearchBattery Development(USABC)Fundamental Research ProjectsFunded byBasic Energy SciencesFunded

40、byVehicle TechnologiesProgramFunded byOffice of Electricity Delivery and Energy ReliabilityEnergy Storage forUtility Applications1718Hybrid & Electric Systems Appropriation:$94.1M totalEnergy Storage Budget$48.2M totalSBIR/STTR, $2.2MVehicle Technologies Program, FY 2008Conventional HEV Battery R&D

41、$18.3MExploratory Technology Research $11.6MPHEV Battery R&D $18.35MVehicle & System Simulation & Testing $28.2MPower Electronics & Electric Mach. $15.5MEnergy Storage $48.2M19Batteries for Advanced Transportation Technologies (BATT): Develop the Next Generation of Lithium BatteriesActivity Focusq D

42、evelop novel materials (cathodes, anodes, electrolytes)q Develop and apply advanced electrochemical modelsq Employ advanced diagnostic tools to investigate failure mechanismsq Coordinate research effort with the DOE Office of ScienceCurrent Participantsq National Laboratories Lawrence Berkeley Natio

43、nal Laboratory Argonne National Laboratory Brookhaven National Laboratory National Renewable Energy Laboratory Oak Ridge National laboratoryq Universities Brigham Young University Clemson University Columbia University Massachusetts Institute of Technology State University of New York, Binghamton St

44、ate University of New York, Stony Brook University of California, Berkeley University of Michigan University of Pittsburgh University of Texas University of UtahFocused Fundamental ResearchSee / 20020406080100EVPHEVHEVCharge DepletingCharge SustainingUnused Energy100%80%60%40%20%0%

45、Battery State of Charge (SOC)HEVPHEVEV(Fully Charged) (Fully Discharged)CS only: 300-500 Wh, 25-40 kW (10 sec) 55% SOC, 300,000 cyclesCS: 300-500 Wh, 25-40 kW (10 sec) 30% SOC, 300,000 cyclesCD: Energy scaled for range (10-40 miles), 5,000 deep discharge cyclesCD only: Energy scaled for 150+ mile ra

46、nge, 1,000 deep discharge cyclesBattery Requirements Uncharged Capacity1-2 kWh, P/E 155-15 kWh, P/E = 3-10 40 kWh, P/E = 2020406080100Battery Size (kWh)Charge Depleting (CD)Charge Sustaining (CS)Unused EnergyBattery Size (kWh)q Key challenges for PHEV battery dual modes of operation (CD and CS) are

47、durability and cost.21Development GoalsHEV Battery RequirementsAvailable Power (kW)25 (40)Available Energy (Wh)300 (500)Cycle Life (cycles)300,000Calendar Life (years)10System Weight (kg)40 (60)System Volume (L)32 (45)Cost ($/kW)20Technologies Being ConsideredNickelate chemistry based on NCA materia

48、lSpinel chemistry based on LiMn2O4Iron phosphate chemistry based on LiFePO4Titanate chemistry based on Li4Ti5O1222Applied ResearchActivity FocusInvestigate cell behaviorUnderstand, extend, and accurately predict Li-ion battery lifeScreen and develop low-cost cell materialsUnderstand and improve abus

49、e tolerance Understand and improve low-temperature performanceOvercome the Commercialization Barriers for Li-ion BatteriesCurrent Participantsq National Laboratories Argonne National Laboratory Brookhaven National Laboratory Idaho National Laboratory Lawrence Berkeley National Laboratory National Re

50、newable Energy Laboratory Sandia National Laboratoriesq Universities Illinois Institute of Technology University of Illinois University of Wisconsinq Industrial material suppliers 39 different material suppliers23Battery DevelopmentUnited States Advanced Battery Consortium (USABC) Activityq Develop

51、full battery systems through competitive subcontracts with the USABC. All subcontracts are at least 50% cost-shared. q Develop performance requirements and standardized test procedures.q Test deliverables and analyze against performance targets using standardized test procedures. Performance testing

52、 at Argonne and Idaho National Laboratories Abuse testing at Sandia National Laboratories Thermal analysis and design support at National Renewable Energy Laboratory Battery simulation and modeling support at Argonne and National Renewable Energy Laboratories24Commercialized1 Phase 1: Materials Deve

53、lopment Phase 2: CellDevelopment Phase 3: BatteryDevelopment Phase 4: CostReductionIntermediate termLong-term, exploratoryNear market-ready765 432CommercializationNiMHLow cost separatorsUltracapacitorsGraphite/Nickelate5.Graphite/Mn spinel 6.Graphite/Iron phosphate7.Li titanate/Mn spinelCost GoalPer

54、formance Goal$20/kW (by 2010)25 kW for 10 sec, 300Wh (by 2010)40 kW for 10 sec, 500Wh (by 2010) HEV Technology Development Roadmap25Develop a 25 kW HEV system using their nano-phase iron-phosphate chemistry.Develop a 40 kW system using a nickelate cell with reduced cost and improved abuse tolerance.

55、 Develop a 25 kW HEV system using a Mn spinel-based cell. (Recently completed.)Develop a 25 kW HEV system using a nano-phase lithium titanate/Mn spinel cell. HEV Battery Development Contracts26Development GoalsPHEV Battery RequirementsPHEV10PHEV40Available Power (kW)4538Available Energy (kWh)CD3.411

56、.6CS0.50.3Cycle Life (cycles)CD5,000CS300,000Calendar Life (years) 10System Weight (kg)60120System Volume (L)4080Cost ($/kWh)500300CD: Charge Depleting, CS: Charge SustainingPower is capped to allow an all-electric mode of driving based on the Urban Dynamometer Driving Schedule (UDDS) cycle.27PHEV Battery StatusNear-term: Existing technologies that work well for HEVs will be re-engineered for PHEV10. First generation design will be used as the baseline. Even for materials that have adequate capacity and energy, an alternative cell for