安全性和高電壓性能研究進(jìn)展PPT通用課件

1、安全性和高電壓性能研究進(jìn)展1、Background Safety issues related with Li-ion Batteries Safe electrolytes for high-voltage batteries2、Organosilicon based electrolytes High-voltage OS-based electrolytes OS-based electrolytes for Si anodes4、SummaryOutlineSafety issues of LIBs:High flammability ofcarbonate electrolytes!

2、LiFePO4 batteryNot safe enough！Safety of Lithium-Ion BatteriesSafety (abuse tolerance): When overcharged, thermalrunaway leads to fires etc. Runaway reaction caused byrelease of oxygen from cathodematerials (e.g., LiCoO2).The development of newSafe electrolyte materials!OOORRDMC: R=CH3DEC: R=CH2CH3O

3、OEC OHighVoltageCathodeMaterialsDischargepotential(V)RedoxcoupleTheoreticalCapacity(mAh/g)PotentialRange(V)LiCoPo44.82+/3+Co1673.05.1LiNiPo45.12+/3+Ni1673.05.5Li3V2(PO4)3LiMPO43.83+/4+/5+V1973.04.8Li2CoP2O74.92+/3+Cob1092.05.5Li2MnP2O74.452+/3+Mnb1102.04.7Li2NiPO4F5.12+/3+Nib1433.05.5LiNiSO4FC5.25.4

4、2+/3+Ni149Li2NiSiO4LiNiMnC4.8O42+/3+Nib1631.5LiNi0.5Mn1.5O44.72+/3+/4+Ni1473.55.0LiFe0.5Mn1.5O44.53+/4+3+/4+Fe,Mn1483.05.3xLi2MnO3(1-x)LiMeO2(0X110 , 163 forADN)Dielectric constant (20-30, 55 for SCN)Disadvantages:Poor compatibility with graphitePoor solubility of LiPF6 LiTFSI (V 4.3 V, corrodes col

5、lector) LiBF4 (inferior ability, poor lowtemperature performance)J Electrochem Soc, 149 (2002)A920; J Phys Chem B, 115 (2011) 12120.Electrochem Commun, 11 (2009) 1418; 11 (2009) 1073.Sulfone-Based Electrolytes Advantages:High oxidationpotential Low flammable High melting point; Poor compatibility wi

6、th graphite; Wetting problem with separatorLi4Ti5O12/1M LiPF6FEC/DMC/D2 3/4/3/LiNi0.5Mn1.5O4 (Data from ANL, USA)OFRf1Rf2OD2OFEC1 C at 55oCFluorinated Based ElectrolytesAdvantages: High oxidative stability High flash point/lowflammability (Safe) Compatible with graphiteODisadvantages: Bad performanc

7、e at elevatedtemperatures (FEC) Harsh synthesis conditions/highcost1M LiPF6 EC/DEC (3/7)1M LiPF6 EC/DMC/MFA (3/3/4)F OH C C O CH3FMFA1M LiPF6 MFALiCo2/ Graphite cell (1 Ah cell); Daikindata (Japan)Fluorinated Based ElectrolytesEnergy & Environmental Science, 6 (2013) 1806; Electrochem Commun, 10 (20

8、08) 783.High Low flammability High oxidation resistance High viscosity(low conductivity & ratecapability) Poor wettingHigh costJ Power Sources, 189 (2009) 331; 225 (2013) 113; 233 (2013) 115.Mix with carbonate or other co-solventperformance Ionic Liquid Electrolytesthermal stability Very low rotatio

9、n barrieraround Si-O axis, (ca.0.8 KJ/mol) low linear isation energy ofthe Si-O-Si angle (1.3kJ/mol).Organosilicon (OS) Electrolytes:High ionic conductivity Non-flammability: Biocompatible Excellent wetting capability Wide liquid phase range(-40200 oC) Low viscosity- comparable withalkylcarbonates M

10、edium wide electrochemicalwindow Very low glass transitiontemperature good thermal stabilityAlternative: Organosilicon ElectrolytesOOOOOR2R2R1R1= H, CH3R2= CH3, CH3CH2Carbonate electrolytesHighly flammable!OJ. Mater. Chem., 2008, 18(31), 3713-17; 2010, 20, 8224-26. Chem. Mater. , 2007, 19, 5734-5741

11、.Implant neuro-stimulator micro cell(27.5 3.2 mm2, 1g)Organosilicon as Safe Electrolytes1. Excellent cyclability；2. Electrochemically stable3. Nonflammable/Safe; 4. Environmental benignConventional electrolytesOS electrolytesMCMB/LiNi0.8Co0.15Al0.05O2,0.8M LiBOB OS electrolytesC/5, 3.0 to 4.0 V;100%

12、 efficiencyJ Power Sources, 228 (2013) 32; 196 (2011) 2255Electrochem Commun, 8 (2006) 429; Chem Commun, 49 (2013) 1190Progress on Organosilicon Electrolytes (Lit.) Ionic conductivity Compatibility with graphite Oxidation potential ( 4.2 V )Challenges of OSelectrolytes:Compounds/cPoT/Cg-/mScm1(0)25C

13、E/VcathodicE/VanodicEW/VSN1SN2SN3BNSTNS2.884.627.163.604.6011.612.312.815.717.3-118-111-98.4-107-1061.101.521.201.281.030.00.00.01.111.055.6015.054.494.11NCH2CH2CH2C Si O CH2CH2O CH3nCNCH2CH2Si(CH3)(3-m)(OCH2CH2OCH3)mCH3dielectric constant oxidation potential Increaseddielectr

14、ic constantIncreasedoxidation potentialHighconductivityOrganosilicon Compounds with Nitrile GroupCH3Discharge Capacity (mAh/g)Efficiency (%)Potenial / VSpecific Capacity / mAhg-1Specific capacity/ mAhg-1Capacity retention (%)Specific capacity/ mAhg01401201008060105100959085803000.7C CC to 4.4V, 0.5C

15、 DC to 3.0 V274 cycles : 85.2 %LCO/OS co-solvent/Graphite50 100 150 200 250Cycle number016014012010080604020180LCO/graphite, 2.7-4.4V, 0.2CBNS / 0.4 M LiODFB+0.6 M LiPF6TNS / 0.4 M LiODFB+0.6 M LiPF6SN1 / 0.4 M LiODFB+0.6 M LiPF640 80 120 160052530030906012018015010 15 20Cycle number0204060100800.2

16、C2C1.5 C1C0.5 C0.2 CMisciblewell withcarbonateEnhancedhigh rateperformance0100 200 300 400 5006000.01.02.0-11M LiPF6 in SN11M LiPF6 in BNS/PC (4:6 in vol.)1M LiPF6 in TNSAs EO arm increase,More compatibilitywith graphite.Organosilicon Compounds with Nitrile Group3.0Cycle numberJ. Power Sour

17、ces, 254, 29-32 (2014)Coulombic Efficiency / %Specific capacity/ mAhg-102040608010008040160120Cycle number8081971009998Retention: 90.4%100 cyclesCE 99.5%LCO/graphite, 3.0-4.4 V0.5C, 143 mAhg-1Comparison with Commercial High-VoltageElectrolytesOur high-voltage OS electrolyte (OS Ionic Liquids)101Comp

18、.Viscosity（mPa.s）DielectricconstantTg()Conductivity-1（mS.cm）Oxidationpotential(V)FMSEOM221.799.5-108.51.464.951SM322.14.44-1120.9?Enhanced physical propertiesFluorinationFluorinated OS Compounds with Oligo (EO)1S3M2, J. Mater. Chem., 2010, 20, 8224; F2MSEO2M unpublished data.-1dQ/dVCap. mAh/gSpecifi

19、c capacity/ mAhgCoulombic efficiency / %Potential (V vs. Li+/Li)F2MSEO2M / 1M LiPF6+0.2MLiODFB0204060804016012080200240Cycle number4.4VLCO/Li, 0.2C8010095908510090.8%95.8%4.5V0.00.1 0.2 0.3 0.40.5Graphite/Li, 0.01-3.0 V1 M LiPF6 PC:DMC:DEC:F2MSEO2M (28:35:35:2 vol.)Unpublished dataFluorinated OS Com

20、pounds with Oligo (EO)Good compatibility with1020Cycle #3040320280graphite!400360High voltage performances:LCO/C cell, 94 cycles4.4V: 96% capacity retention4.5V: 90% capacity retentionSpecific capacity (mAh/g)Current ()Efficiency (%)Potential ( V vs. Li /Li )0204060801006080120100180160140200Cycle n

21、umber040208060100LCO / TMOSC3GC / graphite2.7-4.4 V, C/10Highly polargroupDielectricconstant Concentrationof Li+-1012345+TMOSC3GCTEOSC3GCDSC3GCOOOOSiOOSiOSiOOOOWang JL, et al., 2013, to be submittedCarbonate Functionalized Trialkoxysilanes(RO)3Si(CH2)nOOOOR= CH3O, CH3CH2O; n= 0,2,3ODielectric consta

22、nt as high as37.8!220Current / A3.03.54.04.55.05.56.0320240160800Voltage / V vs. Li/Li+commerical carbonate electrolytecommerical carbonate electrolyte + 30% SN1W.E. platinumC.E. lithiumR.E. lithiumScan rate: 10 mv/s(a)OS based electrolytes for 4.4V LCO/graphite cellcommercial carbonate electrolyte:

23、 GT303 (LB303)commercial carbonate electrolyte + 30% SN1 : GT303+30%SN1-1Specific capacity/ mAhg030609012015012010080commercial carbonate electrolytecommercial carbonate electrolyte+30% SN1LCO/graphite, 3.0-4.4V 0.5CCycle numbercommercial carbonate electrolyte: GT303+ 2%wt. VC+ 2%wt.PScommercial car

24、bonate electrolyte + 30% SN1 :70% TC 4.35+ 30% SN1,0.1 M LiODFB + 1 M LiPF6, 2%wt. VC+ 2%wt.PSOS based electrolytes for 4.4V LCO/graphite cell(b) 160140-1Specific capacity/ mAhg01020304050601000.2C0.5C0.7C1C1.5Ccommerical carbonate electrolytecommerical carbonate electrolyte+30% SN10.2C(c)160140120C

25、ycle numbercommercial carbonate electrolyte: GT303+ 2%wt. VC+ 2%wt.PScommercial carbonate electrolyte + 30% SN1 :70% TC 4.35+ 30% SN1,0.1 M LiODFB + 1 M LiPF6, 2%wt. VC+ 2%wt.PSOS based electrolytes for 4.4V LCO/graphite cellElectrochemical windows Imidazolium ILs: ca. 4V Tertraalkylammonium ILs: ca

26、. 6VR = (CH3)3SiCH2, (CH3)3CCH2A = N(CF3SO2)2, BF4J. Phys.Chem. B, 109, 21576(2005); 111, 4819(2007); 111, 4885(2007); Talanta, 71, 68(2007).N + N R-A+Si NN C4H9-PF6 TertraalkylPhosphonium ILs:excellent thermal stabilityElectrochim. Acta, 51, 5567(2006)Organosilicon Based Ionic LiquidsAdvantages Ove

27、r Carbon Analogues Weake Intermolecular interactions Lower viscosity Low glass transition temperature HydrophobicX = N, P; n = 1, 3;R1=CH3, CH3CH2; R2=Alkyl, alkoxyA = BF4, PF6, TFSI, BOB, NCN2R2R2 SiR2(CH2)nXR1(OCH2CH3)2-AOOOOOOOF3C S N S CF3O OTFSIBO OBOBAnion structures:US 2010029970 A1; WO 20090

28、45609 A1; CHN Pat: CN201010265833.2Organosilicon Based Ionic LiquidsMass Retaintion (%)Current ()OSIonic LiquidSN1IL-TFSIAN1IL-TFSICETMA-TFSImS/cm1.354.291.10cp125.436.0-TdecoC362325329EanodicV0.000.651.30EcathodicV5.395.305.78Novel Organosilicon Based Ionic Liquids012563 4Potential (V)SN1IL-TFSIAN1

29、IL-TFSICEN1IL-TFSI0100500600120100806040200SN1IL-TFSIAN1IL-TFSICEETMAIL-TFSI200 300 400oTemperature ( C)Capacity (mAh/g)Capacity (mAh/g)Efficiency (%)Efficiency (%)00301501209060180010 20 30 40 50 60 70 80 90Cycle2080604010005253003015012090601800.2C2C1.5C1C0.5C10 15 20Cycle number0.2C02080604010012

30、0Cell Performances for Novel OS Ionic LiquidsLCO/Graphite, 2.7-4.4 V, 0.2CSN1IL-TFSI:DMC =1:1 by vol.210Capacity (mAh/g)Efficiency (%)Capacity (mAh/g)Efficiency (%)0102030405060708090100220200180160140120100806040200Cycle Number100806040200NMC-LI cell; CapacityRetention: 96% (100 cycle)SN1IL-TFSI-EM

31、C-1-102462202001801601401201008060402008 10 12 14 16 18 20 22 24 26 28 30Cycle Number100806040200NMC/graphite (2.7-4.6V)SN1IL-TFSI-EMC-1-1Cell Performances for Novel OS Ionic LiquidsCoulombic efficiency / %Specific capacity/ mAhg-1051015202530350804020016012004020Cycle number28Graphite/NMC, 2.7-4.5

32、V, 0.2C2%PS 0.2M LiODFB 0.8 M LiPF6 BNSBNS for 4.5 V graphite/NMC cellProvided by YTQ1008060Specific capacity/ mAhg-1Efficiency (%)05101520250Cycle number(a) 210180150120906030010080604020SN1IL-TFSI for 4.5 and 4.6 V graphite/NMC2.7-4.6 V2.7-4.5 VGraphite/NMC0.2CSN1IL-TFSI/EMC (1:1 by vol.)Capacity/

33、mAh140001200010000800060004000200000100200300400500600700E12A084-1668 Cycle； 83.53%EST: 811 Cycle； 80%10AAE7365270PM3HSE)-11500mAhCommercialization of OS ElectrolytesNMC/OS Electrolyte/C Battery (10 Ah)Number of CycleCharge: CC 10Ato 4.2V; CV 4.2V to 3.5hr or 200mAcut-off at RTDischarge: 10A to 2.75

34、V at RT采測一1s采集一個數(shù)據(jù)兩種電解液的電池在穿刺測試過程中溫升趨勢和最高溫度均沒有明顯差異，即電池內(nèi)部的放熱反應(yīng)方式和程度沒有變化，但有機(jī)硅電解液能有效抑制易燃成分的燃燒。有機(jī)硅電解液與商業(yè)電解液三元動力電池（10 Ah)針刺安全性對比有機(jī)硅電解液電池?zé)熿F噴射力度較小，地上的黑色物質(zhì)少商業(yè)電解液電池?zé)熿F噴射力度較大，地上的黑色物質(zhì)多，部分電池會著火爆炸OS electrolyte batteryPack (10.8V，100Ah)Demonstration of OS Battery PackApplication: Solar Energy Navigation lightColl

35、aboration：GD Maritime Safety Administration (廣州航標(biāo)局）SiC compositeCompatability of OS Electrolyte with Si AnodeDischarge capacity (mAh/g)Capacity retention (%)Columbic efficiency (%)ElectrolyteLB303LB303+FECLB303+ BNSElectrode1st CE1st reversible cap.100th CE100th reversible cap.Capacity retentionSi77

36、.1%270698.8%1365.0%SiC79.7%105498.4%49546.9%Si86.4%308998.7%128841.7%SiC84.2%107596.0%84178.2%Si86.1%334899.4%203560.8%SiC82.0%113996.9%100388.1%Current density: 400mA/g02080100010008000700060005000400030002000Si anode (LB303)Si anode (LB303+FEC)Si anode (LB303+BNS)SiC anode (LB303)SiC anode (LB303+

37、FEC)SiC anode (LB303+BNS)40 60Cycle number1008060020406080100100806040200120Si anode (LB303+BNS)SiC anode (LB303)SiC anode (LB303+FEC)SiC anode (LB303+BNS)Cycle numberSi anode (LB303)Si anode (LB303+FEC)Discharge capacity (mAh/g)Discharge capacity (mAh/g)Columbic efficiency (%)Columbic efficiency (%

38、)Current density: 400mA/g68% capacity retention05010015020010000200040003000SiC (LB303)SiC (LB303+FEC)SiC (LB303+BNS)200406010080LB303+BNSSi85.9%262199.7%1696Cycle numberCurrent density: 600mA/gElectrolyteElectrode1st CE1st reversible capacity200th CE200th reversible capacity050200100002000300040006

39、0005000Si anode (LB303+BNS)100 150Cycle numberCurrent density: 600mA/g6050708010090SiCSi納米硅顆粒負(fù)極材料極片在商業(yè)電解液和使用了FEC添加劑時(shí)，極片在首次嵌脫鋰后電極出現(xiàn)明顯的脫落，在使用了有機(jī)硅電解質(zhì)（BNS）為添加劑時(shí)，極片脫落現(xiàn)象明顯改善。與裸硅負(fù)極材料相比，經(jīng)過碳包覆后制備出的碳硅復(fù)合材料極片在使用商業(yè)電解液時(shí)，經(jīng)過嵌脫鋰后有部分剝落，但情況比裸硅電極已有改善。當(dāng)使用了FEC和BNS為添加劑時(shí)有明顯的改善，極片并為出現(xiàn)類似的剝落現(xiàn)象。Intensity (a.u.)Intensity (a.u.)

40、Intensity (a.u.)Raman shift (cm )Raman shift (cm )Raman shift (cm )Raman dataRef: 1 Adv. Mater. 2013, 25, 449845032 J. Non-Cryst. Solids 2006 , 352 , 4101 .1、BNS作為添加劑易于在Si表面形成含有Si-O-Si的SEI膜2、與傳統(tǒng) 的SEI膜不同，形成的這種SEI膜可能有一定的脫嵌鋰活性(Li2Si2O5)3、在脫鋰后，BNS作為添加劑時(shí)產(chǎn)生的SEI膜較其它兩種電解液相比能穩(wěn)定存在50010001500SiLB303LB303+FECLB

41、303+BNS-1Delithiation at 1.5V500100015002000Si befor cycle50010001500Si-SistretchingLB303LB303+FECLB303+BNS-1Si-O-Sibendingin Li2Si2O5-1Lithiation at 0.01VSi-O stretching vibrationSiIntensity (a.u.)Intensity (a.u.)Intensity (a.u.)Raman shift (cm )Raman shift (cm )Raman shift (cm )500100015002000SiCL

42、B303LB303+FECLB303+BNSSi-O-SibendingLithiation at 0.01VSi-O stretching vibrationin Li2Si2O5-15001000 15002000SiCDelithiation at 1.5VLB303LB303+FECLB303+BNSG bandD band-11、BNS作為添加劑在SiC表面形成含有Si-O-Si的SEI膜2、由于有包覆碳層的存在，以FEC和BNS作為添加劑時(shí)產(chǎn)生的SEI膜都較穩(wěn)Ref: 1Adv. Mater. 2013, 25, 449845032 J. Non-Cryst. Solids 200

43、6 , 352 , 4101 .5001000 15002000SiC anode before cycle-1AnodeSiSiCElectrolyteLithiationDelithiationLithiationDelithiationLB3033.6%46.4%1.8%2.4%LB303+FEC5.5%26.8%4.8%6.3%LB303+BNS14.2%8.6%6.8%9.5%Intensity (a.u.)Intensity (a.u.)1.52.02.5LB303+BNS(Lithiation)LB303+BNS(Delithiation)LB303(Delithiation)K

44、evOCLB303(Lithiation)FSiSi anode0.51.02.02.5LB303+BNS(Delithiation)LB303+BNS(Lithiation)LB303(Delithiation)LB303(Lithiation)SiCanodeSiFOC1.5Kev0.5 1.0Si 元素含量分析1、LB303和LB303+FEC: Si電極在循環(huán)后表面硅含量猛增，SEI膜的破壞硅的裸露2、 BNS作為添加劑時(shí)產(chǎn)生的SEI膜中Si含量高于LB303形成的，證明Si成分參與成膜3、在SiC中碳層的存在對三種電解液來說都有利形成更加穩(wěn)定的SEI膜Transmission (a.

45、u.)Transmission (a.u.)Transmission (a.u.)5002500Delithiation1000 1500 2000Wavenumber (cm-1)LithiationLB303+FECSi anode5002500DelithiationLithiationLB303Si anode1000 1500 2000Wavenumber (cm-1)*1、 (LB303) 870：LiPF6峰的相對強(qiáng)度明顯減小，說明經(jīng)過脫鋰后SEI的分解（Ref: J. Phy. Chem. C 2011, 28, 965-976）2、(LB303+FEC) 870：LiPF61

46、640, 1450,1090, 1810: 為FEC分解產(chǎn)物（Ref: Langmuir 2011, 28, 965-976）5001000150020002500*Si anodeLB303+BNSDelithiationLithiationWavenumber (cm-1)3、(LB303+BNS) 870：LiPF6峰的相對強(qiáng)度減小不明顯，說明經(jīng)過生成的SEI較為穩(wěn)定，對比三種電解液，1060處的Si-O-Si 鍵明顯增強(qiáng)，證實(shí)了SEI膜中的Si-O-Si成分，脫鋰后任然能夠穩(wěn)定存在Transmission (a.u.)Transmission (a.u.)Transmission (a

47、.u.)SiC anode5002500LB303+FECLithiationDelithiationSiC anode1000 1500 2000Wavenumber (cm-1)5001000150020002500DelithiationLithiationWavenumber (cm-1)500 1000 1500 2000 2500SiC anodeLB303DelithiationLithiationWavenumber (cm-1)LB303+BNS1、 SEI結(jié)構(gòu)分析參考Si anode2、 與Si電極不同，由于C的存在，形成的SEI膜更加穩(wěn)定(870：LiPF6峰的相對強(qiáng)度在脫鋰后變化沒有Si電極那么明顯）Si anode (Electrolyte:LB303)發(fā)生膨脹 Lithiation at 0.01V發(fā)生收縮開裂 Delithiati