BYD磷酸铁锂电池性能测试

BYDCOMPANYLIMITED1LiFePO4performance2006-06-21BYDCOMPANYLIMITED2Outline1.WhatisLiFePO4?2.Dischargecurve3.GSMdischarge4.HightemperatureStorage5.Lowtemperaturedischarge6.Cyclelife7.Overcharge8.FireexposureBYDCOMPANYLIMITED3WhatisLiFePO4?•LiFePO4isanewkindofpositivematerial.•LiFePO4alsohasthefunctionthatreleaseorreceiveLi-ionlikeLiCoO2.LiFePO4OlivinestructureFePO4OlivinestructureLiFePO4ChargeDischargeBYDCOMPANYLIMITED4Dischargecurve•LiFePO4hasthesamedischargecurveasLiCoO2.•LiFePO4hasthelowerMPV(Mid-pointvoltage)thanLiCoO2.MPVofLiFePO4is3.1~3.2V,MPVofLiCoO2is3.6~3.7V.BYDCOMPANYLIMITED5GSMdischarge•FollowingshowsGSMdischargecurve(cutoffvoltageis2.8V).GSM1/0.2CGSM2/0.2C1#90.3%86.0%2#88.9%84.7%BYDCOMPANYLIMITED6HightemperatureStorage•FollowingshowstorageresultsofLiFePO4andLiCoO2system.StorageconditionCapacitykeepingratio(capacityafterstorage/capacitybeforestorage)Capacityrecoveringratio(capacityafterrecharge/capacitybeforestorage)60℃,7days85.2%92.8%85℃,48hours75.1%80.2%StorageconditionCapacitykeepingratio(capacityafterstorage/capacitybeforestorage)Capacityrecoveringratio(capacityafterrecharge/capacitybeforestorage)60℃,7days83.1%89.2%85℃,48hours72.5%79.3%LiCoO2LiFePO4BYDCOMPANYLIMITED7Lowtemperaturedischarge•Followingshowsdischargeofdifferenttemperature.Temp.60℃/25℃45℃/25℃0℃/25℃-10℃/25℃-20℃/25℃ratio(%)93.498.272.664.245.4BYDCOMPANYLIMITED8Cyclelife•LiFePO4structurekeepsstablebeforeandafterdischarge,soithasgoodcyclelife.•Basingonexperienceofotherprojects,LiFePO4cyclelifecanbemorethan1000.OlivinestructureFePO4OlivinestructureLiFePO4ChargeDischargeBYDCOMPANYLIMITED9Overcharge•LiFePO4hasgoodsafetyperformance.•Followingshow1C/12Voverchargeresult.ConditionCellNo.Maxtemp.PhenomenaResult1C/12V260#117.10℃Swelling,ventopenlightly,nofire,noexplosion.Pass253#120.05℃Pass271#120.64℃PassBYDCOMPANYLIMITED10Overcharge•Followingshow1C/12Voverchargecurveandcellphotos.BeforetestAftertestBYDCOMPANYLIMITED11Overcharge•LiFePO4hasgoodsafetyperformance.•Followingshow3C/32Voverchargeresult.ConditionCellNo.Maxtemp.PhenomenaResult3C/12V273#145.44℃Swelling,ventopenlightly,nofire,noexplosion.PassBYDCOMPANYLIMITED12Overcharge•Followingshow3C/32Voverchargecurveandcellphotos.AftertestBYDCOMPANYLIMITED13Fireexposure•LiFePO4hasgoodsafetyperformance.•Followingshowthefireexposureresult.CellNo.Voltagebeforetest(V)Impedancebeforetest(mΩ)PhenomenaResult258#3.4758.7Swelling,ventopen,nofire,noexplosion.Pass268#3.4352.8Swelling,ventopen,fire,noexplosion.Pass251#3.5856.0PassBeforetestAftertestBYDCOMPANYLIMITED14