BYD磷酸鐵鋰電池性能測試課件

1、1LiFePO4 performance2019-06-211LiFePO4 performance2019-06-212OutlineWhat is LiFePO4?Discharge curveGSM dischargeHigh temperature StorageLow temperature dischargeCycle lifeOverchargeFire exposure2OutlineWhat is LiFePO4?3What is LiFePO4?LiFePO4 is a new kind of positive material.LiFePO4 also has the f

2、unction that release or receive Li-ion like LiCoO2.LiFePO4Olivine structureFePO4Olivine structureLiFePO4ChargeDischarge3What is LiFePO4?LiFePO4 is a 4Discharge curveLiFePO4 has the same discharge curve as LiCoO2.LiFePO4 has the lower MPV (Mid-point voltage) than LiCoO2. MPV of LiFePO4 is 3.13.2V, MP

3、V of LiCoO2 is 3.63.7V.4Discharge curveLiFePO4 has th5GSM dischargeFollowing shows GSM discharge curve (cut off voltage is 2.8V).GSM1/0.2CGSM2/0.2C1#90.3%86.0%2#88.9%84.7%5GSM dischargeFollowing shows 6High temperature StorageFollowing show storage results of LiFePO4 and LiCoO2 system .Storage condi

4、tionCapacity keeping ratio (capacity after storage / capacity before storage)Capacity recovering ratio (capacity after recharge / capacity before storage)60, 7days85.2%92.8%85, 48hours75.1%80.2%Storage conditionCapacity keeping ratio (capacity after storage / capacity before storage)Capacity recover

5、ing ratio (capacity after recharge / capacity before storage)60, 7days83.1%89.2%85, 48hours72.5%79.3%LiCoO2LiFePO46High temperature StorageFollo7Low temperature dischargeFollowing shows discharge of different temperature.Temp.60/2545/250/25-10/25-20/25ratio(%)93.498.272.664.245.47Low temperature dis

6、chargeFoll8Cycle lifeLiFePO4 structure keeps stable before and after discharge, so it has good cycle life.Basing on experience of other projects, LiFePO4 cycle life can be more than 1000.Olivine structureFePO4Olivine structureLiFePO4ChargeDischarge8Cycle lifeLiFePO4 structure k9OverchargeLiFePO4 has

7、 good safety performance.Following show 1C/12V overcharge result.ConditionCell No.Max temp.PhenomenaResult1C/12V260#117.10Swelling, vent open lightly, no fire, no explosion.Pass253#120.05Pass271#120.64Pass9OverchargeLiFePO4 has good sa10OverchargeFollowing show 1C/12V overcharge curve and cell photo

8、s.Before testAfter test10OverchargeFollowing show 1C/11OverchargeLiFePO4 has good safety performance.Following show 3C/32V overcharge result.ConditionCell No.Max temp.PhenomenaResult3C/12V273#145.44Swelling, vent open lightly, no fire, no explosion.Pass11OverchargeLiFePO4 has good s12OverchargeFollo

9、wing show 3C/32V overcharge curve and cell photos.After test12OverchargeFollowing show 3C/13Fire exposureLiFePO4 has good safety performance.Following show the fire exposure result.Cell No.Voltage before test (V)Impedance before test (m)PhenomenaResult258#3.4758.7 Swelling, vent open, no fire, no explosion.Pas