Description

Advantages of LiFePO4 Battery: Faster charging and safer performance It is clear that the small capacity Li-ion (polymer) Battery containing lithium cobalt oxide (LiCoO2) offers a genuinely viable option for electronics and digital applications. However, lithium cobalt oxide (LiCoO2) is very expensive and un-safe for large capacity Li-ion Battery. Recently lithium iron phosphate (LiFePO4) has been becoming "best-choice" materials in commercial Li-ion (polymer) Batteries for large capacity and high power applications, such as lap-top, power tools, e-wheel chair, e-bike, e-car and e-bus. A LiFePO4 battery has hybrid characters: as safe as lead-acid battery and as powerful as lithium ion cells. The advantages of large format Li-ion (polymer) batteries containing lithium iron phosphate (LiFePO4) are listed as below: 1. Fast charging: During charging process, a conventional Li-ion Battery containing lithium cobalt oxide (LiCoO2) needs two steps to be fully charged: step 1 is using constant current (CC) to get *0% State of Charge (SOC); step 2 takes place when charge voltage reaches 4.2V, upper limit of charging voltage, turning from CC to constant voltage (CV) while the charging current is taping down. The step 1 (*0%SOC) needs two hours and the step 2 (*0%SOC) needs another two hours. LiFePO4 battery can be charged by only one step of CC to reach *5%SOC or be charged by CC+CV to get **0%SOC. The total charging time will be two hours. 2. Large overcharge tolerance and safer performance A LiCoO2 battery has a very narrow overcharge tolerance, about 0.1V over 4.2V of charging voltage plateau and upper limit of charge voltage. Continuous charging over 4.3V would either damage the battery performance, such as cycle life, or result in firing and explosion. A LiFePO4 battery has a much wider overcharge tolerance of about 0.7V from its charging voltage plateau 3.4V. Exothermic heat of chemical reaction with electrolyte measured by DSC after overcharge is only *0J/g for LiFePO4 verse ***0J/g for LiCoO2. The more is the exothermic heat, the larger energy heating up the battery in its abusive condition, the more chance toward firing and explosion. A LiFePO4 battery would be overcharged up to *0V without protection circuit board. It is suitable for large capacity and high power applications. From viewpoint of large overcharge tolerance and safety performance, a LiFePO4 battery is similar to lead-acid battery. 3. Self balance Alike lead-acid battery, a number of LiFePO4 cells in a battery pack in series connection would balance each other during charging process, due to large overcharge tolerance. This self balance character can allow *0% difference between cells for both voltage and capacity inconsistency. 4. Simplifying battery management system (BMS) and battery charger Large overcharge tolerance and self-balance character of LiFePO4 battery would simplify battery protection and balance circuit boards, lowering their cost. One step charging process would allow to use simpler conventional power supplier to charge LiFePO4 battery instead to use a expensive professional Li-ion battery charger. 5. Longer cycle life In comparison with LiCoO2 battery which has a cycle life of **0 cycles, LiFePO4 battery extends its cycle life up to ***0 cycles. 6. High temperature performance It is detrimental to have a LiCoO2 battery working at elevated temperature, such as *0 ?. However, a LiFePO4 battery runs better at elevated temperature, offering *0% more capacity, due to higher lithium ionic conductivity. If you want to know more about our battery, you can write to:arlene at gebattery dot com dot cn.