In the field of new energy vehicles, two mainstream battery technologies are ternary lithium battery and LiFePO4 battery. Although there is a Technology roadmap dispute between the two types of batteries in many fields, the competition in the field of new energy vehicles is the main one. At present, domestic electric vehicles will also consider these two types of batteries when choosing power sources. Next, the editor will take you to understand the differences and advantages of the two types of batteries.
1. From the perspective of safety, the ternary lithium battery will be more active than the LiFePO4 battery. In terms of stability, the LiFePO4 battery has better thermal stability, so it will be safer. But the advancement of battery technology lies in its ability to better leverage its advantages and avoid weaknesses. The magazine battery system safety technology released by GAC Aian has achieved the goal of ensuring that the entire package of ternary lithium batteries does not ignite, elevating the safety standards of ternary lithium batteries to a new level.
2. Due to the relatively high energy density of ternary lithium batteries, they weigh less with the same amount of electricity and occupy less space and consume less electricity in new energy vehicles. Therefore, ternary lithium batteries have a larger discharge current and faster speed, as well as stronger endurance. Therefore, electric vehicles with ternary lithium batteries can travel a longer distance. At present, Lithium iron phosphate batteries are mainly used for city buses. Because their range is relatively short, they need a Charging station within a certain distance to provide charging.
3. Tesla's battery pack consists of approximately 7000 18650 ternary lithium batteries. If there is an internal short circuit in these units or the entire battery pack, an open flame may occur. In the event of a serious collision accident, it may cause a short circuit to ignite. Because the LiFePO4 battery material will not burn in case of a short circuit, and its high-temperature resistance performance is also better than the ternary lithium battery, for safety reasons, passenger buses usually use Lithium iron phosphate batteries as the power source.
4. Although LiFePO4 battery has high-temperature resistance, ternary lithium battery is more excellent in low-temperature resistance, so it is the main Technology roadmap for manufacturing low-temperature lithium batteries. At -20 ° C, the ternary lithium battery can release 70.14% of the capacity, while the LiFePO4 battery only supports the release of 54.94% of the capacity. In addition, at low temperatures, the discharge platform of the ternary lithium battery is much higher than the voltage platform of the LiFePO4 battery, and the startup speed is faster.
5. The ternary lithium battery is better at charging efficiency. The lithium battery adopts current-limiting and voltage-limiting charging. The first stage is constant current charging. At this time, the current is large and the efficiency is high. When the constant current charging reaches a certain voltage, the second stage of constant voltage charging begins. This stage has a smaller current and lower efficiency. We usually measure the charging efficiency by using the ratio of the constant current charging capacity to the total battery capacity, which is called the constant current ratio. The experimental data shows that there is little difference between the two under 10C, but the difference in charging efficiency will widen above 10C. For example, when charging at 20C, the constant current ratio of the ternary lithium battery is 52.75%, while the constant current ratio of the LiFePO4 battery is 10.08%, the former is five times the latter.
6. In terms of battery cycle life, Lithium iron phosphate is superior to lithium ternary. The theoretical lifespan of ternary lithium batteries is 2000 cycles, but basically after 1000 cycles, their capacity will decay to 60%. Even the Tesla brand can only maintain 70% of the power after 3000 cycles, while the LiFePO4 battery can still maintain 80% of the capacity after the same cycle.
Through the comparison of the above aspects, we can preliminarily see the differences and advantages between the ternary lithium battery and the LiFePO4 battery. The LiFePO4 battery has the advantages of high safety, long life, and high-temperature resistance, while the ternary lithium battery has the advantages of lightweight, high charging efficiency, and low-temperature resistance, which is also the reason why the two types of batteries coexist in different application fields.
You must be logged in to post a comment.