Electric car batteries: LiFePO4 Batteries or Lithium ternary batteries?

Due to the different performance characteristics and different application scenarios of lithium iron phosphate batteries and lithium ternary batteries, two technical routes will get support simultaneously. Among them, lithium iron phosphate batteries have the advantages of high safety and long cycle life, which can meet the safety requirements. In commercial vehicles with higher operating frequency and higher standards for space and weight, high-energy-density ternary batteries can achieve a more extended cruising range and meet the needs of individual consumers.

1. Although the lithium iron phosphate battery is resistant to high temperatures, the ternary lithium battery has better low-temperature resistance. It is the leading technical route for manufacturing low-temperature lithium batteries. At minus 20 °C, the ternary lithium battery can release 70.14% of the capacity. Lithium iron phosphate batteries can only remove 54.94% of the capacity. Because under low-temperature conditions, the discharge platform of ternary lithium batteries is much higher than the voltage platform of lithium iron phosphate batteries and starts faster.

2. Lithium ternary batteries have a higher charging efficiency. Lithium battery charging adopts a current-limiting and voltage-limiting method; constant current charging is performed in the first stage. At this time, the current is large, and the efficiency is high. After the continuous current charging reaches a specific voltage, it enters the second stage of constant voltage charging. At this time, the current is small, and the efficiency is low. Therefore, to measure the charging efficiency of the two, the ratio of the constant current charging power to the total battery capacity is called the constant current ratio. The experimental data shows little difference between the two when charging under 10C, but it will open the distance above 10C. When the charging current is at 20C, the constant current ratio of the ternary lithium battery is 52.75%. The constant current ratio of the LiFePO4 battery is 10.08 %; the former is five times that of the latter.

3. In terms of cycle life, lithium iron phosphate batteries are better than lithium ternary batteries. The academic life of ternary lithium batteries is 2000 times, but basically, the capacity decays to 60% when it is cycled 1000 times; even the best brand in the industry, Tesla, can only maintain 70% of the power after 3000 times, while the lithium iron phosphate battery has 80% of the capacity after the same cycle.

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