Lithium iron phosphate battery refers to a lithium ion battery that uses lithium iron phosphate as the positive electrode material. The positive electrode materials of lithium-ion batteries mainly include lithium cobaltate, lithium manganate, lithium nickelate, ternary materials, lithium iron phosphate, etc. Among them, lithium cobalt oxide is the positive electrode material used in most lithium-ion batteries.
The electrochemical performance of the cathode material of lithium iron phosphate battery is relatively stable, which determines that it has a stable charging and discharging platform. It is still very safe under special conditions such as filling, extrusion, and acupuncture. The performance comparison between lithium iron phosphate battery and ternary lithium battery is as follows.
1. The service life of lithium iron phosphate battery and ternary lithium battery
In terms of battery life, lithium iron phosphate energy storage technology is more advantageous than ternary lithium batteries in terms of cycle utilization rate. Under experimental conditions, lithium iron phosphate batteries have a remaining capacity of 84% after 5,000 cycles. The remaining capacity of the ternary lithium battery is 66% after 3900 cycles. Compared with the cycle life, the advantage of the lithium iron phosphate battery is more obvious. In terms of cycle life, compared with the ternary lithium battery, the real life of the lithium iron phosphate battery is much longer. Under the same number of cycles, the remaining capacity of the lithium iron phosphate battery is much more than that of the ternary lithium battery.
2. Low temperature resistance of lithium iron phosphate battery and ternary lithium battery
Under low temperature conditions (the temperature is lower than -10°C), the lithium phosphate battery decays very quickly. After less than 100 charge and discharge cycles, the battery capacity will drop to 20% of the initial capacity, which is basically insulated from the use in cold regions; and The ternary lithium battery has excellent low-temperature performance, and can maintain normal battery capacity at -30°C, which is more suitable for use in low-temperature areas in the north.
3. Safety performance of lithium iron phosphate battery and ternary lithium battery
Under high temperature conditions, the ternary material of the ternary lithium battery will decompose at 200°C, produce a violent chemical reaction, release oxygen atoms, and easily burn or explode under the action of high temperature. The decomposition temperature of the lithium phosphate battery energy storage system is 800°C, and it is not easy to catch fire, and its adaptability to temperature is relatively high.
These two batteries will decompose when they reach a certain temperature. The decomposition temperature of the lithium iron phosphate battery energy storage system is higher than that of the ternary lithium battery, but this does not mean that the safety of the ternary lithium battery is poor. The safety design of the power battery system can be improved through power connection structure, thermal management design, battery management system and other aspects of the system. Manufacturers can strengthen the overcharge protection, over-discharge protection, over-temperature protection, and over-current protection. Improve the design of safety measures to be more perfect and scientific, which can also make the battery work in a safe state. Compared with lithium iron phosphate batteries, ternary lithium batteries are more suitable for current and future household electric vehicles.