Lifepo4 batteries are lithium-ion secondary batteries. One main use is for power batteries. It has great advantages over nickel-hydrogen and nickel-cadmium batteries. Lifepo4 batteries have high charging and discharging efficiency, with a charging and discharging efficiency of over 90% in the discharge state, while lead-acid batteries have a charging and discharging efficiency of around 80%.
The PO bond in lithium iron phosphate crystals is stable and difficult to decompose, and even at high temperatures or overcharging, it will not collapse or generate heat like lithium cobalt, nor will it form strong oxidizing substances, so it has good safety.
It is reported that in actual operations, a small number of samples were found to have combustion during needle puncture or short-circuit tests, but no explosion occurred. In the overcharging experiment, a high-voltage charge several times higher than the self-discharge voltage was used, and it was found that there was still a burst phenomenon. Nevertheless, its overcharging safety has been greatly improved compared to ordinary liquid electrolyte lithium cobalt oxide batteries.
Lifepo4 batteries refer to lithium-ion batteries with lithium iron phosphate as the positive electrode material.
The cycle life of long-life lead-acid batteries is about 300 times, with a maximum of 500 times. The cycle life of lithium iron phosphate power batteries can reach over 2000 cycles, and the standard charging (5-hour rate) can reach 2000 cycles.
A lead-acid battery of the same quality can last for up to 1–1.5 years, with "new half a year, old half a year, and maintenance half a year". However, lithium-ion batteries, when used under the same conditions, have a theoretical lifespan of 7-8 years.
Overall, the theoretical cost-performance ratio is more than four times that of lead-acid batteries. High-current discharge can be quickly charged and discharged using high-current 2C. Under a dedicated charger, charging at 1.5 C for 1.5 minutes can fully charge the battery, and the starting current can reach 2 C, while lead-acid batteries do not have such performance.
The peak temperature of lithium iron phosphate can reach 350°C–500°C, while lithium manganese and cobalt are only around 200°C. The working temperature range is wide (-20C to +75C), and it is resistant to high temperatures. The peak electric heating of lithium iron phosphate can reach 350°C–500°C, while lithium manganese and cobalt are only at 200°C.