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What is the Cycle Life of Lithium Iron Phosphate Batteries?

Feb. 27, 2020

Lithium iron phosphate has good electrochemical performance and low resistance. This is achieved with nanoscale phosphate cathode materials. The main advantages are high rated current and long cycle life; good thermal stability, enhanced safety and tolerance to abuse. The following Lithium Iron Phosphate Battery Manufacturer will give you a detailed introduction to the life of lithium iron phosphate batteries.

If kept at high voltage for a long time, lithium iron phosphate is more resistant to all charging conditions and has less stress than other lithium ion systems. The disadvantage is that the lower nominal voltage of the 3.2V battery makes the specific energy lower than that of cobalt-doped lithium ion batteries. For most batteries, low temperature will reduce performance, and increasing storage temperature will shorten service life, and lithium iron phosphate is no exception. Lithium iron phosphate has a higher self-discharge than other lithium-ion batteries, which may cause aging and bring about balance problems. Although it can be compensated by using high-quality batteries or using advanced battery management systems, both methods Increase the cost of the battery pack. Battery life is very sensitive to impurities in the manufacturing process and cannot withstand moisture doping. Due to the presence of moisture impurities, some batteries have a minimum life of only 50 cycles.

Lithium Iron Phosphate Battery is often used instead of lead acid starter batteries. Four series batteries produce 12.80V, which is similar to the voltage in series of six 2V lead-acid batteries. The vehicle charges lead acid to 14.40V (2.40V / battery) and maintains a floating charge state. The purpose of the float charge is to maintain a full charge level and prevent sulfated lead-acid batteries.

Lithium Iron Phosphate Battery

Lithium Iron Phosphate Battery

By connecting four lithium iron phosphate batteries in series, the voltage of each battery is 3.60V, which is the correct full charge voltage. At this time, the charging should be disconnected, but continue to charge while driving. Lithium iron phosphate tolerates some overcharging; however, as most vehicles keep the voltage at 14.40V for long periods of time during long journeys, it may increase the mechanical stress of lithium iron phosphate batteries. Time will tell us how long lithium iron phosphate can withstand overcharging as a replacement for lead-acid batteries. Low temperature will also reduce the performance of lithium ions, which may affect the starting ability in extreme cases.

Lithium iron phosphate has good safety and long life, moderate specific energy, and enhanced self-discharge ability. Lithium iron phosphate batteries are lithium-ion secondary batteries. One of the main uses is for power batteries, which has great advantages over NI-MH and Ni-Cd batteries. The lithium iron phosphate battery has a higher charge and discharge efficiency, and the charge and discharge efficiency can reach more than 90% in the case of rate discharge, while the lead-acid battery is about 80%.

The P-O bond in the lithium iron phosphate crystal is stable and difficult to decompose. Even at high temperature or overcharge, it will not collapse and generate heat or form strong oxidizing substances like lithium cobaltate, so it has good safety. Some reports pointed out that in actual operation, a small number of samples were found to have burned during acupuncture or short-circuit experiments, but no explosion event occurred. However, in the overcharge experiment, high-voltage charging was used that significantly exceeded the discharge voltage by several times. Nevertheless, its overcharge safety has been greatly improved compared to ordinary liquid electrolyte lithium cobaltate batteries.

However, some experts said that environmental pollution caused by lead-acid batteries mainly occurs in irregular production processes and recycling processes. In the same way, lithium battery belongs to the new energy industry, but it can't avoid the problem of heavy metal pollution. In the processing of metal materials, lead, arsenic, cadmium, mercury, chromium, etc. may be released into dust and water. The battery itself is a chemical substance, so there may be two kinds of pollution: one is the process excreta pollution in the production engineering; the other is the battery pollution after scrapping.

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