The advantages of lithium iron phosphate batteries are:
1 Lithium iron phosphate batteries have a long life and a lifespan of more than 2,000 times. Under the same conditions, lithium iron phosphate batteries can be used for 7 to 8 years.
2 Safe use. Lithium iron phosphate batteries have undergone strict safety testing and will not explode even in a traffic accident.
3 Charging is fast. Using a dedicated charger, the battery can be fully charged at 1.5°C in 40 minutes.
4 Lithium iron phosphate batteries are resistant to high temperatures, and the hot air value of lithium iron phosphate batteries can reach 350-500 degrees Celsius.
5 The lithium iron phosphate battery has a large capacity.
6 Lithium iron phosphate batteries do not have a memory effect.
7 The lithium iron phosphate battery is green, non-toxic, non-polluting,has many sources of raw materials and is cheap.
The disadvantages of lithium iron phosphate batteries are:
1 The plug density of the positive electrode of lithium iron phosphate batteries is low, and the density is generally about 0.8 to 1.3. Big size.
2 The conductivity is poor, the lithium ion diffusion rate is slow, and the actual specific capacity is low when charging and discharging at high times.
3 Lithium iron phosphate batteries have poor performance at low temperatures.
4 The life of a single lithium iron phosphate battery is long, about 2,000 times, but the life of a lithium iron phosphate battery is short, generally about 500 times.
Detailed information:
Improved security performance
The P-O link ins lithium iron phosphate crystal is stable and difficult to decompose even at high temperatures or overcharge. Like lithium cobalt oxide, the structure collapses and generates heat or forms strong oxidizing substances, so it has good safety. According to some reports, in actual operations, a small number of samples burned during acupuncture or short circuit experiments, but no explosion occurred during overload experiments, high voltage charging several times higher than the discharge voltage was used. , and it was found that there were still explosion phenomena. Despite this, its overcharge safety has been significantly improved compared to ordinary liquid electrolyte, lithium and cobalt oxide batteries.
Improved service life
Lithium iron phosphate battery refers to a lithium-ion battery usinglithium iron phosphate as cathode material.
The lifespan of long-life lead-acid batteries is about 300 times, and the maximum is 500 times, while the lifespan of lithium iron phosphate batteries reaches more than 2,000 times when used with standard batteries. When charging (5 hours rate), it can reach 2000 times. Lead-acid batteries of the same quality last “six months for new ones, six months for old ones and another six months for maintenance”, or 1 to 1.5 years at most. However, when used under the same conditions, the theoretical life of lithium iron phosphate batteries will reach 7 to 8 years. Overall, the performance-price ratio is theoretically more than 4 times higher than that of lead-acid batteries. Large current discharge can quickly reach high current 2CTo charge and discharge, with a special charger, the battery can be fully charged en 40 minutes at 1.5°C and the starting current can reach 2°C, while lead batteries do not have this performance.
Good high temperature performance
The electric heating peak of lithium iron phosphate can reach 350℃-500℃, while the maximum value of lithium iron phosphate lithium cobalt oxide is only about 200℃. . It has a wide operating temperature range (-20°C to +75°C) and features high temperature resistance. The electric heating peak of lithium iron phosphate can reach 350℃ - 500℃, while lithium manganate and lithium cobalt oxide are only about 200℃.
Lithium iron phosphate is now generally chosen as the cathode material to power lithium-ion batteries in China. Market analysts from government, scientific research institutes, corporations and even securities companiess are optimistic about this material and are considering it. as a power type lithium-ion battery. The direction of lithium-ion battery development. Analyzing the reasons, there are two main points: First, it is influenced by the direction of research and development in the United States. American companies Valence and A123 were the first to use lithium iron phosphate as the cathode material for lithium-ion batteries. Second, there is no domestically prepared lithium manganate material with good high-temperature cycling and storage properties that can be used in power lithium-ion batteries. However, lithium iron phosphate also has fundamental defects that cannot be ignored, which can be summarized as follows:
1 During the sintering process when preparing iron and lithium phosphate lithium, iron oxide exists at high temperaturesperature. reducing atmosphere. Possibility of being reduced to elemental iron. Elemental iron can cause micro-short circuits in batteries and is the most taboo substance in batteries. This is also the main reason why Japan has not used this material as a cathode material to power lithium-ion batteries.
2. Lithium iron phosphate has some performance defects, such as low tapping density and low packing density, which results in low energy density of lithium-ion batteries. Low temperature performance is poor and even nanonization and carbon coating have not solved this problem. When Dr. Don Hillebrand, director of the Center for Energy Storage Systems at Argonne National Laboratory in the United States, spoke about the low-temperature performance of lithium iron phosphate batteries, he used the word "terrible" todescribe them. Lithium iron phosphate lithium ion batteries have been shown to operate at low temperatures. Electric vehicles cannot operate at temperatures below 0°C.
Although some manufacturers claim that the capacity retention rate of lithium iron phosphate batteries at low temperatures is not bad, it is when the discharge current is small and the cut-off voltage is discharge is very low. In this situation, the device simply cannot start working.
References:
What are the eight advantages of lithium iron phosphate battery
The advantages of this battery include small size and energy density Higher and better resistance to low temperatures. The advantages of batteriesLithium iron phosphate ies are higher safety, longer life, low cost and good high temperature resistance.
The advantages of ternary lithium batteries includeIt has a small surface area, high energy density and good low temperature resistance. It can still maintain a long battery life in low temperature environments and has relatively good cycle performance. However, the disadvantage of ternary lithium batteries is that they have poor performance. high temperature resistance. It is easy to decompose at high temperatures, causing safety problems, especially in the event of a collision or short circuit, which may cause more serious combustion or explosion.
The advantages of lithium iron phosphate batteries are higher safety, longer life, low cost and good weather resistance.high erasures. Lithium iron phosphate batteries have more stable performance at high temperatures and are not prone to decomposition or combustion. , but its disadvantages are relatively low energy density, poor low temperature resistance, and reduced battery life in low temperature environments.
Summary: Lithium iron phosphate battery refers to a lithium-ion battery using lithium iron phosphate as the cathode material. The full name of lithium iron phosphate battery is lithium iron phosphate battery, called lithium iron phosphate battery. Because its performance is particularly suitable for power applications, the word "power" is added to the name, that is, lithium iron phosphate power battery. Some people also call it a “lithium iron (LiFe) battery”. The cathode materials of lithium-ion batteries mainly includePalely lithium cobalt oxide, lithium manganate, lithium nickel oxide, ternary materials, lithium iron phosphate, etc. Among them, lithium cobalt oxide is the cathode material currently used in most lithium-ion batteries. Let's take a look at the advantages and disadvantages of lithium iron phosphate batteries. 1. Eight advantages of lithium iron phosphate batteries
1. Improved safety performance
The P-O bond in lithium iron phosphate crystal is stable and difficult to decompose even at high temperatures or overcharge. Unlike lithium cobalt oxide, the structure will not collapse and generate heat or form strong oxidizing substances, so it provides good safety. According to some reports, in actual operations, a small number of samples burned during acupuncture or short circuit experiments, but no explosions occurred.st produced in overcharging experiments, a high voltage charge several times higher than the discharge voltage was used. , and it was found that there were still explosion phenomena. Despite this, its overcharge safety has been significantly improved compared to ordinary liquid electrolyte, lithium and cobalt oxide batteries.
2. Improved lifespan
Lithium iron phosphate battery refers to a lithium-ion battery using lithium iron phosphate as the cathode material.
The lifespan of long-life lead-acid batteries is about 300 times, and the maximum is 500 times, while the lifespan of lithium iron phosphate batteries reaches more than 2,000 times when used with standard batteries. When charging (5 hours rate), it can reach 2000 times. Lead-acid batteries of the same quality last “six months for new ones, six months for old ones andanother six months for maintenance”, or 1 to 1.5 years maximum. However, when used under the same conditions, the theoretical life of lithium iron phosphate batteries will reach 7 to 8 years. Overall, the performance-price ratio is theoretically more than 4 times higher than that of lead-acid batteries. High current discharge can quickly charge and discharge at a high current of 2C. Under a special charger, the battery can be fully charged in 40 minutes at 1.5C, and the starting current can reach 2C. performance.
3. Good high temperature performance
The electric heating peak of lithium iron phosphate can reach 350℃ - 500℃, while the maximum value of lithium manganate and lithium iron oxide cobalt is only about 200℃. Wide operating temperature range (-20C--+75C), with high temperature resistance, the peak electric heating of phosphatee of iron and lithium can reach 350℃-500℃, while lithium manganate and lithium cobalt oxide are only about 200℃.
4. Large capacity
Has a larger capacity than ordinary batteries (lead-acid, etc.). 5AH-1000AH (single unit)
5. No memory effect
When rechargeable batteries are often operated under conditions where they are often fully charged and not fully discharged, the capacity decreases quickly. fall below the rated capacity value. This phenomenon is called memory effect. Nickel metal hydride and nickel cadmium batteries have memory, but lithium iron phosphate batteries do not have this phenomenon. Regardless of the state the battery is in, it can be charged and used at any time, and there is no need to discharge it first. then charge it.
6. Light weight
The volume of a lithium iron phospha batteryte with the same specifications and capacity is 2/3 that of a lead-acid battery, and its weight is 1/3 that of a lead-acid battery.
7. Environmental protection
The battery is generally considered to be free of heavy metals and rare metals (nickel-metal hydride batteries require rare metals), non-toxic (SGS certified). ), and non-polluting. It complies with European RoHS regulations and is an absolute ecological battery certificate. Therefore, the reason why lithium batteries are favored by the industry is mainly due to environmental protection considerations. Therefore, the battery was included in the national high-tech development plan “863” during the “Tenth Five-Year Plan” period. become a key national project supporting and encouraging development. With China's accession to the WTO, the volume of e-bike exportsChinese electric bikes will increase rapidly, and electric bicycles entering Europe and the United States will need to be equipped with non-polluting batteries.
However, some experts said that environmental pollution caused by lead-acid batteries mainly occurs in the company's non-standard production process and recycling processing links. In the same way, lithium batteries are good for the new energy industry, but they cannot avoid the problem of heavy metal pollution. Lead, arsenic, cadmium, mercury, chromium, etc. can be released into dust and water when processing metal materials. The battery itself is a chemical substance, so it can produce two types of pollution: one is pollution from process effluents of the production project; the other is pollution from batteries after their disposal.
LLithium iron phosphate batteries also have their disadvantages: for example, poor low temperature performance, low setting density of cathode material, and the volume of lithium iron phosphate batteries of the same capacity is larger than that of lithium iron phosphate batteries. ion such as lithium-cobalt oxide, so micro-batteries have no advantage. When used in power batteries, lithium iron phosphate batteries, like other batteries, face battery consistency issues.
8. Comparison of power batteries
At present, the most promising cathode materials for power lithium ion batteries mainly include modified lithium manganate (LiMn2O4) and lithium iron phosphate (LiFePO4) and Lithium-nickel-cobalt manganate ternary materials (Li(Ni,Co,Mn)O2). Due to the lack of cobalt resources, the high costDue to nickel and cobalt and strong price fluctuations, it is generally believed that it is difficult to become the mainstream of power lithium-ion batteries for electric vehicles. However, they can be combined. with spinel manganate, lithium is mixed within a certain range.
2. Disadvantages of lithium iron phosphate batteries
Whether a material has potential for application development, in addition to paying attention to its advantagesIn addition, it is more important to know whether the material has any fundamental defects.
Lithium iron phosphate is now generally chosen as the cathode material to power lithium-ion batteries in China. Market analysts from government, scientific research institutes, enterprises and even securities companies are optimistic about this material and consider it. as a power type lithium-ion battery. Say itction of the development of lithium-ion batteries. Analyzing the reasons, there are two main points: First, it is influenced by the direction of research and development in the United States. American companies Valence and A123 were the first to use lithium iron phosphate as the cathode material for lithium-ion batteries. Second, there is no domestically prepared lithium manganate material with good high-temperature cycling and storage properties that can be used in power lithium-ion batteries. However, lithium iron phosphate also has fundamental defects that cannot be ignored, which can be summarized as follows:
1 During the sintering process when preparing iron and lithium phosphate lithium, iron oxide exists at high temperatures. reducing atmosphere. Possibility of being reduced to elemental iron. Elemental iron can causemicro-short circuits in batteries and is the most taboo substance in batteries. This is also the main reason why Japan has not used this material as a cathode material to power lithium-ion batteries.
2. Lithium iron phosphate has some performance defects, such as low tapping density and low packing density, which results in low energy density of lithium-ion batteries. Low temperature performance is poor and even nanonization and carbon coating have not solved this problem. When Dr. Don Hillebrand, director of the Center for Energy Storage Systems at Argonne National Laboratory in the United States, spoke about the low-temperature performance of lithium iron phosphate batteries, he used the word "terrible" to describe them. Lithium iron phosphate lithium ion batteries have shown that lithium iron phosphate batteries workwork well at low temperature (below 0℃) electric vehicles cannot be driven. Although some manufacturers claim that the capacity retention rate of lithium iron phosphate batteries at low temperatures is not bad, it is when the discharge current is small and the discharge cut-off voltage is very low. In this situation, the device simply cannot start working.
3. The material preparation cost and battery manufacturing cost are high, the battery efficiency is low, and the consistency is poor. Although nanonization and carbon coating of lithium iron phosphate improve the electrochemical performance of the material, it also leads to other problems, such as reduced energy density, increased synthesis cost, poor processing performance electrodes and strict environmental requirements. Although the elementsChemical Li, Fe and P in lithium iron phosphate are abundant and their cost is low, the cost of the prepared lithium iron phosphate product is not low, even if the initial research and production costs development are removed, the cost of the process. material plus the high cost of preparing batteries will make the final cost per unit of energy storage higher.
4. Product consistency is poor. At present, there is no lithium iron phosphate material factory in China that can solve this problem. From the perspective of material preparation, the synthesis reaction of lithium iron phosphate is a complex multi-phase reaction, including solid phase phosphate, iron oxide and lithium salt, as well as a carbon precursor and a reducing gas phase. In this complex reaction process, it is difficult to ensure the consistency of the reaction.
5. Pintellectual property issues. The first patent application for lithium iron phosphate was filed by FXMITTER on June 25, 1993.MAIER&SOEHNEOHG (DE) obtained the application and announced the application results on August 19 of the same year. The basic patent of lithium iron phosphate belongs to the University of Texas in the United States, and the carbon coating patent was applied for by a Canadian. These two fundamental patents cannot be circumvented. If patent royalties are included in the cost, the cost of the product will increase further.