Which is better for lithium iron phosphate battery and ternary lithium battery?

The lithium iron phosphate battery refers to a lithium ion battery using lithium iron phosphate as a positive electrode material. This type of battery is characterized by the absence of precious metal elements (such as cobalt). In actual use, the lithium iron phosphate battery has the advantages of high temperature resistance, strong safety and stability, low price and better cycle performance.

The ternary material lithium battery refers to a lithium battery using nickel-cobalt-manganese oxide as a positive electrode material and graphite as a negative electrode material. Unlike lithium iron phosphate, the voltage platform of the ternary lithium battery is very high, which means that the specific energy and specific power of the ternary lithium battery are larger under the same volume or weight. In addition, ternary lithium batteries have great advantages in terms of large rate charging and low temperature resistance.

On the single battery, there is no such thing as who is better and who is worse. Just applied to the actual use of the scene, the ternary lithium battery is more suitable for the current and future home electric vehicles than the lithium iron phosphate battery.

Ternary material battery is more suitable for passenger cars

Better low temperature discharge performance

China has a vast territory and a complex climate. The temperature changes from the northernmost three northeastern provinces to the southernmost Hainan islands are very rich. Taking Beijing as an example, as the main market for electric vehicles, the highest summer temperature in Beijing is around 40 °C, while in winter it is basically at around 16 °C, or even lower. Such a temperature range is obviously suitable for a ternary lithium battery having a better low temperature performance. The lithium iron phosphate battery, which focuses on high temperature resistance, appears to be somewhat weak in winter in Beijing.

The "relative 25 ° C capacity" refers to the ratio of the discharge capacity at different temperature conditions to the discharge capacity at 25 ° C. This value can accurately reflect the battery's battery life attenuation under different temperature conditions. The closer to 100%, the better the battery performance is.

It can be seen from the above figure that the two types of batteries are discharged at a high temperature of 55 ° C and discharged at a normal temperature of 25 ° C at a normal temperature of 25 ° C, and there is almost no difference in discharge capacity. However, at minus 20 ° C, the ternary lithium battery has a clear advantage compared with the lithium iron phosphate battery.

Higher energy density

According to the information provided by the domestic ternary material 18650 cylindrical battery leading company - BAK battery, the energy density of its 18650 battery has reached 232Wh / kg, and will be further increased to 293Wh / kg. In contrast, the current domestic mainstream lithium iron phosphate battery energy density is only about 150Wh / kg, according to domestic battery industry experts, in the next few years, the energy density of lithium iron phosphate battery can reach 300Wh / kg I hope very embarrassed

Unlike a large electric bus, space is always the first for home electric cars. Lithium iron phosphate batteries with lower energy density will occupy less space in the car, and due to the heavier quality, the battery life during use will also be greatly affected. Relatively speaking, the ternary lithium battery with higher energy density also saves space for the family car while solving the weight problem.

1. Lithium iron phosphate battery: refers to a lithium ion battery using lithium iron phosphate as a positive electrode material. The positive electrode materials of lithium ion batteries mainly include lithium cobaltate, lithium manganate, lithium nickelate, ternary materials, lithium iron phosphate and the like. Among them, lithium cobaltate is the positive electrode material used in most lithium ion batteries.

2. Ternary polymer lithium battery: refers to the lithium battery of lithium nickel cobalt manganese ternary positive electrode material for the positive electrode material. There are many kinds of positive electrode materials for lithium ion battery, mainly lithium cobaltate, lithium manganate, lithium nickelate, Ternary materials, lithium iron phosphate, etc.

3. Reflect the difference in materials, uses and processes.

A battery is a device for energy conversion and storage that converts chemical or physical energy into electrical energy through a reaction.

A battery is a chemical power source consisting of two different compositions of electrochemically active electrodes that make up the positive and negative electrodes. The two electrodes are immersed in an electrolyte that provides media conduction. When connected to an external carrier, it is converted by Internal chemical energy provides energy.

Lithium iron phosphate battery and ternary battery material system is different, lithium iron phosphate is 3.2V voltage platform, cycle life is more than 2000 times, ternary battery is 3.6V voltage platform, cycle life looks different manufacturers, different models And the process, some do 500 cycles, and some can do more than 1000 cycles. The high temperature performance of the iron lithium battery is good, and the low temperature performance of the ternary battery is good. Safety is a piece of iron and lithium. Some discharge data can be referred to.

Lithium iron phosphate battery: refers to a lithium ion battery using lithium iron phosphate as a positive electrode material. Its characteristic is that it does not contain precious elements such as cobalt. The raw material price is low and phosphorus and iron are abundant in the earth's resources, and there is no problem of feeding. Its working voltage is moderate (3.2V), its capacity per unit weight is large (170 mAh/g), high discharge power, fast charging and long cycle life, high stability under high temperature and high heat environment.

Advantages:

Compared with the more common lithium cobalt oxide and lithium manganate batteries currently on the market, lithium iron phosphate batteries have at least five advantages: higher safety, longer service life, and no heavy metals and rare metals (raw materials). Low cost) is fast charging and wide operating temperature range.

Disadvantages:

Lithium iron phosphate has some performance defects, such as low tap density and compaction density, resulting in lower energy density of lithium ion battery; higher material preparation cost and battery manufacturing cost, lower battery yield and poor consistency; poor product consistency; intellectual property issues.

Ternary polymer lithium battery: A lithium battery of a lithium lanthanum manganese oxide (Li(NiCoMn)O2) ternary positive electrode material is used as a positive electrode material. According to Tsinghua University Ouyang Minggao: The "three yuan" material referred to in this survey refers to the "three-dimensional power battery" in the usual saying that the positive electrode is ternary and the negative electrode is graphite in actual research and development applications, there is also a positive electrode is ternary, the negative electrode is lithium titanate, commonly known as "lithium titanate", its performance is relatively safe, long life, does not belong to the common "three yuan" material."

Advantages:

The ternary lithium battery has high energy density and better cycle performance than normal lithium cobaltate. At present, with the continuous improvement of the formula and the perfect structure, the nominal voltage of the battery has reached 3.7V, and the capacity has reached or exceeded the level of lithium cobalt oxide battery.

Disadvantages:

The ternary material power lithium battery mainly includes nickel-cobalt lithium aluminate battery and nickel-cobalt-manganese lithium battery. Due to the high temperature structure of nickel-cobalt aluminum, the high-temperature safety is poor, and the pH value is too high, so that the monomer is flattened, and then it is dangerous and the current cost is high.

Summary: In contrast, the ternary polymer lithium battery does have a better quality than the lithium iron phosphate battery, but at present it has been hindered with the development of new energy, but in general, the ternary polymer lithium battery is better. .

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