Ternary lithium and lithium iron phosphate

As one of the main powers, the battery is one of the most important parts. At present, the power battery in the domestic market is divided into lithium iron phosphate and ternary lithium. Although both are secondary batteries, they can be charged and discharged. But there is still a difference, because the difference leads to a big difference in the area of use. Take a family car as an example to popularize it.

First, the low temperature discharge performance is better

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.

Second, the energy density is higher

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.

Third, the cycle life can be assured

For the family car, the rated cycle life of the ternary material and the lithium iron phosphate power battery far exceeds the actual user's usage habits, so the service life can be completely assured. Taking the current high-capacity 18650 battery of the BAK battery as an example, after 1000 cycles of charge and discharge, the battery capacity can still remain above 90%. Since the author is also the owner of an electric car, it is only the coldest in winter for more than one month. When the warm air is frequently turned on, it can reach 2 days and one charge, and the rest of the time is basically 3-4 days. Assuming an average of 3 days a year to calculate the charge, it takes about 6 times to charge for 1 year, and it takes about 8 years to complete the cycle life of 1000 times. This also basically exceeds the current average change cycle of Chinese consumers.

Fourth, adequate safety of materials and workmanship

The most harmful part of the traditional internal combustion engine vehicle is the fuel with huge energy. The low-explosive liquid fuel like gasoline can easily cause great safety hazard once it leaks. The power battery of the new energy vehicle is monitored by a comprehensive battery management system (BMS), and each battery can get the most accurate control to prevent accidents.

Take the BAK 18650 battery product as an example. In the single cell process, BAK chooses to configure a protective additive and a reactive additive on the positive and negative electrodes to prevent the safety problem caused by the decomposition of the electrolyte. At the same time, safety protection measures such as ceramic diaphragm and negative ceramic coating are added to control the accident from the root cause. In addition, the BAK small cylindrical 18650 battery pack mode maintains a sufficient safety distance between each battery to ensure that a single battery accident does not affect other batteries.

The page contains the contents of the machine translation.