Ternary lithium battery VS lithium iron phosphate battery which kind of power battery should be used?

Although the domestic subsidy policy for new energy vehicles has begun to decline, the increasingly rich infrastructure and increasingly rich alternative models also make consumers begin to accept the popularity of new energy vehicles. In addition to being an alternative solution to the limited purchase area's inability to purchase fuel vehicles, new energy vehicles also have many unique advantages. Quiet driving environment, clean energy types and low car costs, even including the start of the instant output of large torque, can make many friends around driving fuel cars envy.

As the source of power for electric vehicles, the battery is naturally one of the most important parts. Battery life, charge-discharge and other USES of electric vehicles are also closely related to the performance of the battery. At present, the domestic power battery is mainly divided into two factions, according to the different anode materials are divided into lithium iron phosphate pie and ternary materials pie. Although both of them are secondary batteries, which can be used for charging and discharging repeatedly, due to the difference in materials, there is still a big difference in the final performance reflected in the use level.

Lithium ternary batteries or lithium iron phosphate batteries?

To figure out which battery is better, we should first have a simple understanding of the difference between the two.

The so-called lithium iron phosphate battery refers to the lithium ion battery with lithium iron phosphate as the positive electrode material. This type of battery is characterized by the absence of precious metal elements (such as cobalt). The raw material cost of the lithium iron phosphate battery can be compressed very cheaply due to the absence of precious metal materials. In practical use, lithium iron phosphate battery has the advantages of high temperature resistance, strong safety and stability, low price and better cycling performance.

The ternary lithium battery is a lithium battery which USES lithium nickel-cobalt manganate as the positive electrode material and graphite as the negative electrode material. Unlike the lithium iron phosphate, the ternary lithium battery has a high voltage platform, which means the ternary lithium battery has a higher specific energy and specific power under the same volume or weight. In addition, ternary lithium batteries also have great advantages in high power charging, low temperature resistance and other aspects.

I have always believed that there is no good or bad technology, but suitable for different products or environments. There is no such thing as a better or worse battery. Just to put it into practical use, ternary lithium batteries are more suitable for current and future household electric vehicles than lithium iron phosphate batteries.

Why are ternary lithium batteries more suitable for household electric vehicles?

One, low temperature discharge performance is better

China has a vast territory and a complex climate. The temperature changes from the three northeastern provinces in the north to the Hainan islands in the south are very rich. In Beijing, for example, as the main electric car market, Beijing summer high temperature around 40 ℃, while winter is basic about 16 ℃ below zero, even lower. Such a temperature range is obviously suitable for low-temperature performance of better ternary lithium batteries. The high-temperature performance of lithium iron phosphate battery in Beijing in the winter will appear a little weak.

"Relative capacity of 25 ℃" refers to the different temperature conditions to devolve electricity capacity and 25 ℃ when the ratio of discharge capacity. This value can accurately reflect the battery life attenuation in different temperature conditions, the closer to 100%, the better the battery performance.

25 ℃ as a benchmark in normal temperature, two types of cells in 55 ℃ high temperature lowering electricity and room temperature 25 ℃ to devolve electricity, almost no difference between the discharge capacity. But at 20 ℃ below zero, the ternary lithium battery and lithium iron phosphate battery has obvious advantages compared.

Higher energy density

According to the data provided by bick battery, the leading enterprise of 18650 cylindrical battery in China, the energy density of 18650 battery has reached 232Wh/kg, which will be further increased to 293Wh/kg in the future. By contrast, the energy density of the mainstream domestic lithium iron phosphate battery is only about 150Wh/kg at present. According to the analysis of domestic battery industry experts, the hope that the energy density of lithium iron phosphate battery can reach 300Wh/kg in the next few years is very slim.

Unlike the bulky electric buses, for domestic electric cars, space always comes first. The lithium iron phosphate battery with low energy density will occupy a small amount of space in the car, and its battery life will be greatly affected due to its heavier mass. Relatively high energy density ternary lithium batteries solve weight problems and save space for family cars.

3. Higher charging efficiency

In addition to battery life, charging is also an important link in the actual use of electric vehicles, and ternary lithium battery has a great advantage over lithium iron phosphate battery in charging efficiency.

At present, the common charging method in the market is constant current and constant voltage charging. In general, constant current charging is adopted at the beginning of charging. At this time, the current is large and the charging efficiency is relatively higher. After the voltage reaches a certain value, the current is reduced to a constant voltage charge, which can make the battery charge more full. In this process, the ratio of constant current charging capacity to the total battery capacity is called constant current ratio. It is a key measure of the charging efficiency of a battery during charging. Generally, a larger percentage indicates that the charge in the constant current stage is higher, which also proves that the charging efficiency of the battery is higher.

As can be seen from the table, there is no significant difference in constant current ratio between ternary lithium battery and lithium iron phosphate battery when they are charged below 10C, and the constant current ratio and charging efficiency of lithium iron phosphate battery decrease rapidly when they are charged above 10C.

Four, cycle life can rest assured

For the family car, ternary materials and lithium iron phosphate power battery rated cycle life is far beyond the actual use of the user's habits, so the service life can be completely assured. Take the current high-capacity 18650 battery as an example. After 1000 cycles of charging and discharging, the battery capacity can still maintain above 90% of the original. As the author is also the owner of an electric car, only the coldest winter lasts for more than one month in the whole year. It can only be charged once every two days when the warm wind is frequently on, and then it can be charged once every three to four days in the rest of the year. Assuming that the annual average charge is charged once every 3 days, it takes about 6 times of charge for a year of use, and it takes about 8 years for the cycle life to be used up to 1000 times, which is also basically higher than the average car replacement cycle of Chinese consumers at present.

Adequate safe materials and techniques

The most harmful part of traditional internal combustion engine vehicles is the fuel with huge energy. Once the liquid fuel with low ignition point, such as gasoline, which is easy to explode, is leaked, it will easily cause great safety risks. And the new energy vehicle power battery, through the perfect battery management system (BMS) monitoring, each battery can be the most accurate control, to prevent accidents.

Take the bick 18650 battery. In the process of single cell, bick chooses to configure protection additives and reactive additives respectively in the positive and negative poles to prevent safety problems caused by electrolyte decomposition. At the same time add ceramic diaphragm and negative ceramic coating and other safety means to control the accident from the source. In addition, the bick small cylinder 18650 battery pack mode maintains a safe distance between each battery to ensure that a single battery incident will not affect other batteries.

Ternary lithium battery is dominating the future power battery market

In the field of electric vehicles, Tesla in the United States has been the benchmark of many domestic car companies. When it comes to the strength of traditional car companies in developing new energy vehicles, the launch of BMW i3 has become a textbook example. Interestingly, both cars use ternary lithium batteries for power. In contrast, in the domestic market, many automobile manufacturers, such as Jianghuai, BYD and baic, have also started to replace their models that used lithium iron phosphate batteries with three-yuan lithium batteries.

Again, there is no good or bad technology, only good or bad. It is not a coincidence that the choice of battery type happens to coincide with that of domestic and foreign car companies. It is believed that in the near future, the battery market of electric vehicles will be reshuffled.by virtue of its low temperature resistance, high energy density, high charging efficiency, good cycle life and stronger safety, ternary lithium battery will also gain a firm foothold in the new market.

The new alliance was established, and the German government helped car companies jointly develop fuel cell technology AutoR intelligent drive

After the Japanese government, the German government has also added a boost to the fuel cell technology, and the future of fuel cell is a step closer.

Text: AutoR intelligence drives wu pengfei

The German government has formed a 60m euro, three-year alliance with industry leaders to study the mass production of fuel cell reactors for cars.

The alliance, called autostack-industrie, was funded by Germany's federal ministry of transport and digital infrastructure (BMVI) and paid 21.3 million euros in its first year.

The autostack-industrie alliance was formed under the initiative of German automakers and suppliers, aiming to provide technical, economic and technological support for the commercial introduction of fuel cell vehicles in Germany and Europe by 2020.

The alliance, led by BMW, also includes Daimler, denner, ford research and innovation center, kedebao high performance materials, Greenerity, NuCellSys, fuel cell company PowerCellSwedenAB, germany-based umec, Volkswagen group and the German state of baden-wurttemberg solar and hydrogen research center. These companies have made great achievements in automobile manufacturing and fuel cell technology.

BMW has long been involved in fuel cell vehicles (FCV) in Germany. BMW released the FCV prototype based on the i8 and 5 series GT models in 2015, and announced to release the mass production version in 2020.

NorbertBarthle, deputy minister of the federal ministry of transport and digital infrastructure, said emission-free electric driving is an important option for the future driving forces of cars and hydrogen cars, as well as a supplement to battery cars. Germany intends to build its own fuel cell production facilities.

Currently, fuel cell stacks are mostly assembled by hand. Automated assembly can save time and cost, so it is a prerequisite for fuel cell vehicles to be widely available in the market. The partners in the consortium will create a common set of production specifications, produce the battery stack and design the components according to this specification, and then build a prototype of the battery stack. Meanwhile, alliance members are working on a flexible plant with a target capacity of 30,000 fuel cell stacks a year.

Last year, France's alstom launched its first hydrogen fuel cell passenger train, which will first begin service in the German state of Saxony.

The hydrogen fuel cell train, named iLint, has both the fuel tank and fuel cell on top, while the lithium-ion battery and electric motor are located under the passenger seats. The German ministry of transport has ordered 14 iLints to run in the state of Saxony by the end of the year.

Both the establishment of autostack-industrie alliance and the introduction of hydrogen fuel cell train show the German's affirmation of fuel cell and determination to develop this technology.

Not only the germans, but also Japan, South Korea, the United States and other major car manufacturers in the world are building up their capacity for fuel cell technology, and Japan has even elevated it to the level of the government to develop it as a national energy strategy. (why does Japan spare no expense to generate hydrogen energy when three major Japanese auto companies jointly build hydrogen refueling stations for hydrogen cars?)

Toyota and Honda have been particularly keen on hydrogen fuel cell technology, and both Toyota Miran and Honda Clarity FCV models have been mass-produced.

May 23 this year, Nissan motor company, Toyota, Honda, JXTG energy group, idemitsu kosan co., LTD, sutra rock valley industrial co., Tokyo gas co., LTD, toho gas corporation, Japan air liquide company, Toyota tsusho corporation and Japan policy investment Banks such as 10 companies jointly signed a memorandum of understanding, plan in Japan jointly build hydrogen filling station, provide service for fuel cell vehicle (FCV).

The Japanese government's "hydrogen fuel cell strategic plan" shows that it will complete the construction of 160 hydrogen refueling stations by 2020 and achieve the goal of having more than 40,000 hydrogen fuel vehicles by 2020.

Hyundai has also been working on FCV for 16 years. The FCV model has been launched since 2001. In February 2013, ix35FC officially rolled off the production line from busan, South Korea. The car is also the world's first mass-produced hydrogen fuel cell car. A new generation of FE hydrogen fuel concept car was also demonstrated at CES.

The technology, which musk calls "dumb cell" technology, has become increasingly important around the world, and Germany has become the second country after Japan to bring fuel-cell technology to the government level.

"Hydrogen fuel and pure electricity which is the future of new energy vehicles" such a debate although still continue, but the development of fuel cell vehicles has become inevitable, Japan, South Korea, Germany is likely to fuel cell vehicles in the field of three tripartite potential.

The page contains the contents of the machine translation.