What types of batteries do pure electric cars have?

The battery of electric vehicles currently has two mainstream designs. One is represented by Tesilache, who uses a lithium ion battery + a high IQ battery management system to give full play to the advantages of a large energy density of lithium ion. One is represented by many cars. The lithium iron phosphate battery + relatively simple battery management system is used to make full use of the advantages of lithium iron phosphate battery endurance. What are the battery types of pure electric vehicles? For information only!

Type of battery for pure electric vehicle: lithium ternary battery

1, Mi Supplementary discharge current is insufficient

Tesla uses the NCR18650A battery, a typical capacity of 3070mAH, and Matsushita also has a typical capacity of 3350mAH NCR1865B, but did not release Datasheet, only from the NCR1865A used by Tesla. 2C discharge(1C discharge current refers to the current that empties this capacity of the battery within 1 hour. For example, the 1C discharge of the NCR18650A is 3350mA) can also emit more than 3100mAH. It is not known.

The discharge results under different currents are the best under 2C

It is said that Matsushita will launch a 18650 core with a capacity of 4,000 mAH next year. It is said that the performance of the large current has not improved. After the capacity is increased, the 1C current of the corresponding battery pack is relatively increased. With the high energy density of the ternary material(which can exceed 200WH/Kg), the 2C discharge current of the battery pack can already satisfy the motor of the sports car. For example, the 85KWH battery equipped by Tesilagao, from the measured data, the short-term 3C discharge should not be a problem. That is, it corresponds to 342 horsepower, which is very objective.

2, make up for the shortage of fast capacity decay

It can be seen that Tesla's batteries are circulating from 0 % to 100 % at a time under the same charge and discharge current, and the capacity has decayed to 55 % after 900 times. If it is from 0 % to 50 % at a time, even if the capacity of 3000 cycles is still maintained. 70 %. The battery management system tries to maintain the low stress of the battery and works in a cycle of 0 % -50 % or 25 % -75 %, so it can eventually ensure that there is no significant lifetime attenuation for 300,000 kilometers.

3, security

Regardless of which brand of lithium triple-material batteries, there will be open fire after the internal short circuit or positive material encounters water. Even if there is steel shell protection outside the 18650 battery, it still can not withstand extreme shocks. But as long as it does not burn more easily than a diesel fuel tank in an extreme accident, I think Tesla's battery management system has barely solved the battery safety problem.

Through a high-IQ battery management system, Tesla has been able to increase the total score of lithium batteries for three-part materials from 270 to 350 points.

Type of battery for pure electric vehicle: Lithium iron phosphate

Its greatest disadvantage is its low energy density(110WH/Kg) and its large capacity attenuation at low temperatures(about 55 % of the capacity at -10 °C). The advantages are also obvious, especially for China's car companies. China has abundant reserves of lithium, with 13 million tons of proven reserves worldwide and 3.5 million tons of reserves as of 2011. Ferric oxide phosphate reserves of positive materials are abundant, and there is still a lot of room for price exploration after mass production. Our country is very short of cobalt, with half of the world's reserves in Congo, 21 % in Australia and 1 % in China. The cost of producing electric vehicles in our country is very passive when using lithium cobalt acid or a three-way material battery with cobalt.

lithium iron phosphate batteries can be easily discharged at 20C, so mixed cars are equipped with small batteries that first consider lithium iron phosphate batteries. The capacity of 3000 times under the 0 % -100 % cycle decays to 80 %, and the long-term storage decay speed of full-power is not exaggerated. The puncture, short circuit, and high temperature at 350 °C will not explode and burn. These advantages make it less likely that China, especially its car companies, which have developed and produced lithium iron phosphate, will choose other types of batteries.

Type of battery for pure electric vehicle: 3-yuan lithium + excellent battery management system will win

Sometimes a good product may not sell well, and I personally prefer Tesla's lead battery technology: battery management as the core. After an interview with Musk, I learned that Tesla's goal at the top of electric cars was to reduce carbon emissions and make money from clean energy. The opening of patents will lower the threshold of this plan and more manufacturers will follow suit. The more pleased the participating manufacturer, Yueduotesila, this is consistent with their purpose.

Often listen to domestic electric vehicles talk about "curve overtaking." Automobile is a comprehensive industry, including machinery, electronics, automation, materials, basic science, management, finance, law, education, medical care, etc.. Together they constitute the overall level of the automotive industry, and can even be said to be the epitome of the country's comprehensive strength. The present situation of our country is to lag behind the developed countries greatly, the automobile industry also must lag behind the developed countries greatly, with the advantage of a certain component, with the advantage of a few companies can only shorten the gap with others, far from overtaking. I certainly look forward to seeing the car overtake in my lifetime, which will require our efforts and those of the next generation.

As long as Tesla does not get involved in the development of lithium-phosphate electric vehicles, I believe that in the long run, the solution of adopting an excellent battery management system + three-part material lithium-ion batteries will go further than lithium iron phosphate applications.

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