What are the battery types for all-electric cars?

Currently, there are two mainstream designs for the batteries of electric cars. One is represented by Tesla, which adopts the battery management system of ternary lithium battery and high IQ ,it is used to give full play to the advantages of large energy density of ternary lithium battery. One is represented by many cars, which adopts lithium iron phosphate battery and relatively simple battery management system to make full use of the advantages of the endurance of lithium iron phosphate battery. What are the battery types for all-electric cars? For reference only!

Battery type of pure electric vehicle: ternary lithium battery

1.Make up the insufficient charging and discharging current

Tesla NCR18650A type battery is used the typical capacity is 3070 mah, Panasonic has a capacity of 3350 mah typical NCR18650B, but did not release the Data sheet, used only from Tesla NCR18650A look, 2 c discharge (1 c discharge current refers to the capacity of the battery in 1 hour from the current full vent, such as NCR18650A 1 c discharge is 3350 ma) can also be released more than 3100 mah capacity to before.

Different current discharge results, 2C discharge actually the best effect

It is said that Panasonic will launch a 4000mAH 18650 battery cell next year. It is said that there is no improvement in the performance of large current. When the capacity is increased, the 1C current of the corresponding battery pack is increased. With the high energy density of the ternary material (which can exceed 200WH/Kg), the 2C discharge current of the battery pack can satisfy the motor of the sports car. For example, the 85KWH battery with a high configuration of Tesla, from the measured data, the short-term 3C discharge should not be a problem, that is corresponding to 342 horsepower, which is very objective.

2. Make up for the lack of fast capacity attenuation

It can be seen that the battery used in Tesla cars is under the same charging and discharging current, and the capacity has been reduced to 55% after 900 cycles from 0% to 100% each time. If the capacity is reduced from 0% to 50% each time, the capacity can be maintained at 70% even after 3000 cycles. The battery management system tries to keep the battery as low as possible, working in cycles of 0-50% or 25-75%, so that it can eventually travel 300,000 kilometers without significant endurance degradation.

3, safety

No matter which brand of ternary material lithium battery, there will be open fire after internal short circuit or positive electrode material encounters water. Even if 18650 battery is protected by steel shell, it still cannot withstand extreme impact. But as long as it's not more likely to catch fire in an extreme accident than a diesel fuel tank, I think Tesla's battery management system is a near solution to battery safety.

With its highly intelligent battery management system, Tesla has been able to pull the total score of a ternary lithium battery from 270 to 350.

Pure electric vehicle battery type: lithium iron phosphate

Its biggest deficiency lies in the low energy density (110 wh/Kg), low temperature capacity attenuation huge (- capacity under 10 ℃ to 25 ℃ under 55%). The advantages are also quite obvious, especially for China's car companies are even more so. China is rich in lithium ore reserves. By 2011, the world's proven reserves are 13 million tons, and China's reserves are 3.5 million tons. The positive electrode material has abundant reserves of iron oxide phosphate. The country is desperately short of cobalt, with half the world's reserves in Congo, 21 per cent in Australia and just 1 per cent in China. By using lithium cobalt or cobalt ternary materials battery, the cost of production of electric vehicles in China's car companies is very passive.

lithium iron phosphate battery can easily discharge at 20C, so hybrid car configuration small battery first consider lithium iron phosphate battery. The capacity is only attenuated to 80% after 3000 cycles of 0% to 100%, and the attenuation rate is not exaggerated after long-term storage with full power. Puncture, short circuit, 350 ℃ high temperature burning explosion. These advantages make it unlikely that Chinese car-makers, especially those with research and development and production of lithium iron phosphate, will choose other types of batteries.

Battery type of pure electric vehicle: ternary lithium battery + excellent battery management system will win out

Sometimes good products may not sell well. Personally, I am more optimistic about the battery technology led by Tesla: battery management as the core. After watching the interview with musk, I know that the purpose of Tesla to build the top layer of electric cars is to reduce carbon emissions and make profits from clean energy. Opening up the patent would lower the threshold for such a scheme, and more manufacturers would follow suit. The more manufacturers involved, the happier Tesla will be, which is consistent with their purpose.

Often listen to domestic electric cars talk about "curve overtaking." Automobile is a comprehensive industry, including machinery, electronics, automation, materials, basic science, management, finance, law, education, medical care and so on. Together, they constitute the overall level of the automobile industry, and can even be said to be the epitome of the country's comprehensive strength. China's current situation is largely behind the developed countries, the automobile industry must also be significantly behind the developed countries, with a certain part of the advantages, with a few companies operating advantages can only shorten the gap with others, far from overtaking. I certainly expect to see overtaking in my lifetime, and that will take work from us and the next generation.

As long as Tesla does not get involved in the research and development of lithium iron phosphate electric vehicle, I believe that in the long run, the solution of excellent battery management system and ternary lithium battery will go further than the application of lithium iron phosphate.

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