It's winter again.
Can you believe it? In ten years, the winter endurance of new energy vehicles has not fundamentally changed.
Ten years ago, we did not expect that the development speed of new energy was so fast. In the domestic passenger car sales data in 2021, the production and sales of new energy vehicles have reached a new high, and we can see that the new energy army is quietly seizing the market for fuel vehicles.
However, electric vehicles have a clear shortcoming, which occupies the winter anxiety of many car owners - the shortening of the low temperature mileage in winter.
01. Winter endurance anxiety has not improved in ten years?
On December 31, 2021, China Automotive Engineering Research Institute Co., Ltd. (hereinafter referred to as "China Automotive Research Institute") and the National Big Data Alliance for New Energy Vehicles released a white paper saying:
The low-temperature attenuation data of 53 new energy vehicles at home and abroad in the past 10 years show that from 2012 to 2021, the average value and distribution range of the low-temperature mileage retention rate of new energy vehicles have not changed significantly, and the mileage retention rate of 65.38% of new energy vehicles in the low-temperature environment is about 52.8%-67.2%.
In 10 years, the new energy vehicle has not improved significantly in the problem of low temperature mileage? Even new energy vehicles with long cruising range have to be discounted in winter, and the anxiety of electric vehicle use in winter is common.
In this regard, China Automobile Research Institute also released a survey report before, China Automobile Research Institute tested the cruising range in normal temperature (23±3 °C) and low temperature (-7±3 °C) environment, the six models participating in the test have different degrees of endurance attenuation, and the low temperature endurance in winter is greatly reduced.
02. Battery life attenuation, battery is the biggest reason?
Under today's technical conditions, at present, the main types of power batteries used in new energy pure electric vehicles are: lithium iron phosphate batteries and ternary lithium batteries. Even BYD's famous "blade battery" is based on the improvement of lithium iron phosphate battery technology.
The biggest problem with the low temperature endurance attenuation of electric vehicles comes from the battery, which is the short board of the chemical substance of the battery itself. Zhang Hong, secretary general of the New Energy Vehicle Branch of the China Automobile Circulation Association, said: The lower the temperature, the more viscous the electrolyte in the lithium battery will be, which will greatly reduce the activity of the battery, which will cause a significant attenuation of the usable capacity of the battery.
For example, a cup of room temperature water, in the summer, the water in the cup is flowing, and it is easy to drink. In the winter, when the temperature is low, the water in the cup will be frozen, the fluidity will become very poor, and it will take a lot of effort to drink it.
The same is true of the electrolyte in lithium batteries, with poor fluidity at low temperatures in winter, reduced activity, and to achieve the same output energy, more ions must be consumed.
Many people will ask, is it not ok to change the type of battery? The reality is often cruel, with the current technical conditions, new energy electric vehicles can not be separated from lithium batteries. Since the current technology can not replace the type of power battery, so there are some manufacturers in the battery thermal insulation to find ways to break through, followed by other places, such as energy recovery, improve the vehicle drag coefficient, reduce tire rolling resistance and so on has also been improving.
However, the effect has not improved significantly, otherwise it would not have been a technical breakthrough in ten years.
03. Winter endurance has become a difficult point, and many parties strive to break through
Improving the total endurance of the vehicle is the embodiment of increasing the cost, although it is very good in the data of up to 1000 kilometers of endurance, but the anxiety of the low temperature endurance discount in winter is still obvious, which is not the best way.
In a test conducted by ByteDance's automotive media, it was found that among the test models, the Hongguang MINI EV with the lowest total mileage had the highest mileage achievement rate, 60.71%, higher than the industry average of 59.95%.
How does Wuling do it? They are using a technology called cryogenic preheating charging, as well as the battery insulation feature mentioned on appeal. It is possible to start heating the power battery first when it is charged at low temperature, and use battery insulation technology to maintain the battery pack at 20-25 ° C. And Wuling decided to continue research and development in battery intelligent insulation and enter the 2.0 era.
While looking for more low-temperature battery materials and vigorously improving the charging and replenishment facilities, the current urgency seems to be more reliable battery insulation technology, but it is also difficult to solve the anxiety of using electric vehicles in winter.
There is good news here that the second-generation sodium-ion battery that will be launched in the Ningde era is superior to lithium-ion batteries in cold resistance.
What is a sodium-ion battery? The working principle of sodium-ion batteries and lithium-ion batteries is actually very similar, mainly because the material composition is different, and sodium-ion batteries are more hardy and more suitable for use in northern regions.
As early as July 2021, CATL officially released its first generation of sodium-ion batteries. The cell energy density of the sodium-ion battery has reached 160Wh/kg, charged at room temperature for 15 minutes, the power can reach 80%, and in the low temperature environment of minus 20 °C, more than 90% of the discharge retention rate can be achieved. CATL also said at the time that the energy density of its next generation of sodium-ion batteries would exceed 200Wh/kg.
Heat pump air conditioning, waste heat recovery, battery insulation, increase charging and replenishment facilities, research and development of new types of power batteries, etc., all car companies and battery manufacturers have been working hard to develop, from all possible places to improve technology, overcome difficulties.
At present, long-lasting electric vehicles have been seen everywhere, but we hope that in the future, we will no longer have to worry about the winter endurance discount of new energy vehicles.