Recently, many places in the south have ushered in a "magic attack", and the temperature of many provinces and cities in the south, including Guangdong Province, has dropped off a cliff. A video circulating on the Internet shows that a cattle breeder in Maoming City, Guangdong Province, directly froze the old cattle to death because they tied their cattle outside the door for the night. In the video, an old cow is lying motionless on the ground, and the calf next to it is hovering around it.
Image source: Screenshot of the video on the web
There are also netizens who joke: Niu never expected that Guangdong could be so cold...
Image source: Sina Weibo
The Central Meteorological Observatory recently issued a blizzard blue warning, saying that it is expected that at 20:00 today, there will be heavy snow in parts of eastern Hunan, north-central Jiangxi, southern Anhui, central and western Zhejiang, among which there will be heavy snowfall in the mountains of western and northeastern Jiangxi, southern Anhui, and central and western Zhejiang. The depth of snow in the above areas is 3 to 8 cm, and the local area may exceed 10 cm.
The sudden extremely cold weather has made China's weather officials and micros can't help but shout that "the power of the wet and cold attack is too great", and the owners of electric vehicles in the south have deeply felt the fear of being dominated by the cold. In the weather of "cows are frozen to death", are they okay in the electric car?
There are southern electric vehicle owners began to "worry about fear"
In fact, climatic conditions have become one of the important factors affecting the purchase of domestic new energy vehicle consumers. According to public data, in January 2022, the sales of new energy vehicles in Guangdong, Zhejiang and Jiangsu ranked among the top three in the country, with a total monthly sales volume of more than 1.11 million units in the three provinces, while the total sales of new energy vehicles in Heilongjiang, Jilin and Inner Mongolia averaged only 33,000 units, with a gap of more than 30 times.
In the relatively cold northern region, electric vehicle owners can only "strange tricks" in order to extend the mileage as much as possible. Some electric taxi masters put a thick plush quilt to keep passengers covered with cold in order to save electricity; some northern car owners do not turn on heating and manually frost the windshield...
Some southern netizens said: "In the group to see the northern car friends said that they there are more than ten degrees below zero, the electric car endurance is basically 60% off, if you turn on the air conditioning, the car with a range of 300 kilometers can only walk 100 kilometers, the charging is also very slow, the northern tram is really uncomfortable." ”
Today, the sudden extremely cold weather has also made the owners of electric vehicles in the south feel the fear of being dominated by the cold. A southern car owner said on the social platform: "On the cold southern rainy night yesterday, I returned home in fear of 1% battery and charging reminders. This is the last stubbornness of the electric car owner. ”
Previously, the Daily Economic News reporter had conducted a questionnaire survey of nearly 50 new energy car owners, and the results showed that in the non-winter environment, 57.45% of the car owners said that the actual mileage could reach more than 80% of the nominal mileage, but only 8.51% of the owners in winter said that they could achieve this use. 74.47% of new energy car owners said that the vehicle's winter mileage was 50% to 80% of the nominal mileage, and 17% of the owners said that the actual mileage was even less than half of the nominal mileage.
In addition, new energy vehicle owners also have reservations about the publicity and calibration mileage of car companies. In the questionnaire survey of car owners, regarding the question of "do you believe in the manufacturer's publicity and calibration of the mileage of new energy vehicles", the average score of the car owners is 3.09, which means that they are more likely to use the manufacturer's calibration endurance as a reference, but do not fully believe.
Dai Kangwei, general manager of BAIC New Energy, believes that the decline in winter battery life of electric vehicles is closely related to the principle of charging and discharging power batteries. It is understood that the Li ions in the positive electrode of the battery and the Li ions in the electrolyte when charging are aggregated to the negative electrode, and electrons are obtained, which are reduced to Li embedded in the carbon material of the negative electrode. Li embedded in the carbon material of the negative electrode during discharge loses electrons and enters the electrolyte, and the Li ions in the electrolyte move toward the positive electrode. According to other relevant data, in the working environment of -30 ° C, lithium-ion batteries will lose about 9 to 10 times the power, which is also the main reason for the "shrinkage" of the mileage of electric vehicles in winter.
"When the temperature is low, the electrolyte in the battery will become more viscous, the rate of lithium ion migration, and the conductivity of the material itself will further deteriorate, making the battery activity decrease, thereby affecting the battery performance and capacity volatilization, which is externally manifested as the attenuation of the available capacity of the power battery." Dai Kangwei told reporters.
The Winter Olympics "black technology" or solve the stubborn disease
It is worth mentioning that in Zhangjiakou, one of the venues of the 2022 Beijing Winter Olympics, the electric vehicles that provide operation work for the competition area not only have to face the minimum temperature above minus 20 °C, but also face the challenge of crossing mountains and mountains, but still complete the event guarantee task well. How is this done?
"The problem that lithium batteries are not resistant to low temperatures has been solved." Wang Chaoyang, a battery technology scientist, an academician of the National Academy of Inventors and a chair professor at Pennsylvania State University, said that the all-climate battery invented by his team can operate as usual at extremely low temperatures. This technology was selected as one of the top ten technology trends in the 2022 automotive industry, and became one of the core technologies to drive the pure electric vehicles of the Winter Olympics, escorting the 2022 Beijing Winter Olympics.
According to reports, the all-weather battery is embedded with a nickel foil of 10 microns thick as a heating element, so as to achieve control of the positive and negative interfaces. The working process of the heating element is equivalent to creating a fast short circuit inside the battery, when the external ambient temperature is low, the system control current through the nickel foil to cause a controllable internal short circuit and generate heat, thereby quickly increasing the battery temperature to achieve output power. According to Wang Chaoyang, even if the battery is "frozen through" in the environment of -30 ° C, it can self-heat to above zero within 30 seconds through the above device.
"With this fast, low-energy thermal stimulation method, we can make batteries from the most stable and safe materials." When not in use, the chemical interface within the battery maintains a minimum (active) level, ensuring the safety of the battery and the lowest aging rate. When working, the battery reaction interface is instantly adjusted and strengthened with thermal stimulation to ensure high power output. Wang Chaoyang said.
In fact, in addition to the above technical route, heating the battery through the PTC heating system (a component with a large positive temperature coefficient) is also one of the common response methods in the industry to the performance attenuation of low-temperature batteries. Popularly understood, the car end through the PTC heating system to heat the coolant, the coolant after heating into the battery thermal management runner, like floor heating to heat the battery heating.
In addition, increasing the thermal insulation performance of the battery, improving the efficiency of the air conditioning heat pump, and strengthening the power recovery efficiency are also the main technical measures for major car manufacturers to continuously optimize the winter cruising range.
Dai Kangwei suggested that if conditions permit, new energy vehicle owners should still try to park their vehicles in the basement. When driving, you can choose to turn on the power recovery mode to increase the cruising range. If the charging is slow, the owner can choose to charge in time when the vehicle is finished and the battery still has residual temperature to increase the charging efficiency. If it is its own charging pile, you can also choose not to pull out the gun after charging, and the charging facility will play a certain role in keeping the battery warm.
Reporter | Dong Tianyi
Editor| Pei Jianru He Xiaotao, Wang Jiaqi, Du Hengfeng
Proofreader | Sun Zhicheng
| the original article of the daily economic news nbdnews |
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