At low temperatures, new energy buses are temporarily suspended, fuel vehicles are "resurged", and new energy is not working
A few days ago, a passenger transport company in Arshan City, Inner Mongolia, issued a temporary suspension notice:"Due to the sudden drop in temperature and temperature drop some time ago, the mileage of the train did not reach the original mileage, so the operation was temporarily suspended, and the specific recovery period of the announcement is subject to the actual situation. "
What kind of weather is this?According to the report of the Meteorological Observatory, some time ago, the temperature in Arshan was very low, with the lowest temperature around minus 30 degrees Celsius, and on sunny days, the temperature ranged from minus 16 degrees Celsius to minus 20 degrees Celsius.
Under such low temperature conditions, the range of electric vehicles will be greatly affected.
On the one hand, low temperatures will reduce the speed of chemical reactions inside the battery and shorten the life of the battery.
On the other hand, the use of heating equipment also increases at low temperatures, which is bound to increase the electrical load on the battery.
As a result, the range of electric vehicles in the winter months will be greatly reduced or even malfunction.
For example, at a low temperature of minus 10 degrees Celsius, the power of lithium iron phosphate batteries will be reduced by about half;If the temperature continues to drop to minus 20 degrees Celsius, the battery may lose its ability to discharge completely.
In addition, under the low temperature condition of minus 10 degrees Celsius, the capacity of the lithium iron phosphate battery is only 20% of the original after 1000 times of charging and discharging, which means that it is no longer affected by low temperature.
Previously, a Tesla Model 3 owner who uses lithium iron phosphate batteries said that he could drive 420 kilometers after charging in winter, but in fact only drove 240 kilometers. In addition, his range is 50% of what it would normally be, while the actual range is much lower.
The owner of a BYD Han EV in Shanxi also said to **, he said that it was 606 kilometers, but it was only 230 kilometers in winter, which is equivalent to a decrease of 35%。
This is mainly because the cathode material of lithium iron phosphate, the raw material of lithium iron phosphate, is very sensitive to polarization due to poor conductivity, which will lead to capacity reduction or even failure.
At low temperatures, the activity of the electrolyte decreases and the viscosity increases, which increases the fluidity of lithium ions.
In addition, at low temperatures, the thickness of the anode SEI film increases and the resistance increases, which reduces the conductivity of lithium ions.
If a bus company in Inner Mongolia buys a bus with a lithium-ion battery, it will definitely freeze to death.
In contrast, ternary lithium batteries are more suitable for low-temperature environments, because ternary lithium-sulfur batteries use lithium nickel-cobalt-manganese oxide as the positive electrode, graphite as the negative electrode, and lithium hexafluorophosphate as the electrolyte. The material has a high energy density, with a specific capacity of up to 80% of room temperature at minus 10 degrees Celsius and up to 70% at minus 20 degrees Celsius.
When the temperature reaches minus 30 degrees Celsius, the ternary lithium battery finally can't bear it.
Some people say, why not use ternary lithium batteries?Why spend so much effort on lithium iron batteries?
Because it is safer and has a longer lifespan than ternary lithium batteries.
The cathode material of ternary lithium-ion batteries is rich in cobalt, and there are great safety problems under conditions such as overcharge, high temperature, and physical damage.
However, lithium iron phosphate cathode materials have excellent performance in anti-overcharge, anti-high temperature, anti-physical damage, etc.
In terms of service life: lithium iron phosphate batteries can generally reach thousands of cycles. And ternary lithium batteries can only be cycled a few hundred times at most.
Industry experts say that winter battery life is a very common problem, and no matter what type of battery, the battery life will be greatly reduced in low temperature conditions.
This is especially serious for new energy vehicles.
In daily use, due to the harsh climatic conditions, the frequency of charging and discharging is very high, but due to the limited life of the battery, the cruising range of new energy buses is much lower than that of ordinary private cars, generally about 6-7 years.
The battery must be replaced after it runs out, otherwise it will not work. In Baoding City, Hebei Province, 23 bus lines were temporarily suspended due to battery problems.
So, is it so hard to replace the battery?The difficulty is in **?
It is understood that in Baoding, the price of an electric bus to replace the battery is as high as 540,000 yuan.
1 million yuan for a bus and 500,000 yuan for batteries. If I have 500,000 yuan, I can buy an all-gasoline bus, and most importantly, the 500,000 yuan battery can only be used for seven or eight years, and I have to replace it when it runs out.
Therefore, in order to alleviate the financial pressure of Baoding Public Transport Group, it was decided to replace some new energy vehicles and convert them into gasoline vehicles.
However, in October this year, Chenzhou, Hunan Province released a message that the replacement station of old vehicles was 180,000 yuan, and the 8-meter pure electric bus was 630,000 yuan, 10The 5-meter pure electric vehicle is 960,000 yuan.
It seems that replacing the battery is still a way to save money.
How can two batteries be three times apart?Is there really no problem at all?Just asking, no other thoughts.
In December last year, Shandong Yantai Bus Company carried out battery replacement for the first batch of 18 pure electric vehicles, which is the first case in the country.
If all buses in Yantai adopt this scheme, it can reduce the cost of car purchase2$1.6 billion.
Huangshi in Hubei, Wuhan in Hubei, Arshan City in Inner Mongolia, Nanjing in Jiangsu Province and other places are quietly replacing gasoline buses in Yantai.
In this case, Cao Guangping, the founder of Driving Fun Consulting, said that in 2015, the technology of power batteries was still relatively backward, and many power batteries began to have battery life problems after less than 8 years of use.
Coupled with the cold weather in the north, charging problems make the battery range shorter and shorter.
Due to the cancellation of policy subsidies for new energy vehicles, the ** large ** of pure electric buses and power batteries has made traditional fuel vehicles have gradually"Turn over"trend, but at the same time, it also brings the problem of new energy buses.
In addition to the service life of the battery, the difficulty of charging and the fast charging speed have always been a problem that the majority of car owners complain about.
One of the biggest problems is the small number of charging piles and the relatively backward fast charging technology.
China's new energy vehicle pile ratio is only 3:1, far from the ideal 1:1, high-speed service area charging pile unattended, a holiday has to wait in a long line.
On the day of the National Day, in a high-speed service area in China, 20 electric bicycles and 4 charging piles queued for more than 4 hours.
If it is really as advertised, you can run 800 kilometers in ten minutes, then what are you waiting for?
As soon as winter arrives, the temperature drops, the electric bicycle falls out of favor, cannot be on the road, it is difficult to charge, the charging is slow, in short, it is not as worry-free as a gasoline car.
In the past, you could still enjoy some subsidies, but now you can only switch to gasoline cars without subsidies.
In the future, with the advancement of technology, the range of new energy vehicles will definitely be longer, and the infrastructure such as charging piles will also be more perfect, and the charging time of electric vehicles will also be shortened.
A few years ago, major battery companies developed all-solid-state batteries with high energy density, fast charging and discharging speed, and high safety, which will have a huge impact on the development of new energy vehicles once the technology matures and begins to be applied on a large scale.
In some places, the return of new energy buses to fuel does not mean that there is no way out for new energy vehicles, and there is no reason to completely deny the prospect of electric vehicles.
In cold places such as the Northeast and Northwest, it is not necessary to use an electric car, methanol, hydrogen, and hybrid power can be used.
If you want to grow and grow, you must fully consider the status quo, update the technology, and step by step.
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