Attention should be paid to the development of lithium iron phosphate batteries

In recent years, the rapid development of electric vehicles has led to the development of power lithium batteries. As the power source of electric vehicles, the quality of battery performance is not only related to the length of the vehicle's range, but also related to the safety and reliability of the product. It can be said that the development of power batteries determines the future of pure electric vehicles
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.1. Electric vehicles must put safety first
Among the many new energy models, China has the highest subsidies for pure electric vehicles, and subsidies are linked to pure electric mileage, so in recent years there has been a "man-made triple wind" in China. In the case of government departments advocating that batteries are higher than energy targets year by year, the combination of nickel cobalt manganese in the 3 binary materials from the safety of 333, step by step towards 523, 622, 811. With the increase of nickel quantity, the thermal out-of-control temperature and safety of the battery decrease gradually while the material is higher than the capacity. In another nickel-cobalt-aluminum binary material (used by Tesla), nickel accounts for 80% of the share, and similar problems exist.
said that the "triple wind" is "artificial" because it is not due to the natural formation of technological advantages, but the one-sided pursuit of pure electric long-distance policy guidance. The wind is blowing, even has always adhered to the "iron battery" of the big enterprises have also been fascinated, become "follow the wind." Of course, this is not difficult to understand, after all, the survival of enterprises need to profit. This also proves from another angle, the policy power is infinite, no matter what direction of the wind, to blow can be blown up.
, the mileage index for pure electric vehicles is catching up with conventional fuel vehicles, which, in addition to using high-energy batteries, have led to excessive overcharging. These two factors overlap to make the safety of electric vehicles more threatened, accidents are frequent. At one point, the Ministry of Industry and Information Technology called for the suspension of the use of three-yuan lithium-ion batteries, but under the strong appeal of the powerful three-yuan "team" finally had to compromise, agreed that the passenger car with fewer passenger cars can use three-dollar lithium-ion batteries, three-dollar lithium-ion battery bus through the thermal out-of-control test and thermal out-of-control expansion test premise, can also apply for a recommended directory.
a passenger car with a three-yuan lithium-ion battery, can the occupants escape safely? And look at recent accidents. In early May, two people in the front of a Tesla Model S caught fire in Florida after hitting a wall at 90 miles per hour, and one person sitting in the back was thrown out of the car. On May 10, a German driver was trapped and burned to death when a Tesla Model S crashed into a central isolation zone on a highway in southern Switzerland. Within a week, three people were killed in two Tesla electric car fires. It can be seen that the three-yuan lithium-ion battery fire spread too strong, passenger car occupants themselves can not escape, others are difficult to rescue.
facing multiple fires, Tesla says traditional car crashes can also burn. This is a typical strong word. What's more, traditional cars collide without burning.
China has also had a number of electric vehicle combustion incidents, although not as frequent as Tesla, but can not draw the conclusion that China's three-yuan lithium battery than Tesla's three-dollar lithium battery is safer, but the factor should be considered is that most of China's electric passenger cars mileage and battery volume than Tesla less, the proportion of the highway is not as high as Tesla, and China's highway speed limit of 120 km / h. As an electric bus with a large passenger capacity and a long time for passengers to escape, we should attach great importance to the safety of our products.
the author believes that for electric vehicles, whether commercial vehicles or passenger cars, are related to human life, safety must be put first, other issues to make way for it., the safety of power batteries is extremely critical
the safety of electric vehicles mainly depends on the safety of power batteries.
battery pack, like a gasoline tank, is a component containing high-energy substances. The electrolytes in lithium-ion batteries are made from organic solvents and are as flammable as gasoline. Positive oxidants and negative reducers are separated by only a micron-thick diaphragm thick diaphragm, and the internal short circuit heats up; At a certain temperature, the oxidant on the positive pole can react with the electrolyte. A large amount of chemical reaction heat will cause the heat to get out of control, producing a large number of gases, resulting in elevated air pressure, battery rupture, followed by vehicle combustion, explosion.
of the positive oxidants, the temperature at which the battery heats out of control is also different. The lower the thermal out-of-control temperature of the positive material, the worse the safety of the battery. Tesla uses a ternate lithium-ion battery with a thermal out-of-control temperature of less than 200 degrees C, especially when the tern three-way material reaches a certain temperature will also break down and release a very lively primary ecological oxygen, even without the outside oxygen supply, the battery inside the "complete" combustion of the three elements. Imagine that it's safe? This is also the reason why the fire spread rapidly and was difficult to put out after the three-yuan lithium-ion battery caught fire.
in contrast, the oxygen in the lithium phosphate molecule is firmly bound to the root of phosphate, it is difficult to become a fuel, iron phosphate battery heat out of control temperature is much higher, its safety is much higher. Today, the lithium iron phosphate unit battery ratio energy has been increased to 180Wh/Kg, the battery pack ratio energy has reached 151Wh/Kg, its power battery performance can fully meet the needs of extended electric vehicles.
china has the advantage of developing lithium iron phosphate batteries. Led by the China Battery Industry Association, successfully appealed three foreign-funded enterprises iron phosphate lithium battery patent invalid, so that China's iron phosphate lithium battery industry completely free from foreign patent constraints, for the development of new energy vehicles in China to remove obstacles; The author believes that lithium iron phosphate battery should become the development focus of power battery, should encourage continued research and improve product performance.
, the author believes that the scale of the power system energy storage with three-yuan lithium-ion battery is not desirable, even with lithium-ion battery is debatable. For example, it's like an active volcano full of incendiary bombs. Last year, two 2MWh FM power stations caught fire in Shanxi Province, using Samsung's three-yuan positive 18650 lithium-ion battery. Although the cause of the fire is still being argued, some believe it may not be the battery but the electrical part of the cause, but the indisputable fact is that the battery burned out. If you replace it with a battery that doesn't contain organic solvents, it won't be so bad. In July, a fire and explosion at a 4MW/12MWh energy storage plant at a wind farm in South Korea was reported to be the country's fourth three-yuan lithium-ion battery storage plant to burn. These accidents should arouse the vigilance and deep thinking of the decision makers and builders of lithium-ion battery storage power station in China.3. The add-on electric vehicle is an excellent match with the lithium iron phosphate battery
the add-on electric vehicle refers to the addition of a range extender (any kind of power generation device) to the pure electric vehicle, which increases the mileage by generating electricity on the vehicle. The advantages of this type of car are outstanding: battery pack will not overcharge and over-release, life extension, high safety, less battery, subsidy slope, cancellation of the impact of small, easy to market, urban conditions than fuel car fuel savings of more than 50%, more money-saving, can not be external charging, less construction of charging piles, and can be far away Distance driving, if there are charging conditions, the city within 100 kilometers of fuel-saving rate of more than 80%, can continue to use fuel vehicle production, refueling facilities, easy to develop, the newly proposed electric vehicles, direct drive electric vehicles, can eliminate the high current charging and discharge, not only more energy-saving (oil), but also longer battery life.
the use of high-security lithium iron phosphate batteries for extended electric vehicles, not only can improve the safety of the vehicle, but also than energy, power is fully sufficient, long service life. In addition, China is rich in lithium resources, there is no cobalt, nickel resources are restricted.
Therefore, China should take lithium iron phosphate battery as the development focus, so that it can strongly support the marketization of extended electric vehicles, it can effectively eliminate the mileage, safety, price, charging, follow-up battery five anxiety.
some people think that the program or burn oil, is not the ultimate goal of the development of electric vehicles. In other words, the development of add-on electric vehicles is of little significance. In this regard, the author would like to emphasize two points.
is that if China's automobile fuel consumption can be reduced by more than half, the annual fuel saving of nearly 200 million tons, which will help improve the environment, improve energy security.
is that pure electric vehicles are not necessarily the ultimate goal. We should take energy conservation and emission reduction as the standard, evaluate each technical route. In the future, engines for add-on electric cars are likely to burn alcohol without burning oil, similar to cars in Brazil today. Alcohol from solar biomass conversion, do not increase CO2 emissions, if coupled with the development of high thermal efficiency engines, China's automotive energy conservation and emission reduction will make a great breakthrough.
-range electric vehicles are not "transition to pure electric vehicles", but the main force of future vehicles. In particular, the pairing of extended electric vehicles with lithium iron phosphate batteries is even more dramatic.
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