Lithium-iron phosphate batteries and triple-lithium batteries, who will be the ultimate winner?

When it comes to buying new energy cars, most consumers may first think of "policy incentives", which, although a bit awkward, is quite a real reason. In the domestic sales environment, the new energy vehicles to open up the situation, but not only because of "environmental protection" such a long road to the mission. The advantages of new-energy cars in terms of price and maintenance costs do appeal to most consumers who are still focused on car costs at this stage.

However, it is possible that some consumers will temporarily stop their curiosity about new energy vehicles for some reason. This is because they will be somewhat frightened by various incidents of spontaneous combustion of new energy vehicles. And that's why I'm writing this article today. It is not different from buying a time bomb when you don't know the basics of a new energy car -- the merits of the energy module, and you don't know what you need to pay attention to during use.

lithium iron phosphate batteries: mature but not enough

The lithium iron phosphate electrode material is currently the safest lithium ion battery positive electrode material. With its cycle life reaching more than 2,000 times, the standard charging(5 hour rate) can achieve 2,000 times of cycle characteristics. Coupled with the technical threshold and technology decline brought about by the maturity of the industry, many manufacturers will use lithium iron phosphate batteries for various reasons. It can be said that the rise of new energy vehicles and lithium iron phosphate batteries have an inseparable relationship.

However, one of the fatal disadvantages of lithium iron phosphate batteries is that they have poor low temperature performance and even their nanocrystallization and carbon coating do not solve this problem. Studies have shown that a battery with a capacity of 3500mAh, if it works in an environment of -10 °C, after less than 100 charge-discharge cycles, the power will be drastically reduced to 500mAh, and it will basically be scrapped. This is not a good thing for China's vast territory, winter low temperature is indeed more comprehensive national conditions.

In addition, the material preparation cost and the battery manufacturing cost are higher, the battery yield is low, and the consistency is poor. This is also an important reason why many pure electric vehicles can not reach the nominal value. Therefore, we can see that there are many new energy vehicles(whether pure electric or hybrid electric) in the country, or some cheaper new energy vehicles, will choose lithium iron phosphate batteries for different reasons. It can be said that the use of lithium iron phosphate batteries has an indelible foundation for the production and promotion of new energy vehicles.

In contrast, the three-phase polymer lithium battery does have a better quality than the lithium iron phosphate battery, but why is its development hindered?

Three-way Polymer Lithium Battery: The Unsettled Future

Three-element polymer lithium battery refers to a lithium battery of a positive electrode material using lithium nickel-cobalt manganese acid(Li(NiCoMn) O2) three-element positive material, and a three-element composite positive material precursor product. Nickel salt, cobalt salt, manganese salt are used as raw materials., The ratio of nickel cobalt manganese inside can be adjusted according to actual needs. Lithium ternary batteries have a higher energy density, but safety is often questioned.

The reason why there is such a reason is that even if these two materials will decompose at a certain temperature, the three-element lithium material will decompose at a lower 200 degrees, while the lithium iron phosphate material is about 800 degrees. Moreover, the chemical reaction of ternary lithium materials is more intense, which releases oxygen molecules and rapidly burns the electrolyte at high temperatures, causing a chain reaction. To put it simply, lithium ternary materials are more likely to catch fire than lithium iron phosphate materials. However, it should be noted that we are talking about materials, not batteries that are already finished.

It is precisely because of the safety hazards of the ternary lithium material that manufacturers are also trying to curb the direction of accidents. According to the characteristics of easy pyrolysis of ternary lithium materials, manufacturers will do a lot of work on overcharge protection(OVP), overdischarge protection(UVP), overtemperature protection(OTP), overflow protection(OCP). Therefore, the spontaneous combustion event should more consider whether the manufacturer's functions in these links are in place, rather than simply because of choking.

So what is the current use of these two batteries? Let's look at a set of data. Last November, the installed capacity of lithium-iron phosphate batteries accounted for 64.9 % of the electric buses, while the installed capacity of triple-lithium batteries was only 27.6 %. In contrast, in the purely electric passenger car market, lithium triple-ion batteries were installed in more than 76 % last November.

It can be seen that the three lithium battery itself more energy density advantage, should be the future of new energy storage equipment automotive. Now that safety incidents have occurred, it is a good thing that new energy vehicles are still in their infancy. In order to achieve the dual goals of seizing the market and obtaining policy support, many new energy vehicle-related companies have relaxed their technical requirements and mass-produced energy components that can not withstand repeated use for a long time. The environment in which cars work is harsh, and the reasons for safety accidents inevitably increase greatly when these parts are used for long periods of time.

Therefore, we can think that at the meeting of 100 electric vehicles in China, the Director of Equipment of the Ministry of Industry and Information Technology, Zhangxiangmu, issued an assessment of the safety performance of the three-part lithium battery passenger car, which is a standard definition that the relevant departments of the country intend to carry out at the policy level. To promote the emergence of industry standards. Whether it is for consumers or manufacturers, it has a very positive meaning in the future. Therefore, there is no need to hold back because of the news of safety accidents in the online one-sided view of three-way lithium batteries. Materials are dangerous. The key is how to control them firmly.

Batteries for Different Types of New Energy Vehicles: Uniform Requirements

After the battery situation, the author believes that for the new energy vehicles, we also need to briefly introduce the role of batteries in the vehicle. After all, consumers of pure electric cars are still a minority, and more friends are focused on hybrid cars. Hybrid cars can be strictly divided into three types: ordinary hybrid cars, plug-in hybrid cars and augmented hybrid cars.

The arrangement of battery capacity in the above three types of cars happens to be an ordinary hybrid car plug-in hybrid car ≤ augmentation hybrid car. The batteries of ordinary hybrid vehicles are not rechargeable, and the batteries are used for start-up and rapid acceleration; The batteries of plug-in hybrid vehicles increase the capacity and rechargeable on the basis of ordinary hybrid car batteries, and have better acceleration and fuel saving capabilities; The engine of the augmented hybrid car is used to drive electrical power generation and is more inclined to Yuchun electric vehicles.

These three hybrid vehicle models have their own advantages and disadvantages. At this stage, the main force is also based on ordinary hybrid and plug-in hybrid power. It is precisely because the characteristics of the three hybrid cars have common points for battery life and work environment. Therefore, regardless of the model of hybrid car purchased, consumers should pay attention to relevant parameters such as battery material, use environment and best working conditions. Wait. At the same time, the manufacturer should also strictly control the battery quality and related safety settings in the design process to ensure the safety and efficiency of use.

The page contains the contents of the machine translation.