Why do new energy car companies prefer to use ternary lithium ion?

Electric vehicles are an important development direction of new energy vehicles, and the biggest potential safety hazard is non-power lithium batteries. Although my country already has a lot of regulations on battery system safety and battery performance, due to the innate chemical characteristics of power lithium batteries, unstable factors under certain special working conditions can cause spontaneous combustion, and the battery thermal runaway rate of electric vehicles It is hard to estimate that the difficulty of fighting is higher than that of traditional gasoline vehicles. Of course, battery safety has always been the primary consideration for battery manufacturers and car manufacturers at this stage. Taking the two major electric vehicle battery methods on the market, iron phosphate lithium-ion batteries and ternary lithium-ion batteries, for example, we will analyze the differences in safety and advantages and disadvantages of the two today. Lithium iron phosphate batteries are more stable. The biggest difference in safety between lithium iron phosphate batteries and ternary lithium ion batteries is the high temperature resistance. Simply put, whoever can withstand high temperatures has higher stability. This is also true. Determined by their respective chemical characteristics. Take the lithium iron phosphate battery as an example. The PO bond in the lithium iron phosphate crystal will not decompose until it reaches 700-800 degrees Celsius. Even if there is a violent impact, acupuncture and short circuit, it will not release oxygen molecules. There will be no violent burning. Compared with this, the ternary lithium-ion battery will decompose when its interior reaches 250-300 degrees Celsius. When it encounters the combustible electrolyte and carbon materials in the battery, the heat that appears will further aggravate the decomposition, resulting in a deflagration. The instability also makes the ternary lithium-ion battery meet higher requirements in thermal management. Thanks to the high temperature resistance and chemical stability of lithium iron phosphate batteries, most pure electric vehicles in the early stage used almost all lithium iron phosphate batteries. In 2015 and 2014, lithium iron phosphate batteries have always occupied a dominant position in the new energy passenger vehicle market. However, since 2016, the share of ternary lithium-ion batteries has begun to surpass that of lithium iron phosphate batteries, and has been dominating the market for power lithium batteries. What about this? The energy density of ternary lithium-ion batteries is higher. The reason why the ternary lithium-ion battery later dominated the new energy vehicle market is that its energy density is higher than that of lithium iron phosphate batteries, and the country’s new energy policy shows that subsidies and battery energy density It is linked. In other words, the higher the battery energy density, the more subsidies manufacturers can get. Seeing this, many people may question these new energy vehicle manufacturers. In order to make huge profits, they would rather give up the safer lithium iron phosphate lithium-ion batteries, and risk choosing ternary lithium-ion batteries. In fact, lithium iron phosphate battery is not the best choice. According to the information supplied by BAK battery, the energy density of the ternary lithium ion battery of the 18650 battery has reached 232Wh/kg; while the lithium iron phosphate battery has been hovering. About 170-190Wh/kg, plus the former has higher energy density, smaller volume, and lighter weight, which brings improvements in space and endurance, which is unmatched by the latter. Of course, the low temperature resistance of power lithium batteries is also mentioned here. As we all know, the endurance performance of electric vehicles in low temperature environments in winter is relatively painful, and they can basically only play a part of the battery's performance. The performance of lithium iron phosphate batteries and ternary lithium ion batteries at low temperatures are different.The data shows that the battery capacity of lithium iron phosphate batteries at minus 20 degrees Celsius is only 54% of that at room temperature, and the performance of ternary lithium ion batteries Fair, can reach 70% of normal temperature. In terms of low temperature resistance, ternary lithium-ion batteries are indeed more advantageous, which is equivalent to offsetting their own shortcomings of insufficient high temperature resistance. The prospect of lithium iron phosphate batteries can be expected from the current two brand formations that are equipped with power lithium batteries. The assembly share of lithium iron phosphate batteries is basically reflected in BYD models. This is also the safety of BYD DM and EV models. Sex endorsed. Other brands that still use lithium iron phosphate batteries include Tengshi and BAIC. The ternary lithium-ion battery is represented by Tesla, as well as new domestic car-making forces such as Weilai and Xiaopeng. It can be seen that the brands that use this type of battery have the characteristics of high performance and high battery life. They fully meet the current consumer demand for new energy vehicles. With these two advantages, ternary lithium-ion batteries have risen rapidly. Almost overwhelmingly defeated the lithium iron phosphate battery. However, there will always be times when things will reverse. When the time comes to 2020, we have seen the signs of the re-emergence of lithium iron phosphate batteries. BYD Han, which currently masters the core technology of lithium iron phosphate batteries, will launch the latest blade battery technology this year. This technology will not only greatly improve battery safety, with a lifespan of more than 1.2 million kilometers, but also reduce the size of the battery pack by 50%. This technology has undoubtedly greatly promoted the development of lithium iron phosphate batteries. The official said that this technology will be applied to the battery packs of the upcoming Han EV and Tang EV. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete.