However, just some time ago, the domestic Tesla Model 3 confirmed the use of lithium iron phosphate battery, and the emergence of BYD's "blade battery" brought the lithium iron phosphate battery back to the consumer's field of vision. So, is the use of "low-end" lithium iron phosphate battery a "retrogression" in technology? What are the advantages and disadvantages of this technology? Why did it choose "Regression" at the current time node? With these questions, Parker will talk to you today.
In the field of power batteries, lithium ternary and lithium ferrous phosphate are two commonly used lithium ion batteries. Ternary lithium batteries are lithium-ion secondary batteries with ternary polymers such as nickel cobalt lithium manganate or nickel cobalt lithium aluminate as cathode materials, while lithium iron phosphate batteries are named after lithium iron phosphate as cathode materials. "Ternary" contains a precious metal-cobalt. Since 20 17, the global price of cobalt materials has been soaring, and the price of ternary lithium batteries has also risen. In contrast, the manufacture of lithium iron phosphate batteries will be simpler and the cost of materials used will be lower. It does not contain metal elements such as nickel, manganese, aluminum and cobalt, and its manufacturing cost is about 20% lower than that of ternary lithium battery.
According to the research data of real lithium, by the end of 20 19, the unit price of ternary lithium batteries in China will be 1.05 yuan/wh; Unit price of lithium iron phosphate battery 0.8 yuan /Wh. After reaching an agreement with Contemporary Ampere Technology Co., Ltd., Tesla will use lithium iron phosphate batteries on domestic Model 3 and many future models, which can effectively reduce costs. Compared with the current situation, after Tesla replaced the lithium iron phosphate battery, the cost was reduced by at least 10%. This will not only speed up the localization process of parts, but also help Tesla seize more market share with the reduction of car prices.
In addition to low cost, lithium iron phosphate battery also has the characteristics of good stability and high safety. The electrochemical performance of the cathode material of lithium iron phosphate battery is relatively stable, and the battery structure will not change during charging and discharging. In terms of characteristics, it is safer than ternary lithium battery, and it is still not easy to explode even under special circumstances such as short circuit, extrusion and puncture. This can also be seen from the safety test of BYD's "blade battery" some time ago.
It is reported that the thermal runaway temperature of lithium iron phosphate batteries is generally above 500℃, while ternary lithium batteries are lower than 300℃, and some ternary lithium batteries with high nickel ratio are even lower than 200℃. In addition, because it does not contain heavy metals and rare metals, lithium iron phosphate batteries will be relatively environmentally friendly and more conducive to recycling. Therefore, in the early years, lithium iron phosphate battery will become the first choice of new energy vehicles after comprehensive factors such as cost and technology.
In this way, lithium iron phosphate battery seems to be a "high quality and low price" choice, but why has it been "silent" for a long time?
After experiencing the initial stage of new energy development such as "cheat compensation" and uneven product quality, the state will increasingly favor vehicles with long cruising range and high energy density of battery system in terms of subsidies; For ordinary consumers, longer battery life can often bring a more comfortable car experience. Therefore, the products of car companies are constantly moving closer to the direction of "high endurance".
However, the biggest disadvantage of lithium iron phosphate battery is its low energy density and difficult to improve its cruising range. Ternary lithium batteries have gradually become the mainstream of the industry because of their high energy density and longer cruising range. Although the cost will increase a lot after using ternary lithium battery, intuitive battery life improvement, reduction of user mileage anxiety and policy subsidy support will undoubtedly be a better choice. In addition, through measures such as material modification and optimization, surface coating and electrolyte adjustment, the safety can also be well guaranteed.
With the "downhill" of subsidies for new energy vehicles from 2065438 to the end of June 2009, cost has become one of the primary factors considered by electric vehicle enterprises. At present, it seems only a matter of time before subsidies gradually decline and disappear completely. In this way, in order to maintain the product competitiveness of automobile models, car companies need to return to "rationality" in terms of power battery selection, cost and income, and lithium iron phosphate batteries with relatively low cost have returned to the vision of car companies and consumers.
At the same time, with the continuous development of technology, the shortcoming of "poor endurance" of lithium iron phosphate batteries has been gradually improved. In previous years, the energy density of lithium iron phosphate batteries on the market was about 120- 140Wh/kg, and the energy density of the packaged battery system was about 90- 100Wh/kg. On the other hand, ternary lithium battery, Tesla 2 1700 battery cell energy density can reach 300Wh/kg. In recent years, the energy density of lithium iron phosphate batteries mass-produced by battery manufacturers such as BYD, Li Shen and Guo Xuan has reached 190Wh/kg, and it is expected to reach 220Wh/kg.
BYD's "blade battery", which is very popular recently, is actually a battery technology called CTP(Cell To Pack), that is, the battery is directly packaged. Because the battery is flat, a plurality of single "blade" batteries are arranged in an array together, and the length can reach 2500 mm; ; The composite efficiency of the battery core is greatly improved, the volume and energy density are 50% higher than those of the traditional lithium iron phosphate battery, and the service life of the whole vehicle can reach more than one million kilometers. Take BYD Han EV as an example, its battery system energy density reaches 140Wh/kg, and the cruising range under NEDC standard can reach 605km. Compared with a variety of models using ternary lithium batteries, it is not behind in terms of battery life.
Contemporary Ampere Technology Co., Ltd. has taken a similar route. At the end of 20 19, Contemporary Ampere Technology Co., Ltd. and BAIC New Energy released CTP battery packs. The CTP technology of contemporary Amperex Technology Co., Ltd. can improve the volume utilization ratio of battery pack by 15%-20%, increase the production efficiency by 50%, reduce the number of battery pack parts by 40%, and increase the energy density of the system by 10%- 15%, with the maximum reaching over 200Wh/kg.
At the same time, with the maturity of the new energy market, in addition to the relatively "high-end" models such as Tesla Model 3 and BYD Korea EV, pure electric scooter with moderate battery life and high cost performance will also become the new demand of the market. From this point of view, lithium iron phosphate battery with long cycle life and lower cost is more suitable for this type of vehicle than ternary lithium battery.
After reading the above, many people may have doubts: With the development of technology, will lithium iron phosphate battery become the "mainstream" of the market again? Will it compete with ternary lithium batteries?
Although lithium iron phosphate battery can compete with ternary lithium battery by reducing the weight of battery pack and improving the overall energy density of battery pack, lithium iron phosphate battery is limited in material after all; It is difficult for the energy density of its batteries to develop by leaps and bounds, while the energy density of ternary lithium batteries has a larger breakthrough space. In short, ternary lithium batteries have the potential to greatly improve battery life, while lithium iron phosphate batteries will be more difficult.
In addition, the low temperature resistance of lithium iron phosphate battery is much worse than that of ternary lithium battery. According to the experiment, at -20℃, the capacity of lithium iron phosphate battery will shrink by nearly 50%, and the capacity of ternary lithium battery will shrink by 75%. At the same time, the fast charging ability of lithium ferrous phosphate is not as good as that of ternary lithium battery. Generally speaking, lithium iron phosphate batteries will gradually "return" to low-end products. On the contrary, if more usage scenarios (cold resistance, fast charging) and stronger performance are pursued, ternary lithium batteries will remain the relatively mainstream application technology in the future.
I believe that after reading the above words, everyone has a certain understanding of the "return" of lithium iron phosphate batteries. Its return and the improvement of grouping technology are the embodiment of the market becoming more rational. With the acceleration of subsidy recession and the intensification of market competition, I believe there will be more new technologies. Such as fuel cells, all-solid-state batteries and quaternary lithium batteries, all of which make Parker full of expectations. Finally, as a consumer, what do you want to say about the "return" of lithium iron phosphate batteries? Welcome to leave a message below to interact with us.
This article comes from car home, the author of the car manufacturer, and does not represent car home's position.