Pengpai News reporter Senning
"We will achieve mass production of 4680 batteries by the end of the year, but this is difficult to predict because there are many new technologies in it." At the 2022 shareholders' meeting of Tesla (Tesla Inc) in early August, the company's CEO Elon Musk (Elon Musk ) said, "We are confident that we will achieve high productivity, but it may not be until the end of this year before we can achieve high production."
But when he said this, Musk's voice was not very confident. Musk, dressed in black, held a microphone with a solemn face, and his eyes drooped to the ground twice. Compared with the high spirits of two years ago, it seems to be incomparable.
In September 2020, on Tesla's "Battery Day", Musk launched the "epoch-making" Tesla 4680 battery. According to his statement, this battery will achieve a 100GWh production capacity planning in 2022, providing support for at least 1 million electric vehicles.
However, reality is far from what Musk expected.
To this day, Tesla has only started small-scale production of 4680 batteries in the Kato Road factory near Fremont, California and the Austin Gigafactory in Texas . One of Tesla's suppliers, battery manufacturer Japan Panasonic (Panasonic Corporation), made it clear that the 4680 battery is still in the testing stage and large-scale production will not start in April 2023.
Not only did Panasonic delay its mass production plan, but it is rumored that 4680 battery is one of the Chinese partners CATL New Energy Technology Co., Ltd. , the relevant plans are still hazy. On August 17, when a reporter from Pengpai News asked the relevant person in charge of CATL about the company's mass production progress of 4680 batteries, he said that CATL has no information about 4680 batteries that needs to be disclosed.
4680 What happened to the battery? The full name of
4680 cylindrical battery is a 4680 specification cylindrical battery (full pole ear) cylindrical battery. 4680 refers to the specifications of the battery - 46 refers to the diameter of the cylindrical battery with 46mm, and 80 refers to the height of the battery with 80mm.
According to data released by Tesla, compared with the traditional 2170 cylindrical battery, the energy of the 4680 battery will be 5 times that of the former, the vehicle's range will be increased by 16% and the power will be increased by 6 times. In the future, combined with the improvements in battery materials and vehicle design, the net range will increase by as much as 56%, and the production cost can be saved by 54%.
Tesla's Kato Road factory near Fremont, California was originally just a small pilot factory, but now it has become the production of 4680 batteries. The 4680 battery production line of Texas Gigafactory will only be put into production in a small number starting from the second quarter of this year.
At the beginning of this year, the Kato Road factory produced the 1 millionth 4680th battery. In April this year, the first batch of Tesla Model Y loading 4680 battery packs were assembled and delivered at the Texas Super Factory, and the batteries they used were also produced by the factory.
At present, there is no battery production and capacity data disclosed by the Kato Road factory. However, from a document leaked from the Kato Road factory in the first half of this year, we can give a glimpse of the production efficiency of 4680 batteries in the factory. According to the autoevolution website, the leaked document shows that the factory had 14 machines running that day, of which 13 produced "good" batteries, with a pass rate of more than 90%, with one exception. Machine No. 212 produced 82% of "bad" batteries due to training employees from the Texas Gigafactory. According to statistics, the overall production pass rate of batteries on that day was 92%.
In terms of production, the Kato Road factory produced a total of 6,250 4680 batteries on that day, while a Tesla Model Y currently assembled at the Texas Gigafactory requires approximately 690 4680 batteries installed. According to the production of the Kato Road plant on that day, the amount of batteries produced per day supports about 10 Model Ys, which is far lower than the target output of the Texas Gigafactory.
Production efficiency and capacity are still slowly climbing. According to Troy Teslike, an analyst who has long tracked Tesla, the Kato Road plant will be more efficient in August, with 220 battery packs per week, while the Texas Gigafactory will produce 183 battery packs per week. However, Tesla will not be able to produce 5,000 4,680 battery packs per week until May 2023.
. According to the insideevs website, at the end of July, Andrew Baglino, senior vice president of powertrain and energy engineering, said in an investor conference call, "Tesla hopes that the battery factory of Austin can exceed the weekly output of the Kato Road factory by the end of 2022. It is expected that the factory will produce more than 1,000 battery packs per week by the end of the year."
Pengpai News reporter learned that according to Tesla's plan, the annual production capacity of the 4680 battery in the Kato Road factory will reach 10GWh, which can meet the needs of 150,000 electric vehicles. The production capacity of the Texas Super Factory is expected to be built 60GWh within the year. The current 4680 battery capacity under construction also includes Tesla's factory in Berlin, Germany, which is expected to reach 20GWh after completion, but the production capacity will not begin to be released until the fourth quarter of 2022.
The above two pictures are the 4680 battery production line of Tesla's Texas Super Factory
partners. Panasonic, Japan's Japan and LG New Energy Company in South Korea both expressed the production capacity plan of the 4680 battery to the outside world. But Panasonic has previously made it clear that the 4680 battery is still in the testing stage, and the company will gradually expand its production capacity and prepare for comprehensive promotion. It is understood that Panasonic's Wakayama factory in western Japan is building two new production lines this year with a production capacity of about 10 GWh. In the fiscal year 2023 (April 2023-March 2024), the factory will start mass production of 4680 batteries.
South Korea's LG New Energy Company announced in June that it would invest 580 billion won (about 3.8 billion yuan) to establish a new 4680 battery production line at the second factory in Wucang, Chungbek, South Korea, to supply Tesla with a production capacity of 9 GWh, but the time for mass production will be put into the second half of next year.
, Panasonic Energy CEO Kazuo Tadanobu, said in an interview with Bloomberg News that the 4680 battery has the potential to reduce the cost of electric vehicles while maintaining safety and improving performance, thereby driving significant progress in the automotive industry. However, so far, the process has not been easy.
"It's not just about making a bigger battery. The work is not as easy as some people think." Tadonbuki said, "Panisho has been experimenting with this for more than a year." He said that the development process of the battery "requires huge endurance" and changing the shape of the battery requires "a considerable brain nerve." What is the difficulty in mass production of 4680 batteries in
?
Theoretically, cylindrical batteries have the highest technical maturity. In the early stages of Tesla, Panasonic's 1865 cylindrical battery products were used in large quantities, but for electric vehicles, the 1865 battery cell capacity was small (usually not more than 3.5Ah), the number of battery cells required was large (6,000-7,000 cards), and battery management was difficult. Therefore, Tesla and Panasonic further launched the 2170 cylindrical product. A larger volume can accommodate more electrode materials and save structural parts space. 2170 has a certain improvement compared to 1865, but there is no qualitative leap, so it can only be regarded as a fat version of 1865.
In the view of industry insiders, compared with 1865 and 2170 batteries, the mass production of 4680 batteries is very difficult because it is indeed a fusion of multiple innovative technologies.
First of all, it requires high accuracy of the battery winder, and because the battery is large, alignment is more difficult. The main difficulty also lies in the welding process of the ear. What Tesla is most proud of among the 4680 batteries is the battery's unmistakable ear (full-pole ear) technology. The pole ear of the battery cell refers to the metal conductor that leads the positive and negative electrodes from the battery cell, and is the key path for charging and discharging the battery. The material and size of the electrode will affect the internal resistance, overcurrent capability of the battery cell.
The traditional 18650 cylindrical products have small capacity and small output current. They usually only have two pole ears, which are connected to the positive and negative poles (see the left side of the figure below). The 4680 cylinder uses a full-pole ear design, kneading the positive electrode aluminum foil and negative electrode copper foil exposed from both ends of the winding body into one end surface as the electrode ear (see the right side of the figure below). As the number of electrodes increases, the current paths also increase. At the same time, the distance between electrodes can be shortened, thereby greatly reducing the internal resistance of the battery cell, achieving the purpose of effectively reducing the heat production of the battery cell and increasing the energy of the battery cell to quickly charge and discharge the battery cell.
Currently, the production process of all-aluminum ears includes two types: folding method and kneading method.The cut method is a solution adopted by Tesla. It is mainly rolled up by diagonally cutting into pieces. The surface is fluctuating, which can easily cause the polar ear to be inconsistent in contact and poor internal resistance consistency.
In addition, when electrolyte is injected, since both ends are closed by extreme ears, continuous injection of liquid cannot be produced. The kneading method is a solution widely used by domestic Chinese companies. This method uses ultrasonic or mechanical friction to knead the pole ears into the end face. During the flattening process of the electrode, metal debris is easily generated, resulting in excessive self-discharge of the battery cell and even internal short circuit. In addition, the rear end surface of the kneading is denser, making it difficult for the electrolyte to enter the inside of the battery cell. These will become a problem in improving battery productivity.
Second, the space utilization rate of the battery is low. Under the same chemical system, the space utilization rate of large cylindrical batteries is much lower than that of prismatic batteries. If a ternary material is used, the prismatic battery can use ordinary nickel-cobalt manganese (532) or nickel-cobalt manganese (622) materials, but the 4680 battery must use high nickel to have similar power, and its nickel-cobalt manganese content ratio is currently about "811". Although high-nickel ternary compounds have a high energy density, they also mean that the risk of thermal runaway is high and must be taken seriously at the level of system protection.
Third, traditional methods are difficult to dissipate heat. Most of the heat generated by the battery comes from electrochemical itself. Cylindrical batteries generally dissipate the fastest axial heat and slowest on the side. The large volume of the 4680 battery makes this feature more obvious. Under 800V high-voltage charging, the battery will accumulate a lot of heat in a short period of time, and the side heat dissipation speed will slow down. In the long run, it will have a greater impact on the life of the battery. Tesla uses the method to add a water-cooled plate to the top to achieve the effect of two-way cooling on the sides and top. The effect is unknown at present.
Fourth, the negative electrode material is insufficient. The negative electrode of the 4680 battery will be used in the plan to use silicon carbide to increase the energy density. However, silicon carbon negative electrodes also have some disadvantages. For example, the cost is very high; there are many side reactions, large expansion, low charging and discharging efficiency, affecting the quality of the battery; the battery is easily affected by changes in silicon volume. The SEI film (solid electrolyte interface mask) is repeatedly destroyed and modified, and the lithium ion is consumed in large quantities, which may reduce the circulation characteristics and battery capacity.
However, it is quite mysterious that in early August, according to the technical channel The Limiting Factor, which has long been concerned about electric vehicle batteries, dismantled the 4680 battery and conducted chemical analysis. The results show that the negative electrode of the 4680 battery that has been produced is only composed of graphite , and does not contain silicon material.
Perhaps, there is still some patience
Due to the production barrier of 4680 batteries, Tesla has to continue to rely on the 2170 batteries produced by its Texas Super Factory to meet the needs of model Y.
"We have enough 2170 batteries to meet the remaining new car needs this year. Tesla does not need to rely on 4680 batteries this year, but 4680 batteries will play a very important role next year." At the shareholders' meeting, Musk said. The mass production progress of 4680 batteries may not affect Tesla's goal of producing 1.5 million new cars this year, but it will be different in 2023.
Because it is very critical to the smooth mass production of Tesla's electric pickup Cybertruck. When launching the Cybertruck, Tesla promised a series of outstanding performance, and the 4680 battery was necessary to fulfill these promises. Some industry insiders believe that Tesla's 4680's mass production is far behind the original plan, which directly affects the mass production of models such as Cybertruck, electric semi-truck Semi.
However, the good news is not without it. The already-produced 4680 batteries still show advantages in terms of energy density and fast charging performance.
According to the disassembly and test report of Tesla 4680 battery by The Limiting Factor, a 4680 battery weighs about 355g and has a total capacity of about 26.136Ah. According to the rated voltage of 3.7-3.8V, the rated energy is about 96-99Wh. According to simple calculations, the current energy density of the 4680 battery cell is about 272-296Wh/kg. According to Tesla's iteration plan, the energy density of the second-generation 4680 battery will reach 305 Wh/kg, and the third-generation will reach 333 Wh/kg.
As a comparison, the system energy density of BYD 's first generation blade battery is 140Wh/kg, which is expected to be greater than 180Wh/kg in 2025. The system energy density of CATL's latest Kirin battery ternary high-nickel system is 255Wh/kg, and the system can be 160Wh/kg under the lithium iron phosphate system. In terms of energy density, the 4680 battery has certain advantages.
In addition, in April this year, Tesla delivered the Model Y equipped with 4680 batteries produced at the Texas Gigafactory. The first customers who have the opportunity to drive this new model are booking users in the Austin area, and many of them provide a lot of information about the mileage test and charging test of this 4680 battery.
In a test, the user charged the battery on the V3 supercharger in Texas, charging to 9% in 3 minutes, charging from 9% to 50% in 12 minutes, reaching 80% in 34 minutes, reaching 90% in 40 minutes, and reaching 97% in 50 minutes. However, the new battery cannot maintain a maximum charging speed of 250 kilowatts for a long time, and the maximum speed drops faster than the 2170 battery.
"Anyway, it is too early to conduct an appropriate evaluation of the 4680 battery." Some industry insiders commented.
Tesla's senior vice president of powertrain and energy engineering Andrew Bagrino emphasized that Tesla's challenge on the 4680 battery is an engineering problem, not a scientific problem. This means that after sufficient optimization work, Tesla may be able to get out of the mass production dilemma of 4680 batteries.
Editor in charge: Kang Yimei
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-