Recently, Tesla released a message through the official Twitter, showing that the pilot factory in California has produced 1 million 4680 batteries in January, which marks the official entry of 4680 batteries into the mass production stage. Meanwhile, at the time of the announcement, Tesla is expected to begin delivering the new Model Y with a 4680 battery.
The Tesla 4680 battery was first released by Tesla on Battery Day in September 2020, and at the time was described by industry insiders as a technology that was enough to disrupt the industry.
But now, the time has come to 2022, when domestic manufacturers have launched their own battery patent technology. For example, BYD's blade battery, the Great Wall's Dayu battery, and GAC Aean's magazine battery... Coupled with the development of new energy technology, then the question is: as a battery technology two years ago, is it still subversively competitive?
To figure out the answer to this question, you must first figure out what is a 4680 battery? What are the advantages of the 4680 battery?
What is 4680 Battery?
Before talking about the 4680 battery, first popularize the types of batteries with everyone. There are three main ways to package the current power battery - square battery, cylindrical battery and soft pack battery.
According to statistics, the installed capacity of square batteries in the first three quarters of 2021 is about 69.47GWh, and the installed capacity of cylindrical batteries and soft pack power batteries is 6.63GWh and 6.33GWh, respectively. It can be seen that square batteries are absolutely mainstream.
The advantages of the square battery are obvious, and in terms of technology, it can be both winded and laminated, which is more convenient to process. Secondly, the structure of the square battery is very simple, and it is easier to achieve customized production.
Many of the early electric vehicles were "oil to electricity", and the battery space given was varied, and square batteries were easier to "plug" into. And the square battery is the most convenient to make a battery pack, which can make the battery cell as large as possible, thereby maximizing space saving and energy density.
Cylindrical batteries are very familiar to everyone, and they can be seen everywhere in life, such as the "Nanfu No. 5 battery" that we often see in advertisements, which is a cylindrical battery, and the cylindrical battery used by Tesla is this one. However, the cylindrical battery used in the electric vehicle is not the same as the four-wheel drive car we played when we were a child, it is enough to use two "Nanfu", but it is necessary to assemble thousands of cylindrical batteries together.
The main reason why Tesla chose this battery is that its advantages are very obvious. The biggest advantage is that the "shell ratio" is high, and the "shell ratio" of the square battery is only about 90%, because it must be reserved in all directions to allow it to be heated and expanded. The cylindrical battery can reach more than 98% because of the force more uniformly dispersed, which allows it to achieve higher energy density. So this is also why, almost the same battery capacity, Tesla's endurance can often do higher.
However, the disadvantage of the cylindrical battery is also obvious, that is, the impedance is large, so the heat is greater when working, and the energy loss is more. Therefore, this is also the reason why Tesla's BMS battery management system is recognized by the industry. Because the difficulty of battery management is too high, at present, this route is only Tesla to take.
So, how to solve the pain point of cylindrical batteries? Tesla's answer is 4680!
Presumably, friends who know a little about Tesla know that Tesla's power battery naming method has always been simple and rude. The 4680 battery, as the name suggests, is a cylindrical battery with a single cell diameter of 46mm and a height of 80mm.
Compared with the past "1865" and today's "2170", from the naming point of view, 4680 seems to be only a battery that has become larger, from the previous "No. 5 battery" to "No. 2 battery". So some people will ask, what innovation can this have?
Let's explain it to you.
Advantages of the 4680 battery
1. Battery life improvement and cost reduction
First of all, let's do the calculation, assuming that the battery is a perfect cylinder, its volume calculation formula should be V = π * r * h. From 2170 to 4680, its radius and height have increased, and its volume has increased by nearly 5 times.
This means that when this new type of battery is grouped, the connection material and control system between the batteries will be greatly reduced, the volume utilization rate will be further increased, and the weight will be reduced and the endurance will be improved.
Secondly, after the increase in volume, 3,000 batteries were originally produced, but now only more than 500 cells are needed. Tesla estimates that a new production line can increase the capacity of the previous production line by 7 times and reduce the cost by 14%.
In addition, as the diameter of the cell body increases, the gap between their arrangement will also increase, and the heat dissipation line arrangement on the side of the cell will also have more advantages.
More importantly, the output upper limit of the 4680 battery cell is also stronger, and the battery life is further improved, and it is really stronger than five sections!
According to the official, the energy density of the 4680 battery is 5 times that of the existing battery, the battery life is increased by 16%, and the power is increased by 6 times. Range improvements of 16 percent, and new batteries can reduce old costs per kilowatt-hour by 14 percent.
2. Adopt innovative "electrodeless ear" design to reduce impedance
However, as the battery volume increases, the battery impedance also increases simultaneously. For this problem, Tesla's solution is to adopt an innovative "electrodeless ear" design.
The polar ear is a metal conductor derived from the positive and negative collectors, and it is through the pole ear that the current can be connected to the outside of the battery. However, too slender polar ears are not conducive to current conduction, if the current is too large, there will be heat, energy loss increases, and will affect the safety performance.
Tesla's 4680 battery removed the original polar lugs and opted for an uncoated positive/negative material at the end of the collector. Simply put, it is not that there is no polar ear, but the entire end surface has become a polar ear, which greatly reduces the impedance of the battery and solves the heating problem of the cylindrical battery.
3. Battery process innovation
In addition to innovations in shape and design, new batteries also bring new processes in terms of materials and production.
Including battery anodes, new coating processes, and anode material innovations.
Tesla will use a dry cell electrode process, not using solvents, but a small amount (about 5-8%) fine powdered PTFE adhesive mixed with positive/negative powder, through the extruder to form a thin electrode material tape, and then the electrode material tape laminated onto the metal foil collector to form a finished electrode. This process will increase the energy density of the battery and reduce the energy consumption of the production by a factor of 10.
In terms of anode materials, Tesla will start with silicon materials. Silicon can store ten times more electrical energy than graphite, but because its volume changes by up to 400% during the charge and discharge process, it is easy to break, so it has been difficult to replace graphite.
Tesla plans to fundamentally change the ductility of the silicon surface to make it less likely to break, and this technology can increase the battery's endurance by 20%. Tesla named the new material "Tesla Silicon" and cost $1.20/KWh, which is only one-tenth of the existing structured silicon process.
In terms of cathode materials, Tesla reduced the investment construction cost of the battery cathode production line by 66% and the production cost by 76% by improving the cathode production process and reducing the use of water and waste water. At the same time, Tesla launched a battery recycling service, and in the future, new batteries will be produced through recycled old batteries.
Combined with these improvements, Tesla will increase battery life by 54%, reduce the cost per kilowatt-hour by 56%, reduce the investment production cost by 69%, and greatly reduce the production cost in addition to the increase in energy density.
Finally, a sentence to summarize the advantages of the 4680 battery: it can achieve both performance and cost.
4680 battery to leather lithium iron phosphate battery life?
Looking at the current new energy vehicle market, there has been a polarized development. For example, many of the current entry-level models will use lower-cost, better-security lithium iron phosphate batteries.
For example, Tesla Mdoel 3, Model Y standard endurance version models, such as Xiaopeng P7 480 version, Xiaopeng P5 460 version and other entry-level models, they use lithium iron phosphate batteries. The high-end model with the main performance or long-endurance version will be equipped with a ternary lithium battery with higher energy density.
In short, ternary lithium and lithium iron phosphate have their own advantages, and the dispute over the technical route of the two has a long history. However, the arrival of the 4680 battery seems to break this existing battery pattern.
Tesla's 4680 battery uses a ternary cathode material, which has the advantage of high endurance of ternary lithium batteries and the advantages of low cost of lithium iron phosphate batteries. In this regard, there are voices in the industry that the 4680 battery will revolutionize the life of lithium iron phosphate batteries.
In theory, there is nothing wrong with it, but it is not easy to implement!
1. Battery production is difficult
The production of the 4680 battery is not easy, otherwise, it would not have dragged on for nearly two years. Among them, the main difficulty lies in the low yield rate brought about by the extremely high difficulty of polar ear laser welding.
It is reported that the yield of 4680 made by Tesla at the beginning was only 20%, and it will be increased to 80% by October 2021. Now, its yield rate has reached an average of 92%, the highest has reached 97%, and the lowest is 79%, basically reaching the level of mass production.
2. Limited production capacity
The data shows that Tesla will sell 936,000 vehicles in 2021. In 2022, Tesla said that it will not launch new models, choosing to fully expand production capacity, which means that breaking through the million sales mark in 2022 is just the beginning, and it is not impossible for annual sales to reach 1.5 million vehicles.
With such a huge sales volume, Tesla wants to achieve rain and dew, and it is obviously impossible for the 4680 battery to achieve full coverage of the product.
According to Tesla, its production capacity in January was 1 million pieces, and 1 million only installed 1,000 Teslas, that is, each Model Y requires about 1,000 4680 batteries, which is obviously a drop in the bucket compared to Tesla's delivery volume of 1 million a year. Well, in order to meet Tesla's goal of delivering more than 1 million vehicles in 2022, it is essential to purchase friends to make up for production capacity.
At present, Tesla has not only signed a 4-year-long large order for the supply of lithium-ion power battery products with CATL, but also according to rumors, it is signing a contract with BYD for the supply of blade batteries. The type of power battery Tesla needs is a lithium iron phosphate battery.
In short, Tesla will adopt a two-handed strategy in the future, on the one hand, continue to expand the production capacity of 4680 batteries, on the other hand, further expand cooperation with lithium iron phosphate battery manufacturers to meet different versions of models, using different types of battery versions.
In this regard, some analysts said that lithium iron phosphate batteries will still be the main choice direction for the standard version of Tesla's models, and the 4680 battery in addition to the Tesla Model Y in the Texas factory is a high-end model S, Model X and Cyberruck in research and development, as well as large models such as Semi, which has higher energy density requirements. Therefore, experts say that in the short term, it is somewhat difficult for 4680 batteries to achieve universal benefits.
In addition, according to Panasonic, Panasonic will produce 4680 prototype batteries for Tesla as early as 2023, and its annual output of the factory is only 10GWh, which can only meet the battery demand of about 150,000 cars. That is to say, for a long time in the future, lithium iron phosphate batteries will still serve as the main force.
3. Lithium iron phosphate batteries have high safety and low cost
First of all, lithium iron phosphate batteries are safer.
In essence, the 4680 large cylindrical battery is not a breakthrough in battery materials, just like BYD's blade battery, more of a process innovation. To some extent, it is not impossible to use lithium iron phosphate cathode material as the cathode material of the 4680 battery. Just to be able to have a higher endurance, the Tesla 4680 uses a ternary cathode material.
However, compared with ternary lithium batteries, lithium iron phosphate batteries have higher safety, which is also an important reason for BYD and other OEMs to adhere to the lithium iron phosphate battery route. Now with the 4680 battery this set of "black technology", can make ordinary lithium iron phosphate batteries and BYD "blade battery" to achieve "evolution", using the advantages of 4680 battery high performance, not only can improve the endurance of lithium iron phosphate batteries, but also to meet the safety needs of the battery, but also to further reduce costs.
When it comes to cost, this is also the main advantage of lithium iron phosphate batteries.
Since 2021, the price of important power battery raw materials such as lithium and cobalt has been rising. According to market research firm IHS Markit, in late 2021, lithium-ion battery prices rose by about 10% to 20%. According to Bloomberg New Energy Finance (BNEF), the average global price of lithium-ion battery packs by the end of 2021 is $132/kWh (about 840 yuan).
More importantly, cobalt is a scarce resource, and its source depends on imports, which is relatively passive for domestic power battery companies.
In this regard, BYD chairman Wang Chuanfu once said that BYD decided to insist on using lithium iron phosphate batteries from 2008, the main reason behind this is that ternary batteries use a lot of cobalt and nickel, China has no cobalt, nickel is also very little, China can not change from the card neck of oil to the card neck of cobalt and nickel, and the real large-scale use of batteries cannot rely on rare metals.
Therefore, in summary, the 4680 battery will not revolutionize the life of lithium iron phosphate batteries. However, for the current pattern of the new energy market, the commissioning of 4680 batteries may change the existing battery pattern.
Many battery manufacturers followed suit, and a new round of competition began
As we mentioned earlier, there are three main ways to package the current power battery, square battery, cylindrical battery and soft pack battery. In the field of square batteries, the Ningde era dominates. But on cylindrical batteries, other manufacturers are almost all on a horizontal line.
Nowadays, driven by Tesla, the industry will inevitably set off a wave of cylindrical battery trends. Domestic power battery companies will open a new round of competition in the field of cylindrical batteries.
In fact, there are already a number of companies following suit, and are actively localizing 4680 batteries.
In terms of car companies, it is reported that in addition to Tesla's own launch of 4680 batteries, including Porsche, BMW, JAC, Dongfeng and other car companies are also interested or have worked with battery companies to promote the development of large cylindrical batteries, hoping to be applied to related models in the future.
According to relevant industry insiders, Porsche and BMW are working with some battery suppliers to develop large cylindrical batteries, but the specifications and models have not yet been determined. Qin Liwei, deputy director of the battery system department of Jianghuai Automobile New Energy Automobile Research Institute, once revealed that at present, Jianghuai Automobile is planning a new platform based on the 46 series, and will develop 46800/46105 series batteries in the future and realize the whole package of CTP.
In terms of battery manufacturers, power battery companies such as Panasonic, Ningde Times, LG New Energy, and Ewell Lithium Energy have begun to actively lay out 4680 batteries.
It is reported that the Ningde era is accelerating the pace of research and development of large cylindrical batteries "golden hoop sticks", LG Chem has also developed 4680, 4690 and other large cylindrical batteries, hoping to enter the Tesla supply chain again.
The relevant person in charge of Ewell Lithium Energy previously said that the company's 4680 battery plant is under construction, and it is inconvenient for the partner to disclose. Ewell Lithium Energy has publicly stated that the company has completed the strategic layout of large cylindrical batteries, including two major models of 4680 and 4695, and is expected to release 20GWh in production capacity in 2023 and 40GWh in 2024.
In this regard, industry insiders said: large cylindrical batteries have huge advantages in energy density and production costs, and are expected to become an important technical route in the future.