Can 4680 batteries make Tesla the king of batteries?

Recently, Tesla plans to invest an additional US$3.6 billion in the expansion of facilities in Nevada, USA, part of which will be used to manufacture Semi semi-trailer electric trucks, and the other part will be used to produce 4,680 large cylindrical lithium batteries, with a planned annual production capacity of 100GWh.

Since 2014, Tesla has invested a total of 6.2 billion US dollars to build a super factory for the production of automobile motors and electric vehicle batteries. This additional investment is a further expansion of production capacity, and it also shows that Tesla’s “scale effect” is running healthily.

As early as Tesla Battery Day in September 2020, Musk announced that he would build a large cylindrical 4680 battery, and the curtain of his battery dream officially opened.

Later, with the successful landing of the Texas Super Factory, the Trimont Pilot Factory in California, and the Nevada Factory, Musk’s battery dream continued to move forward.

Of course, its own batteries are first used in its own models. According to the plan, electric vehicles such as Tesla’s Model series, Semi semi-trailer trucks, Cyber electric trucks, and Roadster electric sports cars will use 4680 large cylindrical batteries.

Regarding short-term goals, Musk said, “For the 4680 battery team, the goal in 2023 may be to launch a cost-effective battery for cyber electric trucks.”

The long-term goal is to produce more than 1,000GWh of batteries within Tesla.

At present, new energy car companies that have achieved self-developed batteries include BYD, Great Wall Motors, Tesla, GAC, and Weilai Automobile which are already in the state of self-development.

But why can Tesla be called a “model student” of the battery self-development school? The reasons are as follows:

1. The guide of cylindrical batteries

The reason why it is said to be a model student is first of all because the battery technology route is relatively cutting-edge, and it even leads the way.

The so-called 4680 large cylindrical battery, as the name suggests, has a diameter of 46 mm and a height of 80 mm. According to the data released by Tesla, compared with the small cylindrical battery of the Tesla 21700 battery (21mm in diameter and 70mm in height), the 4680 battery The energy capacity is five times that, and the cruising range is increased by about 16%.

At present, there are three types of packaging for power batteries, namely square, cylindrical, and soft packs, among which square batteries are the mainstream. Cylindrical batteries are the earliest shape of lithium batteries. Whether it is square or round, the change of the mainstream technology path is essentially the result of the constant game between cost and performance.

The advantages of 4680 large cylindrical batteries lie in the following points:

First, the 4680 battery has no tabs (full tabs) design, which greatly shortens the distance of electronic movement, reduces the ohmic internal resistance of the battery, and improves the battery rate performance.

Second, cylindrical batteries have a higher tolerance to battery gas production and are compatible with higher-capacity, higher-voltage positive electrodes, and higher-capacity negative electrodes.

Third, the single cell of the cylindrical battery is relatively large, which is conducive to the integrated design of the battery pack without modules and the battery chassis.

The point is that large cylindrical batteries cater to the “appetite” of downstream car companies.

In addition to Tesla, BMW also has a clear R&D plan for 4695 large cylindrical batteries. It is expected to achieve mass production in 2024 and plans to mass produce 100-120GWh 4695 large cylindrical batteries within seven years.

GM is also rumored to be considering using cylindrical batteries instead of pouch batteries.

In addition to BMW and General Motors, Strandis and Volvo are also preparing to switch to large cylindrical batteries.

In China, car companies such as Weilai Automobile, Porsche, Jianghuai Automobile, and Dongfeng Lantu also said that they will equip their mid-to-high-end models with 4680 large cylindrical batteries.

For Tesla, embarking on the road of self-developed batteries is mainly to control costs in the future, ensure the stability of the supply chain, and maximize profits.

Tesla’s self-developed battery chooses the reason of cylindrical battery: the lowest cost and the longest life.

However, at present, Tesla’s large cylindrical batteries are still far from large-scale applications. The sources of batteries for its electric vehicles are still square batteries from the Ningde era and 21700 batteries from Panasonic in Japan.

Tesla Texas Super Factory has four 4680 battery production lines, one of which has been put into production, and the remaining three are in the debugging and installation stages.

In April 2022, some of the Model Y models produced by the Texas Super Factory have been loaded and delivered with 4680 batteries, and the other Model Y models at the factory will continue to be loaded with Panasonic’s 2170 cylindrical batteries.

At the end of 2022, the pilot factory in Tremont, California achieved a major breakthrough in the production of 868,000 4680 battery cells a week, which can supply about 1,000 Tesla Model Y electric vehicles.

Phased results have been revealed. Judging from the successive price cuts of Tesla’s cars years ago, the cost control of self-developed batteries may have played a certain role.

However, it is still far from fully meeting the goal of domestic supply. We must know that Tesla’s total delivery volume in 2022 will be 1.31 million vehicles. For some time to come, “self-research + procurement” will be Tesla’s battery supply strategy.

More importantly, Musk’s battery dream is not to play a “supporting role” for the car, but to create a new business segment.

2. Have the ambition to be an outsider

Like BYD’s path, although Tesla’s self-developed batteries are first for domestic supply, the excess will be considered for export, and it is also eyeing the cake of the energy storage market.

This point can be confirmed by the change of the positive electrode material of the cylindrical battery.

At first, the positive electrode material of Tesla’s cylindrical battery was a high-nickel ternary material but later added lithium iron phosphate material. Starting in 2021, the batteries used by Tesla’s energy storage products Megapacks will switch to iron phosphate. Lithium material, the reason is that lithium iron phosphate battery has higher safety, low energy density, low cost, and is most suitable for energy storage.

According to different positive electrode chemical materials, current lithium-ion batteries have two paths: lithium iron phosphate and nickel-cobalt-manganese ternary lithium, ternary batteries have higher energy density and are usually used to meet the long battery life requirements of electric vehicles, but the stability And the durability are also poor (not suitable for energy storage); in addition, the “unfriendly” upstream price of ternary batteries makes lithium iron phosphate more popular and becomes the main material for power batteries.

The 4680 power battery produced by Tesla uses a high-nickel ternary cathode material, while its energy storage battery is mainly made of lithium iron phosphate.

Musk said that self-developed batteries can be used in both electric vehicles and energy storage products, including Megapack, a large-scale energy storage battery designed for public and commercial projects, and Powerwall, a household energy storage battery.

Musk had predicted that Tesla’s Megapack energy storage business would grow more than its car production business in the future. This view is similar to Zeng Yuqun’s view that the company’s energy storage battery business will be comparable to the power battery business in the future.

Combined with Musk’s expectations for the energy storage business, it can be found that Tesla is not simply a car company, but more like a new energy comprehensive company, similar to BYD, but it is defined as a car company by professional institutions such as securities companies, which cannot reflect the whole picture of the company.

Although the vision is beautiful, 2023 is not yet the bright year of 4680 batteries, and there are many challenges waiting to be solved.

3. Future challenges

In terms of technical difficulties, countless details need to be overcome. Take the electrodeless tab technology of the 4680 battery as an example. The advantage of electrodeless tabs is that the direct connection between the positive and negative current collectors, the cover plate, and the shell doubles the current in the conduction. At the same time, the distance of current conduction is shortened; the disadvantage is that there are more current collector adhesion processes, which is a new challenge.

The mass production of 4680 batteries is very difficult, mainly due to the integration of a number of innovative technologies. For example, it has higher requirements for the accuracy of the battery winding machine, and due to the larger battery size, alignment is more difficult.

In addition, the battery electrode dry coating technology that the 4680 battery originally announced to use has not yet landed.

The negative electrode of the 4680 battery is planned to use silicon carbide to increase energy density, but the cost is high and the supply is insufficient.

Interestingly, in August 2022, The Limiting Factor technical agency in the United States found that the negative electrode of the 4680 battery was only composed of graphite and did not contain silicon materials by disassembling the 4680 battery.

In terms of competitors, in the “arena” of large cylindrical batteries, giants including Ningde Times, Yiwei Lithium Energy, and Guoxuan Hi-Tech are all making efforts.

Ningde Times announced in September 2022 that it will supply cylindrical batteries for pure electric vehicles of the BMW Group’s “new generation” model architecture starting in 2025.

The first large cylindrical 20GWh factory of Yiwei Lithium Energy will be built in Jingmen, Hubei, China, and realize the mass production of the first generation of 280Wh/kg large cylindrical lithium battery products. In addition, a new generation of 4695 large cylindrical batteries will be released in December 2022, with an energy density of 350Wh/kg.

BAK Power plans to invest 13 billion yuan in the Changzhou production base in China, which covers a total area of 450 mu. The first phase plans to build 3 large cylindrical battery production lines and an international R&D center. After the base is completed, the production capacity will reach 30GWh. Enter the scale stage.

Major battery manufacturers have entered into large cylindrical batteries one after another, which will naturally stimulate the demand for related raw materials, which in turn will lead to an increase in upstream prices. For Tesla, it will bring troubles in how to deal with upstream prices.

All in all, compared with new energy vehicles, from self-developed batteries to complete self-supply, and then to the rise of the energy storage sector, for Tesla, the future is still far away. This is a dream and a constant action.