From Wood Mackenzie.
A new cell emerges – and it’s big!
Several years ago, Tesla transitioned from the 18650 cylindrical form factor to the 2170 form factor, yielding a 50% increase in energy per cell. The cell revealed yesterday would increase the dimensions yet again, bringing the diameter to 46 mm and height to 80 mm – the ‘4680 cell’. While the bigger structure alone can cause thermal and rapid charging issues, Tesla claims to have overcome these by using a tabless design. We are yet to see this in any other commercialised electric vehicle (EV) cell; however, production has already commenced, with 10 GWh of annual capacity expected before the end of 2021.
We expect this new development to be implemented in line with guidance, as the change in form factor alone gives the new cell five times more energy capacity and six times more power than previous cells. Tesla also estimates that this will reduce the $/kWh pack cost by 14%. A key question is whether other battery makers will follow. The 4680 cell design is a much greater change to manufacturing than the move to 2170 was. It may take a lot longer before Tesla’s external battery suppliers (or competitors?) get on board with the new form factor.
Graphite has been the go-to anode material since the commercialisation of the lithium-ion cell in 1991. Since then, the industry has pushed for greater use of silicon in the anode to improve energy density and charging capabilities. Silicon can store nine times more lithium than graphite, and many companies have been developing innovative ways to increase the amount of silicon in the anode. While the share of silicon has increased over time, electrode cracking and degradation are still key barriers to producing a silicon-dominant anode. Tesla claims to have overcome this challenge by removing the graphite entirely and using an elastic, ion-conducting polymer coating as a stabiliser. Other methods have utilised complex and costly designs such as graphene and nanotubes, but Tesla’s method is apparently simpler, cheaper and would even provide a 20% boost in range.
It almost seems too good to be true, particularly when companies such as Sila Nanotechnologies and NanoGraf have been focussed solely on addressing this problem for nearly a decade. A transition to silicon-based anodes has always been a risk for graphite demand in the battery sector. Although the risk might seem slightly more tangible now, we still expect graphite-based anodes to dominate in the short to medium term.
Diversification of the cathode
R&D in the battery industry has been heavily focussed on cathode chemistry in recent years. Slight changes to nickel, cobalt and manganese ratios and the comeback of lithium-iron-phosphate have grabbed headlines. That said, Musk took a more high-level approach when discussing the cathode. The move to high-nickel cathodes has been widely accepted and Tesla confirmed that it was in the same boat. It also shares the same challenges that other battery makers have; more nickel comes at the expense of cobalt, and this means lower stability of the cathode. To get around this, ‘novel coating and dopants’ were mentioned. However, without further details, we are not convinced the problem has been solved just yet.
More interestingly was the range of battery chemistries being touted. The nickel-rich cathodes are only going to be reserved for high-performance and commercial vehicles. The company plans on using a nickel-manganese cathode for long-range passenger applications. Targeting a 2:1 nickel manganese ratio, Tesla would be able to produce 50% more of these cells than the high-nickel cells using the same amount of nickel.
Lastly, lithium-iron-phosphate (LFP) was confirmed as an integral part of the company’s portfolio. It appears that LFP will be the chemistry used in cheaper models, which will arguably be the best-selling models in the future. In our latest H1 2020 update, we increased the global share of LFP, but there is clearly some further upside potential. In the post-event Q&A, Tesla emphasised the need for other automakers to develop EVs capable of using a range of cathode chemistries. We expect LFP to make its way out of China and into the global passenger EV market very soon.
Mining closer to home
At Wood Mackenzie, we see battery raw materials supply as one of the biggest barriers to rapid EV adoption. Bringing on new mines is no easy feat. Tesla revealed several new initiatives that would bring battery chemicals production much closer to home.
The first was the development of a North American cathode facility. Not only will this reduce the carbon footprint of the cell but will allow the company to have greater control on its input materials. In the presentation, Musk suggested the removal of the Class 1 nickel dissolution process. While the details from Tesla are vague, this is already widely occurring where mixed sulphides and mixed hydroxide precipitates are already being directly converted into suitable sulphates for cathode production. This underpins our assumption that the battery sector does not explicitly require Class 1 nickel.
Tesla also made it very clear that it aims to move upstream into mine production. Not only has the company acquired a lithium deposit in Nevada, but it claims to have developed a novel lithium extraction method. According to Tesla’s estimates, using its new extraction and processing technology, lithium in Nevada would be enough to support the electrification of the entire US vehicle fleet. Of course, this method will be cheaper, faster and have less environmental impact than anything currently available, as do all new breakthrough technologies. However, it needs to be proven at a commercial scale before the lithium industry will take it seriously and move away from the conventional processing routes. It is very difficult to believe that all the world’s mineralogy and processing experts would not have realised it was so simple to extract lithium in this way.
Many new methods of extracting lithium have been discussed in recent years as the needs of electrification have been realised. Most have numerous challenges. It would be surprising, although of course not impossible, for Tesla to discover the ‘Holy Grail’ of extraction so soon.
70% of global manufacturing capacity by 2030
Tesla aims to reach 100 GWh of inhouse lithium-ion battery cell production capacity by 2022 and 3000 GWh by 2030, which is far greater than any major battery manufacturer has announced. We estimate the total planned cell manufacturing capacity, excluding Tesla, to be 1,300 GWh by 2030. Tesla’s announcement is more than twice the total global pipeline capacity.
So, will Tesla be able to meet these ambitious goals? Currently, Tesla, and its partner Panasonic, produce NCA cells in Reno, Nevada. After a ramp up of nearly three years, annual capacity now stands at around 35 GWh. To make the near-term 100 GWh target, Tesla needs to triple its inhouse production in just 2 years. While this is the first time Tesla plans on manufacturing their own batteries, the planned capacity target is not unachievable even using existing manufacturing set-up.
However, to make the capacity 100 times greater, simply scaling up the assemble lines is not an option. This would require a significant amount of investment, land, and labour for production. Tesla revealed a series of solutions to simplify the entire cell manufacturing process including coating, winding, assembling and formation. Acquiring Grohmann, Maxwell and Hibar systems enables Tesla to vertically integrate its production process and to continuously improve: The powder-to-film process skips solvent application in making electrode thus reducing footprint and energy consumption; New cell design saves time in winding with no need to insert tabs; High-speed continuous motion assembly lines are seven times more efficient than the current lines with a capacity of about 20 GWh each; Tesla power electronics enables 75% reduction in footprint. Tesla also shared a blueprint for its Terafactory and the future of cell manufacturing. The question that remains is how soon Tesla will be able to materialise the design and ramp-up manufacturing while meeting its cost targets.
Tesla’s 2020 Battery Day was full of ambitious plans, ground-breaking technology and endless optimism. The handful of novel technologies presented will need time to be proven and commercialised. Putting a timeline on technological breakthroughs is always risky. Some other developments have been lingering in the battery space for decades, stifled by technical challenges. Will Tesla really be able to overcome these in the space of a few years?
The real key takeaway is that if everything goes to plan, it will only be after 2023 that Tesla will be able to make the low-cost electric vehicle needed for mass-market adoption. In a much less extravagant way, VW revealed a similar timeline only last week.
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