Tesla finally masters dry cathode for its 4680 battery

I still remember Battery Day 2020, when Elon Musk promised a revolution with 4680 batteries and their dry electrode process. Six years later, I can finally confirm: Tesla has reached a milestone.

In its letter to investors on January 30, 2026, the company announced the effective production of both anodes AND cathodes using a dry process. A technical feat that many considered impossible to industrialize.

Bonne Eggleston, VP in charge of 4680 batteries, confirmed on X: these cells now equip certain production Model Ys. After years of skepticism, Tesla proves its vision was achievable.

But beyond technical performance, this mastery opens major strategic perspectives in a tense geopolitical context.

Six years to master a revolutionary process

The Battery Day 2020 remains etched in my memory as a key moment in Tesla’s history. That day, Elon Musk presented the 4680 format – 46 millimeters in diameter, 80 millimeters in height – and especially the dry electrode process, a technology supposed to eliminate solvents in manufacturing.

The stated goals were ambitious: 50% cost reduction and a 16% increase in energy density. Figures that made the electric automotive industry dream.

But between 2021 and 2024, doubt set in. Industrial-scale production difficulties accumulated. Industry analysts and experts expressed their skepticism.

For several years, Tesla only managed to produce anodes using a dry process. The cathode, much more complex to process without solvent, resisted all industrialization efforts.

January 2026 marks the turning point. The Q4 2025 letter to investors officially announces: dry cathode production is operational. Bonne Eggleston confirms on social media that these cells are integrated into Model Y battery packs in production.

The crazy gamble of Battery Day finally becomes reality.

Why the dry electrode process is a game-changer

Advantages of the dry process over conventional production

To fully understand the scope of this innovation, we must return to the basics of traditional manufacturing. Conventional batteries require the use of toxic and expensive solvents to apply active materials to the electrodes.

The dry electrode process completely eliminates these solvents. No more need for these energy-intensive drying steps that slow down production and increase costs. The footprint of manufacturing plants is considerably reduced.

The economic impact is direct and measurable:

• Reduction in unit production costs
• Significantly reduced infrastructure investments
• Accelerated manufacturing rates

Improved intrinsic performance

Beyond economic gains, the dry process improves the battery’s very performance. The compaction of active materials is better, which optimizes electrical conductivity.

Result: a superior energy density which translates into a potential gain in driving range for vehicles equipped with these cells.

I also observe advantages in terms of durability. Less long-term chemical degradation, improved thermal stability, and a potentially extended lifecycle.

These improvements are not anecdotal: they get to the heart of what makes a good electric battery.

The Model Y as a strategic testbed

The choice to deploy these new 4680 batteries on the Model Y, the brand’s iconic vehicle, is no coincidence. It is Tesla’s best-selling vehicle globally, with production volumes that allow for a gradual ramp-up.

The Model Y platform is mature, which facilitates the integration of this new technology without risking disruption to overall production.

But the timing of this announcement reveals a geopolitical dimension that I cannot ignore. We are in the midst of international trade tensions, with increasing tariff risks on imported components.

Mastery of the dry cathode process represents true strategic independence for the American supply chain. This is precisely the issue of production autonomy in the face of geopolitical challenges at play here.

Tesla regains valuable industrial flexibility:

• Less dependence on Asian suppliers
• Ability to produce locally according to markets
• Resilience to logistical disruptions

A broader industrial reorganization

This announcement is part of a larger industrial reorganization. Tesla recently announced the planned end of production for the Tesla Model S and Model X, its premium sedans and SUVs.

This decision frees up considerable production capacity. Resources are reallocated to the Model 3 and Model Y, higher-volume vehicles, as well as to the company’s future projects.

The 4680 batteries are at the heart of this strategy. Their progressive deployment across the entire range constitutes a major competitive advantage against rival manufacturers.

Tesla is also preparing the ground for its autonomous models, particularly robotaxis, which will require high-performance and reliable batteries.

In the medium term, I expect a significant ramp-up in 4680 production. The future $25,000 compact car could well benefit from this technology, which would democratize access to the performance of these new cells.

The impact on the global electric automotive industry will likely be considerable in the coming years.

After six years of development, Tesla demonstrates that its vision for Battery Day 2020 was not just a communication stunt. The mastery of the dry cathode process represents a major technical advance, validated by the company’s official sources, even if its effects on vehicle driving range and costs will be felt gradually.

For me, a Tesla owner, this announcement confirms that the company maintains its technological lead over the competition. The coming months will tell if this innovation lives up to its promises in real-world conditions. One thing is certain: the electric battery industry has just crossed an important threshold.