Date: 2026-06-09 hits: 101
A patent filing submitted by Tesla to the U.S. Patent and Trademark Office reveals a major technological breakthrough: dry cathode technology has achieved industrial-scale mass production, nearly halving the production cost of the 4680 battery.
Currently, most battery cathodes require costly wet slurry processes for production, while dry cathode technology has been a core technological bottleneck for Tesla. After three years of dedicated research, this breakthrough has finally been achieved.
In early 2026, Tesla officially published another patent related to dry cathode technology. This patent confirms that it has successfully achieved industrial-scale mass production of a fully dry cathode and applied this technology to the latest version of the 4680 battery.
The biggest obstacle to mass production of dry cathode technology lies in the material itself. Dry cathode powder is brittle, hard, and highly abrasive; without the aid of toxic liquid solvents, it is impossible to coat it onto metal foil at high speeds.
Tesla's latest published patent (patent number: US 2025/0364562) discloses the technical solution used by the R&D team to overcome this bottleneck. This patent introduces a composite binder system that combines polytetrafluoroethylene (PTFE) with more stable polymers such as polyvinylidene fluoride (PVDF, a high-resistance specialty material).
This composite binder undergoes high-shear airflow milling, which causes it to decompose and form a microscopic spiderweb structure. This structure, without any solvent, firmly binds the electrode active particles through mechanical force, ultimately creating a flexible and self-supporting electrode film.
Tesla also optimized the particle size: using larger-diameter active particles to reduce the overall specific surface area. This design keeps the total binder content below 2%, ensuring normal lithium-ion conduction and unaffected battery performance.
In addition to material formulation optimization, this patent also solves the production speed problem that previously hindered the progress of the 4680 battery project. In the early stages of development, using only pure PTFE, the raw material needed to be repeatedly rolled ten times by a high-pressure roller press to form a usable film, an efficiency that could not meet the needs of large-scale production by automakers.
Tesla states that with the new composite binder, the raw material only needs three rolling cycles to form a complete electrode film. After the rolling process was greatly simplified, production efficiency was increased to three times the original level.
This technological breakthrough has brought significant economic benefits and production advantages. Traditional wet slurry processing requires hundreds of meters of high-energy-consuming drying ovens and costly solvent recovery equipment.
Eliminating these steps can reduce the footprint of Tesla's battery factory by up to 50%. Production calculations show that eliminating the wet process reduces equipment investment in battery production lines by over 40%, and nearly halves the overall electrode production cost.
Performance testing results demonstrate that cost reduction has not sacrificed battery quality: batteries using the dry process retain approximately 90% of their initial capacity after 2000 charge-discharge cycles.
This technological breakthrough has already moved beyond the laboratory. During the Q4 2025 earnings call in January 2026, Tesla confirmed that its Texas Gigafactory had officially begun mass production of this all-dry electrode battery. Bonnie Eggleston, Tesla's Vice President of 4680 Batteries, also announced that both the positive and negative electrodes of the battery now fully utilize the dry process.
These second-generation 4680 batteries are currently being installed in some Model Y vehicles produced at the Austin factory. According to the plan, between 2026 and 2027, this technology will also be gradually and fully applied to Cybertruck and Cybercab Semi electric semi-trailer trucks.
