In a quiet patent filed with the USPTO, Tesla finally conquered one of its greatest challenges to date: the dry cathode.
Today, most cells require an expensive, wet-slurry-based production process for the cathode, while a simpler dry-coating process is used for the anode. Tesla had been openly working on a dry cathode process for nearly three years, in a plan to both economize and simplify the production of a key battery cell component.
The most recent in a series of patents related to dry cathode was published in early 2026, and it tells the story of how Tesla has successfully industrialized a fully dry cathode for the latest variant of the 4680 battery.
Update: Musk has responded to this article on X, stating that it won’t reduce battery costs in half, but it will significantly reduce them.
It will not cut battery costs in half, but it will significantly reduce the cost of battery cathode production
— Elon Musk (@elonmusk) May 26, 2026
The Spider Web Patent
The primary hurdle to mass-producing a dry cathode was the material itself. Dry cathode powder was too brittle and abrasive to coat onto metal foil at high speeds without the help of toxic liquid solvents.
A recent Tesla patent, published as US 2025/0364562, reveals how the engineering team solved this bottleneck. The patent details a composite binder system that combines PTFE (Teflon) with higher-stability polymers such as PVDF (an extremely resistant material).
When processed through high-shear jet milling, this composite binder splinters, forming a microscopic "spider web" structure. This web mechanically locks the active electrode particles together without any solvents, resulting in a flexible, self-supporting film.
To make this work, Tesla also optimized the particle size. By using larger active particles, the system reduces the overall surface area. This allows Tesla to keep the total binder content below 2%, ensuring that lithium ions can still flow freely and maintain battery performance.
Solving the Throughput Nightmare
Beyond just making the chemistry work, the patent solves the manufacturing speed limits that previously stalled the 4680 program. In early development, using pure PTFE required up to ten passes through high-pressure rollers to form a usable film. That process was far too slow for automotive-scale manufacturing.
Tesla notes that the new composite binder allows a cohesive film to form in just three passes. By drastically reducing the roll passes, Tesla essentially tripled its manufacturing speed.
Slashing Costs and Footprint
The financial and operational implications of this breakthrough are massive. Traditional wet-slurry processing requires hundreds of feet of energy-intensive drying ovens and costly solvent recovery systems.
By eliminating these steps, Tesla can dramatically shrink the physical footprint of its battery factories by up to 50 percent. In addition, manufacturing analysis suggests that removing the wet process reduces capital equipment investments by over 40 percent while cutting overall electrode production costs by nearly half.
Performance testing also proves that these cost savings do not compromise quality, as the dry-processed cells retain approximately 90 percent of their initial capacity after 2,000 charge cycles.
On the Road Today
This breakthrough is no longer confined to the laboratory. During the Q4 2025 earnings call in January, Tesla confirmed that Gigafactory Texas is actively mass-producing these fully dry cells. Bonne Eggleston, Tesla's Vice President of 4680 batteries, celebrated the milestone by confirming that both electrodes now use the dry process.
These Gen 2 cells are already being used for select Model Y vehicles produced in Austin, with a wider rollout for the Cybertruck, Cybercab, and Semi expected throughout 2026 and 2027.
