① What’s at Stake
Now that the 46mm cylindrical cell is settling in as an industry standard, at the root of that standard sits Tesla’s US patent US11749842B2, “Cell with a tabless electrode,” registered on September 5, 2023. The LG Energy Solution–EVE Energy ITC Investigation No. 337-TA-1518 covered in an earlier piece is a dispute over 46-series application-level design, but sitting above that, at a more foundational layer, is Tesla’s base patent claiming “the very concept of a tabless cell” itself, which remains active. This patent is set to remain in force until November 4, 2039, casting a shadow over the design table of every cell maker looking to adopt the 46-series for close to the next 15 years.
The industry picture is clear — virtually every major cell maker, including Samsung SDI, AESC, LG Energy Solution, CATL, and EVE Energy, has adopted or is preparing to adopt a tabless structure. The tension arises from the fact that this patent does not claim the function “tabless” in the abstract, but a very specific structural requirement — that the conductive portions be folded to make contact with the cap in a concentric-circle pattern. This piece answers the question of exactly how far this patent’s scope of rights extends, and what design room companies adopting the 46-series actually have.
② Basic Mechanism
US11749842B2 is a patent that redesigns the “exit” through which current leaves a jelly-roll electrode structure. As an analogy: imagine a spiral-wound roll of paper with a handle attached at only one end (the conventional tab structure); this patent changes that to a design where comb-like cuts are made all around the roll’s edge, and every one of those resulting strips is folded and overlapped together at one spot (tabless). The claim requires three core elements. First, a first substrate (the electrode foil) on which multiple conductive portions are arranged, spaced apart from one another by non-conductive portions. Second, this substrate, an insulator, and a second substrate are together wound around a central axis. Third, after winding, the conductive portions are folded onto one another to form a concentric-circle pattern and make substantial contact with the can’s cap (the current-collecting plate).
Source: reconstructed by the editorial team from the claims of US11749842B2
③ Comparison: Claim Element Mapping (Claim Chart)
| Claim element (US11749842B2, Claim 1) | Typical industry 46-series tabless implementation (based on public information) | Implication for scope of rights |
|---|---|---|
| Multiple spaced-apart conductive portions (“flags”) on the first substrate | Most 46-series cells leave an uncoated section at the edge of the electrode foil, forming multiple flags | An element commonly observed across nearly every tabless implementation — narrow room for design-around |
| First and second substrates plus insulator wound around a central axis | A general feature of the cylindrical jelly-roll structure itself | An element effectively satisfied the moment cylindrical is chosen as the form factor |
| Conductive portions folded to form a concentric-circle pattern and contact the cap | The angle at which flags are folded, the overlap method, and the welding pattern differ by company (e.g., radial pressing followed by laser welding vs. ultrasonic welding) | The element with the most room for design variation — designing a radial or grid-type contact pattern instead of a concentric one creates room to avoid literal infringement |
| The can includes a first cap, and the cap has a contact surface | An industry-common top current-collecting-plate structure | A structurally essential element, difficult to design around |
Source: editorial interpretation based on the claims of US11749842B2 (Google Patents public record) and publicly available industry implementation information (not an infringement opinion)
What this table shows: three of the four elements read as close to “structurally essential elements” that are effectively unavoidable for any cylindrical tabless cell, and whether the fold pattern is “concentric” or not is the one element that reads as carrying relatively wide design freedom — this is strictly an interpretation comparing the claim language against publicly known industry implementations, not a determination of actual infringement.
④ Patent Perspective
Looking at the filing history, this patent claims priority from a US provisional application (No. 62/755,685) filed November 5, 2018, was formally filed on November 4, 2019 (application number US16/673,464), published on May 7, 2020 (US20200144676A1), and registered on September 5, 2023. The inventors are Kunio Tsuruta, Mikel Ehrlich Dermer, and Rajeev Dhiman, and the current rights holder is Tesla Inc. The patent has a total of 31 claims, and independent Claim 1 is a device claim that claims the “energy storage device” itself.
An interesting point is that a related follow-on application, US20230402722A1 (“Battery cell with a tabless electrode,” filed September 17, 2021, published December 14, 2023, currently still under examination) — filed under the same Tesla name though not by the identical group of inventors — this time claims not a “device” but a “method of manufacture”: the sequence for folding the flags, and the folding process using rollers and deflectors. This illustrates a typical patent-portfolio strategy in which Tesla defends its tabless technology doubly, through both device claims and method claims.
From an infringement-risk standpoint, the ITC complaint that LG Energy Solution filed against EVE Energy, covered in an earlier trend-analysis piece, was reported as based on a right separate from this Tesla patent; nevertheless, every new entrant adopting the 46-series is, in theory, in a position where it must review two layers at once — “Tesla’s foundational patent” and “LG Energy Solution’s application-level patent.”
Design-around scenarios discussed include designing the flags’ fold shape as a partial-overlap type (radial-sector contact) rather than concentric, or using a “quasi-tabless” structure with an extremely increased tab count instead of going fully tabless — for example, dividing the electrode’s circumference into 8 to 16 sections and placing a short tab in each — to sidestep the “continuous concentric-circle pattern” requirement of the claim itself. That said, whether such a design change would actually avoid not only literal infringement but also infringement under the doctrine of equivalents varies case by case, and this too remains in the realm of possibility rather than a definitive conclusion.
⑤ Limits and Outlook
The optimistic outlook runs as follows: the core idea of the tabless structure has already been commercialized by multiple companies for several years now, and there is an observation that Tesla itself remains open to expanding the ecosystem through licensing, suggesting that the benefits of industry standardization may outweigh patent risk. There is a counter-scenario, however — given that this patent has close to 15 years left until 2039, the more firmly the 46-series locks in as the future standard specification, the more license-negotiation leverage could actually tilt toward the patent holder. In other words, this should be viewed not as a risk of litigation right now, but as a long-term risk in which the center of gravity at the negotiating table shifts as the market grows.
As a strategic alternative, a later-entering company developing its own 46-series cell would find it more cost-effective to front-load, at the earliest design stage, a claim-chart exercise comparing claim against claim for an alternative contact structure that avoids the “concentric contact pattern” requirement, rather than making a design change after mass production has already begun. A practical action for readers (planning/IP staff): if you are considering developing a 46-series cell in-house or through contract manufacturing, build into the process, before the design is finalized, a separate opinion from your in-house IP team or an outside patent firm on whether the contact pattern you intend to adopt literally matches the “concentric circular pattern” requirement of this patent’s Claim 1.