A granted patent is enforceable coverage, and a useful way to read a week's batch is to ask where in the product it sits. In the week ending 20 April 2026, SK On Co., Ltd. — the Korean cell maker that supplies pouch cells to automakers — was issued a set of grants that land not in the cell chemistry but a level up, in the hardware that turns cells into modules and packs. The batch is a reminder that for a cell maker selling into vehicle programs, a large share of the defensible engineering is in assembly, not just active materials.

Two of the grants are the same invention claimed in companion patents. US12603394B2 and US12603393B2 both cover a battery module in which electrode tabs are inserted into holes in a bus-bar plate and joined by a welding bead whose width and height are defined by equations. The third, US12603362B2, covers a pouch cell with conductive units along the sealed periphery that touch to form a circuit. The pouch grant states the construction directly:

The first conductive unit and the second conductive unit are in contact with each other to form an electric circuit along the first peripheral portion or the second peripheral portion.— Lithium secondary battery and battery system including the same, US12603362B2

The footprint leans toward assembly

SK On's granted U.S. footprint is large — roughly 500 records — and its class distribution is telling. Alongside the cell class H01M 10/0525, the most common classifications are pack and housing classes: H01M 50/211 (battery-pack housing), H01M 50/507 and H01M 50/505 (connectors and terminals), and H01M 10/613 (cell cooling). These are the classes of someone whose product is not just a cell but a thermally managed, electrically connected assembly of cells delivered to a vehicle program. The in-window grants — bus-bar welds and pouch-periphery circuits — sit squarely in that part of the portfolio.

Recent grants outside the exact window fill in the same picture and show the chemistry side too. US12658521B2 covers a module with a bus-bar gas outlet venting cell gas away from the stack. US12646795B2 covers a battery device with internal flow spaces to route gas or flames generated in a cell assembly — both safety-and-pack engineering. On the materials side, US12651743B2 covers a silicon-carbon anode active material with pores, indicating the company also holds anode-chemistry coverage. The mid-April batch belongs to the assembly-and-safety strand of that broader program.

The footprint is also recent and still growing. The grant counts by year are weighted toward the last few years — on the order of 80 records issued in 2022, more than 150 in 2023, and over 130 in each of 2024 and 2025 — which is the pattern of a company that scaled its U.S. filing as it scaled its automotive supply business. A cell maker ramping into vehicle programs accumulates exactly this kind of coverage: the cell chemistry classes (H01M 10/0525, the cathode classes H01M 4/525 and H01M 4/505, the silicon and carbon anode classes H01M 4/386 and H01M 4/366) sit alongside the pack, connector, and cooling classes, because qualifying a cell into a vehicle means owning engineering at both the cell and the pack level. The mid-April grants are drawn from the connection-and-housing side of that two-level program.

What module coverage buys a cell supplier

For a reader following the cell supply chain as a business, the value of mapping this is in seeing what a cell maker can fence beyond the cell. Module and pack patents — how tabs are welded to a bus bar, how a pouch seals and connects, how generated gas is vented away from the stack — define enforceable coverage in the integration work that sits between the cell and the vehicle. That is the layer where a supplier's engineering meets an automaker's pack design, and where freedom-to-operate questions land for any rival proposing a comparable module-assembly or venting approach. The bus-bar weld claims, defined by dimensional equations, are an example: the coverage is in a specific welded-joint geometry, the kind of manufacturing detail that qualifies a module into a program.

There is a reason a cell supplier accumulates so much non-chemistry coverage. The cell active materials are where the energy and cost story is written, but they are also the most contested patent territory in the industry, crowded with filings from every major cell maker and materials house. The module, pack, connection, and venting layers are where a supplier's specific way of building a deliverable assembly lives, and they are closer to the automaker relationship — the welded bus bar, the pouch that seals and carries a peripheral circuit, the venting path that routes cell gas safely. Coverage there protects the integration engineering a customer actually qualifies and pays for. The mid-April grants, landing in exactly those classes, are consistent with a supplier whose defensible position is as much about assembly and safety as about the cell inside.

None of these grants disclose how SK On's cells perform or what they cost, and a coverage map is not a verdict on a portfolio's strength. The standard caveats hold: a patent fences what its claims describe — a particular weld geometry, a particular pouch-periphery circuit, a particular venting path — not modules or pouches in general, and the companion bus-bar grants cover one invention, not two distinct ones. But the shape of the set, read against the footprint, is clear: a cell maker accumulating enforceable coverage heavily in the assembly, connection, and safety layers of the pack, with the week's grants adding to the module-and-pouch portion of a roughly 500-record program.