One assignee leads the field with 74 of the 471 records in scope, well ahead of the fifth-ranked filer at 20 and the tenth-ranked filer at 13. The top five combined hold 209 records, or 44.4% of all records in scope, and the top ten hold 61.6%. This concentration is based on the full 100-company assignee ranking the dataset returns, not a curated top-50 or top-100 cut, and it means a small number of filers control a disproportionate share of core process claims.

Filing activity peaked at 33 records in 2022 and had fallen to 15 records by 2024, a documented -25% change over that three-year span. It is not accurate to call the field currently slowing, however, because publication typically lags filing by roughly 18 months, so 2025 and 2026 counts are still incomplete and will rise as more filings publish. The safest read is that activity has cooled from its 2022 peak, with the true trajectory for the last two years not yet visible.

The overwhelming majority — 93.6% of the 471 records in scope — fall under IPC class C22B, covering metal extraction and refining processes. Smaller but meaningful overlaps appear in C01G compounds of other metals (23.4%), B01D separation processes such as filtration (11.3%), and H01M batteries and cells (10.0%). Because a single record can carry multiple IPC codes, these percentages add to more than 100%, but the gap between C22B and every other class shows that core refining process claims, not downstream battery integration, are where the bulk of the art sits.