Filing activity concentrates around a cluster of Chinese battery-materials and recycling-linked assignees, including Brunp-affiliated entities and Hubei Wanrun New Energy, alongside lower but historically present filing from Korean and Japanese cell makers such as Samsung SDI and LG Energy Solution. The recycling-linked cluster stands out for co-filing patterns, with the strongest co-assignee pair in the dataset (71 shared filings) linking two Brunp affiliates. No single assignee holds a dominant share of the 2,656 tracked families; the field is a long tail beneath a handful of moderately active filers.

Filing rose from 74 families in 2017 to a peak of 327 in 2025, but the growth was uneven rather than steady, with 2022 already at 246 — close to the eventual peak years earlier. Recent-year momentum data shows every actively tracked assignee filing less than the year before, with declines ranging from -25% to -89%. That pattern reads as a plateau and early pullback rather than continued expansion, though the partial 2026 count is understated due to normal publication lag.

This Hubei Wanrun filing, published 2024-11-28, claims a lithium iron phosphate positive electrode material with high tap density, made by grinding and spraying a mixed iron-lithium-carbon-dopant solution into a precursor powder and sintering it at high temperature. The claimed advantages are high specific capacity alongside the tap-density improvement, achieved through what the filing describes as a simpler, more controllable and more productive process than prior approaches. Anyone developing a tap-density-focused LFP synthesis route should review this filing’s process steps closely before committing to a similar grind-and-spray precursor method.