Solid Oxide Electrolysis Ammonia Patents: Leaders & Trends 2026
- 71.9% concentration. The top 5 assignees hold 69 of the 96 records in scope, with the leader alone filing 38 — this field is not fragmented.
- Filings peaked in 2022 at 19, and the trend since is flat to declining, though the most recent year is always undercounted given the ~18-month publication lag.
- 92.7% of records sit in C25B, electrolytic production of compounds, meaning claim density is heaviest on the electrolysis side, not on downstream ammonia synthesis integration.
Filing growth compares 2021 (9 records) with 2024 (18) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 96 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
This dataset tracks patent activity at the intersection of solid oxide electrolysis cells (SOEC) and the systems built around them — steam supply, heat recovery, part-load efficiency, degradation rate management, nitrogen supply and low-temperature routes. The search string targets documents that describe high-temperature electrolysis heat integration rather than generic fuel-cell or electrolyser claims, so the 96 records in scope are a filtered slice of a much larger SOEC prior art base.
Coverage runs from 2015 through the 2026-07-31 cut-off. Because publication typically lags filing by around 18 months, activity in the final year or two of any chart here is understated relative to what has actually been filed.
Filing trend and technology composition
Two views of the same 96 records: how filing activity has moved year over year, and which IPC subclasses carry the claims.
Filing trend, 2017–2026
Filings rose to a peak of 19 in 2022 and have not exceeded that level since; the 2017 starting point of 11 records shows this was already an active area at the start of the coverage window, not an emerging one. Read the tail years cautiously — the 2026 figure of 0 reflects the publication lag, not a stop in filing.
IPC subclass composition
C25B (electrolytic production of compounds) appears on 92.7% of records, confirming that most claims are anchored on the electrolysis cell itself. H01M (batteries, cells & fuel cells) at 49.0% shows heavy overlap with fuel-cell architecture, while C03C and C04B — glass/enamel and ceramics — sit far lower at 12.5% and 11.5%, marking the materials and sealing side as comparatively thin. Because records can carry multiple classes, these shares add up to more than 100% of the 96 records and should not be summed.
Shares are the percentage of the 96 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Solid Oxide Electrolysis Coupled Ammonia Synthesis with Eureka
This page is one run against one query. Ask Eureka your own question about solid oxide electrolysis coupled ammonia synthesis and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited records and a representative filing
Heat recovery system for hydrogen production with solid oxide electrolysis cell (US20250075345A1)
A heat recovery system for hydrogen production with a solid oxide electrolysis cell, including a water storage tank, a solar cell panel, a low-temperature metal hydrogen storage tank, an evaporator, a high-temperature metal hydrogen storage tank, a heat exchanger, a solid oxide electrolysis cell, a separator, and a reactor is provided. After water in the water storage tank sequentially passes through the solar cell panel, the low-temperature metal hydrogen storage tank, the evaporator, the high-temperature metal hydrogen storage tank, and the heat exchanger for multi-stage heat exchange, water vapor reaching the working temperature enters the solid oxide electrolysis cell.Filed by Jiangsu University of Science and Technology, published 2025-03-06.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20170292197A1 | Carbon gasification assisted solid oxide electrolysis cell | 27 |
| 2 | US20120003552A1 | Method for improving the efficiency and durability of electrical energy storage using solid oxide electrolysi… | 26 |
| 3 | WO2019219340A1 | Method for the direct reduction of iron ore | 15 |
| 4 | WO2018080571A1 | Solid oxide electrolysis with internal heater | 15 |
| 5 | US20190226101A1 | Solid oxide fuel cell with internal reformer | 14 |
| 6 | US20190229352A1 | Solid oxide cell with internal heater | 11 |
| 7 | WO2018080570A1 | Solid oxide fuel cell with internal reformer | 10 |
| 8 | US20140234744A1 | Stack assembly | 10 |
| 9 | EP2766947A1 | Stack assembly | 9 |
| 10 | US20120193223A1 | Sealing glass for solid oxide electrolysis cell (SOEC) stacks | 9 |
Citation counts favour older records simply because they have had more time to be cited — treat this as a signal of influence within the searched corpus, not of current technical importance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Three patterns stand out once the ranking, trend and IPC composition are read together.
The field is led, not fragmented
With the leading assignee alone accounting for 38 records and the top 5 combined holding 71.9% of all 96 records in scope, freedom-to-operate work here has to start with the leader's portfolio, not a broad landscape scan. The top 10 extend that to 88.5%, leaving a genuinely small long tail.
Growth has flattened since the peak
Filing activity climbed from 11 records in 2017 to a peak of 19 in 2022, then has not surpassed that level. Several of the most active named assignees show zero filings in the latest year, though this partly reflects the reporting lag rather than a confirmed pullback.
Electrolysis claims dominate, integration claims less so
C25B (electrolytic production of compounds) covers the overwhelming majority of records, while classes tied to materials and sealing (C03C, C04B) and to boiler feed-water control (F22D) or gasket/seal design (F16J) each cover only one to twelve records. That gap suggests the system-integration layer around the cell is comparatively open.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to solid oxide electrolysis coupled ammonia synthesis, with the prior art for and against each one.
Who holds the claims, and where the gate sits
A small group of assignees controls most of the filing activity in this dataset, but the technical routes they have not claimed are visible in the IPC gaps.
One assignee sets the baseline art
The leading assignee's 38 records represent the single largest bloc in the ranking of 27 companies, making its claim set the first reference point for any new filing in this space.
Collaboration is narrow and named at the inventor level
The strongest co-assignee pairs in the dataset repeat across the same small set of individuals, pointing to a compact inventor network rather than broad industry-wide co-development.
Momentum has cooled among established filers
Multiple assignees that built the leader group show no filings in the most recent year, including a recorded -100% year-on-year change for one filer. Given the publication lag, this should be read as a slowdown signal rather than a confirmed exit.
| Assignee | Recent year | YoY |
|---|---|---|
| Haldor Topsoe A/S | 0 | — |
| Topsoe Fuel Cell A/S | 0 | — |
| Precision Combustion, Inc. | 0 | — |
| Mitsubishi Heavy Industries, Ltd. | 0 | — |
| Versa Power Systems Ltd. | 0 | — |
| Aisin Corporation | 0 | -100% |
| University of Yamanashi | 0 | — |
| Toyota Central R&D Labs, Inc. | 0 | — |
Where to take this
The dataset points to specific next steps depending on whether the goal is freedom-to-operate, white-space filing, or monitoring.
Map the leader's full claim set
With 38 of 96 records held by a single assignee, any new filing in solid oxide electrolysis heat integration should start by mapping that portfolio's independent claims before drafting.
Explore assignee portfolios in EurekaTest the under-claimed branches
Nitrogen supply integration, part-load efficiency control and sealing materials show thin filing density relative to the core C25B claims — each is a candidate for a first-mover filing.
Run a white-space search in EurekaTrack momentum, not just rank
Several top-ranked assignees show zero filings in the latest year. Watching whether that holds past the publication-lag window matters more than the static ranking.
Set up monitoring in EurekaFrequently asked questions
The ranking covers 27 companies, and it is concentrated: the top 5 assignees together hold 69 of the 96 records in scope, or 71.9%. The single leading assignee accounts for 38 records on its own, well ahead of fifth place at 5 and tenth place at 2. Any competitive or freedom-to-operate assessment in this space should treat that leader's portfolio as the primary reference point rather than spreading attention evenly across the ranked list.
Filing activity rose from 11 records in 2017 to a peak of 19 in 2022, and has not exceeded that level since. Several named leading assignees show zero filings in the most recent year, with one showing a recorded -100% year-on-year change. That said, publication typically lags actual filing by around 18 months, so the last year or two of any chart understates true activity and should not be read as a confirmed stop.
C25B, electrolytic production of compounds, appears on 92.7% of the 96 records in scope, making it by far the dominant class. H01M, batteries, cells & fuel cells, follows at 49.0%. Materials-focused classes like C03C (glass and enamel compositions) and C04B (ceramics, cement and refractories) sit much lower, at 12.5% and 11.5% respectively, indicating the cell-level electrolysis claims are far more crowded than the surrounding materials and sealing art.
The IPC composition shows a sharp drop-off outside the core C25B and H01M classes: materials and ceramics classes cover roughly one in ten records, and niche areas like boiler feed-water control and seal/gasket design each appear on just a single record. Practically, that points to nitrogen supply integration, part-load efficiency control, degradation-rate mitigation and sealing materials as areas where claim space is comparatively open relative to the crowded electrolysis-cell core.
The most-cited record in this dataset, on carbon-gasification-assisted solid oxide electrolysis, carries 27 citations, with a handful of others in the mid-teens covering internal heating and internal reformer designs. High citation counts inside a searched corpus tend to favour older filings simply because they have had more time to accumulate citations, so these figures are best read as a signal of historical influence on the field rather than a ranking of what matters most today.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.