Solid Oxide Electrolyzer Membrane Patents: Leaders & Trends 2026
- Filing peaked in 2021 at 25 families, then slid back toward the 2022 midpoint of 19 — the field is flattening, not accelerating, even before the reporting lag on the newest years is accounted for.
- C25B carries 92 of 99 records, but 53 also sit in H01M8/12 fuel-cell classes — most filers are claiming the electrolysis and fuel-cell operating modes of the same stack together.
- Co-filing is rare — only 7 pairs total, and the strongest links are a single automaker's ties to its own university and research-institute partners, not cross-industry alliances.
Filing growth compares 2021 (25 records) with 2024 (5) — 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 99 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
This dataset tracks 99 patent families filed between 2017 and mid-2026 that combine solid oxide electrolyzer or electrolysis cell (SOEC) terminology with claims specific to solid oxide electrolytes — yttria-stabilized zirconia, scandia-stabilized zirconia, or proton-conducting ceramic electrolytes — narrowed further to the core electrolytic-production and fuel-cell IPC classes. It is a tight, technically-specific slice of the wider hydrogen electrolyzer field, built to separate membrane and electrolyte claims from the broader SOEC stack, balance-of-plant and system-integration filings that dominate most electrolyzer patent counts.
Because publication typically lags filing by around 18 months, the 2025 and 2026 counts in the trend chart are undercounts by construction — treat the recent downturn as a floor, not a confirmed peak-and-decline. The receiving-office spread, weighted toward the United States, Europe and Canada with a smaller but consistent Korean and Japanese presence, points to filers protecting core markets rather than chasing broad global coverage.
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Filing trend and technology composition
Two views of the same 99 families: how filing activity has moved year over year, and which IPC subclasses carry the underlying claims.
Filing trend, 2017–2026
Filings rose from 6 in 2017 to a peak of 25 in 2021, eased to 19 by the 2022 midpoint, and continue trending down into the most recent, still-incomplete years — consistent with a claim space that filled up quickly rather than one still opening.
IPC subclass distribution
C25B (electrolytic production of compounds) anchors 92 of 99 records, with H01M (batteries, cells & fuel cells) present in 53 — evidence that most applicants draft claims covering both electrolysis and fuel-cell modes of the same solid oxide stack. Ceramics (C04B), glass (C03B/C03C) and separation (B01D) subclasses appear only in the single digits, marking them as adjacent rather than core to this claim set.
Shares are the percentage of the 99 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Solid Oxide Electrolyzer Membrane with Eureka
This page is one run against one query. Ask Eureka your own question about solid oxide electrolyzer membrane and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited records in this dataset
US11165073B2 — Solid oxide electrolysis cell with internal heater
An individual solid oxide cell built as a sandwich of oxygen electrode, solid oxide electrolyte, fuel electrode, fuel manifold and at least one mesh layer. In one configuration the mesh supports a reforming catalyst so the cell functions as a solid oxide fuel cell with an embedded reformer, internally steam-reforming or partially oxidizing a gaseous hydrocarbon such as methane into hydrogen and carbon monoxide for conversion inside the cell.Assigned to Precision Combustion, Inc.; granted 2021-11-02.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20160355932A1 | Method for operating an SOEC-type stack reactor for producing methane in the absence of available electricity | 53 |
| 2 | WO2017116307A1 | A promising co- electrolyzer for the direct use of FLUE gas from power plant | 20 |
| 3 | US20180066371A1 | Method for preparing fuel electrode of solid oxide electrolysis cells embedded with bimetallic catalyst | 20 |
| 4 | WO2018080571A1 | Solid oxide electrolysis with internal heater | 15 |
| 5 | JP2017507239A | 有効な電力がない状態においてメタンの生成のためにSOECタイプのスタック反応器を作動させる方法 | 15 |
| 6 | KR1020170114259A | Method for manufacturing solid oxide fuel cell and solid oxide electrolyte cell | 13 |
| 7 | US20230155214A1 | Electrolyzer system with steam generation and method of operating same | 12 |
| 8 | US20220349076A1 | Solid oxide electrolyzer systems containing hydrogen pump and method of operating thereof | 7 |
| 9 | US20230110742A1 | Metal Support, Electrochemical Element, Electrochemical Module, Electrochemical Device, Energy System, Solid … | 7 |
| 10 | US9670586B1 | Solid oxide fuel cells, electrolyzers, and sensors, and methods of making and using the same | 7 |
Citation counts inside this corpus are a signal of influence on later filers, not of current commercial relevance — older records accumulate citations simply by being available longer to cite.
Patent titles are shown in the language they were filed in, not translated, so that each record stays verifiable against the original filing — a translated title will not match in Eureka or in any national register. Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the numbers say
Reading filing volume, IPC spread and citation concentration together points to a field with an occupied core and thin, contested edges.
Growth has flattened, not accelerated
The peak year on record is 2021 at 25 families; by the 2022 midpoint filings had already dropped to 19, and the trend continues downward into the still-incomplete recent years. That pattern is more consistent with a claim space filling up than one still expanding.
Electrolysis and fuel-cell claims are drafted together
More than half of the dataset sits in both C25B (electrolytic production) and H01M (fuel cells), meaning most applicants are claiming a single solid oxide stack across both its electrolysis and power-generation operating modes rather than filing separately for each.
Influence is concentrated in a handful of early filings
The most-cited record carries more than double the citations of the next tier, which itself clusters around 15–20. That concentration suggests a small number of foundational filings shaped how later applicants drafted around methane co-production and internal-heater configurations.
Co-filing is the exception, not the norm
Only seven co-assignee pairs appear across the entire dataset, and the strongest of them link a single automaker to its own university and government-institute partners. Cross-company joint filings are essentially absent, which is unusual for a technology this capital-intensive.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to solid oxide electrolyzer membrane, with the prior art for and against each one.
| Assignee | Co-assignee | Shared families |
|---|---|---|
| Hyundai Motor Company | Kia Motors Corporation | 3 |
| Hyundai Motor Company | UI (UNIVERSITY IND FOUNDATION) YONSEI UNIVERSITY | 3 |
| Hyundai Motor Company | Korea Institute of Science and Technology (KIST) | 1 |
| Hyundai Motor Company | Kia Corporation | 1 |
| Hyundai Motor Company | Yonsei University Industry Foundation | 1 |
| Korea Institute of Science and Technology (KIST) | Kia Motors Corporation | 1 |
| Korea Institute of Science and Technology (KIST) | UI (UNIVERSITY IND FOUNDATION) YONSEI UNIVERSITY | 1 |
The densest co-assignee links trace back to one automotive group and its academic and government-research partners, not to alliances between competing manufacturers.
Who is active, and where the field is open
Assignee momentum in the most recent year is uniformly flat or negative across the names tracked here, which fits a filing count that peaked mid-decade and has been easing since — several previously active filers show no filings in the latest year at all.
Even established filers have gone quiet
Multiple assignees that were active earlier in the period — including energy-technology and industrial-gas specialists — show zero filings in the most recent year and year-over-year declines of -100% where a prior-year baseline exists. That is consistent with the broader flattening in the filing trend rather than any single company's retreat.
One automotive group anchors the densest links
The strongest co-assignee pairing in the dataset connects an automaker to its own university partner, each appearing together on three families; a second pairing links the same automaker to a national science and technology research institute.
Coverage concentrates on three markets
The United States receives the largest share of filings by a wide margin, with Europe and Canada next; South Korea and Japan each carry single-digit shares. That spread suggests applicants are protecting home and near-term commercial markets rather than filing for broad global coverage.
| Assignee | Recent year | YoY |
|---|---|---|
| Bloom Energy Corporation | 0 | -100% |
| Haldor Topsoe A/S | 0 | -100% |
| Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA) | 0 | — |
| Osaka Gas Co., Ltd. | 0 | — |
| Precision Combustion, Inc. | 0 | — |
| Ceres Intellectual Property Company Limited | 0 | — |
| Hyundai Motor Company | 0 | -100% |
| Saudi Arabian Oil Company (Saudi Aramco) | 0 | -100% |
Where to take this from here
The landscape points to a field with an occupied core and a thin, contested edge. Two directions are worth pursuing depending on whether the goal is defensive clearance or offensive filing.
Run a freedom-to-operate check on reversible-mode claims
With 53 of 99 families spanning both electrolysis and fuel-cell IPC classes, any product that switches between generating and consuming hydrogen needs its own claim scope checked against this overlap specifically.
Explore reversible SOEC claims in Eureka →Map the under-claimed sub-areas before drafting
Proton-conducting electrolyte compositions and internal-heater integration show materially thinner filing density than the core zirconia-electrolyte claims — a first-filer advantage may still exist there.
Run a white-space search in Eureka →Common questions on this landscape
The membrane, or electrolyte layer, is the ceramic component — typically yttria- or scandia-stabilized zirconia, or a proton-conducting ceramic — that conducts oxygen or hydrogen ions between the electrodes while blocking electron flow. It is patented separately from stack, housing and balance-of-plant claims because its composition, microstructure and processing method directly determine efficiency, degradation rate and operating temperature, making it a distinct and commercially valuable claim target. This dataset was deliberately narrowed to electrolyte-specific claims within the broader SOEC filing universe for that reason.
The dataset shows a field without one dominant assignee controlling the space; filing activity and co-assignee links instead cluster around a small number of energy-technology firms, an automotive group with academic and government-research partners, and several industrial-gas and combustion specialists. Recent-year momentum has gone flat or negative for most of the previously active names, which fits the overall filing trend easing after its 2021 peak. Anyone assessing competitive position should weight recent-year activity more heavily than historical filing counts, given the publication lag on the newest years.
No — filings peaked at 25 families in 2021 and had already fallen to 19 by the 2022 midpoint, with the trend continuing downward since. Some of the apparent decline in 2025 and 2026 is an artifact of the roughly 18-month lag between filing and publication, so the true recent-year count is understated. Even allowing for that lag, the trajectory looks like a claim space that filled quickly in the late 2010s and early 2020s rather than one still in an expansion phase.
Filing density is heavily concentrated in core zirconia-based electrolyte claims under C25B, while adjacent branches — proton-conducting ceramic compositions, internal-heater thermal integration, bimetallic fuel-electrode catalyst embedding, and reversible electrolysis/fuel-cell mode-switching — show materially thinner coverage. That does not guarantee those areas are easy to claim, but it does mean fewer prior filings stand in the way of a well-drafted first claim there. Co-electrolysis of flue gas or CO2 streams is another branch with only isolated filings rather than a developed claim thicket.
US11165073B2, assigned to Precision Combustion, Inc. and granted in November 2021, claims a specific sandwich construction — oxygen electrode, solid oxide electrolyte, fuel electrode, fuel manifold and at least one mesh layer — with an embodiment where the mesh carries a reforming catalyst enabling internal steam reforming of a hydrocarbon fuel. It is one of the more heavily cited records in this dataset, meaning many later filers have drafted around or referenced it. Anyone building an internally-reformed solid oxide cell with a mesh-supported catalyst layer in that same electrode order should have counsel review this claim scope specifically before finalizing a design.
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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.