Alkaline Electrolyzer Efficiency Enhancement Patent Landscape 2026
- Filing is still accelerating, not maturing. the 2022 midpoint sits at just 2 filings against a 2018 peak of 15, and the curve is climbing again toward 2026 — this is a field re-opening, not winding down.
- Claim activity is concentrated almost entirely in one subclass. all 93 records sit in C25B, with H01M, B01J and C01B trailing far behind — efficiency gains are being claimed as electrolytic-cell architecture first, catalysis and materials second.
- Europe outpaces the US as a filing venue. 32 EPO records against 20 US filings suggests European applicants are setting the pace on where efficiency claims get tested first.
Filing growth compares 2021 (6 records) with 2024 (7) — 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 93 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
This dataset tracks patent families addressing cell voltage reduction, overpotential reduction, current density improvement and energy efficiency in alkaline water electrolysis, filtered to the core electrolytic-production IPC classes (C25B1/04, C25B11, C25B15). It captures 93 published families filed between 2015 and the 2026 cut-off, spanning bipolar cell design, electrode and catalyst chemistry, and system-level separation of hydrogen and oxygen from circulating electrolyte.
Publication lags filing by roughly 18 months, so 2025 and 2026 counts will keep rising as more applications publish; treat the most recent two years as a floor, not a ceiling.
Filing trend and technology composition
Two views of the same 93 families: how filing activity has moved year over year, and which IPC subclasses carry the claims.
Filing trend, 2017–2026
Filings sat near zero through 2017, spiked to a peak of 15 in 2018, then cooled through a 2022 trough of 2 before climbing again toward 2026 — a pattern consistent with an initial wave of foundational cell-design filings followed by a second wave now building around system efficiency.
IPC subclass distribution
C25B accounts for every record by definition of the search, but the secondary classes show where efficiency work spills over: H01M (batteries and fuel cells) and B01J (catalysis) are the two largest adjacent classes, with C01B, C02F, B01D and C07C appearing only in single digits — evidence that efficiency claims are still framed mostly as electrolytic-cell engineering rather than as materials science.
Shares are the percentage of the 93 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Alkaline Electrolyzer Efficiency Enhancement with Eureka
This page is one run against one query. Ask Eureka your own question about alkaline electrolyzer efficiency enhancement and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited records and a representative filing
US12344951B2 — System and a method for alkaline water electrolysis
A system for alkaline water electrolysis includes electrolysis cells, a hydrogen separator tank, a first piping from the electrolysis cells to the hydrogen separator tank, an oxygen separator tank, a second piping from the electrolysis cells to the oxygen separator tank, and a third piping for conducting liquid electrolyte from the hydrogen separator tank and from the oxygen separator tank back to the electrolysis cells. The system includes an ultrasound source for applying ultrasound on the liquid electrolyte contained by the first piping. The ultrasound enhances the separation of dissolved hydrogen gas from the liquid electrolyte, and thus energy efficiency of…Filed by Lappeenrannan-Lahden teknillinen yliopisto LUT, published 2025-07-01 — a system-level claim on ultrasonic gas separation rather than a materials or catalyst claim.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20150203976A1 | Bipolar alkaline water electrolysis unit and electrolytic cell | 34 |
| 2 | US20210115573A1 | Electrolysis vessel for alkaline water electrolysis | 15 |
| 3 | EP3388553A1 | Negative electrode, method for producing same, electrolytic cell using same, and hydrogen production method | 12 |
| 4 | US20200040473A1 | Chemically Resistant, Oxidic Electrocatalyst For Oxygen Evolution During Alkaline Water Electrolysis | 11 |
| 5 | US20240003028A1 | Alkaline water electrolysis system and method of operating alkaline water electrolysis system | 9 |
| 6 | US9683300B2 | Bipolar alkaline water electrolysis unit and electrolytic cell | 9 |
| 7 | US20220380915A1 | Elastic mat for alkaline water electrolysis vessel | 7 |
| 8 | US20220325425A1 | A system and a method for alkaline water electrolysis | 7 |
| 9 | EP3604619A1 | Anode, bipolar electrolytic cell, and method for producing hydrogen | 7 |
| 10 | US20220259749A1 | Nickel-iron catalytic material, preparation method therefor, and use thereof in hydrogen production through w… | 6 |
Citation counts favour older filings simply because they have had longer to accumulate them; read this table as a map of influence to date, not of current best practice.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Three readings of the same corpus: where the claim space is dense, where the venue choices point, and what the citation pattern actually tells a filer.
A second wave, not a plateau
The peak came early, in 2018, and the field cooled sharply before the current uptick. That shape argues against reading the field as saturated — it argues for a first generation of cell-design patents now being followed by a second generation built around efficiency retrofits and system integration.
Europe is the primary proving ground
With EPO filings outnumbering US filings by a wide margin, and Australia and India each ahead of China in this corpus, freedom-to-operate work should start in Europe rather than assume the US is the reference jurisdiction.
Cell architecture still leads chemistry
Every record sits in C25B by construction of the search, but the next-largest classes — H01M and B01J — are an order of magnitude smaller. That gap signals efficiency gains are mostly being pursued through electrolyzer and cell design rather than through catalyst or electrode chemistry, leaving the latter comparatively open.
Influence sits with the oldest bipolar-cell claim
The most-cited record in this corpus is a 2015 bipolar cell design, over twice as cited as the next entry. That is a citation-age effect as much as a merit signal — newer filings on separator tanks and oxidic catalysts have not had time to accumulate equivalent citation counts.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to alkaline electrolyzer efficiency enhancement, with the prior art for and against each one.
| Assignee | Co-assignee | Shared families |
|---|---|---|
| SANTANA CAMPOS RODRIGUES JOSE JOAO | SECIL CIA GERAL DE CAL E CIMENTO | 1 |
The strongest co-assignee pair in this corpus — Santana Campos Rodrigues Jose Joao with Secil Cia Geral de Cal e Cimento — appears only once, and no other pair repeats. Co-assignment is essentially absent here; nearly all filings in this space are single-assignee.
Who is filing, and where the gaps sit
Recent-year momentum across named assignees is flat or negative across the board in this corpus, which is more a reflection of publication lag than of a cooling field — filings made in 2025 and 2026 are still working through to publication.
Flat recent-year counts reflect lag, not exit
Asahi Kasei Corporation (Asahi Kasei), Dalian Institute of Chemical Physics, Chinese Academy of Sciences (Dalian Institute of Chemical Physics, CAS), and Lappeenranta University of Technology (LUT University) (LUT University) all show zero filings in the latest tracked year. Given the 18-month publication lag, this reads as a data-cutoff artefact rather than withdrawal from the field.
Two assignees show a sharp year-over-year drop
Tokuyama Corporation and Evonik Operations GmbH each show a -100% year-on-year change, moving from active filing to zero in the latest window. Whether this is a strategic pause or simply unpublished pending applications cannot be determined from filing counts alone.
Almost no joint filing
The single co-assignee pair identified in this corpus appears exactly once, with no repeat pairings elsewhere. Most applicants in alkaline electrolyzer efficiency file solo, which makes licensing-in or co-development deals harder to spot from the patent record alone and more a matter of direct outreach.
| Assignee | Recent year | YoY |
|---|---|---|
| Asahi Kasei Corporation | 0 | — |
| Tokuyama Corporation | 0 | -100% |
| Lappeenranta University of Technology (LUT University) | 0 | — |
| thyssenkrupp Uhde Chlorine Engineers GmbH | 0 | — |
| Dalian Institute of Chemical Physics, Chinese Academy of Sciences | 0 | — |
| Evonik Operations GmbH | 0 | -100% |
| SANTANA CAMPOS RODRIGUES JOSE JOAO | 0 | — |
| Forschungszentrum Jülich GmbH | 0 | — |
Where to take this
The trend and player data point to specific next steps depending on whether the goal is freedom-to-operate, licensing or R&D prioritisation.
Check freedom-to-operate against the EPO cluster first
With 32 of the tracked filings routed through the EPO against 20 in the US, a European FTO search should come before a US one for anyone building a bipolar-cell or separator-tank product.
Run an FTO check in EurekaWatch the catalyst-chemistry gap
B01J and C01B remain far smaller than C25B in this corpus. If oxidic and non-precious OER catalyst work accelerates, it will likely show up there first, ahead of the cell-architecture classes.
Track B01J and C01B filings in EurekaCommon questions on this landscape
This landscape only includes families that combine alkaline electrolysis terminology (alkaline electrolyzer, alkaline water electrolysis, AWE) with an explicit efficiency term — cell voltage reduction, current density improvement, energy efficiency or overpotential reduction — in the title or claims, and that classify under C25B1/04, C25B11 or C25B15. A patent on alkaline electrolysis generally that does not make an efficiency claim, or one classified only in an adjacent class like H01M, would not appear here. That framing means the 93 families represent efficiency-specific claims, not the entire alkaline electrolysis patent universe.
The data shows a peak of 15 filings in 2018, a fall to a 2022 midpoint of just 2, and a renewed climb toward 2026. This pattern is typical of a technology area that had an early cluster of foundational cell-design patents, went through a quieter period while those designs were commercialised and tested, and is now seeing a second wave of filings likely tied to renewed hydrogen-economy investment. Because publication lags filing by around 18 months, the 2025–2026 counts will continue to rise as more applications clear examination and publish.
Start with the European Patent Office. In this corpus, EPO-routed filings (32) outnumber US filings (20) by a considerable margin, with Australia and India also ahead of China. That ordering suggests European applicants have been more active in staking out claims in this specific efficiency niche, so an FTO clearance that only checks US prior art risks missing the densest part of the claim landscape.
Cell design and electrolytic-production engineering dominate: all 93 records classify under C25B, while the next-largest adjacent classes — H01M (batteries and fuel cells) at 11 and B01J (catalysis) at 10 — are an order of magnitude smaller. This does not mean catalyst chemistry is unimportant; it means the claim space there is comparatively less crowded, which is relevant if you are deciding where a catalyst-focused filing is more likely to clear novelty.
Not necessarily. Citation counts accumulate over time, so older filings such as the 2015 bipolar-cell patent that leads this corpus's citation table have simply had more years to be cited than a 2024 filing on separator-tank design. Treat citation rank as a measure of historical influence within this searched set, not as a signal that the cited invention is still the best available approach. Newer filings addressing system-level efficiency, like ultrasonic electrolyte degassing, may be technically more relevant despite lower citation counts.
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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.