Alkaline Water Electrolysis Patent Landscape 2026
Alkaline Water Electrolysis Patent Landscape in 2026
Alkaline water electrolysis is a growth-stage field with 4,665 patent families on record, led by De Nora Permelec and anchored in Europe and the United States. The field expanded sharply through 2022 and remains well above prior multi-year activity levels, even as annual volume has eased from its peak.
De Nora Permelec leads a moderately concentrated field with a strong Japanese and European core
De Nora Permelec Ltd holds the top position with 314 patent families, followed by Asahi Kasei (242) and Industrie De Nora (205), forming a clear first tier. The top five filers together account for 29% of the combined output of the hundred largest filers.
The gap between the first-tier trio and the next cluster—ThyssenKrupp Uhde Chlorine Engineers (159), Yokohama National University (144), and Kawasaki Heavy Industries (120)—is meaningful but not prohibitive, indicating that challengers with focused strategies can close ground. Below rank six, counts drop quickly toward the 40–100 range.
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 1 | De Nora Permelec Ltd | 314 | |
| 2 | Asahi Kasei Corporation | 242 | |
| 3 | Industrie De Nora S.p.A. | 205 | |
| 4 | ThyssenKrupp Uhde Chlorine Engineers GmbH | 159 | |
| 5 | Yokohama National University | 144 | |
| 6 | Kawasaki Heavy Industries Ltd | 120 | |
| 7 | Tokuyama Corporation | 101 | |
| 8 | Agfa-Gevaert NV | 97 | |
| 9 | Verdagy Inc | 94 | |
| 10 | Stuart Energy Systems Corp | 89 |
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 11 | Sumitomo Electric Industries Ltd | 81 | |
| 12 | Panasonic Intellectual Property Management Co Ltd | 71 | |
| 13 | VITO (Flemish Institute for Technological Research) | 65 | |
| 14 | Infinium Technology LLC | 61 | |
| 15 | SIEMENS ENERGY GLOBAL GMBH & CO KG | 57 | |
| 16 | Hysata Pty Ltd | 53 | |
| 17 | AIR PROD & CHEM INC | 51 | |
| 18 | Key DH IP Inc | 48 | |
| 19 | Nippon Shokubai Co Ltd | 48 | |
| 20 | Toray Industries Inc | 45 |
The sustained dominance of De Nora entities across both the electrode manufacturing and industrial electrolyzer segments reflects decades of platform IP; new entrants such as Verdagy and Hysata signal that capital-backed startups are now competing for adjacent claims in cell architecture and membrane engineering.
The most recent 18–24 months of filings are under-counted due to patent publication lag, so apparent near-term softening should not be read as a structural decline. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
A 2021–2022 filing surge reflects the hydrogen economy inflection; electrode and cell IP dominate the technology mix
The annual trend chart and technology composition chart together reveal both the pace of competitive entry and the sub-fields where innovation is concentrated and sparse.
Annual filing trend
Filings roughly doubled from 2017 to 2018, held steady through 2020, then surged to a peak in 2022 before easing. The three-year recent window sits 120% above the prior three-year window, confirming multi-year growth despite the post-2022 moderation. Data from 2024 onward is materially under-counted due to publication lag and should not be interpreted as a real decline.
↗ Hover for values · click a bar to ask EurekaTechnology composition
C25B (electrolytic production of compounds) overwhelmingly dominates, reflecting the core electrolyzer, electrode, and membrane IP. H01M (batteries, cells and fuel cells) and C01B (non-metallic elements and inorganic compounds) form a secondary layer, followed by B01J (catalysis), B01D (separation), and C02F (water treatment), each representing smaller but non-trivial adjacent clusters that signal system-level and downstream integration work.
↗ Hover for values · click a bar to ask EurekaHighly cited patent families surfaced by the query
Citation-heavy patent families returned by the query. Use this section as citation context, not as a curated list of the most topic-specific patents.
Anode for alkaline water electrolysis and method f…
Provided are an anode for alkaline water electrolysis that can achieve a low overpotential at low cost, and a method for producing the anode for alkaline water electrolysis. An anode for alkaline water electrolysis having electrode catalyst layers <b>2, 3</b> composed of a first catalyst component having either a nickel-cobalt spinel oxide or a… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Optimizing photovoltaic-electrolyzer efficiency | 324 |
| 2 | Optimizing photovoltaic-electrolyzer efficiency | 214 |
| 3 | Electrolyser and components therefor | 195 |
| 4 | Method and system for synthesizing fuel from dilut… | 161 |
| 5 | Renewable energy system for hydrogen production an… | 158 |
| 6 | Process for producing liquid fuel from carbon diox… | 144 |
| 7 | Method and apparatus for integrated water deioniza… | 143 |
| 8 | Bipolar alkaline water electrolysis unit and elect… | 141 |
Ranked by total forward citations. Citation counts favour older and broadly cited patent families, and broad or adjacent patents may appear when they match the search scope. Treat this section as citation context, not as a curated list of the most topic-specific patents. Some patent titles may be shown in their original, non-English language where an accurate translation could not be guaranteed.
What the competitive structure means for R&D investment decisions
The field’s growth stage, moderate concentration, and active co-filing network define both the risks and the entry paths available to new or expanding participants.
Growth stage, past its 2022 annual peak but multi-year expansion intact
The field is classified as Growth: the recent three-year filing window is 120% above the prior three-year window, confirming that cumulative R&D investment is still rising on a multi-year basis. Annual volume peaked in 2022 and has since eased, partly due to publication lag in the most recent years. Entrants arriving now face an established but not yet mature IP landscape, with meaningful room to differentiate in sub-segments not yet densely covered.
Growth · post-2022 peakModerate concentration with a clear first-tier trio and a competitive second tier
The top five filers hold 29% of the hundred largest filers’ combined output, indicating moderate rather than extreme concentration. The three De Nora-affiliated entities collectively dominate electrode and cell architecture IP. ThyssenKrupp Uhde and Yokohama National University represent credible challengers, and startups such as Verdagy (94 patent families) and Hysata (53 patent families) show that late-stage entrants can accumulate meaningful positions quickly.
Moderate concentrationDe Nora Permelec anchors a dense co-filing network with Japanese academic and industrial partners
The most active co-filing pair is De Nora Permelec and Yokohama National University (132 joint filings), followed by De Nora Permelec and Kawasaki Heavy Industries (94) and Yokohama National University and Kawasaki Heavy Industries (54). Yokohama National University also co-files frequently with Kyoto University (36 joint filings). This cluster of Japanese industry-academia partnerships is the dominant collaboration axis in the field, with ThyssenKrupp Uhde and Tosoh forming a secondary pairing (11 joint filings).
Industry-academia networkEurope and North America lead filings; China is a rising third jurisdiction
Europe (EPO) and the United States are the top two filing destinations, with China ranking third. WIPO PCT filings indicate applicants are pursuing broad multi-market protection. Australia and Canada rank fifth and sixth respectively, reflecting active commercialization interest in resource-rich markets. South Korea and Japan have lower absolute filing counts at this jurisdiction level, though Japanese applicants dominate the applicant ranking, suggesting home-country filing strategies are captured elsewhere.
Europe & US dominantGo beyond the landscape: Eureka’s TRIZ Solution agent breaks down an R&D problem and returns patented concept solutions, each with a technical approach and cited patent & literature evidence.
| Applicant | Collaborator | Co-filings |
|---|---|---|
| De Nora Permelec Ltd | Yokohama National University | 132 |
| De Nora Permelec Ltd | Kawasaki Heavy Industries Ltd | 94 |
| Yokohama National University | Kawasaki Heavy Industries Ltd | 54 |
| Yokohama National University | Kyoto University | 36 |
| Kawasaki Heavy Industries Ltd | ThyssenKrupp Uhde Chlorine Engineers | 34 |
| De Nora Permelec Ltd | Kyoto University | 33 |
| De Nora Permelec Ltd | ThyssenKrupp Uhde Chlorine Engineers | 21 |
| ThyssenKrupp Uhde Chlorine Engineers GmbH | Tosoh Corporation | 11 |
| Yokohama National University | Sumitomo Electric Industries Ltd | 11 |
| De Nora Permelec Ltd | Chlorine Engineers Corp | 6 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
De Nora Permelec and Industrie De Nora hold different trajectories despite shared lineage
The top two independent leaders by patent family count—De Nora Permelec and Asahi Kasei—represent contrasting momentum profiles; the De Nora industrial subsidiary shows the strongest recent acceleration among the large filers.
De Nora Permelec Ltd
De Nora Permelec holds 314 patent families, the largest portfolio in the field, concentrated in electrolytic compound production (C25B1, C25B11, C25B9). Despite this scale, recent-period filings show a trend of –68% versus the prior three years, suggesting the entity is consolidating rather than aggressively expanding its claim footprint. Its dense co-filing relationships with Yokohama National University and Kawasaki Heavy Industries reinforce its position in electrode materials and cell stack design.
patent families: 314Industrie De Nora S.p.A.
Industrie De Nora holds 205 patent families with a recent-period filing trend of 3.9× versus the prior three-year window, making it one of the fastest-growing large filers in the field. Its technical focus mirrors the parent entity across C25B1, C25B11, and C25B9, but the acceleration suggests an active strategy to extend IP coverage in cell architecture and electrode production, potentially positioning for the scale-up of green hydrogen projects.
patent families: 205| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| De Nora Permelec Ltd | 33 | ▼ -68% |
| Asahi Kasei Corporation | 59 | ▼ -20% |
| Industrie De Nora S.p.A. | 128 | ▲ 3.9× vs prior 3-yr |
| ThyssenKrupp Uhde Chlorine Engineers GmbH | 119 | ▲ 4.8× vs prior 3-yr |
| Yokohama National University | 20 | ▼ -76% |
| Kawasaki Heavy Industries Ltd | 4 | ▼ -86% |
| Tokuyama Corporation | 23 | ▼ -66% |
| Agfa-Gevaert NV | 47 | ▲ +104% |
Under-served adjacent branches worth monitoring for entry or partnership
Several IPC branches adjacent to the dominant C25B core have relatively low patent density despite clear technical relevance to alkaline water electrolysis systems. These are observations of relative sparsity; they should be evaluated against specific technical goals and freedom-to-operate needs before being treated as entry opportunities.
B01D · Separation Processes
With 324 records, separation processes—including membrane filtration, gas-liquid separation, and electrolyte management—sit at the boundary of the core electrolyzer cell and balance-of-plant engineering. Gas purity and electrolyte circulation are known performance bottlenecks in alkaline systems, yet this branch remains sparsely covered relative to C25B. An entrant with expertise in membrane or filtration engineering could address system-level differentiation here, particularly for high-current-density or variable-load operation.
Search this in Eureka →C02F · Water and Wastewater Treatment
C02F accounts for 259 records, covering water purification and conditioning relevant to feed-water quality in alkaline electrolyzers. Dissolved impurities and carbonate contamination are practical operational challenges, yet dedicated IP addressing water pre-treatment specifically for alkaline electrolysis is sparse. This branch may represent a realistic entry path for water-treatment specialists seeking to serve the green hydrogen supply chain without competing directly on electrolyzer cell IP.
Search this in Eureka →How the leading applicants differ across core technology sub-routes
Strength of each leader across the main technology routes.
| Player | C25B 1 · Electrolytic production of compounds | C25B 9 · Electrolytic production of compounds | C25B 11 · Electrolytic production of compounds | C25B 15 · Electrolytic production of compounds | C25B 13 · Electrolytic production of compounds |
|---|---|---|---|---|---|
| De Nora Permelec Ltd | Strong · 216 | Strong · 157 | Strong · 209 | Moderate · 101 | Emerging · 37 |
| Asahi Kasei Corporation | Strong · 165 | Strong · 185 | Moderate · 82 | Strong · 111 | Moderate · 68 |
| Industrie De Nora S.p.A. | Strong · 187 | Moderate · 89 | Strong · 110 | Emerging · 31 | Absent |
| ThyssenKrupp Uhde Chlorine Engineers GmbH | Strong · 113 | Strong · 142 | Absent | Moderate · 47 | Absent |
| Yokohama National University | Strong · 110 | Moderate · 56 | Strong · 129 | Absent | Absent |
| Kawasaki Heavy Industries Ltd | Strong · 97 | Strong · 70 | Strong · 69 | Absent | Moderate · 33 |
| Tokuyama Corporation | Strong · 70 | Strong · 93 | Absent | Moderate · 37 | Moderate · 30 |
Frequently asked questions
The corpus covers 4,665 patent families globally. This represents the broadest measure of innovation activity in the field across all major jurisdictions.
De Nora Permelec Ltd holds the largest portfolio with 314 patent families, followed by Asahi Kasei (242) and Industrie De Nora (205).
Europe (EPO) leads with the highest filing count, followed closely by the United States and then China. WIPO PCT filings rank fourth, indicating broad multi-market protection strategies are common.
The field is in a Growth stage. The recent three-year filing window is 120% above the prior three-year window. Annual volume peaked in 2022 and has eased since, but recent years are also under-counted due to publication lag, so the multi-year expansion trend remains intact.
The most active co-filing pair is De Nora Permelec and Yokohama National University with 132 joint filings, followed by De Nora Permelec and Kawasaki Heavy Industries (94), and Yokohama National University with Kawasaki Heavy Industries (54). These pairings form the dominant industry-academia collaboration cluster.
B01D (separation processes) and C02F (water and wastewater treatment) are the most notable under-served adjacent branches relative to the dominant C25B core. Both have plausible technical relevance to electrolyzer system performance—gas purity management and feed-water conditioning respectively—but carry comparatively low filing density.
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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.
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