Alkaline Water Electrolysis Patent Landscape 2026
De Nora Permelec leads a moderately concentrated field with 88 patent families, anchored by a tightly coupled Japanese consortium that dominates electrode and cell-design activity. Filing activity has grown strongly on a multi-year basis, with the field still in a Growth life-cycle stage, though the most recent period is subject to publication lag.
De Nora Permelec leads a field anchored by Japanese industrials and academic partners
De Nora Permelec holds the top position with 88 patent families, ahead of Yokohama National University and Asahi Kasei (56 patent families each), followed by Agfa-Gevaert at 40 and Kawasaki Heavy Industries at 33. The top five filers together account for 35% of the hundred largest filers’ combined total, indicating moderate concentration with meaningful room for challengers.
A clear tier gap separates the top three from the mid-table: the leader’s count is roughly 57% larger than the fifth-ranked applicant’s. Below rank five, activity fragments across academic institutions, national research bodies, and Chinese hydrogen-energy start-ups, none individually approaching the leading cluster.
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 1 | De Nora Permelec Ltd | 88 | |
| 2 | Yokohama National University | 56 | |
| 3 | Asahi Kasei Corporation | 56 | |
| 4 | Agfa-Gevaert NV | 40 | |
| 5 | Kawasaki Heavy Industries Ltd | 33 | |
| 6 | Kyoto University | 24 | |
| 7 | Industrie De Nora SpA | 23 | |
| 8 | ABB (Schweiz) AG | 17 | |
| 9 | Dalian Institute of Chemical Physics, Chinese Academy of Sciences | 15 | |
| 10 | Huaneng Clean Energy Research Institute | 15 |
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 11 | Richards William R | 14 | |
| 12 | Tsinghua University | 14 | |
| 13 | Tongji University | 14 | |
| 14 | Stiesdal Hydrogen A/S | 10 | |
| 15 | Shandong Lankun Hydrogen Energy Technology Co Ltd | 10 | |
| 16 | Jiangsu Shuangliang Hydrogen Energy Technology Co Ltd | 10 | |
| 17 | Volker Alan L | 7 | |
| 18 | Beijing Yineng Hydrogen Source Technology Co Ltd | 7 | |
| 19 | Inner Mongolia Green Hydrogen Technology Co Ltd | 7 | |
| 20 | SUNGROW HYDROGEN SCI &TECH CO LTD | 7 |
The leaders’ positions reflect long-standing industrial electrode and electrolyzer cell expertise. De Nora Permelec and its Italian affiliate Industrie De Nora together form a combined entity with substantial depth in electrode materials (C25B11) and hydrogen production cells (C25B1), reinforcing barriers through both patent breadth and close university collaboration.
Patent families filed in the most recent 18–24 months are under-counted due to publication lag; ranking positions for recent entrants should be treated as provisional. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Rapid multi-year growth concentrated in core electrolytic chemistry, with adjacent branches lightly covered
The filing trend and technology composition charts together reveal a field in active expansion whose innovation is overwhelmingly focused on one core IPC class, leaving several technically adjacent areas sparsely populated.
Annual filing trend
Annual filings grew from 26 in 2017 to a reported peak of 183 in 2024, a 272% increase over the multi-year window, consistent with a Growth life-cycle stage. The 2025 and 2026 bars are understated by publication lag and should not be read as a slowdown; the underlying trajectory remains upward on a multi-year basis.
↗ Hover for values · click a bar to ask EurekaTechnology composition
C25B (electrolytic production of compounds) dominates the branch mix overwhelmingly, confirming that the field’s patent activity is tightly coupled to core electrolyzer chemistry and electrode design. Adjacent branches—B01J (catalysis), C25D (electroplating), H01M (batteries/fuel cells), B01D (separation), and C01B (inorganic compounds)—each carry only a small fraction of activity relative to the dominant class, signaling under-served technical adjacencies.
↗ 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.
Composite for electrocatalysis and preparation met…
The present invention relates to a method of preparing a composite material, in particular one useful as a catalyst in an electrolytic hydrogen evolution reaction and/or the oxygen evolution reaction and/or urea oxidation-assisted water electrolysis. Provided is a method of preparing a composite material, the method comprising the steps of:<ul… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | 一种大型碱性电解水制氢装置的综合热管理系统 | 84 |
| 2 | Bipolar electrolytic vessel, bipolar electrolytic … | 40 |
| 3 | Self-derivative iron-containing nickel anode for w… | 34 |
| 4 | Bipolar alkaline water electrolysis unit and elect… | 34 |
| 5 | 一种碱性水电解Ni基三维网状梯度合金析氢阴极 | 30 |
| 6 | 一种电解水制氢耦合海水淡化系统及方法 | 23 |
| 7 | 一种大型碱性电解水制氢装置的综合热管理系统 | 22 |
| 8 | Anode for alkaline water electrolysis | 22 |
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
China-heavy filing geography shapes both the risk and opportunity profile for new entrants and incumbents alike.
Growth stage: annual volume still expanding on a multi-year basis
The lifecycle is classified as Growth, driven by a 272% increase in annual filings across the evidence window with the peak reported in 2024. The field has not yet entered a consolidation or plateau phase, meaning early-mover advantages in novel electrode architectures and cell configurations remain achievable. R&D investment made now can still stake meaningful positions before the landscape hardens.
Growth lifecycleModerate concentration with a tight top-three cluster
The top five filers hold 35% of the hundred largest filers’ combined total, with the leading three separated from the rest by a visible tier gap. This structure means the core electrode and cell-design space is defended but not impenetrable; mid-table applicants such as Stiesdal Hydrogen and several Chinese energy companies are building positions. Adjacent branches with low share offer lower barriers for new entrants willing to invest in less-covered technical territory.
Tier gap visibleA dominant Japanese consortium drives co-filing activity
The most active co-filing relationship is between De Nora Permelec and Yokohama National University, sharing 58 joint patent families, followed by De Nora Permelec and Kawasaki Heavy Industries (36 families) and Yokohama National University and Kawasaki Heavy Industries (25 families). De Nora Permelec and Kyoto University, as well as Yokohama National University and Kyoto University, each share 24 joint families. This consortium-style collaboration creates a tightly integrated IP cluster that is difficult for outsiders to replicate quickly without comparable academic partnerships.
Consortium-ledChina dominates filing geography; Europe and the US are secondary
China accounts for the largest share of patent records filed in this corpus, followed by the European Patent Office and the United States. WIPO PCT filings and India round out the top five jurisdictions. The concentration of filings in China reflects both domestic green-hydrogen policy momentum and the activity of Chinese state-owned and private hydrogen energy companies appearing in the mid-table rankings. Applicants seeking global freedom to operate should prioritize EPO and US prosecution alongside any China strategy.
China-led geographyGo 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 | 58 |
| De Nora Permelec Ltd | Kawasaki Heavy Industries Ltd | 36 |
| Yokohama National University | Kawasaki Heavy Industries Ltd | 25 |
| De Nora Permelec Ltd | Kyoto University | 24 |
| Yokohama National University | Kyoto University | 24 |
| Industrie De Nora SpA | Cameron Health Inc | 2 |
| De Nora Permelec Ltd | thyssenkrupp Uhde Chlorine Engineers | 1 |
| De Nora Permelec Ltd | Chlorine Engineers Corp | 1 |
| Yokohama National University | De Nora Permelec Ltd FUJISAWA SHI | 1 |
| Kawasaki Heavy Industries Ltd | De Nora Permelec Ltd FUJISAWA SHI | 1 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
De Nora Permelec leads; Agfa-Gevaert enters with membrane-focused positioning
The top two players by patent families reflect distinct technical emphases: electrode and cell-design depth at the leader versus membrane and separator innovation at the leading challenger. Momentum signals among mid-table applicants show several new entrants accelerating rapidly.
De Nora Permelec Ltd
De Nora Permelec holds 88 patent families, the largest portfolio in the corpus, concentrated in C25B11 (electrode materials, 83 records), C25B1 (hydrogen production cells, 69 records), and C25B9 (cell assemblies, 26 records). Its deep co-filing relationships with Yokohama National University and Kawasaki Heavy Industries reinforce its electrode-to-system coverage. The applicantMomentum data does not list a recent-period trend for De Nora Permelec specifically, so near-term trajectory is evidence pending at this level of granularity.
patent families: 88Agfa-Gevaert NV
Agfa-Gevaert holds 40 patent families and shows a momentum trend of new entrant, indicating its current activity emerged in the recent filing window from a small or absent prior base. Its focus is differentiated from the leader: C25B13 (diaphragms and membranes, 39 records) and C25B1 (39 records) point to a membrane and separator strategy, complementing rather than directly replicating the electrode-centric positions held by the De Nora consortium.
patent families: 40| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| Asahi Kasei Corporation | 7 | ▲ new entrant |
| Agfa-Gevaert NV | 28 | ▲ new entrant |
| Industrie De Nora SpA | 9 | ▼ -31% |
| ABB (Schweiz) AG | 11 | ▲ new entrant |
| Tongji University | 8 | ▲ new entrant |
| Dalian Institute of Chemical Physics, Chinese Academy of Sciences | 8 | ▲ new entrant |
Catalysis, separation, and inorganic chemistry are under-served adjacent branches
Several IPC branches appear adjacent to the dominant C25B core but carry only a small share of total patent records, suggesting areas where technical activity is sparse relative to their plausible relevance to alkaline electrolysis performance.
B01J · Catalysis and chemical/physical processes
B01J carries a small fraction of records relative to C25B, yet non-precious-metal catalysts are central to reducing the cost of alkaline electrolyzers. Yokohama National University and Kyoto University already show B01J23 activity, confirming technical adjacency. An entrant with catalyst-synthesis expertise could build a defensible position here without directly competing on electrode architecture, where the De Nora consortium is deeply entrenched. The entry path is clearest through academic collaboration targeting nickel- and iron-based catalyst innovation.
Search this in Eureka →B01D · Separation processes
B01D (filtration, membrane separation) has a low share of records despite its relevance to gas-liquid separation inside alkaline electrolyzers and downstream hydrogen purification. As electrolyzer scale increases, separation efficiency becomes a system-level cost driver. The branch is lightly contested in this corpus, and an entrant with industrial gas-separation or membrane-fabrication capabilities could establish a position that complements, rather than conflicts with, the electrode and cell IP held by current leaders.
Search this in Eureka →How leaders differ across electrode, cell, membrane, and catalysis routes
Route coverage across the main technology branches in the current evidence set.
| 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 · 69 | Moderate · 26 | Strong · 83 | Moderate · 23 | Absent |
| Asahi Kasei Corporation | Strong · 52 | Strong · 52 | Strong · 35 | Moderate · 19 | Moderate · 11 |
| Yokohama National University | Strong · 44 | Emerging · 10 | Strong · 57 | Emerging · 7 | Absent |
| Agfa-Gevaert NV | Strong · 37 | Moderate · 19 | Absent | Absent | Strong · 39 |
| Kawasaki Heavy Industries Ltd | Strong · 35 | Moderate · 16 | Strong · 35 | Absent | Absent |
| Industrie De Nora SpA | Strong · 25 | Moderate · 9 | Moderate · 12 | Moderate · 9 | Absent |
| ABB (Schweiz) AG | Strong · 16 | Strong · 17 | Absent | Strong · 13 | Absent |
Frequently asked questions
De Nora Permelec Ltd leads with 88 patent families, concentrated in electrode materials (C25B11) and hydrogen production cells (C25B1). Yokohama National University and Asahi Kasei each hold 56 patent families, forming the second tier.
Annual filings grew by 272% across the evidence window, from 26 families in 2017 to a reported peak of 183 in 2024. The lifecycle is classified as Growth. The most recent filing years are under-counted due to publication lag and should not be read as a slowdown.
China is the leading filing jurisdiction, followed by the European Patent Office and the United States. WIPO PCT and India round out the top five. The China lead reflects both domestic green-hydrogen policy and the growing presence of Chinese state-owned and private hydrogen companies in the mid-table rankings.
C25B (electrolytic production of compounds) dominates the technology composition. Adjacent branches with comparatively low activity include B01J (catalysis), C25D (electroplating/surface treatment), H01M (batteries and fuel cells), B01D (separation processes), and C01B (inorganic compounds), each representing a small share of total patent records relative to C25B.
The most active co-filing relationship is between De Nora Permelec and Yokohama National University with 58 joint patent families. De Nora Permelec and Kawasaki Heavy Industries share 36 joint families, Yokohama National University and Kawasaki Heavy Industries share 25, and De Nora Permelec and Kyoto University, as well as Yokohama National University and Kyoto University, each share 24 joint families.
Based on the evidence, B01J (catalysis and chemical/physical processes) and B01D (separation processes) are among the most sparsely covered adjacent branches relative to their technical relevance to alkaline electrolysis performance. Both are areas where the incumbent electrode-and-cell consortium has limited depth, and where catalyst-synthesis or industrial-membrane expertise could support a differentiated filing position. These are observations of relative sparsity, not validated commercial opportunities; a full feasibility assessment is needed before committing R&D resources.
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