Alkaline Electrolyzer Balance of Plant Patent Landscape
The alkaline electrolyzer balance of plant space is highly concentrated, with a single incumbent holding a commanding share and a cohort of newer Chinese and European challengers entering on a multi-year growth trajectory. The field is still expanding on a multi-year basis, though annual volume has eased from its 2018 peak and recent years remain understated by publication lag.
Asahi Kasei dominates a highly concentrated field with emerging Chinese challengers
Asahi Kasei Kogyo Kabushiki Kaisha leads the applicant ranking with 54 patent records, more than four times the second-ranked Tokuyama Corp at 12 patent records, establishing a dominant first-tier position that no other single applicant approaches.
The top five filers account for 49% of the combined total across the hundred largest filers, signalling a highly concentrated competitive structure where incumbents hold structural advantages in core cell architecture, diaphragm, and electrolyte circulation IP.
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 1 | Asahi Kasei Corporation | 54 | |
| 2 | Tokuyama Corporation | 12 | |
| 3 | De Nora Permelec Ltd | 9 | |
| 4 | Cameron Health Inc. | 7 | |
| 5 | Tongji University | 5 | |
| 6 | Industrie De Nora SpA | 5 | |
| 7 | Nippon Shokubai Co., Ltd. | 5 | |
| 8 | Qingdao Chuangqi Xinde New Energy Technology Co., Ltd. | 4 | |
| 9 | Xi’an LONGi Hydrogen Technology Co., Ltd. | 3 | |
| 10 | SUNGROW HYDROGEN SCI &TECH CO LTD | 3 |
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 11 | Huaneng Clean Energy Research Institute | 3 | |
| 12 | Sichuan Huaneng Jialingjiang Hydropower Co., Ltd. | 2 | |
| 13 | HGEN Inc. | 2 | |
| 14 | China Three Gorges Corporation | 2 | |
| 15 | Sichuan Huaneng Hydrogen Technology Co., Ltd. | 2 | |
| 16 | Xi’an Jiaotong University | 2 | |
| 17 | Huaneng Mingtai Electric Power Co., Ltd. | 2 | |
| 18 | Huaneng Group Technology Innovation Center Co., Ltd. | 2 | |
| 19 | Sichuan Huaneng Fujiang Hydropower Co., Ltd. | 2 | |
| 20 | EAST CHINA UNIV OF SCI & TECH | 2 |
The leaders’ positions imply that any new entrant must either design around the dense C25B cluster owned by the top tier or identify under-served adjacent branches — such as separation, water treatment, or thermal management — where incumbent coverage is comparatively sparse.
Filing counts for 2024–2025 are understated due to patent publication lag of 18–24 months; apparent softness in those years should not be interpreted as declining activity. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Multi-year growth driven by Chinese filers, with core electrolytic production dominating the technology mix
The annual filing trend and technology composition together reveal a field whose expansion is broad-based across electrolytic production sub-classes, with secondary branches in separation, energy storage interfaces, and water treatment indicating emerging system-integration themes.
Annual filing trend
Activity peaked in 2018 then moderated, before recovering through 2021–2023. The most recent three-year window sits well above the prior three-year window (138% growth), confirming multi-year expansion even as year-on-year figures have eased from the 2018 peak. Data for 2024–2026 are incomplete due to publication lag and should not be read as a sustained decline.
↗ Hover for values · click a bar to ask EurekaTechnology composition
C25B (electrolytic production of compounds) dominates the IPC mix with 150 records, reflecting deep coverage of cell hardware and process chemistry. Secondary branches — H01M (batteries/fuel cells), C01B (inorganic compounds), B01D (separation), and C02F (water/wastewater treatment) — each carry fewer than 15 records, confirming these as sparse but technically relevant adjacent areas within the broader system.
↗ 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.
Alkaline water electrolysis system and method of o…
An alkaline water electrolysis system (<b>70</b>) includes a rectifier (<b>74</b>) that is connected to a fluctuating power source and converts an AC power to a DC power; a plurality of bipolar electrolyzers (<b>50</b>_<b>1</b>) to (<b>50</b>_N) that generate hydrogen and oxygen through electrolysis of water using an electrolytic solution based on a… (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 | Diaphragm for alkaline water electrolysis, alkalin… | 36 |
| 4 | Diaphragm for alkaline water electrolysis, alkalin… | 27 |
| 5 | Water electrolysis system, water electrolysis meth… | 17 |
| 6 | Apparatus for alkaline water electrolysis, and gas… | 16 |
| 7 | 一种碱性制氢电解槽的碱液循环系统及其工作方法 | 15 |
| 8 | 一种利用微细纤维诱导气泡聚并提高电解效率的装置及方法 | 14 |
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
Four structural observations — maturity, concentration, collaboration patterns, and geography — define the strategic options available to teams entering or expanding in alkaline electrolyzer balance of plant.
Growth stage with easing annual pace
The field is classified as Growth: the recent three-year filing window is 138% above the prior three-year window, confirming sustained multi-year expansion. However, annual volume has eased from its 2018 peak, and the most recent years are further understated by publication lag. Teams should treat the multi-year trend as the reliable signal rather than any single recent year.
Growth stageSingle incumbent with four-to-one lead; challengers accelerating
Asahi Kasei’s 54-record position versus Tokuyama Corp’s 12 records illustrates a steep tier gap at the top. The top five filers hold 49% of the hundred largest filers’ combined total, leaving meaningful room for challengers. Several new entrants — including De Nora, Nippon Shokubai, Cameron Health, and Qingdao Chuangqi — have entered the recent filing window, signalling that the moat is not impenetrable.
High concentrationNascent co-filing activity between industrial and academic partners
The most active co-filing pairs are Industrie De Nora with Cameron Health (2 joint records), and Nippon Shokubai with National University Corporation Yokohama National University (2 joint records). Tongji University and Suzhou Jingli Hydrogen Making Equipment have also co-filed once, as have the two Qingdao Chuangqi entities. These pairings suggest early-stage technology transfer between established chemical engineers and academic electrochemistry groups, particularly in electrode and membrane research.
Early-stage alliancesChina leads filings; Europe is the second jurisdiction for defensive coverage
China accounts for 53 patent records — the largest single jurisdiction — reflecting the rapid scale-up of domestic green hydrogen projects. Europe (EPO) follows with 43 records, underscoring that incumbents seek broad protection across major market regions. Australia and the United States each carry 11 records, while PCT filings number 5, suggesting selective rather than blanket global prosecution strategies.
China-led, Europe keyGo 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 |
|---|---|---|
| Industrie De Nora SpA | Cameron Health Inc. | 2 |
| Nippon Shokubai Co., Ltd. | National University Corporation Yokohama National University | 2 |
| Tongji University | Suzhou Jingli Hydrogen Making Equipment Co., Ltd. | 1 |
| Qingdao Chuangqi Xinde New Energy Technology Co., Ltd. | Qingdao Chuangqi Xinde New Energy Equipment Technology Co., Ltd. | 1 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
Asahi Kasei anchors the field; De Nora and Nippon Shokubai enter as fresh challengers
The leader-challenger gap in this landscape is unusually wide, but the momentum data show that the incumbents’ dominance is being contested by newly active filers concentrated in the C25B electrolytic production cluster.
Asahi Kasei Kogyo Kabushiki Kaisha
Asahi Kasei holds 54 patent records, more than four times any other applicant, with technology emphasis concentrated across C25B 9 (cell/vessel design), C25B 1 (hydrogen/chlorine production), and C25B 11 (electrodes). Its recent three-year filing trajectory shows a ▼ –30% decline from its prior period, suggesting a mature, defense-oriented posture rather than aggressive expansion.
patent records: 54De Nora (Permelec + Industrie)
De Nora operates through two entities — De Nora Permelec Ltd (9 patent records) and Industrie De Nora SpA (5 patent records) — and both are flagged as new entrants in the recent filing window (▲ new entrant). Their combined technology focus spans C25B 9, C25B 1, C25B 15 (auxiliary electrodes/electrolytes), and notably H01M 8 (fuel cell hardware), indicating a system-integration strategy that extends beyond core cell chemistry into broader balance-of-plant components.
patent records: 14 combined| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| Asahi Kasei Corporation | 7 | ▼ -30% |
| Industrie De Nora SpA | 8 | ▲ new entrant |
| Nippon Shokubai Co., Ltd. | 4 | ▲ new entrant |
| Tongji University | 1 | ▲ new entrant |
| Cameron Health Inc. | 5 | ▲ new entrant |
| Qingdao Chuangqi Xinde New Energy Technology Co., Ltd. | 4 | ▲ new entrant |
| Sungrow Hydrogen Science & Technology Co., Ltd. | 3 | ▲ new entrant |
| Xi’an LONGi Hydrogen Technology Co., Ltd. | 3 | ▲ new entrant |
Under-served routes in separation, water treatment, and energy storage interfaces
The dominant C25B class is densely covered; four adjacent IPC branches carry fewer than 14 records each and represent technically plausible but sparsely patented areas within the alkaline electrolyzer balance-of-plant system.
B01D · Separation processes (gas-liquid, filtration, membrane)
With only 10 patent records, B01D covers separation and filtration processes that are central to hydrogen purification and gas-liquid disengagement in alkaline electrolyzers — direct balance-of-plant functions. Sparse coverage relative to the C25B core suggests that downstream purification train components (demisters, scrubbers, drying stages) are under-protected. Teams with expertise in industrial gas separation could find entry paths here that complement, rather than clash with, incumbent cell-hardware IP.
Search this in Eureka →C02F · Water and wastewater treatment (feed-water conditioning)
C02F carries only 9 patent records despite feed-water quality being a critical operational variable for alkaline electrolyzers — impurities accelerate membrane degradation and increase specific energy consumption. The sparsity suggests that feed-water conditioning, KOH management, and electrolyte purification circuits are under-explored in the patent literature. Academic co-filers such as Tongji University and Xi’an Jiaotong University could be natural partners for entry into this sub-space.
Search this in Eureka →How leading applicants differ by technology route across C25B sub-classes
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 15 · Electrolytic production of compounds | C25B 11 · Electrolytic production of compounds | C25B 13 · Electrolytic production of compounds |
|---|---|---|---|---|---|
| Asahi Kasei Corporation | Strong · 45 | Strong · 47 | Moderate · 21 | Strong · 27 | Moderate · 18 |
| Tokuyama Corporation | Strong · 11 | Strong · 12 | Moderate · 6 | Moderate · 4 | Moderate · 5 |
| De Nora Permelec Ltd | Strong · 8 | Strong · 9 | Strong · 8 | Strong · 6 | Absent |
| Industrie De Nora SpA | Strong · 9 | Strong · 9 | Strong · 9 | Absent | Absent |
| Nippon Shokubai Co., Ltd. | Strong · 5 | Strong · 5 | Absent | Absent | Strong · 5 |
| Cameron Health Inc. | Strong · 5 | Strong · 4 | Strong · 4 | Absent | Absent |
| Tongji University | Strong · 5 | Strong · 3 | Strong · 4 | Absent | Absent |
Frequently asked questions
The landscape contains 132 patent families in scope. This corpus underpins all applicant rankings and trend analyses in this report.
Asahi Kasei Kogyo Kabushiki Kaisha leads with 54 patent records — more than four times the second-ranked Tokuyama Corp at 12 patent records. Its focus is concentrated in C25B sub-classes covering cell design, hydrogen production, and electrode technology.
The field is in a Growth stage: the most recent three-year filing window is 138% above the prior three-year window. Annual volume has eased from its 2018 peak, and 2024–2025 figures are further understated by publication lag, so the multi-year expansion remains the reliable signal.
China leads with 53 patent records, followed by Europe (EPO) with 43. Australia and the United States each carry 11 records, with India at 7 and PCT filings at 5. This reflects both strong domestic Chinese green-hydrogen investment and incumbent European/Japanese applicants seeking broad protection.
Four co-filing pairs are evident: Industrie De Nora with Cameron Health (2 joint records), Nippon Shokubai with National University Corporation Yokohama National University (2 joint records), Tongji University with Suzhou Jingli Hydrogen Making Equipment (1 record), and the two Qingdao Chuangqi entities (1 record). These pairings span industrial-academic and commercial-commercial structures.
B01D (separation processes) at 10 patent records and C02F (water and wastewater treatment) at 9 patent records are the sparsest branches with direct relevance to balance-of-plant functions such as gas purification and feed-water conditioning. F28D (heat-exchange apparatus) at 3 records is even sparser but has plausible relevance to thermal management within the electrolyzer system.
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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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