SOFC vs Alkaline Reconstruct SOEC Patent Landscape
The SOFC/alkaline/SOEC space is highly concentrated, with the top five filers commanding 60% of the hundred largest filers’ combined volume and two European institutions—CEA and Haldor Topsoe—holding clear leads. The field is still expanding on a multi-year basis, though annual volume has eased from its 2023 peak and the most recent filing years remain understated by publication lag.
CEA and Topsoe lead a concentrated, two-tier field
The Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA) sits at the top of the applicant ranking with 350 patent families, followed by Haldor Topsoe with 245 and Bloom Energy with 116, establishing a pronounced first tier far ahead of the rest.
The top five filers—CEA, Haldor Topsoe, Bloom Energy, Technical University of Denmark, and Samsung Electro-Mechanics—hold 60% of the hundred largest filers’ combined total, signaling a highly concentrated competitive structure with a sharp drop-off after the fifth rank.
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 1 | Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA) | 350 | |
| 2 | Haldor Topsoe | 245 | |
| 3 | Bloom Energy Corporation | 116 | |
| 4 | Technical University of Denmark (DTU) | 115 | |
| 5 | Samsung Electro-Mechanics Co., Ltd. | 43 | |
| 6 | Ceres Intellectual Property Company Limited | 40 | |
| 7 | Mitsubishi Heavy Industries, Ltd. | 32 | |
| 8 | Toyota Central R&D Labs, Inc. | 26 | |
| 9 | Elcogen | 20 | |
| 10 | Shanghai Institute of Applied Physics, Chinese Academy of Sciences | 16 |
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 11 | Niterra Co., Ltd. | 13 | |
| 12 | Versa Power Systems Ltd. | 13 | |
| 13 | Precision Combustion Inc. | 12 | |
| 14 | Mitsubishi Electric Corporation | 10 | |
| 15 | Tsinghua University | 10 | |
| 16 | Flexitallic Investments Inc. | 9 | |
| 17 | Zhejiang Zhentai Energy Technology Co., Ltd. | 9 | |
| 18 | KOREA INST OF SCI & TECH | 9 | |
| 19 | Korea Institute of Energy Research (KIER) | 9 | |
| 20 | Osaka Gas Co., Ltd. | 9 |
The dominance of CEA and Topsoe, both with deep reversible solid oxide cell portfolios spanning both fuel-cell and electrolysis classifications, means any new entrant must either differentiate by application domain or by geography to avoid direct portfolio conflicts.
Filing counts for 2024–2026 are understated due to patent publication lag of 18–24 months; the apparent recent moderation should not be interpreted as a market withdrawal. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Multi-year growth with a 2023 activity peak; electrochemical production dominates the technology mix
The annual filing trend and IPC technology composition charts together reveal a field whose pace accelerated sharply between 2021 and 2023 before easing, with electrolytic compound production and fuel cell classifications jointly accounting for the overwhelming share of activity.
Annual filing trend
Annual filings climbed from 50 in 2019 to a peak of 277 in 2023, representing the clearest expansion signal. Values for 2024 (164) and 2025 (97) reflect publication lag and should be treated as preliminary floors, not true activity levels. The three-year recent window sits 161% above the prior three-year window, confirming net multi-year growth despite the easing from the 2023 peak.
↗ Hover for values · click a bar to ask EurekaTechnology composition
C25B (electrolytic production of compounds) and H01M (batteries, cells, and fuel cells) together account for the vast majority of IPC coverage, reflecting the dual SOEC/SOFC character of the corpus. Adjacent classes such as C01B (non-metallic elements and inorganic compounds), B01D (separation processes), C04B (ceramics and refractories), and C23C (coating and surface deposition) each have materially lower representation, pointing to under-served technical branches.
↗ 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.
Microwave-assisted Solid Oxide Electrolysis Cell (…
A method of enhancing an electrolysis reaction in a solid oxide electrolysis cell (SOEC) for hydrogen production featuring: providing a water vapor stream to a cathode chamber of a SOEC; wherein the SOEC has an cathode chamber and an anode chamber, wherein the cathode chamber contains a catalyst; and wherein the catalyst has one or more conducting oxides… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Hybrid electrochemical cell | 67 |
| 2 | Solid oxide cell (SOC) operation method and solid … | 65 |
| 3 | Ejector for solid oxide electrolysis cell stack sy… | 63 |
| 4 | 高温水蒸気電解[SOEC]、固体酸化物形燃料電池[SOFC]および/または可逆高温燃料電池[rSOC… | 55 |
| 5 | Elementary unit for reactor performing water elect… | 53 |
| 6 | Fuel cell unit and fuel cell stack | 42 |
| 7 | Method for the manufacture of reversible solid oxi… | 42 |
| 8 | A multi-layer coating | 35 |
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 stage, concentration, collaboration networks, and jurisdictional spread—shape where a new entrant or incumbent should focus attention.
Growth stage, easing from its 2023 peak
The lifecycle evidence places this field in the Growth stage: the recent three-year filing window is 161% above the prior three-year window, confirming sustained multi-year expansion. Annual volume peaked in 2023 at 277 filings and has since eased, though 2024–2025 figures are further compressed by publication lag. The implication is that the field is active but past its steepest acceleration phase.
Growth · post-peak annualTop five hold 60% of the leading cohort’s volume
The top five filers—CEA, Haldor Topsoe, Bloom Energy, Technical University of Denmark, and Samsung Electro-Mechanics—collectively hold 60% of the hundred largest filers’ combined total. The gap between rank 1 (350 patent families) and rank 5 (43 patent families) is stark, indicating entrenched incumbency at the top. Tiers below rank 10 are individually small, suggesting room for focused niche positions.
High concentrationMitsubishi Heavy–Mitsubishi Power and Toyota CRI–Denso are the most active co-filing pairs
The most active co-filing relationship is between Mitsubishi Heavy Industries and Mitsubishi Power, with 8 joint patent families, reflecting intra-group integration around large-scale SOEC systems. Toyota Central R&D and Denso follow with 7 co-filings, indicating automotive-adjacent fuel cell collaboration. CEA co-files with both CNRS and the University of Orléans (3 families each), while Haldor Topsoe and DTU share 3 joint families, cementing the European academic–industrial axis.
Intra-group + academic tiesChina leads filings; Europe and the US are major secondary markets
China is the leading filing jurisdiction, followed by Japan, Europe (EPO), WIPO/PCT, and the United States. The broad PCT and EPO presence by the top European players (CEA, Topsoe, DTU) indicates global prosecution strategies. South Korea and Australia also appear as meaningful jurisdictions. Notably, China’s lead reflects both domestic filers and inbound filings from multinationals seeking market coverage.
China-led; global coverageGo 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 |
|---|---|---|
| Mitsubishi Heavy Industries, Ltd. | Mitsubishi Power, Ltd. | 8 |
| Toyota Central R&D Labs, Inc. | Denso Corporation | 7 |
| Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA) | Centre National de la Recherche Scientifique (CNRS) | 3 |
| Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA) | University of Orléans | 3 |
| Haldor Topsoe | Technical University of Denmark (DTU) | 3 |
| Technical University of Denmark (DTU) | Topsoe Fuel Cell A/S | 2 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
CEA and Haldor Topsoe lead with complementary electrolysis and fuel-cell emphases
The two largest filers both span the full SOEC/SOFC spectrum but show different technical weighting and momentum trajectories, providing a contrast in portfolio strategy.
Commissariat à l’Énergie Atomique (CEA)
CEA holds 350 patent families, the largest portfolio in the corpus. Its technology emphasis spans H01M 8 (fuel cells), C25B 9 (electrolytic cell apparatus), and C25B 1 (electrolytic production of inorganic compounds), reflecting broad reversible solid oxide cell coverage. Momentum is positive at +65% in the recent period, consistent with sustained R&D commitment rather than a mature harvest phase.
families: 350Haldor Topsoe
Haldor Topsoe holds 245 patent families and shows the strongest momentum among established players at +119% in the recent period, indicating an accelerating prosecution strategy. Its focus is anchored in C25B 9 (electrolytic apparatus) and C25B 1 (electrolytic inorganic production), with H01M 8 (fuel cells) as a secondary pillar—suggesting a shift toward SOEC and hydrogen production relative to pure SOFC coverage.
families: 245| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA) | 99 | ▲ +65% |
| Haldor Topsoe | 114 | ▲ +119% |
| Technical University of Denmark (DTU) | 4 | ▲ new entrant |
| Bloom Energy Corporation | 105 | ▲ new entrant |
| Samsung Electro-Mechanics Co., Ltd. | 38 | ▲ new entrant |
| Ceres Intellectual Property Company Limited | 6 | ▼ -82% |
| Mitsubishi Heavy Industries, Ltd. | 26 | ▲ new entrant |
| Toyota Central R&D Labs, Inc. | 4 | ▲ new entrant |
Under-served IPC branches adjacent to the dominant electrochemical core
Several IPC classes appear at low share relative to the dominant C25B and H01M core; two stand out as having plausible technical relevance and realistic entry paths for players with existing solid oxide cell expertise.
C04B · Ceramics, cement & refractories
C04B accounts for 37 patent records, a 1% share of the corpus. Ceramic electrolyte and electrode engineering is a foundational enabler for SOEC performance and durability, yet patent activity in this class is sparse relative to the system-level and electrochemical classes. Players with materials science capabilities—particularly in zirconia, ceria, or perovskite formulations—could establish differentiated positions here. Entry paths include co-filing with existing ceramic manufacturers or via academic partnerships already active in the field.
Search this in Eureka →C23C · Coating & surface deposition
C23C also sits at 37 patent records and a 1% share, despite thin-film and coating processes being directly relevant to SOEC stack fabrication—electrode deposition, protective coatings for interconnects, and barrier layers all fall within this class. The low count suggests that coating-specific IP is largely absent or folded into broader system claims, leaving a potential gap for process-focused entrants with physical vapor deposition or atomic layer deposition expertise.
Search this in Eureka →How leading applicants differ across SOEC, SOFC, and adjacent technology routes
Route coverage across the main technology branches in the current evidence set.
| Player | H01M 8 · Batteries, cells & fuel cells | C25B 9 · Electrolytic production of compounds | C25B 1 · Electrolytic production of compounds | C25B 15 · Electrolytic production of compounds | H01M 4 · Batteries, cells & fuel cells |
|---|---|---|---|---|---|
| Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA) | Strong · 325 | Strong · 265 | Strong · 230 | Moderate · 149 | Emerging · 7 |
| Haldor Topsoe | Strong · 135 | Strong · 145 | Strong · 134 | Strong · 107 | Emerging · 7 |
| Bloom Energy Corporation | Strong · 61 | Strong · 92 | Strong · 99 | Strong · 65 | Emerging · 19 |
| Technical University of Denmark (DTU) | Strong · 117 | Emerging · 18 | Absent | Absent | Strong · 90 |
| Samsung Electro-Mechanics Co., Ltd. | Strong · 41 | Strong · 21 | Moderate · 20 | Absent | Moderate · 20 |
| Ceres Intellectual Property Company Limited | Strong · 38 | Strong · 24 | Strong · 26 | Absent | Absent |
| Mitsubishi Heavy Industries, Ltd. | Absent | Strong · 32 | Strong · 32 | Strong · 18 | Absent |
Frequently asked questions
The analysis covers 1,225 patent families in scope globally. This is the baseline figure from which all rankings and trend data are derived.
The Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA) of France leads with 350 patent families, followed by Haldor Topsoe with 245. Together they represent the most substantial portfolios in the field.
On a multi-year basis, yes: the recent three-year filing window is 161% above the prior three-year window. Annual volume peaked in 2023 at 277 filings and has since eased, but 2024–2025 figures are understated by patent publication lag of 18–24 months and should not be read as a true decline.
China is the leading filing jurisdiction, followed by Japan, Europe (EPO), WIPO/PCT, and the United States. South Korea and Australia are also materially represented. The broad PCT and EPO presence by top European filers indicates that global prosecution is standard practice for the leading players.
The most-cited works cover hybrid electrochemical cell designs (67 citations), SOC operation methods (65 citations), and ejector systems for SOEC stacks (63 citations). A patent covering high-temperature steam electrolysis, SOFC, and reversible SOC technology also ranks highly with 55 citations.
Based on relative IPC sparsity, C04B (ceramics and refractories) and C23C (coating and surface deposition) each represent under-served adjacent branches with direct technical relevance to SOEC stack fabrication. Both sit at roughly 1% share of the corpus despite their foundational role in cell performance and durability.
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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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