Redox Flow Battery Electrolyte Patent Landscape 2026
Redox Flow Battery Electrolyte Patent Landscape in 2026
Redox flow battery electrolyte IP is a concentrated, maturing field dominated by Lockheed Martin Advanced Energy Storage LLC, with the United States as the primary filing jurisdiction and annual volume now easing from its 2019 peak. A small cohort of defense, utility, and academic players holds the high-citation positions, leaving limited open terrain in core electrochemistry — though adjacent inorganic and heterocyclic chemistry branches remain comparatively sparse.
Lockheed Martin leads a tightly concentrated field with a significant share gap over challengers
Lockheed Martin Advanced Energy Storage LLC is the clear leader, holding 33 patent records — nearly double the count of the next-ranked applicant, Sumitomo Electric Industries Ltd at 17. The top five applicants together account for 38% of the combined total among the hundred largest filers, signaling a structurally concentrated competitive space.
A distinct tier gap separates the top two applicants from the mid-field. Massachusetts Institute of Technology (14 patent records), 24M Technologies Inc (12), and. The Kansai Electric Power Co (11) form a closely grouped second tier, followed by a long tail of single-digit filers. This sharp drop-off indicates that a handful of organizations set the technical agenda.
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 1 | Lockheed Martin Advanced Energy Storage LLC | 33 | |
| 2 | Sumitomo Electric Industries Ltd | 17 | |
| 3 | Massachusetts Institute of Technology | 14 | |
| 4 | 24M Technologies Inc | 12 | |
| 5 | The Kansai Electric Power Co | 11 | |
| 6 | CmBlu Energy AG | 10 | |
| 7 | Invinity Energy Systems (Canada) Corp | 9 | |
| 8 | Imergy Power Systems | 8 | |
| 9 | Institute of Metal Research, Chinese Academy of Sciences | 7 | |
| 10 | ESS Tech Inc | 6 |
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 11 | Lotte Chemical Corporation | 5 | |
| 12 | Battelle Memorial Institute | 5 | |
| 13 | Coventya Inc | 4 | |
| 14 | Sungshin Women’s University Industry-Academic Cooperation Foundation | 4 | |
| 15 | Primus Power Corporation | 4 | |
| 16 | Delectrik Systems Pte Ltd | 4 | |
| 17 | Indian Institute of Technology | 3 | |
| 18 | EnerVault Corporation | 3 | |
| 19 | Golden Energy Fuel Cell | 3 | |
| 20 | VRB Energy Inc | 3 |
Lockheed Martin’s commanding lead, alongside the presence of a major Japanese utility (Kansai Electric) and a leading research institution (MIT), suggests the field is shaped by both defense/industrial program spending and academic electrolyte chemistry research — rather than by broad commercial competition across many firms.
Note that the most recent 18–24 months of filings are subject to publication lag and will likely undercount actual activity; apparent low volumes in 2024–2026 should be interpreted cautiously. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Filing activity peaked in 2019 and has eased; electrochemical cell IP dominates the technology mix
The annual filing trend reveals a field that surged to its 2019 peak and has since contracted on a multi-year basis, while the IPC composition confirms that H01M (batteries, cells, and fuel cells) is overwhelmingly dominant, with a set of smaller adjacent branches attracting only marginal attention.
Annual filing trend
Filings rose to a peak of 16 records in 2019, dipped sharply through 2021–2022 (5 and 4 records respectively), recovered modestly to 12 in 2023, and trail off in 2024–2026 — figures that reflect publication lag rather than necessarily a continued decline. The multi-year window shows a net contraction of 44% from the recent prior period, consistent with a field past its primary growth phase.
↗ Hover for values · click a bar to ask EurekaTechnology composition
H01M (batteries, cells, and fuel cells) accounts for the substantial majority of IPC-coded records. C01G (compounds of other metals), C07D (heterocyclic compounds), and B60L (electric vehicle propulsion) each carry low double-digit or single-digit counts, pointing to niche but structurally adjacent activity in metal-compound formulation, organic electrolyte chemistry, and mobility applications.
↗ 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.
Redox flow battery electrolyte and redox flow batt…
The present invention relates to: a redox flow battery electrolyte comprising a zinc/bromine (Zn/Br) redox couple, a quaternary ammonium bromide including at least one alkylene alkoxy group, and water; and a zinc/bromine (Zn/Br) redox flow battery comprising the redox flow battery electrolyte. (excerpt from the patent abstract)
Open this patent in Eureka →| # | Patent | Citations |
|---|---|---|
| 1 | High energy density redox flow device | 457 |
| 2 | High energy density redox flow device | 343 |
| 3 | High energy density redox flow device | 236 |
| 4 | High energy density redox flow device | 185 |
| 5 | High energy density redox flow device | 129 |
| 6 | Rebalancing electrolytes in redox flow battery sys… | 107 |
| 7 | Methods for the preparation and purification of el… | 100 |
| 8 | Electrolyte for redox flow battery, and redox flow… | 98 |
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 allocation decisions
The combination of a concentrated leader set, a declining filing rate, and narrow technology breadth shapes the strategic options available to new and existing entrants in redox flow battery electrolyte IP.
Field is in decline from a 2019 peak
Annual filing volume peaked in 2019 and has eased substantially since, with the multi-year window showing a 44% contraction. This lifecycle position — past-peak decline — suggests the core electrochemical cell electrolyte space is approaching saturation for primary patent filings. New entrants should expect established prior art density in vanadium and aqueous electrolyte systems; differentiation will likely require novel chemistries or process improvements rather than incremental reformulations.
Lifecycle: DeclineTop five filers hold 38% of the largest-filer pool
The top five applicants — Lockheed Martin Advanced Energy Storage LLC, Sumitomo Electric Industries Ltd, Massachusetts Institute of Technology, 24M Technologies Inc, and The Kansai Electric Power Co — account for 38% of the combined patent records among the hundred largest filers. This level of concentration means that core technology positions are heavily defended. Challengers in mid-field (CmBlu Energy AG at 10, Invinity Energy Systems Canada at 9) have carved narrower niches but face significant prior art barriers in the most-cited claim spaces.
High concentrationSumitomo–Kansai Electric is the dominant co-filing pair
The most active co-filing relationship in the corpus is between Sumitomo Electric Industries Ltd and The Kansai Electric Power Co, with 11 jointly filed records — a deep, long-running industrial partnership spanning cell design and vanadium electrolyte chemistry. Sumitomo also co-files with Nippon Chemical Industrial (2 records), and Kansai Electric pairs with Nippon Chemical Industrial separately. MIT and 24M Technologies share 2 co-filed records, reflecting a university-spinout collaboration model. MIT and A123 Systems LLC also share 1 co-filed record.
Partnership-drivenUS leads; Europe, China, and PCT routes provide secondary coverage
The United States is the primary filing jurisdiction with 53 patent records, well ahead of Europe via EPO (31), China (30), and WIPO PCT (20). Canada and India each register 13 records, and Japan follows at 10. This multi-pole geographic spread — with notable Chinese and Indian presence — indicates that leading filers are pursuing broad international protection, and that any freedom-to-operate analysis must cover at minimum the US, EPO, and Chinese patent offices.
US-led, multi-jurisdictionGo 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 |
|---|---|---|
| Sumitomo Electric Industries Ltd | The Kansai Electric Power Co | 11 |
| Sumitomo Electric Industries Ltd | Nippon Chemical Industrial Co Ltd | 2 |
| 24M Technologies Inc | Massachusetts Institute of Technology | 2 |
| The Kansai Electric Power Co | Nippon Chemical Industrial Co Ltd | 2 |
| VARADARAJAN ARAVAMUTHAN | Delectrik Systems Pte Ltd | 2 |
| Massachusetts Institute of Technology | A123 Systems LLC | 1 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
Lockheed Martin dominates cell-level IP; Sumitomo Electric anchors the vanadium-utility axis
Two organizations define the competitive frontier: a defense-industrial leader with broad cell and stack IP, and a Japanese industrial-utility partnership with deep vanadium compound coverage. Below them, academic and startup players occupy specialized sub-domains.
Lockheed Martin Advanced Energy Storage LLC
With 33 patent records — the largest portfolio in this corpus — Lockheed Martin Advanced Energy Storage LLC concentrates its activity across H01M 4 and H01M 8 (electrode and fuel cell/flow cell systems), with minimal spread into other IPC branches. Momentum data shows recent filing activity categorized as a new entrant pattern in the most recent window, suggesting the bulk of its portfolio was built in earlier periods. Its dominance in high-citation ‘high energy density redox flow device’ patents underscores its foundational position in energy-dense electrolyte architectures.
patent records: 33Sumitomo Electric Industries Ltd
Sumitomo Electric Industries Ltd holds 17 patent records and is distinguished by its coverage of C01G 31 (vanadium compounds) alongside H01M 8 and H01M 10 — reflecting its deep integration of vanadium electrolyte chemistry with cell and battery system design. Its 11-record co-filing relationship with The Kansai Electric Power Co is the most active partnership in the field, amplifying its effective reach. This industrial-utility axis gives Sumitomo a practical deployment advantage that pure-research filers cannot easily replicate.
patent records: 17| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| Lockheed Martin Advanced Energy Storage LLC | 4 | ▲ new entrant |
| Institute of Metal Research, Chinese Academy of Sciences | 1 | ▲ new entrant |
Under-served IPC branches adjacent to the dominant electrolyte core
Beyond H01M, several IPC branches show low record counts relative to the core, indicating areas where the existing IP thicket is thinner. These are observations of relative sparsity; technical and commercial value must be assessed independently before treating them as entry opportunities.
C07D · Heterocyclic compounds
With only 11 patent records and a 4% share of IPC-coded records, heterocyclic compound chemistry — relevant to organic and quinone-based flow battery electrolytes — is sparsely covered relative to the dominant H01M class. CmBlu Energy AG is the primary filer active in C07D 241, with 6 records. The technical rationale is strong: organic electrolytes based on heterocyclic scaffolds (e.g., quinones, phenazines) are a recognized alternative to vanadium systems, offering earth-abundant feedstocks. The sparse filing environment suggests that novel heterocyclic electrolyte structures may still be claimable, particularly for aqueous organic flow batteries.
Search this in Eureka →C25B · Electrolytic production of compounds
C25B accounts for only 5 patent records at a 2% share, making it one of the least-populated adjacent branches. The Institute of Metal Research, Chinese Academy of Sciences is the primary filer here with 4 C25B records, focused on electrolytic production processes relevant to electrolyte preparation and rebalancing. For organizations interested in electrolyte manufacturing process IP — rather than end-use formulation — this branch offers a comparatively open filing environment. Entry would be most defensible for actors with process chemistry or electrochemical engineering capabilities distinct from the dominant cell-design filers.
Search this in Eureka →How leading applicants differ across technology routes
Strength of each leader across the main technology routes.
| Player | H01M 8 · Batteries, cells & fuel cells | H01M 4 · Batteries, cells & fuel cells | H01M 10 · Batteries, cells & fuel cells | H01M 6 · Batteries, cells & fuel cells | C01G 31 · Compounds of other metals |
|---|---|---|---|---|---|
| Lockheed Martin Advanced Energy Storage LLC | Strong · 32 | Strong · 32 | Absent | Absent | Absent |
| Sumitomo Electric Industries Ltd | Strong · 17 | Absent | Strong · 16 | Emerging · 1 | Strong · 11 |
| The Kansai Electric Power Co | Strong · 11 | Absent | Strong · 11 | Emerging · 1 | Strong · 11 |
| 24M Technologies Inc | Moderate · 6 | Strong · 13 | Absent | Emerging · 1 | Absent |
| Invinity Energy Systems (Canada) Corp | Strong · 9 | Absent | Strong · 8 | Absent | Absent |
| Massachusetts Institute of Technology | Absent | Strong · 10 | Absent | Strong · 6 | Absent |
| ESS Tech Inc | Strong · 5 | Strong · 5 | Absent | Absent | Absent |
Frequently asked questions
Lockheed Martin Advanced Energy Storage LLC leads with 33 patent records, followed by Sumitomo Electric Industries Ltd (17), Massachusetts Institute of Technology (14), 24M Technologies Inc (12), and The Kansai Electric Power Co (11).
The corpus analyzed contains 81 patent families in scope, providing a snapshot of the global IP landscape for this technology.
The United States is the leading filing jurisdiction with 53 patent records, followed by Europe via EPO (31), China (30), WIPO PCT (20), Canada (13), and India (13). Japan registers 10 records.
Based on filing trend data, the field is assessed as being in a decline phase. Annual filings peaked at 16 records in 2019 and have eased substantially since, with the multi-year window showing a 44% contraction from the recent prior period. Recent low figures for 2024–2026 also reflect publication lag and should be interpreted cautiously.
The dominant co-filing partnership is between Sumitomo Electric Industries Ltd and The Kansai Electric Power Co, with 11 jointly filed records. Sumitomo also co-files with Nippon Chemical Industrial (2 records), and MIT has co-filed with both 24M Technologies Inc (2 records) and A123 Systems LLC (1 record).
The IPC branches with the lowest record counts adjacent to the dominant H01M class include C25B (electrolytic production of compounds, 5 records), C07D (heterocyclic compounds, 11 records), and C01B (non-metallic elements and inorganic compounds, 8 records). These represent comparatively open filing environments, though technical and commercial fit must be assessed independently.
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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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