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Run your analysis now →https://www.patsnap.com/resources/blog/rd-blog/organic-and-aqueous-flow-chemistries-patent-landscape/ · Patsnap · data cut-off 2026-07-31 · downloaded from the live page
Patent Landscape · Flow BatteriesOrganic and Aqueous Flow Chemistry Patents: Filing Trends and Leading Claimants
- Filings rose +433% from 2021 to 2024, the fastest sustained run in this dataset, peaking at 16 records in 2024 before publication lag thins the 2025-2026 count.
- One assignee leads with 16 records, but the ranking drops to single digits by fifth place and to 1 record at tenth — a long tail of academic and single-filing entrants sits behind the leader.
- Heterocyclic chemistry (C07D) touches 28.8% of the 52 records, far ahead of acyclic/carbocyclic (C07C, 11.5%) and organo-metallic routes (C07F, 5.8%), showing where molecular-design claims concentrate.
52
Published Records
+433%
Filing Growth 2021→2024
US
Leading Jurisdiction
10
Active Filers Ranked
Filing growth compares 2021 (3 records) with 2024 (16) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field.
Published byPatsnap Research··7 min readSourced from Patsnap Eureka
Overview
What this landscape covers
This review tracks patent activity at the intersection of organic and aqueous redox flow battery chemistries — filings that combine flow-cell architecture with molecular-stability concerns such as solubility limits, active-species crossover, decomposition pathways and redox-potential tuning. The scope spans 52 published records filed between 2015 and the 2026 data cut-off, drawn from a search string that pairs flow-battery terminology with the specific failure modes and design levers that separate a working aqueous organic system from a laboratory curiosity.
Because publication lags filing by roughly eighteen months, the most recent one to two years in any trend understate real filing activity; 2024 is the last year in this set that can be read as a complete picture.
Filing activity and technology composition, 2015-2026
Source: Patsnap Eureka. Assignee ranking and totals. Derived from a Patsnap search on Organic and Aqueous Flow Chemistries covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
The Numbers
Filing trend and technology composition
Two views of the same 52-record dataset: how filing volume has moved year over year, and how those records distribute across IPC subclasses.
A sharp run-up through 2024
Annual filings moved from 4 in 2017 to a peak of 16 in 2024, including the +433% jump recorded between 2021 (3 filings) and 2024. Treat 2025 and 2026 figures as incomplete rather than as a slowdown — the drop reflects publication lag, not falling interest.
Where the chemistry claims sit
Every record in scope carries H01M (batteries, cells and fuel cells) by definition of the search. Within that, 28.8% of the 52 records also carry C07D (heterocyclic compounds) — the quinone and phenazine-derivative chemistry that dominates aqueous organic redox couples — while C07C (acyclic/carbocyclic, 11.5%) and C07F (organo-metallic, 5.8%) cover smaller, more specialised molecular-design branches.
Shares are the percentage of the 52 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Source: Patsnap Eureka. Filing trend and technology composition. Derived from a Patsnap search on Organic and Aqueous Flow Chemistries covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.
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The most-cited prior art
Representative filing
US20140370403A1 — Inexpensive metal-free organic redox flow battery (ORBAT) for grid-scale storage
UNIVERSITY OF SOUTHERN CALIFORNIA
A flow battery includes a positive electrode, a positive electrode electrolyte, a negative electrode, a negative electrode electrolyte, and a polymer electrolyte membrane interposed between the positive electrode and the negative electrode. The positive electrode electrolyte includes water and a first redox couple built from an organic compound with a moiety in conjugation with a second moiety, reduced during discharge and reoxidized on charge. The negative electrode electrolyte includes water and a second redox couple.Filed by University of Southern California, published 2014-12-18; the family's related documents are among the most-cited records in this dataset.
Highest-cited records in scope
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20140370403A1 | Inexpensive metal-free organic redox flow battery (ORBAT) for grid-scale storage | 91 |
| 2 | US20180366757A1 | Highly stable phenazine derivatives for aqueous redox flow batteries | 35 |
| 3 | WO2014204985A1 | Inexpensive metal-free organic redox flow battery (ORBAT) for grid-scale storage | 31 |
| 4 | WO2019157437A1 | Quinones having high capacity retention for use as electrolytes in aqueous redox flow batteries | 19 |
| 5 | US9614245B2 | Inexpensive metal-free organic redox flow battery (ORBAT) for grid-scale storage | 11 |
| 6 | CN114874211A | 一类酰亚胺衍生物及制备方法和在液流电池中的应用 | 9 |
| 7 | WO2018231926A1 | Highly stable phenazine derivatives for aqueous redox flow batteries | 8 |
| 8 | US20210009497A1 | Quinones having high capacity retention for use as electrolytes in aqueous redox flow batteries | 5 |
| 9 | CN116143800A | 一类含硫族元素紫精衍生物及其制备方法和在液流电池体系中的应用 | 4 |
| 10 | US10454124B2 | Highly stable phenazine derivatives for aqueous redox flow batteries | 4 |
Citation counts inside a searched corpus favour older filings that have had more time to accumulate references — read them as a signal of influence on the field, not of current commercial relevance.
Patent titles are shown in the language they were filed in, not translated, so that each record stays verifiable against the original filing — a translated title will not match in Eureka or in any national register. Each row carries its publication number; clicking a row searches Eureka by that number.
Source: Patsnap Eureka. Citation counts and representative records. Derived from a Patsnap search on Organic and Aqueous Flow Chemistries covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
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What the data means for R&D and IP strategy
Three patterns stand out once filing volume, assignee concentration and citation weight are read together.
Filing momentum
+433%
2021 → 2024 filing growth
The field is still in its build-out phase
Filings quadrupled-plus between 2021 and 2024, with the 16-record peak arriving in the most recently complete year. That trajectory points to a technology space still attracting new entrants rather than one that has settled into a stable claim structure.
Read 2025-2026 counts as provisional, not declining.
Assignee spread
16 vs 1
leader vs tenth-place record count
A single leader, then a long tail
The ranked leader holds 16 records against a tenth-place count of just 1, with fifth place already down to 3. That gap suggests one organisation has built sustained coverage while most other named assignees hold only isolated filings.
Ten assignees make up the entire ranking returned for this dataset.
Molecular focus
28.8%
of 52 records carry C07D heterocyclic claims
Heterocyclic redox couples are the busiest sub-branch
Quinone and phenazine-type heterocyclic chemistry appears in over a quarter of records, well ahead of acyclic/carbocyclic and organo-metallic alternatives. New filers should expect denser prior art exactly where molecular-stability claims on heterocyclic redox couples are concerned.
C07C and C07F remain comparatively open by comparison.
Eureka AI Agent
Looking for what nobody has claimed yet?
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to organic and aqueous flow chemistries, with the prior art for and against each one.
Source: Patsnap Eureka. Co-assignee relationships and derived observations. Derived from a Patsnap search on Organic and Aqueous Flow Chemistries covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
Players
Who is filing, and where the openings sit
The ranking covers 10 assignees — universities, research institutes and one named battery company — with filing counts that fall off quickly after the leader.
Leader
16 records
top-ranked assignee
One organisation dominates the ranking
The top-ranked assignee holds 16 records, well clear of the field. Its recent-year momentum has flattened to zero in the latest year, consistent with the publication-lag effect seen across the whole dataset rather than a genuine pullback.
Momentum figures for 2025-2026 should be read cautiously.
Mid-tier
3 records
fifth-place assignee
A cluster of university and institute filers
Below the leader, filing counts drop quickly — fifth place sits at just 3 records. Several of the named assignees are universities or public research institutes, suggesting the field still has a strong academic-research character alongside commercial activity.
One co-assignee pairing links a university with a regional energy-research institute.
Long tail
1 record
tenth-place assignee
Single-filing entrants fill out the ranking
The bottom of the ranking sits at a single record, typical of a field where smaller labs and newer companies file opportunistically rather than building a sustained portfolio. That pattern leaves room for a well-timed filing to stand out rather than compete against dense blocking claims.
Ten assignees make up the full ranking returned for this search.
Recent-year filing momentum by assignee
| Assignee | Recent year | YoY |
|---|---|---|
| XL BATTERIES INC | 0 | -100% |
| University of Southern California | 0 | — |
| President and Fellows of Harvard College | 0 | — |
| Battelle Memorial Institute | 0 | — |
| Xi'an Jiaotong University | 0 | — |
| University of Coimbra | 0 | — |
| The Regents of the University of Michigan | 0 | -100% |
| Shengzhou Yangtze River Delta New Energy Industry-Education Integration Research Institute | 0 | — |
Source: Patsnap Eureka. Assignee-level momentum. Derived from a Patsnap search on Organic and Aqueous Flow Chemistries covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
What's Next
Where to take this analysis
The dataset points to specific next questions for teams deciding where to file or where to license around existing claims.
Map the heterocyclic claim boundary
With 28.8% of records touching C07D, a freedom-to-operate review of quinone and phenazine-derivative claims is the highest-value next step before committing to a heterocyclic redox couple.
Explore heterocyclic claim scopeTrack the leader's next filings
The top-ranked assignee's 16-record portfolio is the benchmark against which any new heterocyclic or aqueous organic filing will be measured for novelty.
Watch leading assignee activityTest white-space branches directly
Organo-metallic redox mediators and non-quinone acyclic couples show thinner coverage than the heterocyclic core, worth a targeted search before drafting claims there.
Run a white-space searchSource: Patsnap Eureka. Forward-looking reading of the same dataset. Derived from a Patsnap search on Organic and Aqueous Flow Chemistries covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
FAQ
Common questions on organic and aqueous flow battery patents
In this dataset, records are pulled together by pairing flow-battery terminology with organic or aqueous-organic redox couples, including quinone redox couples, and specific technical failure modes such as molecular stability, solubility limits, active-species crossover, decomposition pathways, cell-voltage-window and redox-potential tuning. Every one of the 52 records in scope also carries an H01M classification, meaning they are formally classified as battery, cell or fuel-cell technology. Practically, this covers flow-cell architectures where the redox-active species is a carbon-based molecule rather than a transition-metal ion, aimed at lower material cost and reduced toxicity compared with vanadium or other metal-based flow chemistries.
The ranked leader in this dataset holds 16 records, well ahead of the rest of the field, which falls to 3 records by fifth place and just 1 record at tenth. The ranking includes ten assignees in total, spanning universities, public research institutes and at least one named battery company, so the field is not dominated by a single commercial player in the way some more mature battery chemistries are. Anyone assessing freedom to operate should look closely at the leader's full portfolio rather than assuming coverage is evenly spread.
Yes, based on the filing trend available: annual filings grew from 4 in 2017 to a peak of 16 in 2024, including a +433% increase between 2021 and 2024 alone. Filing counts shown for 2025 and 2026 are lower, but that reflects the roughly eighteen-month lag between filing and publication rather than a genuine slowdown, so those most recent years should not be read as a declining trend. 2024 is the most recent year in this dataset that can be treated as a complete picture of filing activity.
US20140370403A1, filed by University of Southern California and published in 2014, describes a flow battery using aqueous electrolytes on both electrodes built around organic redox couples with conjugated moieties that are reduced on discharge and reoxidized on charge, separated by a polymer electrolyte membrane. It is the most-cited record in this dataset, with related family members also appearing among the top-cited filings, indicating its claims have shaped a large amount of subsequent work on metal-free aqueous organic redox chemistry. Anyone designing a new cell architecture around aqueous organic redox couples with conjugated organic moieties should review this filing and its family closely before finalising claim language.
The clearest under-claimed areas relative to the dataset's heterocyclic core (C07D, 28.8% of 52 records) are organo-metallic redox mediators (C07F, only 5.8% of records) and non-quinone acyclic or carbocyclic redox couples (C07C, 11.5%). Claims addressing cell-voltage-window widening, crossover-suppressing membrane pairings and decomposition-pathway stabilizers also appear thinner than core molecular-stability claims on heterocyclic species. These branches are worth a targeted prior-art search before drafting, since they sit adjacent to a densely filed core rather than being unclaimed territory in absolute terms.
Answers are grounded in the same dataset. Derived from a Patsnap search on Organic and Aqueous Flow Chemistries covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
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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.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company's registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.