EDLC Current Collector Patents: Who Leads, Where the Gaps Are 2026
A data-backed look at electric double layer capacitor current collector patents from 2015 to 2026: filing trends, technology composition, leading assignees, and where the claim space is still open.
Filing growth = 2021 (2 records) → 2024 (5); 2024 is the last year we treat as complete. Top-5 share = the 5 largest assignees ÷ all 876 records in scope (CR5), not the ranked leaders only.
What this landscape covers
This landscape covers 876 published records filed or published between 2015 and 2026 that combine electric double layer capacitor (EDLC) subject matter with current collector claims, classified under H01G11 (capacitors) and H01M4 (battery and cell electrodes). The search deliberately spans both capacitor-specific and battery-electrode classification because current collector foil, coating and interface art is shared prior art across both device types — a formulation claimed for a lithium cell electrode frequently reads onto an EDLC current collector and vice versa.
The scope is narrow by design: it isolates the current collector — the metal foil substrate and its conductive coating or interface layer — rather than the broader EDLC electrode or electrolyte stack. That makes the dataset useful for freedom-to-operate work on foil composition, undercoat chemistry and adhesion technology specifically, rather than for EDLC device claims in general.
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Filing trend and technology composition
Two views of the same 876-record dataset: how filing activity has moved year over year, and which IPC subclasses the records actually sit in.
Filing trend, 2017–2026
Filings ran from 9 in 2017 to a peak of 20 in 2018, then eased. Because publication lags filing by roughly 18 months, the 2025–2026 tail is understated by definition and should not be read as a slowdown. The clearest complete-year signal is 2021 to 2024, where filings rose from 2 to 5 — a +150% increase over that three-year span.
Publication lags filing by roughly 18 months, so 2025 onwards are still filling in. Growth rates on this page therefore end at 2024; running them to the last bar would understate the field.
Technology composition by IPC subclass
H01G (capacitors) covers 98.1% of the 876 records, confirming the search is squarely on-topic, while H01M (batteries, cells & fuel cells) reaches 28.1% — the clearest evidence that current collector art is filed jointly across capacitor and battery classifications. Smaller subclasses such as C08L, C09D and C01B, each around 3% of records, mark where polymer binder, coating and inorganic-compound chemistry intersects the core foil claims; a record can carry more than one class, so these shares add to more than 100%.
Shares are the percentage of the 876 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Electric Double Layer Capacitor Current Collector Patent Landscape with Eureka
This page is one run against one query. Ask Eureka your own question about electric double layer capacitor current collector patent landscape and every answer comes back with the patent numbers behind it.
Try EurekaRepresentative filing and most-cited prior art
Conductive composition for coating a current collector for a battery or an electrical double layer capacitor, current collector for battery or electrical double layer capacitor, battery, and electrical double layer capacitor
A conductive composition for coating a current collector of coating a current collector for a battery or an electrical double layer capacitor, where the adhesion properties between a battery current collector and an active material layer are increased to improve the battery characteristics is presented. A battery using the battery current collector using the composition is also presented. The conductive composition for coating the current collector includes a vinylsilane copolymer, a polycarboxylic acid, and a conductive auxiliary. The formulation of the vinylsilane copolymer is also presented.Filed by Kyoritsu Chemical & Co., Ltd. — illustrative of the coating-composition branch of this landscape rather than the foil-substrate branch.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20020122985A1 | Battery active material powder mixture, electrode composition for batteries, secondary cell electrode, second… | 203 |
| 2 | US5953204A | Electric double layer capacitor | 153 |
| 3 | JP2008060060A | Coating liquid for manufacturing electrode plate, undercoating agent, and use thereof | 147 |
| 4 | JP1999162470A | Aluminum foil for current collector, its manufacture current collector, secondary battery and electric double… | 128 |
| 5 | US20040146786A1 | Nonaqueous electolytic solution, composition for polymer gel electrolyte, polymer gel electrolyte, secondary … | 123 |
| 6 | US6574092B2 | Carbonaceous material, polarizable electrode for electrical double-layer capacitor, and electrical double-lay… | 113 |
| 7 | JP2001351688A | Complex element of cell and capacitor | 101 |
| 8 | US20100110613A1 | Ultracapacitor electrode with controlled iron content | 88 |
| 9 | US20010021097A1 | Electric double layer capacitor | 83 |
| 10 | US20130330617A1 | Electrode foil, current collector, electrode, and electric energy storage element using same | 72 |
Citation counts favour older records in a searched corpus and should be read as a signal of influence, not of current relevance — the two highest-cited documents here date to 1999 and 2002.
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Browse MCP servers →What the numbers say about this field
Four readings of the dataset that matter for a freedom-to-operate or whitespace assessment.
The top of the field is tight, the tail is long
Five assignees account for 28.4% of all 876 records, and the leader alone holds 71 — well ahead of the fifth-place holder at 33. Filing this dense at the top usually means foil-alloy composition and undercoat formulation claims from the leading players are already well staked out.
Recent complete-year activity is rising, not falling
Filings grew from 2 in 2021 to 5 in 2024, a +150% increase across the last three years that can be treated as complete. The 2018 peak of 20 has not been matched since, but the 2025–2026 dip reflects publication lag rather than a real drop in activity.
Current collector art crosses capacitor and battery classification lines
98.1% of records sit in H01G, but 28.1% are also classified in H01M, batteries and cells. Anyone drafting or searching in this space needs to clear both classifications, since foil and coating claims are routinely filed to cover both device types.
Filing activity is concentrated in Japan and Korea
Japan (250) and South Korea (195) lead the receiving offices ahead of the United States (158) and the EPO (130), with China (42) and the WIPO PCT route (28) well behind. That ordering points to where prosecution and opposition activity for this art is most likely to be contested.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to electric double layer capacitor current collector patent landscape, with the prior art for and against each one.
Where to take this analysis
The dataset points to specific follow-up work rather than a single conclusion.
Map the coating-chemistry sub-branch separately
C08L, C09D and C01B each sit around 3% of the 876 records but cluster around undercoat and binder chemistry — a narrower search here would surface the real assignee concentration in that niche.
Explore coating chemistry in EurekaTrack the 2021–2024 filing acceleration by assignee
The +150% rise in filings from 2021 to 2024 is a field-wide figure; breaking it down by assignee would show whether new entrants or incumbents are driving it.
Run an assignee-level trend queryWatch the Japan–Korea prosecution corridor
With Japan and South Korea together well ahead of the US and EPO as receiving offices, opposition and invalidation activity in this art is more likely to originate there.
Check office-level filing detailCommon questions about this landscape
In this landscape, a current collector patent is one that claims the metal foil substrate, its alloy composition, or a conductive coating and adhesion layer applied to that foil, specifically in the context of an electric double layer capacitor or a shared battery-electrode application. The 876 records here were pulled from IPC classes H01G11 (capacitors) and H01M4 (battery electrodes) because the same foil and coating art is routinely filed to cover both device types. It excludes broader EDLC electrode or electrolyte claims that do not touch the collector itself.
The ranked leaders show a concentrated top tier: the single leading assignee holds 71 records, and the top five assignees combined account for 28.4% of all 876 records in scope. That concentration eases past the top ten, which together reach 45.5% of records, meaning the remainder of the field is a long tail of smaller and single-filing entrants. Anyone assessing freedom to operate should expect the densest prior art around the leading names' foil-alloy and undercoat formulations.
Complete-year data shows growth: filings rose from 2 in 2021 to 5 in 2024, a +150% increase over that span. The field's historical peak was 20 filings in 2018, and activity has not returned to that level since, but recent years should not be read as a slowdown — publication lags filing by roughly 18 months, so 2025 and 2026 figures are still filling in and will rise as later publications are indexed. The reliable trend read stops at 2024.
98.1% of the 876 records sit in H01G (capacitors) while 28.1% also carry an H01M (batteries, cells & fuel cells) classification, because the current collector foil and its coating are largely agnostic to whether the finished device is an EDLC or a battery cell. Manufacturers and material suppliers file the same alloy, lamination or undercoat claims to cover both applications. A search or freedom-to-operate check limited to one classification alone will miss a meaningful share of relevant prior art.
The smaller IPC subclasses in this dataset — C08L polymer compositions, C09D coatings and inks, C01B inorganic compounds, and B82Y nanotechnology applications — each sit at only 2.4% to 3.2% of the 876 records, far below the dominant foil and capacitor classes. That gap suggests coating chemistry variants, nanostructured conductive additives, and inorganic interface layers are comparatively under-claimed relative to core foil-alloy and lamination art, and are worth a closer look before assuming the space is closed.
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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.