Electric Double-Layer Capacitor Cell Design Patent Snapshot
The electric double-layer capacitor (EDLC) cell design field is Japan-dominated and moderately concentrated, with Panasonic Holdings leading a roster of established Japanese electronics and automotive suppliers. The field is in a growth phase on a multi-year basis, though annual filing volume has eased from its 2017 peak and the most recent years remain understated by publication lag.
Panasonic leads a Japan-anchored, moderately concentrated field
Panasonic Holdings Corp ranks first with 103 patent records, followed by Tokin Corp (83), NEC Corp (62), Meidensha Corp (53), and AGC Inc (49). These five leaders together account for 42% of the combined total across the ranked applicants visible in this query, signaling meaningful but not overwhelming concentration.
A clear tier gap separates the top five from the next tier — Elna Co Ltd (48), Honda Motor Co Ltd (37), UD Trucks Corp (35), Murata Manufacturing Co Ltd (29), and Kyocera Corp (26) — indicating that a second cohort of capable competitors exists but at materially lower volume.
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 1 | Panasonic Holdings Corp | 103 | |
| 2 | Tokin Corp | 83 | |
| 3 | NEC Corporation | 62 | |
| 4 | Meidensha Corporation | 53 | |
| 5 | AGC Inc | 49 | |
| 6 | Elna Co Ltd | 48 | |
| 7 | Honda Motor Co Ltd | 37 | |
| 8 | UD Trucks Corporation | 35 | |
| 9 | Murata Manufacturing Co Ltd | 29 | |
| 10 | Kyocera Corporation | 26 |
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 11 | Nisshinbo Industries Inc | 18 | |
| 12 | Maxell Ltd | 18 | |
| 13 | Seiko Instruments Inc | 16 | |
| 14 | Power Systems Co Ltd | 15 | |
| 15 | Japan Radio Co Ltd | 15 | |
| 16 | Isuzu Motors Ltd | 14 | |
| 17 | TDK Corporation | 12 | |
| 18 | Sanyo Electric Co Ltd | 11 | |
| 19 | Kawasaki Heavy Industries Ltd | 10 | |
| 20 | Mitsubishi Electric Corporation | 9 |
Panasonic’s lead, combined with the breadth of Japanese industrial names in the top twenty, indicates that the core cell design know-how is held primarily by domestic Japanese electronics and automotive-adjacent firms, creating a structurally high barrier for new entrants seeking to challenge the front-runners in core capacitor technology.
Filing counts for the most recent 18–24 months are understated due to publication lag and should be read as a floor rather than a ceiling; the visible assignee structure described here reflects the accumulated record to date.
Multi-year growth persists, anchored by core capacitor IP
Two charts together show the pace of new filings over time and the distribution of technology sub-areas, revealing both where the field is heading and where the bulk of existing IP sits.
Annual filing trend
Filings peaked in 2017, then eased sharply, with scattered activity in 2019, 2023, and 2024. The recent three-year window sits well above the prior three-year window — a 50% uplift — confirming net multi-year growth, but the low absolute counts in 2024–2026 are largely an artifact of publication lag and should not be read as a sustained decline.
↗ Hover for values · click a bar to ask EurekaTechnology composition
H01G (Capacitors) is visible in overwhelmingly, reflecting the core nature of this landscape. Secondary branches — H01M (Batteries, cells & fuel cells), H02J (Power supply & grid systems), C01B (Non-metallic elements & inorganic compounds), and B60L (Electric vehicle propulsion) — each hold a small share, pointing to application adjacencies in energy storage systems and EV integration.
↗ 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.
Electric double-layer capacitor
An electric double-layer capacitor includes one or a group of electric double-layer capacitor element(s), an electrode structural member comprising of electrode plates and an insulating plate, stacked on the electric double-layer capacitor element(s), and a case for enclosing the electric double-layer capacitor element(s) and the electrode structural… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Carbon material for electric double-layer capacito… | 189 |
| 2 | Electric double-layer capacitor | 125 |
| 3 | Electric double-layer capacitor and manufacture th… | 84 |
| 4 | Electric double layer capacitor | 83 |
| 5 | Active carbon electrode and its manufacturing meth… | 77 |
| 6 | Electric double-layer capacitor | 66 |
| 7 | Multi-layer type electric double-layer capacitor | 63 |
| 8 | Electric double-layer capacitor | 63 |
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 lenses — maturity, concentration, collaboration, and geography — help an R&D team locate where effort is likely to yield differentiated IP versus where established players hold decisive positions.
Growth phase, past annual peak
The lifecycle stage is Growth. Recent three-year filings are 50% above the prior three-year window, so the field continues to expand on a multi-year basis. However, annual volume has eased from its 2017 peak, meaning the window for establishing foundational positions has narrowed; incremental and application-layer filings now represent the more accessible entry points.
Growth · post-2017 peakModerate concentration with a clear second tier
The top five filers hold 42% of the ranked applicants visible in this query’ combined total, a level that signals meaningful incumbent strength without full lock-in. The second tier — six to ten ranked applicants — retains significant volume, suggesting the field rewards focused specialization. An entrant targeting a specific sub-architecture or material system can still accumulate a defensible position.
Top-5 share: 42%AGC–Elna partnership is visible in co-filing activity
The most active co-filing pair is AGC Inc (Asahi Glass) and Elna Co Ltd, with 36 joint patent records — far exceeding any other pairing. NEC Corp co-files with Japan Science and Technology Agency (6 records) and with NEC Tokin Ceramics (3 records). Tokin Corp also collaborates with NEC Tokin Ceramics (3 records). These relationships suggest that materials-to-component integration and public-private R&D are the primary collaborative axes in this field.
AGC–Elna: 36 joint recordsJapan-centric, with secondary US and Asian filing
Japan leads jurisdiction filings by a wide margin, followed by the United States, China, South Korea, and Europe (EPO). WIPO PCT filings are present but modest. This geographic skew means that IP protection outside Japan — particularly in China and South Korea, which are growing EDLC manufacturing bases — may be underserved relative to the underlying technology activity, presenting a gap for applicants with global ambitions.
Lead office: JapanGo 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 |
|---|---|---|
| AGC Inc | Elna Co Ltd | 36 |
| NEC Corporation | Japan Science and Technology Agency | 6 |
| NEC Corporation | NEC Tokin Ceramics Co Ltd | 3 |
| Tokin Corp | NEC Tokin Ceramics Co Ltd | 3 |
| AGC Inc | Okamura Research Institute Co Ltd | 3 |
| Elna Co Ltd | Okamura Research Institute Co Ltd | 3 |
| Meidensha Corporation | Chubu Electric Power Co Inc | 2 |
| NEC Corporation | Hyogo NEC Co Ltd | 1 |
| Honda Motor Co Ltd | Japan Carlit Co Ltd | 1 |
| Honda Motor Co Ltd | Kuraray Chemical Co Ltd | 1 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
Assignee snapshot from the current evidence set
The applicants below are visible in this query result. Because the evidence set is relatively small, read this section as a directional snapshot rather than a full competitive ranking.
Panasonic Holdings Corp
Panasonic Holdings Corp leads the field with 103 patent records, focused tightly on H01G 11 (104 records) and H01G 9 (98 records) — the two core capacitor sub-classes — with a minor extension into H01G 13 (4 records). This concentration indicates deep, narrow expertise in fundamental cell architecture. Applicant momentum data is not available in the current evidence set, so trajectory cannot be confirmed.
patent records: 103Tokin Corp
Tokin Corp holds 83 patent records and, like Panasonic, concentrates in H01G 11 (65 records) and H01G 9 (49 records), but also shows a secondary presence in H01M 10 (Batteries, cells & fuel cells, 4 records), suggesting some cross-technology exploration into hybrid energy storage. Applicant momentum data is not available in the current evidence set, so trajectory cannot be confirmed.
patent records: 83Frequently asked questions
The evidence dataset covers 28 patent families in scope for electric double-layer capacitor cell design at the family level. Applicant rankings and IPC branch counts are reported at the patent-record level and can exceed the family count because a single family can generate multiple records across jurisdictions and classifications.
Panasonic Holdings Corp leads with 103 patent records, followed by Tokin Corp (83 records) and NEC Corp (62 records). All three concentrate primarily in the H01G capacitor sub-classes.
Japan is the leading jurisdiction by a substantial margin, reflecting the dominance of Japanese electronics and automotive-adjacent companies in the applicant ranking. The United States, China, and South Korea represent the next tier of filing activity.
The field is classified as Growth. Recent three-year filings are 50% above the prior three-year window on a multi-year basis. Annual volume peaked in 2017 and has since eased, with 2024–2026 counts understated by publication lag.
AGC Inc (Asahi Glass) and Elna Co Ltd are the most active co-filing pair, with 36 joint patent records. NEC Corp co-files with Japan Science and Technology Agency (6 records) and with NEC Tokin Ceramics (3 records). These partnerships span materials suppliers and component manufacturers.
The most-cited patent in the corpus relates to carbon material for electric double-layer capacitors (189 citations), followed by a foundational electric double-layer capacitor patent (125 citations), a patent on EDLC manufacturing methods (84 citations), and a multi-layer type EDLC patent (63 citations). These highly cited works concentrate on electrode materials and cell architecture fundamentals.
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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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