Electric Double-Layer Capacitor Electrolyte Patent Landscape
Electric Double-Layer Capacitor Electrolyte Patent Landscape in 2026
The electric double-layer capacitor (EDLC) electrolyte field is a mature, Japan-dominated space with 26 patent families in scope and activity concentrated among a small cohort of Japanese materials and electronics firms. Annual filing volume has plateaued near its 2017 peak, while a multi-year window still shows positive growth, signaling a field in late-growth transition rather than expansion.
AGC and Panasonic lead a concentrated, Japan-anchored competitive field
AGC Inc. and Panasonic Holdings Corporation sit atop the applicant ranking, each with the largest patent-record counts among the top 100 filers, placing them in a clear leadership tier above all challengers.
The top five filers account for 37% of the combined total of the hundred largest filers, a notable concentration for a specialty electrochemistry segment. A second tier of Japanese industrial firms — including ELNA, Central Glass, Mitsubishi Chemical, and Nisshinbo — holds meaningful but significantly smaller positions, creating a two-tier structure.
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 1 | AGC Inc. | 73 | |
| 2 | Panasonic Holdings Corporation | 72 | |
| 3 | ELNA Co. Ltd. | 37 | |
| 4 | Central Glass Co. Ltd. | 26 | |
| 5 | Mitsubishi Chemical Corporation | 19 | |
| 6 | Nisshinbo Industries Inc. | 18 | |
| 7 | TOKIN Corporation | 18 | |
| 8 | The Japan Carlit Co. Ltd. | 17 | |
| 9 | Nippon Chemi-Con Corporation | 17 | |
| 10 | Daikin Industries Ltd. | 17 |
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 11 | Bridgestone Corporation | 16 | |
| 12 | Power Systems Co. Ltd. | 15 | |
| 13 | Honda Motor Co. Ltd. | 13 | |
| 14 | Taiyo Yuden Co. Ltd. | 12 | |
| 15 | NEC Corporation | 10 | |
| 16 | Yoshiyuki Yoshio | 10 | |
| 17 | Nantong Jianghai Capacitor Co. Ltd. | 10 | |
| 18 | Sachem Inc. | 9 | |
| 19 | Ioxus Japan Co. Ltd. | 9 | |
| 20 | Meidensha Corporation | 8 |
The leaders’ positions imply deep, long-established IP portfolios in core electrolyte chemistry and capacitor architecture; new entrants attempting to displace them in mainstream organic electrolyte formulations face substantial prior-art density and freedom-to-operate constraints.
The most recent 18–24 months of filings are subject to publication lag and likely under-represent actual activity; year-on-year comparisons for 2024–2026 should be treated with caution. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Filing volume has plateaued since 2017; capacitor-class IP dominates the technology mix
Two structural features define this landscape: annual filing activity that peaked in 2017 and has since settled at a low, steady rate; and a technology composition overwhelmingly anchored in the H01G capacitor class, with secondary branches in batteries, inorganic chemistry, and conductors.
Annual filing trend
Filings peaked at eight families in 2017 and have since leveled off at low single-digit annual counts through 2018–2025. Years 2025 and 2026 are under-counted due to publication lag and should not be read as terminal decline.
↗ Hover for values · click a bar to ask EurekaTechnology composition
H01G (Capacitors) accounts for the dominant share of patent records, underscoring that EDLC electrolyte IP is filed primarily as capacitor-device art. H01M (Batteries, cells and fuel cells) forms a meaningful secondary branch, reflecting crossover interest in electrolyte formulations applicable to energy storage broadly. Branches such as C01B (Non-metallic elements and inorganic compounds), H01B (Cables, conductors and insulators), and C07F (Organo-metallic compounds) each represent smaller but distinct technical threads.
↗ 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.
Non-aqueous electrolyte electric double-layer capa…
A non-aqueous electrolyte electric double-layer capacitor which has superior resistance to deterioration and superior properties at low temperatures while maintaining electrical characteristics such as sufficient electric conductivity and the like, and a non-aqueous electrolyte of the capacitor has low surface resistance.A first aspect of the non-aqueous… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Electric double-layer capacitor | 361 |
| 2 | Electric double-layer capacitor | 226 |
| 3 | Carbon material for electric double-layer capacito… | 189 |
| 4 | Electric double-layer capacitor and carbon materia… | 175 |
| 5 | Electrolyte for electrochemical device and battery… | 131 |
| 6 | Electric double-layer capacitor | 125 |
| 7 | Electric double-layer capacitor and carbon materia… | 106 |
| 8 | Electric double-layer capacitor | 97 |
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
The combination of a mature lifecycle, high. Japan concentration, and persistent H01G dominance shapes where genuine whitespace remains and where entry barriers are highest.
Field is in late-growth/maturity phase with plateaued annual volume
Annual filings have plateaued near the 2017 peak, consistent with a field that has exhausted most first-order innovation opportunities in conventional organic electrolyte chemistry. The multi-year window still registers positive growth of 17%, indicating the corpus is accumulating but at a decelerating rate. R&D investment should target differentiated formulations — ionic liquids, solid-state or hybrid systems — rather than incremental modifications of established solvent-salt combinations.
Lifecycle: MaturityTop five filers hold 37% of the hundred largest filers’ combined total
AGC and Panasonic together command the top two positions, with a measurable gap to the third-ranked ELNA. This two-tier structure means the dominant players have already staked out the core electrolyte IP terrain. Challengers and new entrants have the strongest differentiation pathway through adjacent branches — inorganic electrolytes, polymer additives, or nanotechnology-enabled formulations — where the incumbents’ portfolios are comparatively thin.
High concentrationAGC–ELNA partnership is the field’s dominant co-filing relationship
The most active co-applicant pair is AGC Inc. (Asahi Glass) and ELNA Co. Ltd., with 37 jointly filed records — by far the largest collaboration count in the dataset. Power Systems KK and the individual inventor Yoshiyuki Yoshio account for eight joint records, and Panasonic and Sanyo Chemical Industries share three. These concentrated partnerships suggest that major IP formation in this field has been driven by tight bilateral R&D relationships rather than broad consortia.
Bilateral partnershipsJapan is the primary filing jurisdiction; US and Korea are secondary targets
Japan leads all jurisdictions by a wide margin in patent-record count, consistent with the applicant roster being almost entirely Japanese. The United States and South Korea rank second and third respectively, followed by the EPO and China. PCT filings are modest, suggesting limited global filing ambitions among most portfolio holders. For companies seeking to enter or license in this space, Japan national filings are the essential starting point for freedom-to-operate analysis.
Japan-centricGo 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. | 37 |
| Power Systems Co. Ltd. | Yoshiyuki Yoshio | 8 |
| Panasonic Corporation | Sanyo Chemical Industries Ltd. | 3 |
| Power Systems Co. Ltd. | The Japan Carlit Co. Ltd. | 3 |
| Nisshinbo Industries Inc. | Nisshinbo Holdings Inc. | 3 |
| The Japan Carlit Co. Ltd. | Honda Motor Co. Ltd. | 1 |
| Mitsubishi Chemical Corporation | Mitsubishi Petrochemical Co. Ltd. | 1 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
AGC and Panasonic lead on volume; AGC anchors the field’s largest co-filing network
The two leading applicants are closely matched on patent-record count and share the same primary technology focus in H01G capacitor classes, but diverge in secondary emphases and ecosystem roles.
AGC Inc.
AGC Inc. (formerly Asahi Glass) holds the top-ranked position with 73 patent records, concentrated in H01G 11 and H01G 9 capacitor subclasses, with a smaller nanotechnology thread in B82Y 99. Crucially, AGC anchors the field’s largest co-filing relationship with ELNA Co. Ltd. (37 joint records), indicating that a significant portion of its portfolio was built through collaborative R&D. Momentum data is not available in the current evidence set.
patent records: 73Panasonic Holdings Corporation
Panasonic Holdings Corporation is the second-ranked applicant with 72 patent records — nearly identical to AGC’s count — spread across H01G 11, H01G 9, and a notable H01M 10 battery/cell thread. This crossover into H01M distinguishes Panasonic from the pure-capacitor focus of AGC and ELNA, reflecting its broader energy storage platform strategy. Momentum data is not available in the current evidence set.
patent records: 72Under-served branches in inorganic chemistry, conductors, and nanotechnology
Several IPC branches adjacent to the dominant H01G core have low patent-record counts relative to the total corpus, indicating areas where prior-art density is lower. These are observations of relative sparsity; technical merit and commercial viability require independent validation.
C01B · Non-metallic elements and inorganic compounds
With 43 patent records and a 5% share of the corpus, C01B is the largest adjacent branch but remains sparse compared to H01G. This branch captures inorganic electrolyte precursors, activated carbon synthesis, and non-metallic ionic conductors. For entrants with materials-chemistry competence, this branch offers a plausible entry path into EDLC electrolyte IP without directly competing in the densely filed H01G core — particularly relevant for solid or quasi-solid inorganic electrolyte formulations gaining traction in next-generation capacitors.
Search this in Eureka →B82Y · Nanotechnology applications
B82Y holds only 8 patent records and a 1% share, making it the sparsest substantive branch in the corpus. Nanotechnology-enabled electrolytes — such as those incorporating functionalized carbon nanotubes, graphene-based ion-transport layers, or nanostructured solid electrolytes — represent a technically plausible area where the existing IP density is low. AGC has a small presence here, but no applicant has established a dominant position. Entry would require specialized nanomaterials expertise and is best assessed alongside C01B filings for combined freedom-to-operate.
Search this in Eureka →How leading applicants differ across technology routes
Strength of each leader across the main technology routes.
| Player | H01G 11 · Capacitors | H01G 9 · Capacitors | H01M 10 · Batteries, cells & fuel cells | H01M 6 · Batteries, cells & fuel cells | C01B 31 · Non-metallic elements & inorganic compounds |
|---|---|---|---|---|---|
| Panasonic Corporation | Strong · 75 | Strong · 68 | Moderate · 17 | Emerging · 4 | Absent |
| AGC Inc. | Strong · 74 | Strong · 53 | Absent | Absent | Absent |
| Central Glass Co. Ltd. | Strong · 26 | Strong · 19 | Strong · 26 | Strong · 22 | Absent |
| ELNA Co. Ltd. | Strong · 37 | Strong · 37 | Absent | Absent | Absent |
| Power Systems Co. Ltd. | Strong · 22 | Strong · 20 | Absent | Absent | Emerging · 2 |
| Nisshinbo Industries Inc. | Strong · 21 | Strong · 20 | Emerging · 3 | Absent | Absent |
| NEC Corporation | Strong · 19 | Strong · 19 | Absent | Absent | Emerging · 2 |
Frequently asked questions
The evidence covers 26 patent families in scope for electric double-layer capacitor electrolytes.
AGC Inc. holds the top position with 73 patent records among the top 100 ranked applicants, followed closely by Panasonic Holdings Corporation with 72 patent records.
Japan leads all jurisdictions with 383 patent records, reflecting the heavily Japanese applicant base. The United States ranks second with 55 records, followed by South Korea with 41.
The field is assessed as being in the Maturity stage. Annual filings have plateaued near the 2017 peak, though the multi-year window still registers a 17% growth figure across the full evidence period.
The most active co-filing pair is AGC Inc. (Asahi Glass) and ELNA Co. Ltd., with 37 jointly filed records. Power Systems KK and inventor Yoshiyuki Yoshio account for the next-largest collaboration with 8 joint records, followed by several pairs with 3 or fewer joint records.
The sparsest branches relative to the H01G core are B82Y (Nanotechnology applications, 8 patent records) and C07C (Acyclic and carbocyclic compounds, 13 records). C01B (Non-metallic elements and inorganic compounds, 43 records) is the largest adjacent branch and remains significantly smaller than the dominant capacitor class.
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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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