CDI Charge-Discharge Control Patent Landscape 2026
The CDI charge-discharge control field is moderately concentrated, with Samsung Electronics and Stockholm Water Tech AB jointly leading, and activity dominated by water-treatment applications under C02F. Annual filing volume has plateaued near its 2018 peak, while several adjacent branches — notably electrolytic compound production and advanced electrode materials — remain comparatively sparse.
Samsung and Stockholm Water Tech lead a fragmented but concentrated top tier
Samsung Electronics and Stockholm Water Tech AB share the top ranking, each with 8 patent records, followed by Jilin University, Foshan Shunde Midea Water Dispenser Manufacturing, and Midea Group, each with 4 patent records. The top five filers collectively account for 34% of the hundred largest filers’ combined total, signalling a moderately concentrated field.
Below the two co-leaders, the ranking disperses quickly across universities and smaller industrial players, most holding two or three patent records. This broad mid-tier, with no clear second-place challenger substantially closing the gap on the leaders, points to an open competitive field rather than a two-firm duopoly.
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 1 | Samsung Electronics Co., Ltd. | 8 | |
| 2 | Stockholm Water Tech AB | 8 | |
| 3 | Jilin University | 4 | |
| 4 | Foshan Shunde Midea Water Dispenser Manufacturing Co., Ltd. | 4 | |
| 5 | Midea Group Co., Ltd. | 4 | |
| 6 | Shenyang Institute of Chemical Technology | 3 | |
| 7 | Nanyang Technological University | 3 | |
| 8 | WUHAN UNIV OF SCI & TECH | 3 | |
| 9 | Voltea | 3 | |
| 10 | KOREA INST OF CIVIL ENG & BUILDING TECH | 3 |
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 11 | École de Technologie Supérieure | 2 | |
| 12 | Jiangsu Maymuse Environmental Technology Co., Ltd. | 2 | |
| 13 | Jacon | 2 | |
| 14 | Korea Institute of Energy Research | 2 | |
| 15 | Changzhou University | 2 | |
| 16 | KOREA ADVANCED INST OF SCI & TECH | 2 | |
| 17 | Hyundae Steel Co., Ltd. | 2 | |
| 18 | KOREA UNIV RES & BUSINESS FOUND | 2 | |
| 19 | National Taiwan University | 2 | |
| 20 | DOOSAN HEAVY IND & CONSTR CO LTD | 2 |
The leaders’ positions reflect deep expertise in core capacitive deionization water-treatment processes (C02F), giving them a prior-art foundation that late entrants must design around, particularly in electrode cycling and ion-exchange membrane control methods.
The most recent 18–24 months of filings are subject to publication lag and are therefore likely under-counted; trend readings near the current date should be interpreted with that in mind. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Filing activity has plateaued since a 2018 peak; water treatment dominates the technology mix
The annual filing trend and technology-composition charts together reveal a maturing field anchored in water-treatment chemistry, with limited but notable satellite activity in separation and electrolytic processes.
Annual filing trend
Filings peaked in 2018 with 10 records, then settled into a 4–6 record annual range through 2023. A visible uptick appears in 2024 (9 records), though this figure should be read cautiously given publication lag — the 2025 and 2026 counts are almost certainly incomplete. The multi-year window still shows modest positive growth of 6%, consistent with a plateau rather than a decline.
↗ Hover for values · click a bar to ask EurekaTechnology composition
C02F (water and wastewater treatment) commands 74 records, far ahead of all other classes, confirming that charge-discharge control is overwhelmingly applied to desalination and ion-removal contexts. B01D (separation processes) is the next largest branch at 12 records, followed by C25B (electrolytic production) at 7. All remaining IPC classes each hold 3 or fewer records, underscoring the narrow application focus of the current corpus.
↗ 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.
Capacitive deionization water purification system …
Provided are a capacitive deionization (CDI) water purification system using citric circulation water in a circulation tank for a desorption process, and a control method therefor, the CDI water purification system being implemented to separately include a circulation tank capable of supplying circulation water used only for ion desorption in a desorption… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Method and apparatus for capacitive deionization a… | 368 |
| 2 | Capacitive deionization device | 30 |
| 3 | Method and apparatus for capacitive deionization, … | 22 |
| 4 | Electrode containing a hybrid nanomaterial of grap… | 18 |
| 5 | Control method of capacitive deionization device | 16 |
| 6 | Capacitive deionization device and method of contr… | 13 |
| 7 | 一种纳米钛渗碳电极电容去离子装置 | 12 |
| 8 | 一种履带状回转式电极电容去离子装置与方法 | 11 |
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 strategy
The combination of a plateauing filing rate, a concentrated top tier, and a narrow technology focus in C02F creates both risks and openings for teams entering or expanding in this space.
Field has plateaued near its 2018 peak
Annual filings have plateaued near their 2018 high and have not returned to that peak level on a sustained basis, placing the field in a mature stage. On a multi-year basis, the 6% recent growth figure suggests the field is not contracting, but the era of rapid accumulation of foundational filings appears to have passed. Teams entering now face an established prior-art landscape and must differentiate through novel control algorithms, electrode geometries, or application domains.
Mature / PlateauModerate concentration with a broad mid-tier
The top five filers hold 34% of the hundred largest filers’ combined total — a moderate concentration level. The co-leaders Samsung Electronics and Stockholm Water Tech AB hold equal positions at 8 patent records each, with no single dominant player. The wide mid-tier of universities and smaller industrials means that targeted filing in a sub-niche can establish a defensible position without confronting a single monolithic blocker.
Moderate ConcentrationTwo active co-filing pairs identified
Midea Group and Foshan Shunde Midea Water Dispenser Manufacturing co-filed 4 records together, reflecting an integrated corporate-subsidiary R&D relationship. Shenyang Institute of Chemical Technology and Wuhan University of Science and Technology co-filed 3 records, representing an academic cross-institutional pairing. No large-scale industry–academia consortia are evident, leaving that collaboration model as an under-exploited structural option.
Limited CollaborationChina and South Korea lead filing activity; US and EPO form a secondary tier
China leads with 18 patent records, closely followed by South Korea with 17, reflecting the concentration of both industrial and academic filers in those jurisdictions. The United States ranks third at 12 records, with Europe (EPO) and WIPO (PCT) each at 7. The Netherlands, Singapore, Taiwan, and several other jurisdictions each hold small counts. Teams seeking broad commercial protection should prioritize a China–Korea–US–EPO filing strategy.
Asia-Led GeographyGo 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 |
|---|---|---|
| Midea Group Co., Ltd. | Foshan Shunde Midea Water Dispenser Manufacturing Co., Ltd. | 4 |
| Shenyang Institute of Chemical Technology | Wuhan University of Science and Technology | 3 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
Samsung Electronics and Stockholm Water Tech AB lead; Midea and Jilin University are new entrants with momentum
The top two filers are tied on volume but differ in geographic focus and institutional type: one is a global electronics conglomerate, the other a specialized water-technology company. Below them, several organizations entered recently with notable momentum.
Samsung Electronics
Samsung Electronics holds 8 patent records, all concentrated in C02F 1 (water and wastewater treatment), with satellite coverage in B01D 61 (separation processes) and C25B 15 (electrolytic production). Its breadth across core and adjacent classes suggests a platform-level CDI strategy rather than narrow point solutions. Momentum data places Samsung in the established tier without a flagged recent surge, consistent with a mature portfolio being selectively maintained.
patent records: 8Stockholm Water Tech AB
Stockholm Water Tech AB also holds 8 patent records, focused exclusively on C02F 1 and B01D separation classes — a tighter, more application-specific profile than Samsung’s. Its equal rank despite a narrower IPC spread indicates depth in core CDI water-treatment process control. Midea Group and Jilin University each entered as new entrants in the recent window with 4 patent records, representing the most active new momentum in the current period.
patent records: 8| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| Midea Group Co., Ltd. | 4 | ▲ new entrant |
| Jilin University | 4 | ▲ new entrant |
| Foshan Shunde Midea Water Dispenser Manufacturing Co., Ltd. | 4 | ▲ new entrant |
| Korea Institute of Civil Engineering and Building Technology | 2 | ▲ new entrant |
Electrolytic compound production and advanced electrode materials are under-served adjacent branches
Several IPC classes adjacent to the dominant C02F core hold only a handful of records each, and may represent areas where differentiated CDI charge-discharge control research could find less crowded prior art.
C25B · Electrolytic production of compounds
C25B holds 7 records — the largest of the sparse branches — representing electrolytic compound production. CDI charge-discharge control overlaps naturally with electrolytic processes when electrode reactions produce or consume ions beyond simple adsorption cycles. The relatively low filing count relative to C02F suggests that control methods specifically optimized for electrolytic CDI variants (e.g., chlorine generation, hydrogen evolution suppression) remain under-developed. Teams with electrochemistry expertise in Samsung’s C25B 15 sub-class have a potential first-mover angle in this sub-domain.
Search this in Eureka →C01B / C08B / C08L · Inorganic compounds and polymer electrode materials
C01B (non-metallic elements and inorganic compounds), C08B (polysaccharides and derivatives), and C08L (polymer compositions) each hold only 3 records. Nanyang Technological University is notably the only filer with C01B 32 and C08B 37 coverage, reflecting graphene-based and biopolymer electrode material research. Charge-discharge control strategies that co-optimize electrode material chemistry — such as capacitance-aware cycling for novel carbon architectures or ion-selective polymer membranes — are sparsely covered and represent an observation of relative sparsity with plausible technical value for materials-oriented R&D teams.
Search this in Eureka →How leading applicants differ by technology route
Route coverage across the main technology branches in the current evidence set.
| Player | C02F 1 · Water & wastewater treatment | B01D 61 · Separation processes (filtration etc.) | C02F 103 · Water & wastewater treatment | C25B 15 · Electrolytic production of compounds | C02F 101 · Water & wastewater treatment |
|---|---|---|---|---|---|
| Samsung Electronics Co., Ltd. | Strong · 8 | Emerging · 1 | Absent | Emerging · 1 | Absent |
| Stockholm Water Tech AB | Strong · 8 | Emerging · 1 | Emerging · 1 | Absent | Absent |
| Jilin University | Strong · 4 | Absent | Absent | Absent | Moderate · 2 |
| Korea Institute of Civil Engineering and Building Technology | Strong · 3 | Strong · 2 | Moderate · 1 | Absent | Absent |
| Foshan Shunde Midea Water Dispenser Manufacturing Co., Ltd. | Strong · 4 | Absent | Absent | Absent | Absent |
| Midea Group Co., Ltd. | Strong · 4 | Absent | Absent | Absent | Absent |
| Nanyang Technological University | Strong · 3 | Absent | Absent | Absent | Absent |
Frequently asked questions
The corpus examined contains 50 patent families in scope, drawing on filings across major global patent offices including China, South Korea, the United States, and EPO.
Samsung Electronics and Stockholm Water Tech AB are joint leaders, each with 8 patent records. They are followed by Jilin University, Foshan Shunde Midea Water Dispenser Manufacturing, and Midea Group, each with 4 patent records.
China leads with 18 patent records, followed closely by South Korea with 17. The United States ranks third at 12 records, with Europe (EPO) and WIPO (PCT) each contributing 7 records.
C02F (water and wastewater treatment) is overwhelmingly dominant at 74 records. B01D (separation processes) is a distant second at 12 records, followed by C25B (electrolytic production of compounds) at 7 records.
The field is in a mature stage. Annual filings peaked in 2018 at 10 records and have since plateaued in a 4–6 record annual range. A 6% recent growth figure on a multi-year basis indicates the field is not contracting, but it is no longer in a rapid-accumulation phase.
Midea Group, Jilin University, and Foshan Shunde Midea Water Dispenser Manufacturing are all flagged as new entrants in the recent filing window, each with 4 recent patent records. Korea Institute of Civil Engineering and Building Technology is also a new entrant with 2 recent records.
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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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