CDI Water Treatment Patent Landscape 2026
The CDI water treatment patent field is in a growth stage, with Samsung Electronics holding the lead position among a moderately concentrated set of corporate and institutional filers. China and South Korea together dominate filing activity, and the technology mix remains anchored in core water treatment processes with meaningful adjacent white space in electrode materials and electrolytic production.
Samsung leads a moderately concentrated field with strong Korean and Chinese participation
Samsung Electronics heads the applicant ranking with 81 patent records, followed by Siontech with 68 and Doosan Heavy Industries and Construction with 51. The top five filers — Samsung Electronics, Siontech, Doosan Heavy Industries and Construction, Unilever NV, and Kyungdong Navien — together account for 24% of the combined total among the hundred largest filers.
The 24% top-five share among the hundred largest filers indicates moderate rather than extreme concentration: no single player commands a dominant bloc, and the second through sixth ranked applicants are clustered within a relatively narrow band of 45–68 patent records each. This leaves meaningful room for challengers to establish differentiated positions.
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 1 | Samsung Electronics Co., Ltd. | 81 | |
| 2 | Siontech Co., Ltd. | 68 | |
| 3 | DOOSAN HEAVY IND & CONSTR CO LTD | 51 | |
| 4 | Unilever NV | 48 | |
| 5 | Kyungdong Navien Co., Ltd. | 45 | |
| 6 | Coway Co., Ltd. | 45 | |
| 7 | Foshan Shunde Midea Water Dispenser Manufacturing Co., Ltd. | 38 | |
| 8 | Midea Group Co., Ltd. | 38 | |
| 9 | Unilever PLC | 31 | |
| 10 | Lawrence Livermore National Security LLC | 31 |
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 11 | Enpar Technologies Inc. | 24 | |
| 12 | Tongji University | 21 | |
| 13 | Korea Institute of Energy Research | 18 | |
| 14 | Ecolab USA Inc. | 18 | |
| 15 | Voltea | 17 | |
| 16 | The Regents of the University of California | 17 | |
| 17 | Stockholm Water Technology AB | 16 | |
| 18 | Jacon | 14 | |
| 19 | DWI Leibniz Institute for Interactive Materials | 13 | |
| 20 | Shell Internationale Research Maatschappij BV | 12 |
Samsung’s lead, combined with the presence of Korean industrials (Siontech, Doosan, Kyungdong Navien, Coway) and Chinese appliance manufacturers (Midea Group, Foshan Shunde Midea), signals that the competitive frontier spans both component-level CDI technology and consumer/commercial water-treatment product integration.
Filing counts for the most recent 18–24 months are under-represented due to standard patent publication lag; the field’s true recent activity is higher than raw counts suggest. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Annual filings rising with core treatment processes dominant; electrode and electrolytic branches offer adjacent entry
The filing trend and technology composition together reveal a field in active growth with a well-defined primary cluster and several lower-density adjacent branches that are technically proximate to the core.
Annual filing trend
Annual filings have trended upward across the window, with the 2024 cohort recording the highest single-year count observed. The 2025 and 2026 figures are materially under-counted due to publication lag and should not be read as a slowdown; the evidence confirms the field remains in a growth stage with a 30% recent-window increase.
↗ Hover for values · click a bar to ask EurekaTechnology composition
C02F (water and wastewater treatment) is the dominant IPC class by a wide margin, reflecting the core CDI application focus. B01D (separation processes) is the next largest cluster. The third through fifth branches — C25B (electrolytic production), H01G (capacitors), and B01J (chemical and physical processes) — are proportionally smaller, representing adjacent technical foundations for electrode and cell design that remain comparatively under-filed.
↗ 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 electrode comprising activ…
Disclosed herein are a capacitive deionization electrode including activated waste coffee grounds, a method of manufacturing the same, and a water-treatment apparatus including the same. The capacitive deionization electrode includes activated waste coffee grounds having a large specific surface area and an appropriate pore size distribution. The… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Method and apparatus for capacitive deionization a… | 368 |
| 2 | Method and apparatus for capacitive deionization, … | 301 |
| 3 | Method and apparatus for capacitive deionization a… | 267 |
| 4 | Fabricating solid carbon porous electrodes from po… | 179 |
| 5 | Method and apparatus for integrated water deioniza… | 143 |
| 6 | Replaceable flow-through capacitors for removing c… | 138 |
| 7 | Apparatus for integrated water deionization, elect… | 130 |
| 8 | Means for limiting and ameliorating electrode shor… | 120 |
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 observations — maturity stage, concentration, collaboration networks, and geographic footprint — each carry distinct implications for where new entrants or incumbents can most efficiently deploy R&D resources.
Growth stage: annual filings rising with a 30% recent-window increase
The lifecycle evidence classifies CDI water treatment as a Growth stage field. Annual filing volume has increased 30% over the recent window and the 2024 cohort is the highest on record. The field has not yet reached a plateau, meaning early mover advantages in emerging sub-segments are still available but the window is narrowing as incumbents consolidate positions.
Growth stageModerate concentration: top five hold 24% share among the hundred largest filers
With 24% of the hundred-largest-filer total held by five applicants, no single player has locked up the landscape. The second through sixth ranked filers are tightly grouped, suggesting the competitive order can shift with sustained filing programs. New entrants with differentiated electrode or system architectures can realistically enter the ranking within a few years.
Moderate concentrationMidea Group and Foshan Shunde Midea are the most active co-filers, followed by the Unilever entities
The strongest co-filing pair is Midea Group and Foshan Shunde Midea Water Dispenser Manufacturing, with 38 joint records — reflecting integrated product development across a parent and manufacturing subsidiary. Unilever NV and Unilever PLC co-file on 19 records, and Unilever NV also collaborates with Conopco on 5 records. Siontech and Kyungdong Navien share 15 joint records, indicating a supply-chain or licensing partnership in the Korean market. Samsung Electronics co-files with Handok Clean Tech (4 records), Sungkyunkwan University (3 records), Korea University (2 records), and Pohang University of Science and Technology (2 records), spanning industrial and academic channels.
Ecosystem partnershipsChina is the lead filing jurisdiction; South Korea and the US are secondary hubs
China accounts for the largest share of patent records among all jurisdictions, followed by South Korea and the United States. Europe (EPO) and WIPO (PCT) filings indicate that leading applicants are seeking multi-regional protection, particularly in the Korean and Chinese applicant cohorts. Markets such as India, Australia, and Canada have meaningful but smaller filing counts, suggesting selective international prosecution strategies rather than blanket global coverage.
Asia-Pacific ledGo 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. | 38 |
| Unilever NV | Unilever PLC | 19 |
| Siontech Co., Ltd. | Kyungdong Navien Co., Ltd. | 15 |
| Unilever NV | Conopco Inc. | 5 |
| Unilever PLC | Conopco Inc. | 5 |
| Samsung Electronics Co., Ltd. | Handok Clean Tech Co., Ltd. | 4 |
| Samsung Electronics Co., Ltd. | Sungkyunkwan University Industry-Academic Cooperation Foundation | 3 |
| Siontech Co., Ltd. | Kyungdong Navien | 3 |
| Samsung Electronics Co., Ltd. | Korea University Research and Business Foundation | 2 |
| Samsung Electronics Co., Ltd. | Pohang University of Science and Technology Industry-Academic Cooperation Foundation | 2 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
Samsung Electronics and Siontech lead by volume, with Midea Group surging as a new entrant
The applicant ranking reveals two tiers: an established Korean-led front group anchored in core C02F treatment methods, and a rapidly emerging Chinese appliance cohort entering with new-entrant momentum. Trajectory signals differ sharply between the two.
Samsung Electronics
Samsung Electronics holds the top position with 81 patent records. Its technology emphasis is concentrated in C02F 1 (water and wastewater treatment, 81 records), with secondary coverage in B01D 61 (separation processes, 14 records) and C25B 11 (electrolytic production, 8 records). Its momentum trend is marked as a new entrant in the most recent period, with 15 recent records — suggesting a renewed or refocused filing program after an earlier active phase. Co-filing relationships with Sungkyunkwan University, Korea University, and Pohang University of Science and Technology indicate continued engagement with academic electrode research.
patent records: 81Midea Group
Midea Group ranks eighth overall with 38 patent records and files jointly with its manufacturing affiliate Foshan Shunde Midea Water Dispenser Manufacturing, which also holds 38 records. Both entities show a new-entrant momentum signal with 36 recent records each — indicating that virtually all of their portfolio has been filed in the most recent period, representing the sharpest growth ramp among tracked applicants. Their technology focus is also centered on C02F 1 (38 records) with additional coverage in C02F 101 and C02F 9, reflecting a consumer product integration orientation rather than fundamental electrode science.
patent records: 38| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| Samsung Electronics Co., Ltd. | 15 | ▲ new entrant |
| Siontech Co., Ltd. | 1 | ▼ -97% |
| Midea Group Co., Ltd. | 36 | ▲ new entrant |
| Foshan Shunde Midea Water Dispenser Manufacturing Co., Ltd. | 36 | ▲ new entrant |
Electrolytic production and capacitor materials are under-served relative to the core treatment class
Several IPC branches appear adjacent to the dominant C02F core but hold materially lower filing shares. Two branches stand out as having plausible technical value and realistic entry paths for CDI-focused filers.
C25B · Electrolytic production of compounds
C25B covers electrolytic cell design and compound production processes directly relevant to CDI electrode and regeneration chemistry. With a 5% share among tracked branches, it is substantially below the C02F core, yet Siontech — the second-ranked applicant — shows notable overlap here with 22 records in C25B 11, suggesting technical adjacency is real. For a new entrant with electrode chemistry expertise, filing in C25B alongside C02F could establish a differentiated position in CDI cell architecture that the majority of applicants have not staked out.
Search this in Eureka →H01G · Capacitors
H01G covers capacitor design and materials, which are directly foundational to CDI electrode performance. At a 4% share of the corpus, this branch is sparse relative to the scale of the underlying technology’s dependence on high-surface-area carbon capacitor electrodes. Unilever PLC has 10 records in H01G 11, and Lawrence Livermore National Security appears in this space via its porous carbon electrode work reflected in top-cited patents. An entrant with advanced carbon materials or pseudocapacitive electrode expertise could find this branch comparatively open, with top-cited prior art concentrated in a small number of foundational references.
Search this in Eureka →How leading applicants differ across CDI technology routes
Route coverage across the main technology branches in the current evidence set.
| Player | C02F 1 · Water & wastewater treatment | C02F 103 · Water & wastewater treatment | C02F 101 · Water & wastewater treatment | B01D 61 · Separation processes (filtration etc.) | C25B 11 · Electrolytic production of compounds |
|---|---|---|---|---|---|
| Samsung Electronics Co., Ltd. | Strong · 81 | Absent | Absent | Emerging · 14 | Emerging · 8 |
| Siontech Co., Ltd. | Strong · 68 | Absent | Absent | Absent | Moderate · 22 |
| Doosan Heavy Industries & Construction Co., Ltd. | Strong · 54 | Moderate · 17 | Absent | Emerging · 10 | Emerging · 5 |
| Unilever NV | Strong · 54 | Moderate · 11 | Moderate · 11 | Absent | Absent |
| Foshan Shunde Midea Water Dispenser Manufacturing Co., Ltd. | Strong · 38 | Absent | Strong · 22 | Absent | Absent |
| Midea Group Co., Ltd. | Strong · 38 | Absent | Strong · 22 | Absent | Absent |
| Korea Institute of Energy Research | Strong · 23 | Moderate · 7 | Absent | Strong · 15 | Emerging · 4 |
Frequently asked questions
Samsung Electronics holds the top position with 81 patent records in the CDI water treatment corpus, followed by Siontech with 68 and Doosan Heavy Industries and Construction with 51.
China is the leading jurisdiction by patent records, followed by South Korea and the United States. Europe (EPO) and WIPO (PCT) are the next most active, indicating that major applicants pursue multi-regional protection strategies.
The field is classified as Growth stage with a 30% increase in the recent filing window. The 2024 annual cohort is the highest on record. Filing counts for 2025 and 2026 are under-represented due to publication lag and do not reflect a slowdown.
C02F (water and wastewater treatment) is the dominant IPC class by a large margin. B01D (separation processes) is the second largest cluster, followed by C25B (electrolytic production), H01G (capacitors), and B01J (chemical and physical processes).
Yes. The most active co-filing pair is Midea Group and Foshan Shunde Midea Water Dispenser Manufacturing with 38 joint records. Unilever NV and Unilever PLC share 19 records, and Siontech and Kyungdong Navien co-file on 15 records. Samsung Electronics also maintains academic co-filing relationships with Sungkyunkwan University, Korea University, and Pohang University of Science and Technology.
C25B (electrolytic production of compounds) and H01G (capacitors) are the most technically proximate branches with materially lower filing shares relative to the dominant C02F core — 5% and 4% respectively. Both are foundational to CDI electrode and cell design, and filing activity in these branches is concentrated among a small number of applicants, leaving room for differentiated entrants.
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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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