Grid-Scale Energy Storage Patent Landscape 2026
Grid-Scale Energy Storage Patent Landscape in 2026
Sumitomo Electric Industries holds a commanding lead in a field that reached peak annual volume in 2023 and is still up on a multi-year basis, with the top five filers accounting for nearly a third of the hundred largest filers’ combined total. Activity is heavily concentrated in electrochemical cell and flow-battery technology, while adjacent branches such as power conversion and electrolytic synthesis remain comparatively sparse.
Sumitomo Electric leads a moderately concentrated field with a clear tier gap
The corpus spans 13,363 patent families. Ranked by patent families, Sumitomo Electric Industries holds first place with 1,681 families — more than double the second-ranked filer, Lockheed Martin Advanced Energy Storage at 645 families.
The top five filers — Sumitomo Electric, Lockheed Martin Advanced Energy Storage, Dalian Institute of Chemical Physics, ESS Tech, and LG Chem — together account for roughly 30% of the hundred largest filers’ combined total, signalling moderate concentration with a pronounced tier gap between the leader and the rest of the field.
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 1 | Sumitomo Electric Industries Ltd | 1,681 | |
| 2 | Lockheed Martin Advanced Energy Storage LLC | 645 | |
| 3 | Dalian Institute of Chemical Physics, Chinese Academy of Sciences | 556 | |
| 4 | ESS Tech Inc | 463 | |
| 5 | LG Chem Ltd | 434 | |
| 6 | Dalian Rongke Power | 274 | |
| 7 | Lotte Chemical Corp | 268 | |
| 8 | State Grid Corporation of China | 267 | |
| 9 | The Kansai Electric Power Co | 243 | |
| 10 | UOP LLC | 193 |
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 11 | LG Energy Solution Ltd | 192 | |
| 12 | GRST International Ltd | 187 | |
| 13 | Resonac Holdings Corp | 183 | |
| 14 | RTX Corp | 153 | |
| 15 | Panasonic Intellectual Property Management Co Ltd | 152 | |
| 16 | Battelle Memorial Institute | 146 | |
| 17 | United Technologies Corp | 142 | |
| 18 | Asahi Kasei Corp | 136 | |
| 19 | Korea Institute of Energy Research | 132 | |
| 20 | China Electric Power Research Institute Co Ltd | 131 |
Sumitomo’s scale reflects decades of commitment to vanadium redox flow battery technology, giving it broad blocking positions across cell chemistry, stack design, and membrane materials; challengers and newcomers must navigate or design around this dense portfolio cluster.
Applicant rankings and the corpus total are measured in patent families. Technology-branch (IPC), route-matrix, and jurisdiction figures are at the patent-record level — one family can carry several IPC classes or be filed across multiple offices, so those counts can exceed the family total and the two measures are not directly comparable. The most recent 18–24 months of filing data are under-counted due to publication lag.
Annual volume plateaued near its 2023 peak; electrochemical cells dominate the technology mix
The filing trend and technology-composition charts together show where investment has gone and how activity has evolved: a field that grew meaningfully over the multi-year window but has plateaued at the record level, overwhelmingly focused on core battery and cell technology with adjacent branches still lightly populated.
Annual filing trend
Annual family filings grew from 2017 through a 2023 peak, consistent with a maturing field still ahead of its long-run average on a multi-year basis. Volume in 2024 eased from the 2023 high; 2025 and 2026 figures are materially under-counted due to publication lag and should not be read as a continued decline.
↗ Hover for values · click a bar to ask EurekaTechnology composition
H01M (batteries, cells, and fuel cells) dominates the patent-record mix by a wide margin, reflecting the field’s deep grounding in electrochemical storage chemistry. H02J (power supply and grid systems) is the second most active branch, followed by smaller clusters in electrolytic production, measurement, polymer processing, and vehicle propulsion — each representing a fraction of H01M activity.
↗ Hover for values · click a bar to ask EurekaFoundational and most-cited patents
The most-cited families that anchor this space. Hover a row and click to open it in Eureka.
Redox flow battery system for distributed energy s…
A large stack redox flow battery system provides a solution to the energy storage challenge of many types of renewable energy systems. Independent reaction cells arranged in a cascade configuration are configured according to state of charge conditions expected in each cell. The large stack redox flow battery system can support multi-megawatt… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Apparatus and method for use in storing energy | 841 |
| 2 | Battery energy storage power conditioning system | 268 |
| 3 | High energy density redox flow device | 236 |
| 4 | Redox flow battery system and cell stack | 235 |
| 5 | Cascade Redox Flow Battery Systems | 227 |
| 6 | High energy density vanadium electrolyte solutions… | 219 |
| 7 | Electrochemical Energy Storage Systems and Methods | 218 |
| 8 | A monitoring system and method for megawatt level … | 204 |
Ranked by total forward citations. Citation counts accrue over time, so this list favours older, broadly-cited patents and may include general-purpose work beyond the specific topic; treat it as foundational context rather than a current-activity ranking.
What the competitive structure means for R&D investment decisions
The combination of a maturing life cycle, moderate top-tier concentration, strong co-development activity among incumbents, and US-led jurisdictional coverage shapes the risk and opportunity profile for new entrants and established players alike.
Field has reached maturity: annual volume plateaued near the 2023 peak
The lifecycle assessment categorises grid-scale energy storage as Mature, with annual filings having plateaued near their 2023 peak. The multi-year window still reflects net growth of approximately 20%, but the era of rapid year-on-year expansion has passed. New entrants face a high prior-art density and should expect intensive freedom-to-operate analysis before filing in core electrochemical cell subclasses.
Mature · peaked 2023Moderate concentration with a sharp leader gap and active mid-tier
The top five filers hold roughly 30% of the hundred largest filers’ combined family total, indicating moderate overall concentration. However, Sumitomo Electric’s 1,681 families versus Lockheed Martin Advanced Energy Storage’s 645 represents a pronounced intra-tier gap at the top. A diverse mid-tier — including national labs, utilities, chemical companies, and start-ups — keeps the field competitive below the leader level and suggests room for targeted niche strategies.
Moderate concentrationSumitomo Electric anchors the most active co-filing network, primarily with Japanese utilities and materials partners
The most active co-filing pair is Sumitomo Electric Industries and Kansai Electric Power, with 195 jointly filed families — by far the largest collaborative cluster in the dataset. Sumitomo Electric also co-files with Toyobo, Toyobo MC, Teijin, and Asahi Kasei Electronic Materials. A second cluster links Dalian Institute of Chemical Physics with Dalian Rongke Power (25 families), and Lotte Chemical co-files with Korea Advanced Institute of Science and Technology and with ZBB Energy. These patterns indicate that utility-manufacturer and research institute-commercialiser partnerships are the dominant collaborative model.
Utility–manufacturer pairsUS leads filing activity at the patent-record level; China and EPO follow closely
At the patent-record level, the United States is the leading jurisdiction, followed by China and Europe (EPO). WIPO PCT filings are substantial, indicating broad international protection strategies among top filers. Australia and South Korea also register meaningful activity. Coverage in emerging energy markets — Brazil, Southeast Asia, the Middle East — remains sparse, which may reflect either limited local demand or an early-mover opportunity for applicants targeting those deployment regions.
US-led, global reachGo 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 |
|---|---|---|
| Sumitomo Electric Industries Ltd | The Kansai Electric Power Co | 195 |
| Dalian Institute of Chemical Physics, Chinese Academy of Sciences | Dalian Rongke Power | 25 |
| Sumitomo Electric Industries Ltd | Toyobo Co Ltd | 20 |
| Sumitomo Electric Industries Ltd | Toyobo MC Co Ltd | 13 |
| Sumitomo Electric Industries Ltd | Teijin Ltd | 12 |
| Sumitomo Electric Industries Ltd | Garlock Holdings Inc | 9 |
| Lotte Chemical Corp | Korea Advanced Institute of Science and Technology (KAIST) | 9 |
| Sumitomo Electric Industries Ltd | Asahi Kasei Electronic Materials Corp | 8 |
| Lotte Chemical Corp | ZBB Energy Corp | 7 |
| Lotte Chemical Corp | SUNGSHIN WOMENS UNIV IND ACADEMIC COOP FOUND | 7 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
Sumitomo Electric leads on volume; ESS Tech and UOP LLC show the strongest recent momentum
The applicant ranking is measured in patent families. The top two positions are held by specialists in flow-battery and long-duration electrochemical storage, while momentum data reveal diverging trajectories across the leading group.
Sumitomo Electric Industries
With 1,681 patent families, Sumitomo Electric Industries holds a portfolio nearly 2.6 times larger than the second-ranked filer. Its technology focus is concentrated overwhelmingly in H01M 8 (fuel cells and redox flow cells), with secondary positions in H01M 4 (electrodes) and H01M 10 (secondary batteries). Recent filing momentum has eased sharply (down approximately 43% in the recent window versus the prior period), consistent with a mature, deeply established position rather than aggressive expansion. Its co-development relationship with Kansai Electric Power — 195 jointly filed families — reinforces its utility-scale deployment orientation.
families: 1,681ESS Tech
ESS Tech holds 463 patent families and ranks fourth overall. Its technology focus mirrors the field leader — strongest in H01M 8, with secondary coverage in H01M 4 and H02J 7 (grid power management) — but its recent filing momentum is positive at approximately +15% versus the prior period, suggesting active portfolio expansion. The H02J 7 presence, absent in Sumitomo’s top sub-classes, indicates ESS Tech is extending IP coverage toward grid-interface and power-management functionality alongside core cell chemistry.
families: 463| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| Sumitomo Electric Industries Ltd | 97 | ▼ -43% |
| Lockheed Martin Advanced Energy Storage LLC | 56 | ▲ +19% |
| ESS Tech Inc | 181 | ▲ +15% |
| LG Chem Ltd | 1 | ▼ -98% |
| Lotte Chemical Corp | 1 | ▼ -95% |
| Dalian Institute of Chemical Physics, Chinese Academy of Sciences | 43 | ▲ +16% |
| UOP LLC | 126 | ▲ +117% |
Under-served adjacent branches in power conversion, electrolytic synthesis, and grid measurement
Several IPC classes adjacent to the dominant H01M cluster carry patent-record counts that are small relative to the overall corpus. These are observations of relative sparsity; they qualify as candidate opportunities only where there is also plausible technical value and a realistic entry path.
H02M · Power conversion (AC/DC, DC/DC, inverters)
H02M accounts for 454 patent records — roughly one forty-second the volume of H01M. Grid-scale storage systems inherently require power conversion at both charge and discharge; the sparse coverage here suggests that converter topology, efficiency optimisation, and integration architectures for large battery banks are not being claimed as aggressively as the electrochemical core. For engineers working on system-level integration, this branch presents a plausible area where focused filings could achieve differentiated positioning.
Search this in Eureka →C25B · Electrolytic production of compounds
C25B carries 600 patent records, primarily adjacent to flow-battery electrolyte and hydrogen production contexts. As grid-scale storage increasingly intersects with green hydrogen and electrolytic synthesis of energy carriers, this branch sits at a technically coherent convergence point. The record count is low relative to H01M, and the field is less entrenched, offering a potential entry path for applicants combining electrochemical storage expertise with electrolysis process engineering — though commercial readiness of grid-coupled electrolysis remains an open question.
Search this in Eureka →How leading applicants differ by technology sub-class emphasis
Strength of each leader across the main technology routes.
| Player | H01M 8 · Batteries, cells & fuel cells | H01M 10 · Batteries, cells & fuel cells | H01M 4 · Batteries, cells & fuel cells | H02J 3 · Power supply & grid systems | H02J 7 · Power supply & grid systems |
|---|---|---|---|---|---|
| Sumitomo Electric Industries Ltd | Strong · 1,492 | Emerging · 112 | Emerging · 265 | Absent | Emerging · 25 |
| Lockheed Martin Advanced Energy Storage LLC | Strong · 490 | Emerging · 92 | Moderate · 138 | Absent | Absent |
| ESS Tech Inc | Strong · 419 | Absent | Emerging · 67 | Absent | Absent |
| LG Chem Ltd | Strong · 313 | Moderate · 66 | Moderate · 99 | Absent | Absent |
| The Kansai Electric Power Co | Strong · 203 | Moderate · 85 | Absent | Absent | Absent |
| Resonac Holdings Corp | Strong · 175 | Absent | Strong · 92 | Absent | Absent |
| GRST International Ltd | Absent | Strong · 130 | Strong · 85 | Absent | Absent |
Frequently asked questions
The corpus covers 13,363 patent families globally. Applicant rankings and the corpus total are measured at the patent-family level; technology-branch and jurisdiction counts are at the patent-record level and can exceed the family total because one family may be filed in multiple offices or classified under multiple IPC codes.
Sumitomo Electric Industries leads with 1,681 patent families — approximately 2.6 times the second-ranked filer, Lockheed Martin Advanced Energy Storage, which holds 645 families. This gap reflects Sumitomo’s decades-long commitment to vanadium redox flow battery technology.
The field is assessed as Mature. Annual filing volume plateaued near the 2023 peak; the multi-year window still reflects approximately 20% growth, but year-on-year expansion has levelled off. New entrants face high prior-art density, particularly in core H01M electrochemical cell subclasses.
At the patent-record level, the United States is the leading jurisdiction, followed by China and Europe (EPO). WIPO PCT filings are also substantial. These figures are at the patent-record level; a single family can be filed in multiple offices, so jurisdiction totals exceed the family count.
Among the top filers tracked, UOP LLC shows the strongest recent momentum at approximately +117% versus the prior period — though this likely reflects a small prior base. ESS Tech (+15%) and Lockheed Martin Advanced Energy Storage (+19%) show positive but more moderate growth. By contrast, LG Chem (-98%) and Lotte Chemical (-95%) have seen sharp recent reductions, and Sumitomo Electric has eased by approximately 43%.
The most active co-filing pair is Sumitomo Electric Industries and Kansai Electric Power, with 195 jointly filed families. Sumitomo Electric also co-files with Toyobo, Toyobo MC, Teijin, and Asahi Kasei Electronic Materials. A second notable cluster links Dalian Institute of Chemical Physics with Dalian Rongke Power (25 families). These utility-manufacturer and research-institute-commercialiser pairings are the dominant collaborative model in the field.
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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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