Bipolar Battery State Estimation Patent Landscape 2026
Bipolar Battery State Estimation Patent Landscape in 2026
The bipolar battery state estimation patent space is highly concentrated, with Nissan Motor dominating the corpus and Japanese automotive and materials firms accounting for the majority of activity. The field is still expanding on a multi-year basis, though annual volume has eased from its 2022 peak and the most recent years are further understated by publication lag.
Nissan Motor leads a highly concentrated niche with limited independent challengers
Nissan Motor Co Ltd holds the top position in bipolar battery state estimation, ranking first among all filers. The top five filers together account for 84% of the hundred largest filers’ combined patent records, a level of concentration that signals a tightly controlled niche rather than a broadly contested technology area.
The tier gap below Nissan is substantial: the second-ranked filer, Subaru Corp, holds a materially smaller share of patent records, and the remaining ranked applicants each hold only one or two records. This means the competitive structure is essentially a single dominant player supported by a loose cluster of early-stage or niche participants.
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 1 | Nissan Motor Co Ltd | 18 | |
| 2 | Subaru Corp | 5 | |
| 3 | APB Corp | 2 | |
| 4 | Guangzhou Yangxin Technology Research Co Ltd | 1 | |
| 5 | Chongqing Qinxiong Motorcycle Sales Co Ltd | 1 | |
| 6 | Sanyo Chemical Industries Ltd | 1 | |
| 7 | Toyota Motor Corporation | 1 | |
| 8 | Denso Corporation | 1 | |
| 9 | Hangzhou Zhanhong Technology Co Ltd | 1 | |
| 10 | Firefly International Energy Co | 1 |
Nissan’s position implies deep, sustained commitment to bipolar battery system-level monitoring — spanning cell chemistry, power supply management, and vehicle integration — whereas the challengers are predominantly focused on narrower technical sub-problems such as electrical measurement or vehicle propulsion.
Filing counts for the most recent 18–24 months should be treated as provisional due to standard patent publication lag; apparent inactivity in 2024–2025 does not reflect actual R&D output. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Activity has grown on a multi-year basis, with core cell-chemistry and power-supply branches dominant
The annual filing trend and IPC technology composition together reveal a field that accelerated meaningfully from 2021 onward and is built primarily around battery cell fundamentals and power-supply integration, with vehicle-specific and measurement sub-classes occupying secondary positions.
Annual filing trend
Filings were negligible through 2020, rose noticeably in 2021–2022, and have eased since — consistent with the growth stage characterization of a field expanding on a multi-year basis from an earlier low base. The 2022 peak reflects the point of highest annual intensity. The apparent zero-count in 2024 and near-zero in 2025 should be read cautiously given publication lag, not as a real decline.
↗ Hover for values · click a bar to ask EurekaTechnology composition
H01M (batteries, cells and fuel cells) and H02J (power supply and grid systems) together dominate the IPC branch mix, reflecting that most work addresses fundamental cell architecture and charging/management integration. B60L (electric vehicle propulsion) and G01R (electric and magnetic measurement) form a secondary tier, confirming that state estimation for traction applications and sensing methods are meaningful but subordinate themes.
↗ 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.
Laminated battery
A bipolar battery (<b>2</b>) is constructed by laminating a plurality of bipolar electrodes (<b>3</b>), each constituted by a layer-form collector (<b>4</b>), a positive electrode active material layer (<b>5</b>) disposed on one surface of the collector (<b>4</b>), and a negative electrode active material layer (<b>6</b>) disposed on another surface of the… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Bipolar battery, battery pack with multiple bipola… | 48 |
| 2 | Bipolar battery, battery packs and a vehicle insta… | 31 |
| 3 | Bipolar Battery Having Carbon Foam Current Collect… | 22 |
| 4 | Bipolar battery | 16 |
| 5 | Bipolar battery and electric vehicle | 8 |
| 6 | Laminated battery | 7 |
| 7 | Power source control system for vehicle | 2 |
| 8 | Battery system | 2 |
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 positioning
A narrow, growth-stage corpus with one dominant incumbent and several new entrants presents both a fast-follower risk and a genuine opportunity for differentiated technical entry, particularly in adjacent sensing and protective-circuit branches that remain sparsely covered.
Early growth: multi-year expansion from a very low base, annual volume easing from 2022 peak
The lifecycle evidence places this field firmly in the Growth stage. Three-year recent filings sit well above the prior three-year window (100% growth), indicating the topic is still attracting new entrants and broadening technical scope. However, annual volume has eased from the 2022 peak, so the field is not yet in sustained high-volume production, and the most recent years remain understated by publication lag.
Growth stageSingle dominant incumbent with a fragmented challenger tier
The top five filers hold 84% of the hundred largest filers’ combined patent records, and Nissan alone represents the largest single share. The remaining ranked applicants each hold one or two records. For a new entrant, freedom-to-operate analysis should focus heavily on Nissan’s portfolio, while the challenger tier is thin enough that differentiated filings in adjacent branches could establish a meaningful position quickly.
High concentrationOne identified co-filing pair: APB Corp and Sanyo Chemical Industries
The only documented co-applicant relationship in this corpus is between APB Corp and Sanyo Chemical Industries, who share one co-filed record. This single collaboration suggests that inter-company IP development is nascent in this niche, and that most knowledge is being internalized rather than shared through formal joint filings. The ecosystem has not yet converged around a standard consortium model.
Low collaborationJapan and the United States are co-leading filing jurisdictions; China and Europe follow
Japan and the United States are tied as the leading filing destinations, each with 8 patent records, followed by China and Europe (EPO) with 5 each. Malaysia and Brazil appear as smaller outliers, suggesting early-stage international protection in emerging EV markets. The Japan-first pattern aligns with the dominance of Japanese automotive and materials firms in the applicant ranking.
Japan–US dual leadGo 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 |
|---|---|---|
| APB Corp | 三洋化成工业株式会社 | 1 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
Nissan Motor leads on cell chemistry and power management; Subaru enters on measurement and EV propulsion
Two organizations have established a meaningful multi-record position in this space. Nissan Motor anchors the field with deep coverage across cell-level and system-level classes, while Subaru Corp has emerged as a new entrant with a distinct focus on electrical measurement and vehicle propulsion integration.
Nissan Motor Co Ltd
Nissan holds the largest position in this corpus with 18 patent records. Its technical emphasis spans H01M 10 (battery cell fundamentals), H01M 50 (battery assembly and enclosures), and H02J 7 (charging and power supply management) — a combination that covers the full system stack from cell-level state monitoring to vehicle charging integration. No momentum trend data is listed for Nissan in the recent-vs-prior window, indicating its position predates the recent growth phase.
18 patent recordsSubaru Corp
Subaru holds 5 patent records and is classified as a new entrant (trend: ▲ new entrant) with 3 recent-period records. Its technical focus is distinctly differentiated from Nissan’s: Subaru’s filings concentrate on G01R 31 (electrical measurement and diagnostics), B60L 58 (EV-specific battery management), and B60K 6 (hybrid propulsion drive). This positions Subaru as a measurement-and-vehicle-integration specialist rather than a cell-chemistry incumbent.
5 patent records| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| 株式会社斯巴鲁 | 3 | ▲ new entrant |
| APB Corp | 1 | ▲ new entrant |
| Chongqing Qinxiong Motorcycle Sales Co Ltd | 1 | ▲ new entrant |
| 株式会社电装 | 1 | ▲ new entrant |
Under-served adjacent branches in protective circuits, thermal sensing, and variable control
Several IPC branches adjacent to the dominant H01M and H02J core are represented by only one or two patent records each, making them under-served relative to their technical relevance to bipolar battery state estimation in real-world deployment.
G01K · Temperature measurement
With only 2 patent records and a 3% share of IPC assignments, temperature measurement is sparsely covered despite its direct relevance to state-of-health estimation in bipolar battery stacks, where thermal gradients across bipolar plates are a known failure mode. APB Corp has filed in this branch. Entry here through thermal sensing algorithms or distributed temperature sensor integration could complement existing state-of-charge methods with limited overlap against the dominant portfolios.
Search this in Eureka →H02H · Protective circuit arrangements
H02H holds the lowest share in the corpus with 1 patent record and a 2% IPC assignment share, yet protective circuit design is directly relevant to fault detection and over-voltage monitoring in bipolar cell architectures. Denso Corp holds the one identified record in this branch. This represents an under-served intersection between state estimation outputs and real-time protection actuation — a plausible entry path for power electronics or BMS semiconductor suppliers.
Search this in Eureka →How leading filers differ across IPC technology routes
Strength of each leader across the main technology routes.
| Player | H01M 10 · Batteries, cells & fuel cells | H02J 7 · Power supply & grid systems | H01M 50 · Batteries, cells & fuel cells | H01M 2 · Batteries, cells & fuel cells | G01R 31 · Electric & magnetic measurement |
|---|---|---|---|---|---|
| 日产自动车株式会社 | Strong · 13 | Strong · 7 | Strong · 8 | Moderate · 6 | Absent |
| 株式会社斯巴鲁 | Moderate · 2 | Moderate · 2 | Absent | Absent | Strong · 5 |
| APB Corp | Strong · 2 | Strong · 2 | Absent | Absent | Absent |
Frequently asked questions
The evidence covers 12 patent families in scope globally. This is a small, specialized corpus reflecting the niche status of bipolar battery architectures relative to conventional lithium-ion battery management.
Nissan Motor Co Ltd is the leading filer with 18 patent records, well ahead of the second-ranked filer, Subaru Corp, which holds 5 patent records. The top five filers collectively account for 84% of the hundred largest filers’ combined records.
The field is in the Growth stage. Recent three-year filings are 100% above the prior three-year window, confirming multi-year expansion. However, annual volume has eased from its 2022 peak, and the most recent years are understated by publication lag.
Japan and the United States are tied as the leading filing destinations with 8 patent records each, followed by China and Europe (EPO) with 5 each. Malaysia and Brazil have smaller representation, suggesting early-stage protection in emerging EV markets.
One co-filing relationship is documented: APB Corp and Sanyo Chemical Industries share one co-filed record. Inter-company IP collaboration remains nascent in this niche, with most development internalized by individual applicants.
G01K (temperature measurement), H02H (protective circuit arrangements), and G05F (electric and magnetic variable control) each hold 2 or fewer patent records, representing 3% or less of IPC assignments. These branches are adjacent to the dominant H01M and H02J core and represent under-served technical areas worth monitoring for new entrants.
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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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