Cell Aging & Grading Patents: Who Leads, Where Gaps Are 2026
- Concentrated but not locked up. the top 5 assignees hold 47.1% of all 17 records in scope, and the leader files only 2 — there is no dominant blocker to design around.
- Filing nearly doubled in three years. from 2 records in 2021 to 4 in 2024 (+100%), with 2024 the peak year so far and China the overwhelming receiving office (15 of 17).
- Measurement and sorting overlap heavily. G01R electric measurement (58.8%) and B07C object sorting (6 of 17) both intersect H01M battery claims, showing grading is being claimed as an instrumented process, not just a battery spec.
Filing growth compares 2021 (2 records) with 2024 (4) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 17 records in scope (CR5), not by the ranked leaders only.
What this patent landscape covers
Cell aging and grading after formation covers the step where finished lithium-ion or sodium-ion cells sit in a controlled aging period, then get sorted into capacity or performance bins before pack assembly. The patent activity tracked here sits at the intersection of self-discharge screening, open-circuit-voltage measurement and sorting-criteria logic — the instrumentation and decision rules that turn a batch of freshly formed cells into graded, shippable inventory. This is a narrow, equipment-and-process-adjacent field rather than a battery-chemistry one: claims tend to describe measurement sequences, aging duration protocols, or sorting/regrouping methods rather than new cell materials.
The dataset in scope is small — 17 published records — which means single filings can meaningfully shift a company's ranking, and any percentage should be read against that denominator rather than treated as a market-wide statistic.
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Filing trends and technology composition
Two views of the same 17-record dataset: how filing activity has moved year over year, and which IPC subclasses the claims actually sit in.
Filing trend: a small but rising field
Annual filings moved from 2 records in 2017 to a peak of 4 in 2024, with 2021-2024 marking a +100% climb. Note that 2025 and 2026 figures are undercounted because publication typically lags filing by roughly 18 months — the apparent tail-off is a data artefact of the cut-off, not a real slowdown.
Where the claims concentrate
G01R (electric and magnetic measurement) touches 58.8% of records and H01M (batteries and cells) touches 52.9%, confirming that most filings pair a battery claim with a measurement method. B07C (object sorting) appears in 35.3% of records, showing that physical sorting/handling logic is claimed alongside the electrical criteria in over a third of the field. G01G (weighing) and G06F (data processing) each appear in a single record, marking them as thin, largely open branches rather than crowded ones.
Shares are the percentage of the 17 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Cell Aging and Grading After Formation with Eureka
This page is one run against one query. Ask Eureka your own question about cell aging and grading after formation and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited records in this dataset
A high safety sodium ion battery and its capacity grading method and application
Filed by Benan Energy Technology (Shanghai) Co., Ltd, this filing (SG10202401468RA) pairs a sodium-ion cell design with a capacity-grading method and its application, filed through the Singapore receiving office rather than China.One of only 2 records in this dataset routed through SG rather than CN, and dated close to the cut-off — a marker of where non-China filers are starting to stake claims in sodium-ion grading specifically.
View full filing| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | CN108172918A | 一种锂电池快速化成分容方法 | 21 |
| 2 | CN102903957A | 一种快速筛选磷酸铁锂电池自放电的方法 | 21 |
| 3 | CN114558800A | 一种动力电池梯次利用的筛选重组方法及系统 | 12 |
| 4 | CN113447838A | 一种锂电池自放电检测方法及装置 | 6 |
| 5 | CN117169749A | 电池容量预测模型的生成方法、预测方法及其装置 | 4 |
| 6 | CN113917347A | 评估电池自放电标准的方法 | 4 |
| 7 | CN115350953A | 锂离子电池筛选方法与装置、电子设备、存储介质 | 3 |
| 8 | CN110867557A | 一种锂离子电池二维码追溯方法 | 2 |
| 9 | CN119627269A | 可缩短K值测试周期的锂离子电池化成分容方法和应用 | 1 |
Citation counts favour older filings simply because they have had more time to be cited within the searched corpus — read them as a signal of influence on how the field's screening methods were framed, not as a ranking of current importance.
Patent titles are shown in the language they were filed in, not translated, so that each record stays verifiable against the original filing — a translated title will not match in Eureka or in any national register. Publication numbers are shown where the record carries one (9 of 9 rows); clicking a row searches Eureka by that number.
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Three readings of the same dataset, aimed at where to file, who to watch, and what is still open.
No single assignee dominates
The leader in this dataset holds only 2 records; the top 5 combined account for 47.1% of all 17 records in scope. That is meaningful concentration for a field this size, but it is not a blocking position — a well-drafted claim can still find room around any single leader's portfolio.
Growth is real but recent, and understated further out
Filings doubled from 2 in 2021 to 4 in 2024, the peak year recorded so far. Because publication lags filing by roughly 18 months, the 2025-2026 figures will fill in over time and should not yet be read as a plateau or decline.
Filing is overwhelmingly China-routed
China accounts for 15 of the 17 records in scope, with the remaining 2 routed through Singapore. That skew suggests the commercial pressure to formalise aging and grading protocols is currently concentrated in Chinese cell manufacturing, with only early signals of filing elsewhere.
Measurement and battery claims are usually paired
G01R (measurement) appears in 58.8% of records and H01M (batteries) in 52.9%; the overlap between them indicates that most applicants are claiming the measurement method and the battery context together rather than filing pure instrumentation patents.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to cell aging and grading after formation, with the prior art for and against each one.
Who is filing, and where the activity is thin
The ranked assignee list returned by the dataset covers 15 companies, counted in records — not a top-50 or top-100 cut, simply the full set the data endpoint returns for this search.
The top position is held narrowly
The leading assignee in this dataset holds 2 records, only one ahead of the field's fifth and tenth positions. That narrow spread is typical of an emerging process niche rather than a mature, consolidated one.
Recent-year activity is uneven across filers
Some assignees show a filing in the latest year while previously prominent names in this list show none, including one with a -100% year-on-year change. This is consistent with a small dataset where individual filing decisions move the picture year to year.
Co-filing is rare, not a network
Only one co-assignee pair appears in the dataset, linking a storage-technology unit with its parent energy company. That scarcity suggests most work here is being developed and filed in-house rather than through joint ventures.
| Assignee | Recent year | YoY |
|---|---|---|
| Chuzhou Guoxuan New Energy Power Co., Ltd. | 1 | — |
| Hubei EVE Power Co., Ltd. | 0 | — |
| Hefei Guoxuan High-Tech Power Energy Co., Ltd. | 0 | — |
| BENAN ENERGY TECHNOLOGY (SHANGHAI) CO LTD | 0 | — |
| SVOLT Energy Technology Co., Ltd. | 0 | — |
| Ruipu Lanjun Energy (REPT BATTERO) Co., Ltd. | 0 | -100% |
| Zhejiang Jinko Energy Storage Co., Ltd. | 0 | -100% |
| Jiangling Motors Corporation, Ltd. | 0 | — |
Where to take this analysis
The dataset points to a small but rising field with room to file around the current leaders — the next steps depend on whether you are clearing a specific claim or scanning for whitespace.
Check freedom to operate around the leader
With no assignee holding more than 2 records, a targeted clearance search against the top 5 combined (47.1% of the field) is more useful than a broad landscape scan.
Run a clearance search in EurekaTrack the sodium-ion grading angle
The most recent representative filing pairs sodium-ion chemistry with a grading method — an area with only 2 Singapore-routed records so far.
Monitor this branch in EurekaWatch the understated 2025-2026 years
Publication lag means the last two years of filings are still arriving; re-check the trend once more 2025 filings publish.
Set a filing alert in EurekaCommon questions about cell aging and grading patents
It refers to the post-formation stage where finished cells rest for a controlled period and are then sorted using measurements such as open-circuit voltage, self-discharge rate, or capacity. Patents in this dataset combine that measurement step with sorting criteria or aging-duration protocols. It sits between cell manufacturing and pack assembly, so filings often mix H01M battery language with G01R measurement claims and, in over a third of cases, B07C sorting-and-handling claims.
The dataset's ranked list covers 15 companies, and no single filer dominates: the leading assignee holds only 2 of the 17 records in scope, with the fifth- and tenth-ranked assignees each holding 1. The top 5 combined account for 47.1% of all records, and the top 10 combined reach 76.5%, so concentration exists but is spread across a fairly wide set of players rather than locked to one or two firms.
Filings grew from 2 records in 2021 to 4 in 2024, a +100% increase, with 2024 the highest single year recorded in the dataset so far. The 2025 and 2026 figures look lower, but that reflects the roughly 18-month lag between filing and publication rather than an actual decline — those years are still filling in as more filings publish.
The thinnest branches by record count are G01G (weighing-based approaches) and G06F (software/data-processing approaches to sorting), each appearing in only 1 of the 17 records, compared with 58.8% for G01R measurement claims. Sodium-ion-specific grading protocols and warehouse-footprint optimisation for aging racks also show minimal coverage in this dataset, making them reasonable areas to scout before assuming a crowded field.
Fifteen of the 17 records in scope were filed through the China receiving office, with the remaining 2 through Singapore. This concentration likely reflects where large-scale cell manufacturing and formation-line throughput pressures are currently most acute, pushing manufacturers there to formalise aging and grading protocols into filed patents sooner than manufacturers elsewhere.
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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.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.