Lithium-Sulfur Battery Formation Process Patents: Leaders & Trends 2026
- Filing has cooled since its 2017 peak of 39 records, with a partial 2026 count of just 1 — a sign the field has consolidated around known activation routes rather than expanding into new ones.
- H01M dominates at 265 of 309 records, but C01B (67) and H01G (44) show meaningful overlap into sulfur chemistry and capacitor-adjacent activation methods.
- Recent-year momentum has gone flat across every major assignee, including LG Chem, LG Energy Solution and Sion Power, all showing zero filings in the latest tracked year.
What this landscape covers
This landscape tracks patent families describing formation cycling, SEI formation and activation processes specific to lithium-sulfur batteries — the initial-cycle protocols used to stabilize the sulfur cathode and lithium anode interface before a cell enters normal service. The search spans 309 patent families filed between 2015 and mid-2026, capturing both dedicated Li-S activation methods and adjacent electrolyte and electrode work claimed alongside them.
Because publication typically lags filing by around 18 months, the most recent year of data understates real filing activity; the apparent decline toward 2026 should be read with that lag in mind rather than as a confirmed collapse in interest.
Filing trend and technology composition
Two views of the same 309 families: how filing volume has moved year over year, and which IPC subclasses the claims actually sit in.
A peak in 2017, then a plateau
Filings peaked at 39 in 2017, held near the midpoint value of 32 by 2022, and have not shown renewed growth since. This pattern is consistent with a technology area where core activation protocols were staked out early and subsequent filings refine rather than expand the claim space.
Concentrated in batteries, with sulfur chemistry and capacitor overlap
H01M (batteries, cells & fuel cells) accounts for 265 of 309 records, confirming this is fundamentally a battery-manufacturing dataset. C01B (67) reflects the non-metallic/inorganic compound chemistry inherent to sulfur cathodes, while H01G (44) points to meaningful cross-filing into capacitor-adjacent electrode and electrolyte work. Smaller counts in H01B, B01J, C09C, G01R and C08G mark narrower, more specialized activation-adjacent claims.
Shares are the percentage of the 309 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Lithium-Sulfur Battery Formation Process with Eureka
This page is one run against one query. Ask Eureka your own question about lithium-sulfur battery formation process and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited prior art and a representative recent filing
EP4657594A1 — Manufacturing method for a lithium-sulfur battery (LG Energy Solution)
The disclosure covers a method for manufacturing a lithium-sulfur battery through an activation process based on initial discharge. It specifies activation via constant voltage (CV) discharge performed before the initial charge step, a sequencing choice the filing states can significantly reduce initial discharge time during activation.Filed by LG Energy Solution Ltd., published 2025-12-03.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20110052998A1 | Sulfur-carbon nanocomposites and their application as cathode materials in lithium-sulfur batteries | 168 |
| 2 | US20110076572A1 | Non-aqueous electrolytes for electrochemical cells | 150 |
| 3 | US20150236322A1 | Electrode protection using electrolyte-inhibiting ion conductor | 125 |
| 4 | US20120081838A1 | Enhanced packing of energy storage particles | 107 |
| 5 | US8654507B2 | Enhanced packing of energy storage particles | 106 |
| 6 | US20140255780A1 | Electrochemical cells comprising fibril materials, such as fibril cellulose materials | 99 |
| 7 | US9490478B2 | Electrochemical cells comprising fibril materials | 80 |
| 8 | US9653750B2 | Electrode protection using a composite comprising an electrolyte-inhibiting ion conductor | 73 |
| 9 | US20150236320A1 | Electrode protection using a composite comprising an electrolyte-inhibiting ion conductor | 68 |
| 10 | WO2013066448A2 | Polymer-sulfur composite materials for electrodes in li-s energy storage devices | 58 |
Citation counts favour older filings simply because they have had more time to accumulate citations within the searched corpus — treat this table as a map of influential prior art, not of current filing activity.
Each row carries its publication number; clicking a row searches Eureka by that number.
Put your own technology through the same analysis
Eureka on the web
When you want the answer in the next five minutes.
The agent works the prompt against patents and technical literature, citing every source.
Run your analysis now →MCP server & REST API
When it has to run inside your own pipeline.
Patent search, landscape analysis and assignee resolution as MCP tools. Drop them into any agent framework, or call REST directly.
Browse MCP servers →What the numbers imply for strategy
Three observations that shape where to file, cite and watch.
Peak filing is behind this field, not ahead of it
The 2017 peak of 39 filings, followed by a 2022 midpoint of 32 and a near-empty 2026 count, describes a technology that has already been substantially claimed. New entrants should expect to build around existing activation-protocol claims rather than stake out fresh, uncontested ground in the core H01M space.
Even the most active filers have gone quiet
LG Chem, LG Energy Solution, Sion Power, the University of California, University of Michigan and E2 Delaware all show zero filings in the most recent tracked year. That flatness across the whole leaderboard — not just one firm slowing down — suggests either a genuine lull or a publication-lag gap not yet visible in the data.
Core battery claims dominate, chemistry and capacitor claims trail
With 67 records in C01B and 44 in H01G, a meaningful minority of filings frame activation and formation work through sulfur chemistry or capacitor-adjacent language rather than pure battery-cell claims. That framing gap is worth checking before assuming a search under H01M alone is complete.
Collaboration is limited but concentrated
Only six co-assignee pairs appear in the dataset, with the strongest pairing linking E2 Delaware and the Spanish National Research Council (CSIC) at 9 shared families. This points to a handful of durable research partnerships rather than a broad collaborative ecosystem.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to lithium-sulfur battery formation process, with the prior art for and against each one.
Assignees and where the claim space still has room
Filing activity concentrates among a small group of battery makers and university research offices, with collaboration limited to a few durable pairings.
LG Chem and LG Energy Solution lead historical volume, but have gone quiet
Both entities show zero filings in the most recent tracked year, alongside a -100% YoY figure for LG Energy Solution. Their historical volume still anchors the field's core activation-protocol claims, evidenced by the recent EP4657594A1 filing on CV-discharge activation sequencing.
E2 Delaware pairs closely with academic sulfur-chemistry research
The strongest co-assignee pairing in the dataset links E2 Delaware with the Spanish National Research Council (CSIC), suggesting a sustained joint effort on sulfur-cathode materials feeding into activation-process claims.
University research offices hold steady but not growing positions
Both the University of California and University of Michigan boards of regents appear among tracked assignees with zero filings in the latest year, indicating mature patent portfolios rather than active new prosecution in this specific niche.
| Assignee | Recent year | YoY |
|---|---|---|
| LG Chem, Ltd. | 0 | — |
| LG Energy Solution, Ltd. | 0 | -100% |
| Sion Power Corporation | 0 | — |
| The Regents of the University of California | 0 | — |
| The Regents of the University of Michigan | 0 | — |
| II-VI Delaware, Inc. | 0 | — |
| Li-S Energy Ltd. | 0 | — |
| Leyden Energy, Inc. | 0 | -100% |
Where to take this analysis
The trend and assignee data point to a mature but not closed claim landscape. These are reasonable next steps for a deeper technical or freedom-to-operate review.
Map claims against the under-claimed branches
Cross-check specific claim language in the C01B, H01G and H01B overlap areas against your own process steps before assuming H01M coverage alone is decisive.
Explore white space in EurekaWatch for the 18-month publication lag to resolve
The 2025-2026 filing counts will fill in over the next 12-18 months; re-check momentum figures for LG Energy Solution and other recent filers once later publications land.
Track assignee momentum in EurekaReview the CV-discharge activation claims directly
EP4657594A1 sets out a specific constant-voltage discharge sequencing step; anyone designing an activation protocol should compare their own discharge sequencing against its claim scope.
Open the full record in EurekaCommon questions about this landscape
These are patents covering the initial-cycle steps used to stabilize a lithium-sulfur cell before normal operation, including formation cycling protocols, SEI (solid electrolyte interphase) formation methods, and activation sequences such as controlled initial charge or discharge. This dataset captures 309 patent families matching that scope, filed between 2015 and mid-2026. Most are classified under H01M (batteries and cells), with meaningful overlap into sulfur chemistry (C01B) and capacitor-related electrode work (H01G).
The dataset shows 39 filings in 2017, the highest single-year count in the range, followed by a gradual decline to a 2022 midpoint of 32 and just 1 filing recorded so far in 2026. This pattern typically reflects an early wave of foundational activation-protocol claims being staked out, followed by incremental refinement rather than new expansion. Because publication lags filing by roughly 18 months, the very recent years understate true filing activity and should not be read as a confirmed drop-off yet.
LG Chem and its affiliate LG Energy Solution show significant historical activity, including a recent representative filing (EP4657594A1) on constant-voltage discharge activation sequencing. Sion Power, the University of California, University of Michigan, and E2 Delaware also appear among tracked assignees. Notably, all of these leading filers show zero filings in the most recent tracked year, suggesting either a genuine slowdown or filings still working through the publication pipeline.
Claim density is heaviest in core H01M battery-cell activation methods, but thinner in adjacent areas such as in-situ SEI impedance monitoring during activation, capacitor-hybrid formation protocols, and catalytic pre-treatment of sulfur composites under B01J. These branches show lower record counts (11 for B01J, 8 for C09C, 7 for G01R) relative to the 265 records under H01M, indicating less-crowded claim space worth reviewing before filing a new application in this field.
The most-cited records in this corpus, such as US20110052998A1 with 168 citations, are older filings that have simply had more years to accumulate citations, not necessarily the most relevant art to a new filing today. Citation count is best treated as a signal of historical influence on the field's foundational sulfur-carbon cathode and electrolyte work, rather than a measure of current technical relevance. A freedom-to-operate review should still examine recent filings like EP4657594A1 alongside the highly-cited older patents.
Research Lithium-Sulfur Battery Formation Process in depth with Eureka
Go past this page: query the whole lithium-sulfur battery formation process corpus yourself, in your own scope.
Every answer comes back with patent numbers you can open.
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.