Lithium-Sulfur Battery Patents: Who Leads, Where Gaps Are 2026
- Filing peaked in 2018 at 17 families then cooled sharply before a fresh acceleration into the current decade, with 2022 as low as 1 family — a lull, not a retreat.
- 96% of records sit in H01M alone batteries, cells and fuel cells dominate the classification spread; only a handful of families reach into heterocyclic chemistry, electroplating, nanotechnology or polymer processing.
- The most-cited record dates to 2014 a liquid electrolyte patent for capacity and cycling retention carries 49 citations, more than four times the next most-cited family — a strong signal of foundational influence, not current activity.
What the lithium-sulfur patent record shows
Lithium-sulfur chemistry promises energy density well beyond conventional lithium-ion, but its patent record is thin and uneven compared with mainstream battery filings. Across the 56 families captured here, filing activity starts in 2015, spikes in 2018, and then falls away before climbing again toward the data cut-off. That is consistent with a technology still working through the polysulfide shuttle and sulfur host material problems that have kept lithium-sulfur out of commercial cells: cathode stability, electrolyte-to-sulfur ratio, and areal loading all recur as claim language across the corpus.
Because publication lags filing by roughly 18 months, the most recent year in the trend understates real filing activity — 2026 in particular should be read as a partial count, not a decline.
Filing trend and technology composition
The dataset spans publications from 2015 through the mid-2026 cut-off, filtered to lithium-sulfur battery claims touching polysulfide shuttle control, sulfur host materials, electrolyte-to-sulfur ratio, areal loading or cycle retention.
A peak in 2018, a lull, then renewed acceleration
Filings ran from 3 families in 2017 to a peak of 17 in 2018, dropped to a single family by 2022, and have been climbing since — the shape of a niche chemistry going through a research trough before a second wave of commercial interest.
Concentrated almost entirely in H01M
H01M — batteries, cells and fuel cells — covers every one of the 56 families. The next largest classes, heterocyclic compounds and electroplating, appear in only two families each, meaning claim activity outside core electrochemical cell design is still marginal.
Shares are the percentage of the 56 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Lithium-Sulfur Batteries with Eureka
This page is one run against one query. Ask Eureka your own question about lithium-sulfur batteries and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited records and a representative filing
Cathode for Li-S battery (WO2024180256A1)
The filing describes a layered construction process: nucleating metal ions on a graphene oxide or reduced graphene oxide sheet, growing a metal-organic framework from those bound ions with a polyfunctional ligand, and then infusing elemental sulphur into the resulting MOF-on-graphene structure to form the cathode material.Filed by the Norwegian University of Science and Technology (NTNU), 2024-09-06.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20140170459A1 | Liquid Electrolyte for Increasing Capacity and Cycling Retention of Lithium Sulfur Battery | 49 |
| 2 | US20180287121A1 | Li-S Battery with Carbon Coated Separator | 21 |
| 3 | US20160172667A1 | Multilayered Sulfur Composite Cathodes for Lithium Sulfur Batteries | 19 |
| 4 | US20200227725A1 | Lithium sulfur batteries and components thereof | 15 |
| 5 | WO2016094301A1 | Multilayered sulfur composite cathodes for lithium sulfur batteries | 11 |
| 6 | WO2018224374A1 | Electrolyte for an alkali-sulfur battery, alkali-sulfur battery containing the electrolyte, and uses of the e… | 10 |
| 7 | CN107864687A | 混合锂离子的传导膜改善锂硫电池和其他储能装置的性能 | 10 |
| 8 | WO2017036522A1 | Li-s battery with carbon coated separator | 10 |
| 9 | US20190229366A1 | Lithium battery using lithium polysulfide as the cathode active material | 9 |
| 10 | CN109004163A | 一种具有防止多硫化物穿梭效应的锂硫电池隔膜-硫正极复合包组件 | 9 |
Citation counts reflect influence within the searched corpus and skew toward older filings; treat them as a map of foundational prior art rather than a ranking of current relevance.
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. Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the numbers actually indicate
Four figures from this dataset matter more than the headline count of 56 families — each changes how a filing or freedom-to-operate decision should be read.
The 2018 peak was not the start of a trend
A single-year spike followed by a multi-year collapse suggests a wave of early speculative filing around sulfur cathode and electrolyte formulations, rather than sustained institutional investment. The renewed climb toward 2026 looks like a second, more deliberate wave.
Almost no claim activity outside cell design
Every family in the corpus touches H01M. The scattering into C07D, C25D, B05B, B82Y, C01B, C08F and C08J — one or two families each — points to isolated experiments in coating chemistry and materials processing rather than an established secondary claim front.
One 2014 filing anchors the field's prior art
The liquid electrolyte patent for capacity and cycling retention is cited more than twice as often as the next record. New filers in electrolyte formulation should expect this family to surface in any freedom-to-operate search.
PCT filing outpaces any single national office
More families entered via the PCT route than through the US or European offices individually, suggesting applicants are seeking broad optionality before committing to specific jurisdictions — typical of a chemistry still short of a settled commercial path.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to lithium-sulfur batteries, with the prior art for and against each one.
Who is filing, and where the gate sits
Recent-year filing momentum is muted across the named assignees in this dataset — several show zero filings in the latest year, and one shows a full year-on-year drop to zero. That pattern is consistent with the broader trough visible in the filing trend rather than any single firm exiting the field.
University assignees dominate but have gone quiet recently
Institutions including Cornell, the University of Southern California, and Florida State University's research foundation appear in the assignee set, but none show filings in the most recent year captured — consistent with the broader mid-decade lull rather than a wind-down of research.
NTNU's filing dropped to zero after its 2024 filing
The Norwegian University of Science and Technology, source of the representative WO2024180256A1 filing on MOF-on-graphene cathodes, shows a full year-on-year decline to zero in the latest tracked year — a single-filing spike rather than a sustained program, on current evidence.
Materials suppliers show sporadic rather than continuous activity
Lubrizol's presence in the assignee set points to specialty chemical companies testing electrolyte or additive claims in this space, but the latest-year figures show no continuation of that activity, again in line with the corpus-wide trough.
| Assignee | Recent year | YoY |
|---|---|---|
| University of Southern California | 0 | — |
| Cornell University | 0 | — |
| Norwegian University of Science and Technology (NTNU) | 0 | -100% |
| Fraunhofer-Gesellschaft | 0 | — |
| Florida State University Research Foundation | 0 | — |
| Lubrizol Corporation | 0 | — |
| West Virginia University | 0 | — |
| Talasens Regulation Association | 0 | — |
Where to take this next
The filing data points to a chemistry between waves — thin recent output from named assignees, but classification and citation patterns that mark out where the next round of claims is likely to land.
Map the sulfur host material sub-claims
With only a handful of families reaching outside H01M into materials processing classes, a targeted search on host material composition would surface whether that ground is genuinely open or simply unindexed here.
Explore in Eureka →Track the post-2022 filing recovery
The climb from a single family in 2022 back toward multiple filings by 2026 is the most decision-relevant trend in this dataset — worth revisiting each quarter as new publications land.
Explore in Eureka →Run a freedom-to-operate check against the 2014 electrolyte patent
Its 49 citations make it the single most likely piece of prior art to complicate a new electrolyte-formulation filing in this space.
Explore in Eureka →Common questions on lithium-sulfur battery patents
By citation count within this corpus, the most influential single family is a 2014 US filing on liquid electrolyte formulations for increasing capacity and cycling retention, cited 49 times — more than four times the next most-cited record. Several other highly-cited families cover sulfur composite cathode structures and carbon-coated separators. High citation counts favour older filings simply because they have had more time to be cited, so treat this as a map of foundational prior art rather than a live leaderboard of current market leaders.
Filing activity peaked at 17 families in 2018 and fell to as low as 1 family by 2022 before climbing again toward the current data cut-off. That pattern typically reflects an early wave of speculative or exploratory filings around a promising chemistry, followed by a period where fewer teams were ready to file new claims while the underlying science — particularly polysulfide shuttle control and cathode stability — matured. The renewed increase toward 2026 suggests a second, more deliberate filing wave is underway, though the most recent year is always undercounted due to publication lag.
The search terms behind this dataset — polysulfide shuttle, sulfur host material, electrolyte-to-sulfur ratio, areal loading and cycle retention — point to the core unsolved engineering problems in lithium-sulfur cells. Almost all 56 families sit within IPC class H01M, covering battery and cell design directly, with only isolated filings reaching into heterocyclic chemistry, electroplating or polymer processing. That concentration shows the field is still focused on core cell architecture rather than downstream manufacturing or auxiliary materials.
The classification data shows almost no claim activity outside core battery cell design (H01M), with only one or two families each in adjacent classes like electroplating, nanotechnology and polymer processing. That thinness suggests under-claimed ground in areas such as MOF-on-graphene sulfur host structures, specific electrolyte-to-sulfur ratio formulations, and areal loading control methods — all mentioned in claim language but not yet densely covered by granted families in this dataset. A dedicated novelty search in those specific sub-areas is more likely to surface open ground than a general search on lithium-sulfur chemistry as a whole.
The PCT route through WIPO accounts for the largest single group of filings at 17, ahead of the European Patent Office at 14 and the United States at 13, with China, Austria and India each showing smaller counts. The lead held by PCT filings over any single national office suggests many applicants are preserving broad international optionality rather than committing early to a specific jurisdiction, which is typical for a chemistry that has not yet settled on a dominant commercial market.
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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.