US 9190222

I'll search for authoritative information on this patent, including any litigation or docket activity.

Let me try more targeted searches.

US Patent 9,190,222 — Analyst Summary

Search coverage and limitations (read first)

I searched for the specific number 9,190,222 (and US9190222B1 / 9,190,222). Results:

• USPTO / Google Patents bibliographic data: returned the correct patent. The authoritative full text supplied in my working context is the primary source below.
• CAFC 2026 dockets: The CAFC "Scheduled Cases" listing (July 2026 panels) returned no case involving U.S. Patent No. 9,190,222. Searches for litigation returned only unrelated matters.
• No district-court or PTAB proceeding naming 9,190,222 was found in my searches. This is a negative finding, not proof that none exists.

Critical anti-conflation warning (per the strict "interpret identifiers literally" rule): Several search hits reference a "’222 patent" owned by Masimo (e.g., Masimo v. Nellcor, Fed. Cir. No. 04-1495; Masimo v. Philips, D. Del. 1:22‑cv‑01378). Those are U.S. Patent No. 6,263,222 — a different patent entirely ("Signal Processing Apparatus," pulse oximetry). Number 6,263,222 ≠ 9,190,222. Do not attribute those cases to this patent. Likewise, the Samsung/IOENGINE 2026 suit involves patents 7,861,006 / 9,059,969 / 10,397,374 / 10,447,819 / 10,992,786 — none is 9,190,222.

Bibliographic data (authoritative)

Assignment records noted: 2013‑04‑16 assignments of Kelkar & Zhang to NC A&T, and Fong & Lai to South Dakota School of Mines.

Abstract (verbatim)

"The present application discloses carbonaceous nano-fibrous materials developed by electrospinning mixtures of alkali lignin with a polymer at varied mass ratios. The present application also discloses processing of the lignin/polymer fibers via progressive heat treatments for stabilization, pre-carbonization and carbonization. The resulting carbon nanofibers maintain a uniform shape and have high specific surface area."

Plain-language technology overview

The invention turns alkali (Kraft) lignin — a cheap, abundant wood-pulping by-product — into free-standing carbon nanofiber mats usable as binder-free supercapacitor electrodes. Lignin is co-dissolved with a water-soluble carrier polymer (chiefly poly(vinyl alcohol), PVA) in water, electrospun into precursor nanofibers, then run through a slow, staged ("progressive") heat treatment: stabilization in air, pre-carbonization in inert gas, and final carbonization. The slow ramp rates are the point — they crosslink the fibers so they survive high-temperature carbonization without melting, fusing, or losing shape. Lignin content can go up to ~70 wt%. The result: 100–1000 nm fibers, a highly amorphous/porous carbon, BET surface area reaching ~583 m²/g and specific capacitance ~64 F/g at 400 mA/g, with ~90% retention after 6,000 cycles.

Independent claims — plain-language overview

Caveat on provenance: The authoritative text provided to me contains the abstract and the full specification (field, background, summary, definitions, examples) but does not include a verbatim, numbered claim set, and my searches did not retrieve the issued claims. The overviews below are reconstructed from the Summary of the Invention, which mirrors the claim language, plus claim-occurrence signals in the patent's own keyword index (which flags claims containing "lignin," "carbon nanofiber," "stabilization," "carbonization," "poly(vinyl alcohol)," "aqueous solvent," "cross-linking," "impurity," "oxygen," and "capacitor"). Treat claim numbering as unverified; treat the substance as well-grounded.

1. Method of manufacture via stabilized + pre-carbonized intermediates. A method of making carbon nanofibers that starts from intermediate nanofibers already stabilized by heating in an oxygen-containing (air) atmosphere, then performs pre-carbonization: heating those stabilized fibers in an inert atmosphere to at least ~400 °C at a rate of up to ~2 °C/min, yielding pre-carbonized nanofibers. (The specification's narrower variants recite heating to ≥500 °C at ≤1 °C/min.)

2. Method of preparing carbon nanofibers — electrospinning step. A method comprising electrospinning a mixture of alkali lignin and a polymer (aqueous solution electrospinning with a water-soluble polymer such as PVA; or melt electrospinning with PVA/PEO; or non-aqueous/PAN).

3. Full four-stage method (a)–(d). A method comprising: (a) electrospinning a mixture of alkali lignin and a polymer; (b) stabilization — heating the spun fibers in an oxygen-containing atmosphere to a stabilization temperature of at least ~100 °C at ≤2 °C/min (progressive, to a final stabilization temperature of at least ~200 °C at ≤1 °C/min in one variant); (c) pre-carbonization — heating the stabilized fibers in an inert atmosphere to at least ~400 °C at ≤~0.2 °C/min, held for a time sufficient to increase crosslinking; (d) carbonization — heating in an inert atmosphere (or vacuum) to at least ~700 °C (range ~700–2200 °C) at ≤~10 °C/min, held long enough to remove most non-carbon elements. A narrower embodiment recites ≤0.1 °C/min in (c) and holds of ≥30 min in (c) and (d), with (b) run at 0.05–1 °C/min.

4. Carbon nanofiber product. Carbon nanofibers (made by the disclosed methods) characterized by the specified physical properties: (a) BET specific surface area of at least ~500 m²/g (a narrower variant recites ≥550 m²/g); and/or (b) total pore volume of at least ~0.1 cm³/g (variants: ≥0.25 or ≥0.3 cm³/g) by N₂ sorption; and/or (c) average pore size no more than ~4 nm (variant: ≤5 nm) by N₂ sorption. Related product language recites 250–750 m²/g with a peak pore volume >0.03–0.04 cm³/nm/g for pores <2–5 nm.

5. Electric double-layer capacitor (article). An electric double layer capacitor comprising a carbon nanofiber as disclosed, where the electrode exhibits a specific capacitance of at least 60 F/g at a current density of 400 mA/g. (The specification's broader range is ~10–75 F/g, up to ~100 F/g.)

Verification notes and uncertainties

• No litigation found: I could not locate any CAFC 2026 docket entry, appeal, or district-court case naming U.S. 9,190,222. Absence of a hit is not confirmation of absence; a subscription docket service (PACER, Docket Navigator) would be needed to confirm with confidence.
• Claim set not independently retrieved: The verbatim issued claims were not in the provided text and were not returned by search. The independent-claim overview is an inference from the specification's Summary and the patent's own claim-keyword index. If you need binding claim text (e.g., for a FTO or invalidity analysis), pull the claims directly from USPTO PatentCenter / Google Patents for US9190222B1.
• Possible related PCT: WO2014/025794 (PCT/US2013/053808) appeared in search results with a large claim set and Rule 6.4(a) multiple-dependent-claim observations. I cannot confirm it is the PCT counterpart to this application (its filing date differs from 13/830,043's 2013‑03‑14). Flagged as unverified, not asserted.
• Deadline/date clarity: The task header lists "current date April 26, 2026," while the document fetch is stamped 2026‑09‑28. I have not relied on either date for any legal conclusion (e.g., term expiry); the listed adjusted expiration 2033‑10‑06 is the patent office's own data and includes any patent term adjustment. Any maintenance-fee or expiration analysis should be re-verified at the time of use.

I'll search for litigation involving US patent 9190222 across the specified sources.

Let me run more targeted searches across litigation databases.

Let me try a few more targeted searches, including university-owner and CourtListener/PACER-style queries.

Litigation Search Report — U.S. Patent No. 9,190,222

Bottom line: I found no known litigation involving U.S. Patent No. 9,190,222 in any of the sources searched. I cannot identify a plaintiff, defendant, jurisdiction, case number, filing date, or outcome because no such case appears to exist in the searchable record.

What I searched

I ran targeted queries designed to surface docket-level litigation records, including:

• Unified Patents litigation/patent portal queries (portal.unifiedpatents.com/litigation/...).
• General patent-litigation queries phrasing the number both ways (9,190,222 and 9190222) with terms like "litigation," "lawsuit," "infringement," and "defendant."
• Owner-based queries (the patent's assignees, South Dakota School of Mines and Technology and North Carolina Agricultural and Technical State University, plus "carbon nanofiber lignin").

None of the returns referenced U.S. Patent No. 9,190,222 as a patent-in-suit.

Important caution — similar numbers that are NOT this patent

Several search hits involve numerically similar but different patents. Do not conflate these with 9,190,222:

Per the strict instruction to interpret identifiers literally, I am explicitly not treating any of these as U.S. Patent No. 9,190,222.

Context on the patent itself

U.S. Patent No. 9,190,222 ("Production of carbonaceous nano-fibrous materials with ultra-high specific surface area from alkali (Kraft) lignin") issued 2015-11-17 from Application No. 13/830,043, filed 2013-03-14, claiming priority to Provisional Application 61/656,813 (2012-06-07). It is owned by two academic institutions (South Dakota School of Mines and Technology; North Carolina Agricultural and Technical State University). University-owned, materials-science patents of this type are rarely asserted in litigation, which is consistent with the absence of any docket record I could locate.

Limitations / caveats

• I could not directly query PACER, and my access to the Unified Patents litigation caselist was indirect (via search indexing rather than a live portal query). A docket-level search on PACER/Unified Patents/CourtListener using the exact number 9,190,222 would be the confirmatory step.
• My searches did not surface any PTAB proceeding (IPR/PGR), ITC investigation, or district-court/CAFC case naming this patent either.
• If you need a definitive litigation clearance, I recommend a direct PACER docket search and a Unified Patents / Docket Alarm query on the exact number. As of this search, however, the best available answer is that no litigation involving U.S. Patent No. 9,190,222 is known.

I'll verify the structured "no PTAB proceedings" signal with targeted searches before finalizing.

Proceedings overview

Total AIA trial proceedings on file for U.S. Patent No. 9,190,222: 0. The canonical structured source ("PTAB proceedings on file" block, sourced from the USPTO Open Data Portal) reports no IPR, no PGR, and no CBM proceeding naming this patent, and my confirmatory web searches surfaced none. Breakdown by status is therefore N/A (0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denied).

Bottom-line defensive posture: This is the opposite of a hardened patent — it is an untested one. Every claim of the patent stands exactly as issued on 2015-11-17. There is no IPR estoppel to exploit, no cancelled claim to point to, and no PTAB record to mine for admissions. But there is equally no defensive benefit: a defendant today cannot say "this patent has already been beaten" and cannot leverage a prior institution decision holding. The patent has simply never been challenged at the PTAB.

Important: Because there are no proceedings, I cannot populate the per-proceeding template (filed date, panel, grounds, institution decision, FWD, appeal). I will not invent a proceeding number or an FWD. What follows is what the absence of proceedings means, plus the false positives I had to clear off the table.

No proceedings to itemize

There is nothing to list under the ### {PROCEEDING_NUMBER} — {Petitioner} v. {Patent Owner} heading. Below are the near-miss identifiers that search returned and that must not be conflated with this patent (per the strict instruction to read identifiers literally):

The only substantive hit for the actual patent (US9190222B1, priority 2012-06-07, assignees South Dakota School of Mines & Technology and North Carolina Agricultural and Technical State University) came from a Google Patents citation listing — i.e., the patent is cited by other documents, not challenged in an AIA trial. Citation ≠ proceeding.

Strategic summary

Claim status of 9,190,222: ALL CLAIMS UNTESTED. Because no petition was ever filed, no claim has been cancelled, confirmed, or even construed by the Board. The patent issued 2015-11-17 from Application No. 13/830,043 (filed 2013-03-14, priority to provisional 61/656,813 filed 2012-06-07) and, per the structured record, remains active with an adjusted expiration of 2033-10-06. For a defendant, this is a clean-slate patent: the full claim set is live and available to the patent owner, and the patent owner has no adverse PTAB record to explain away.

Estoppel landscape — no estoppel exists yet, but the § 315(b) clock is the operative constraint. No final written decision has issued, so § 315(e)(2) estoppel has not attached to anyone. That means a defendant is free to file an IPR on any § 102/§ 103 ground based on patents or printed publications, subject only to the ordinary rules. The practical timing rule is § 315(b): a petition is barred if filed more than one year after the petitioner, RPI, or privy is served with a complaint alleging infringement of this patent. If you have been sued on 9,190,222 and more than a year has elapsed since service, IPR is barred for you personally, and your remaining invalidity avenues are district-court/jury and ex parte reexamination (§ 315(e) does not bind a reexam). If you are within the one-year window, the whole printed-publications art space is open — there is no § 325(d) "already before the Office" problem to disarm.

Pattern signals — none. No petitioner has filed even a first IPR, so there is no serial-filer pattern, no defensive aggregator (Unified Patents, RPX, or similar) in the chain, and no Federal Circuit appeal docket. This is consistent with the earlier finding that the patent has attracted no known litigation: the absence of litigation and the absence of IPRs are mutually reinforcing. University-owned materials-science patents of this type are typically never asserted and therefore never challenged. If your client has received a demand or complaint, that would make it the first assertion event this patent has ever seen — worth confirming, because it changes the calculus from "dormant academic patent" to "newly activated."

One framework note to keep straight: CBM review is unavailable here — the patent claims carbon nanofiber manufacture and an electric double-layer capacitor electrode, not a "financial product or service," so it is ineligible for CBM. PGR is also unavailable now: post-AIA PGR must be filed within nine months of grant, i.e., by roughly 2016-08-17, which has long passed. That leaves IPR (and ex parte reexamination) as the only PTAB-side validity vehicle.

Recommended next steps

• If you are a defendant and the complaint is recent (within ~10 months of service): the § 315(b) window is open. Commission a novelty/obviousness search against the 2012-06-07 priority date, focusing on printed publications on lignin/PVA electrospinning, oxidative thermal stabilization of lignin fibers, and slow-rate pre-carbonization. The patent's own prosecution history and cited art are the natural starting point. Confirm the exact service date before calendaring.
• If you are a defendant and more than one year has passed since service: IPR is time-barred for you and your privies. Do not spend on a petition that will be denied under § 315(b). Redirect to district-court invalidity (including § 112 and non-printed-publication prior art, which IPR cannot reach) and consider ex parte reexamination, which carries no § 315(b) bar and no estoppel.
• If you have not been sued: there is nothing time-sensitive on the PTAB side. The patent is untested and, as of this analysis, unasserted. Monitor for a first complaint — that event starts the § 315(b) clock and is the trigger for the defensive workstream.
• No active proceedings exist, so there are no trial-stage milestones (institution deadline, oral hearing, FWD due date) to track. This should be stated plainly to any decision-maker relying on this report: the PTAB docket for 9,190,222 is empty.
• Confirmatory step for a litigation-grade opinion: run a direct PTAB E2E / Patent Trial and Appeal Board End-to-End search and a CourtListener docket query on the exact number 9,190,222, plus a USPTO PatentCenter "proceedings" lookup. My conclusion rests on the ODP-derived structured block plus web-search corroboration; I could not execute a live E2E docket query. I found no evidence of any PTAB proceeding, but a live docket pull is the definitive check.

Limitation / honesty note: I found no final written decision, institution decision, settlement, or Federal Circuit appeal for this patent — because I found no proceeding at all. I have not linked to any PTAB or CourtListener opinion, since none exists for 9,190,222; linking to the Greenthread/11,121,222 or 10,269,222 materials would be exactly the conflation this task warns against.

I'll research the assignment record for US 9,190,222 across the specified sources.

Let me search more specifically for the assignment records and inventor affiliations.

Let me try to find the specific assignment reel/frame records and correspondent details.

Assignment & Ownership Analysis — U.S. Patent No. 9,190,222

Source-access note (read first): I could not perform a live query against USPTO Assignment Center (assignmentcenter.uspto.gov). The assignment facts below are reconstructed from (a) the Google Patents legal-events record embedded in the authoritative patent text (which lists two recorded assignments, both dated 2013-04-16), (b) uspto.report's SDSM&T assignee page (which confirms 9,190,222 / 13/830,043, first-named inventor "Zhang, et al."), and (c) NC A&T's institutional research-profile pages listing the four inventors. Critically, none of these accessible sources expose the reel/frame number or the correspondent of record. I am flagging that gap rather than inventing values — per the operating rule against fabrication. A confirmatory reel/frame + correspondent pull must be run directly on Assignment Center using the exact number.

Link for verification: https://assignmentcenter.uspto.gov/ and https://assignment.uspto.gov/patent/index.html#/patent/search?q=9190222

Inventors

Pattern observations: This is a two-institution joint invention. The recorded assignments split exactly along employer lines (Zhang + Kelkar → NC A&T; Fong + Lai → SDSM&T), which is the normal duty-to-assign outcome for a cross-university collaboration, not a distress signal. I found no evidence that any inventor departed the original assignee within 12 months of filing, and no evidence of a portfolio fire-sale around the 2013 filing. (Caveat: inventor-mobility is only determinable from CV/lab records I could partially retrieve, not from assignment data alone.)

Original assignee

Two co-owners are named on the issued patent, and both remain the current assignee in the Google Patents record — i.e., no change of ownership since issuance:

1. South Dakota School of Mines and Technology (SDSM&T) — a public engineering/technology university (Rapid City, SD). Primary line of business: higher education / research, not product manufacturing. Status: operating (public institution; not acquired, dissolved, or in bankruptcy).
2. North Carolina Agricultural and Technical State University (NC A&T) — a public land-grant HBCU (Greensboro, NC). Primary line of business: higher education / research. Status: operating (public institution; not acquired, dissolved, or in bankruptcy).

Product embodiment: Neither assignee ships a commercial product embodying the claims. The patent describes binder-free carbon-nanofiber electrode mats for supercapacitors; the work was grant-funded (e.g., the inventors' projects list NSF SBIR and DOE/NASA/DoD funding). Commercialization, if any, would occur through university technology-transfer licensing — and I found no such license or transfer recorded.

Assignment timeline

Two assignments are of record, both recorded 2013-04-16 (about one month after the 2013-03-14 non-provisional filing), matching the two-institution split.

• Executed date: not exposed in accessible sources / recorded 2013-04-16 — Reel NNNNNN/NNNN (not retrievable; not fabricated)

  • Conveyance: Assignment (inventor-to-institution)
  • Assignor: Ajit Kelkar; Lifeng Zhang
  • Assignee: North Carolina Agricultural and Technical State University
  • Correspondent: not retrievable from accessible sources — Assignment Center must be queried to capture the attorney/firm of record. No recurrence flag can be given without it.
  • Context: Initial academic assignment — two inventors convey rights to their home institution. Not a fire-sale or securitization.

• Executed date: not exposed in accessible sources / recorded 2013-04-16 — Reel NNNNNN/NNNN (not retrievable; not fabricated)

  • Conveyance: Assignment (inventor-to-institution)
  • Assignor: Hao Fong; Chuilin Lai
  • Assignee: South Dakota School of Mines and Technology
  • Correspondent: not retrievable from accessible sources (see above).
  • Context: Initial academic assignment — the SDSM&T inventors convey rights to SDSM&T.

No post-issuance assignments, security interests, name changes, mergers, or releases are of record in the sources I could access. Related non-assignment legal events (Google Patents): application filed 2013-03-14; priority to Provisional 61/656,813 filed 2012-06-07; granted and published 2015-11-17; status Active; adjusted expiration 2033-10-06.

Timeline diagram

timeline
    title Ownership of US 9190222
    2012 : Provisional 61/656,813 filed Jun 7
    2013 : Nonprovisional 13/830,043 filed Mar 14
         : Zhang and Kelkar assign to NCAT
         : Fong and Lai assign to SDSMT
    2015 : Patent issues Nov 17
    2033 : Adjusted expiration Oct 6

NPE / troll-pattern signals

1. Shell-entity transfer — Not present. No licensing-only LLC ("IP / Patents / Holdings / Ventures") appears anywhere in the chain. Both assignees are public universities. The only recorded transfers are inventor→university assignments (2013-04-16).
2. Known asserter in the chain — Not present. Neither assignee nor any recorded party matches Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Conversant/Mosaid, Vringo, Pendrell, Round Rock, or any Unified/RPX high-frequency-plaintiff list. No such entity appears in the record at all.
3. Repeat correspondent across the chain — Unclear / cannot assess. The correspondent of record is not exposed in the sources I could reach. This signal cannot be scored either way; it requires a live Assignment Center pull. (Not scored as "present" without the attorney name.)
4. Cascading transfers — Not present. There are no chained LLC-to-LLC transfers; only two same-date, one-hop academic assignments in 2013.
5. Pre-litigation transfer — Not present. No infringement suit naming this patent exists (consistent with the litigation summary already generated), so no transfer can be tied to a pre-suit window.
6. Bankruptcy fire-sale — Not present. Both assignees are solvent public state institutions; there is no Chapter 7/11 event in the chain.
7. Privateering — Not present. No operating company transferred the patent to an NPE to assert on its behalf.
8. Defensive aggregator (anti-NPE) — Not present. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. It terminates at the two original academic co-owners. (This is a separate fact from the "non-asserting" nature of academic ownership.)

Verdict

Insufficient data (no records, or only the original assignment).

Justification: The only assignments of record are the two inventor→university conveyances recorded 2013-04-16 (NC A&T receiving from Kelkar/Zhang; SDSM&T receiving from Fong/Lai). Ownership has not changed since issuance — the Google Patents current-assignee field still lists both universities — and no litigation, PTAB proceeding, license, security interest, or NPE-adjacent transfer is of record. This is the textbook non-asserting, academic co-ownership profile, so none of the eight NPE signals is affirmatively present; however, because I could not retrieve the reel/frame numbers or the correspondent of record from a live Assignment Center query, I cannot fully close out the "repeat correspondent" signal (Signal 3) and therefore select "Insufficient data" rather than a clean "Defensive / non-asserting" call.

Verification link: https://assignmentcenter.uspto.gov/ (search by patent number 9,190,222; also https://assignment.uspto.gov/patent/index.html#/patent/search?q=9190222). Confirm reel/frame and the correspondent of record there to complete Signal 3.

I'll search for the patent and its cited prior art references.

Let me access the patent's citation record directly.

Prior-Art Analysis — U.S. Patent No. 9,190,222

Methodological note (read first)

I was able to confirm the patent's identity and bibliographic data, but I was not able to retrieve the authoritative front-page "References Cited" list of US 9,190,222 verbatim through the search tooling available within this task's step budget. Google Patents/Justia returned the patent's specification, abstract, and family data, and multiple foreign search reports for sibling/related lignin-carbon-fiber filings — but not the literal US front-page citation list.

Per the operating rule against fabrication, I am therefore presenting the prior art below in two clearly labeled tiers:

• Tier 1 — references that appear in the corresponding patent-family / field search reports for this exact subject matter (JP 2011504970 A, ES 2531462 B2, and the EP 2216431 A1 family citations) and are the recognized keystone references in lignin-carbon-fiber art. I treat these as high-confidence prior art, but flag that I did not verify them as the literal "References Cited" entries on the US 9,190,222 face.
• Tier 2 — non-patent literature that is indisputably prior art (published before the June 7, 2012 priority date) and directly on point.

Do not treat the specific claim numbers below as verified. I could not retrieve the granted claim set of US 9,190,222; I therefore map each reference to claim categories (as reflected in the specification's own summary of the claims) rather than to numbered claims.

Governing law — a threshold point

Application 13/830,043 was filed March 14, 2013 — two days before the AIA first-to-file effective date of March 16, 2013. The US 9,190,222 claims therefore continue to be governed by pre-AIA 35 U.S.C. § 102, not AIA § 102(a)(1)/(a)(2). This matters: the analysis below uses pre-AIA § 102(a)/(b)/(e) categories, and the priority date is the June 7, 2012 provisional (61/656,813).

Tier 1 — Patent references

1. US 3,461,082 A — Otani et al.

• Full citation: Otani, S. et al., "Method for producing carbonized lignin fiber," U.S. Patent 3,461,082 A; assignee Nippon Kayaku K.K.
• Dates: Priority 1964-10-10 (JP); granted/published 1969-08-12.
• Description: A foundational process for converting lignin into carbonized fiber: spinning lignin into fiber, subjecting it to an oxidative/infusibilizing (stabilization) heat step, then carbonizing. This is the earliest art in the field and discloses the generic "lignin → stabilize → carbonize" sequence.
• § 102 exposure: § 102(b) (published more than one year before the 2013 filing; also before the 2012 priority). Potentially anticipates only the broadest generic method features — i.e., any claim whose novelty rests solely on "heating lignin fibers in an oxygen-containing atmosphere" then carbonizing. Because it does not disclose electrospinning, the alkali lignin/PVA blend, or the claimed progressive heating-rate schedule, it would not anticipate claims reciting electrospinning, polymer blends, or the 0.05–0.2 °C/min pre-carbonization rates; for those it is at most § 103 material.

2. US 5,344,921 A — Sudo et al.

• Full citation: Sudo, K. et al.; U.S. Patent 5,344,921 A.
• Dates: Granted/published 1994-09-06.
• Description: Lignin-based carbon fiber production (steam-exploded/lignin precursor work in the Sudo lineage).
• § 102 exposure: § 102(b). Relevant to the pre-carbonization / thermal-treatment method claims only as a generic showing that lignin fiber is heat-treated before carbonization. Does not disclose electrospinning or alkali lignin/PVA, so it is not anticipatory of the electrospinning claims.

3. US 2007/0142225 A1 — Baker, F.S.

• Full citation: Baker, F.S., U.S. Pub. 2007/0142225 A1.
• Dates: Published 2007-06-21.
• Description: Lignin-derived carbon fiber processing; appears as an "A" category citation in the sibling search report (JP 2011504970 A) and in the Spanish search report for the related Málaga filing (as D04).
• § 102 exposure: § 102(a)/(b) as a printed publication. Relevant to broad method claims on making carbon fiber from lignin; does not by itself anticipate the electrospinning/blend/progressive-heating combination.

4. US 2007/0048521 A1 — Istvan

• Full citation: Istvan, U.S. Pub. 2007/0048521 A1.
• Dates: Published 2007-03-01.
• Description: Cited in the same sibling search report (paras. [14–15], [31]) as background to lignin-fiber processing.
• § 102 exposure: § 102(a)/(b), background/"A" art only; no anticipation of the characterized claims.

5. (Family citation) BE 757620 A — Bayer AG

• Full citation: BE 757620 A, "Carbon fiber preparation process," Bayer AG.
• Dates: Published 1971-04-16.
• Description: Carbon-fiber preparation process (appears in the family citation list shared with the lignin-carbon-fiber family).
• § 102 exposure: § 102(b), generic process background; does not disclose lignin/PVA electrospinning.

Flag on these Tier-1 entries: The Otani (US 3,461,082) and Sudo (US 5,344,921) references, plus Baker US 2007/0142225 and Istvan US 2007/0048521, are exactly the set that recurs across the sibling/field search reports I retrieved. That recurrence strongly suggests they are also the core cited art on US 9,190,222, but this is an inference, not a verified face-page reading. I recommend confirming against the actual "References Cited" block of US 9,190,222 (USPTO PatentCenter / Google Patents "Patent Citations") before relying on it for a validity opinion.

Tier 2 — Non-patent prior art (all published before the 2012-06-07 priority date)

These are the references most dangerous to the US 9,190,222 claims, because they combine electrospinning + lignin + the stabilization/carbonization heat sequence — the very combination the patent claims.

A. Ruiz-Rosas, R. et al., Carbon (2010)

• Full citation: Ruiz-Rosas, R., Bedia, J., Lallave, M., Loscertales, I.G., Barrero, A., Rodríguez-Mirasol, J., Cordero, T., "The production of submicron diameter carbon fibers by the electrospinning of lignin," Carbon, 2010, Vol. 48, pp. 696–705.
• Date: 2010 (published before priority).
• Description: Electrospinning of Alcell lignin (in ethanol) into submicron fibers, followed by oxidative stabilization at ~200 °C and carbonization in N₂ at 600–1000 °C; reported specific surface areas of ~1178–1195 m²/g, pore volume ~0.52 cm³/g, diameters 400 nm–1 µm.
• § 102 exposure: § 102(a)/(b). Directly anticipatory-risk to the electrospinning + stabilization + carbonization method claims and to the high-surface-area carbon-nanofiber product claims (the ~500–583 m²/g and even the higher ranges described in the patent are within this reference's disclosure). Under pre-AIA § 102(b) this is the single most relevant anticipatory reference. It does not disclose alkali (Kraft) lignin or PVA, which may rescue claims that expressly require alkali lignin/PVA blends.

B. Lallave, M. et al., Advanced Materials (2007)

• Full citation: Lallave, M. et al., "Filled and hollow carbon nanofibers by coaxial electrospinning of Alcell lignin without binder polymers," Adv. Mater., 2007, 19(23), 4292–4296.
• Date: 2007.
• Description: Coaxial electrospinning of binder-free lignin into carbon nanofibers.
• § 102 exposure: § 102(b). Anticipatory as to claims reciting electrospun lignin nanofibers carbonized to carbon nanofibers without an added binder polymer; cuts against the patent's stated novelty of "binder-free" electrodes.

C. Kadla, J.F. et al., Carbon (2002)

• Full citation: Kadla, J.F., Kubo, S., Venditti, R.A., Gilbert, R.D., Compere, A.L., Griffith, W., "Lignin-based carbon fibers for composite fiber applications," Carbon, 2002, Vol. 40(15), pp. 2913–2920.
• Date: 2002.
• Description: Lignin/polymer (incl. lignin–PVA-type) blend fibers converted to carbon fiber; a classic reference on blending lignin with a fiber-forming polymer.
• § 102 exposure: § 102(b). Relevant to claims reciting a lignin + polymer blend precursor; may anticipate claims that do not narrowly require the electrospinning solvent/ratio specifics.

D. Baker, D.A. & Rials, T.G., J. Appl. Polym. Sci. (2013) / Baker, D.A. et al. (2012)

• Full citation: Baker, D.A., Gallego, N.C., Baker, F.S., "On the characterization and spinning of an organic-purified lignin toward the manufacture of low-cost carbon fiber," J. Appl. Polym. Sci., 2012, 124(1), 227–234 (and the companion 2013 review, J. Appl. Polym. Sci., 130, 713–728).
• Date: 2012 (before priority).
• Description: Spinning and characterization of purified lignin as a low-cost carbon-fiber precursor.
• § 102 exposure: § 102(a)/(b), background/obviousness art on lignin spinning feedstocks.

Consolidated § 102 map (by claim category, not claim number)

⚠️ Critical timing flag on the EDLC/capacitance data: The inventors' own paper — Lai, C., Zhou, Z., Zhang, L., Kelkar, A., Fong, H., J. Power Sources, 2014, 247, 134–141 (the "free-standing … alkali lignin … binder-free electrodes" paper) — reports the 64 F/g value quoted in the patent. It was published after the June 7, 2012 priority date, so it is not prior art to US 9,190,222 (it is the inventors' own post-priority disclosure). Do not cite it as invalidating art. I flag it because it surfaces repeatedly in the literature and could be misidentified as a § 102(a) reference.

Bottom line

• Most relevant prior art: Ruiz-Rosas et al., Carbon 48:696–705 (2010) — it is the closest single reference, disclosing electrospun-lignin-derived carbon fibers with oxidative stabilization, inert-atmosphere carbonization, and higher surface areas/pore volumes than the patent's exemplified values. It poses a genuine § 102(b) anticipation risk to the electrospinning method claims and to the carbon-nanofiber product claims (surface area / pore volume / pore size ranges), and a § 103 risk to the progressive-heating-rate claims.
• Next most relevant: Lallave et al., Adv. Mater. 2007 (coaxial/binder-free electrospun lignin carbon nanofibers) and Kadla et al., Carbon 2002 (lignin/polymer blend carbon fibers). Together they disclose the electrospinning-of-lignin-plus-polymer and binder-free concepts.
• Most likely actually-cited (Tier 1) patent art: US 3,461,082 (Otani), US 5,344,921 (Sudo), US 2007/0142225 (Baker), US 2007/0048521 (Istvan), BE 757620 — but I could not verify these as the literal front-page citations of US 9,190,222, so treat the mapping as provisional.

Caveats and recommended verification step

1. Unverified citation list. I retrieved sibling/field search reports (JP 2011504970 A; ES 2531462 B2; EP 2216431 A1 family), not the US 9,190,222 face-page "References Cited." Confirm the actual US citation list via USPTO PatentCenter or Google Patents' "Patent Citations" tab for US 9,190,222 before relying on Tier 1.
2. Claim numbers not verified. My § 102 mapping is by claim category, because I could not retrieve the granted claim set. Do not attribute these to specific claim numbers without checking the issued claims.
3. No non-corrected identifiers. All numbers above are given literally as retrieved. I did not conflate US 9,190,222 with the numerically similar patents flagged in the earlier litigation section (e.g., 9,022,022; 9,889,022; 6,263,222).
4. Pre-AIA law applies (application filed 2013-03-14, before the AIA's 2013-03-16 date), so the § 102(a)/(b)/(e) framework — not AIA § 102(a)(1)/(a)(2) — governs.

I'll research the prior art landscape for this patent. Let me run targeted searches on the cited references and the relevant technical field.

I have a strong prior-art landscape. Let me verify details and dates on the key references and check for any patent prior art cited in the family.

Obviousness Analysis — U.S. Patent No. 9,190,222 under 35 U.S.C. § 103

0. Scope, provenance, and the prior-art record actually available

Two threshold points before the analysis, consistent with the anti-conflation discipline applied in the earlier sections:

(a) The "Prior Art section of this page" as supplied contains no reference list. The patent document I was given includes only the prior-art keyword index ("nanofibers, heating, lignin, polymer, carbon") and the CPC classifications (D01F 9/17; D01D 5/0007; H01G 11/34, 11/36, 11/86). It does not contain a front-page "References Cited" list, an IDS, or an examiner's cited-art table. I therefore built the prior-art record from the technical literature that (i) the specification itself cites or relies on and (ii) my searches surfaced as pre‑June‑7‑2012 art in the same field. I could not retrieve the verbatim issued claim set (the provided text has the abstract and specification but no numbered claims), so claim numbering below is reconstructed from the Summary of the Invention as previously flagged; treat the substance as well-grounded and the numbering as unverified.

(b) Governing law frame. App. No. 13/830,043 was filed 2013‑03‑14 with priority to provisional 61/656,813 (2012‑06‑07). It is therefore an AIA (first‑inventor‑to‑file) patent; § 103 is applied under the KSR framework with the § 102(a)(1)/(a)(2) categories. A reference dated before 2012‑06‑07 is prior art; the inventors' own AIChE Annual Meeting abstract (Oct. 19, 2011) is a disclosure by the inventors and is likely excepted under § 102(b)(1)(A) (grace period), so I do not rely on it.

Legal standard applied (Graham/KSR). A claim is obvious if the differences between the claim and the prior art are such that the subject matter as a whole would have been obvious to a PHOSIT at the time of the invention. Under KSR Int'l v. Teleflex (2007), a combination is obvious where (1) the references are analogous art; (2) each claimed element is disclosed or suggested; (3) there is a rational motivation to combine (design need, market pressure, predictable variation, "obvious to try"); and (4) the combination yields no unexpected result beyond its predictable sum. A claim drawn to a result-effective variable (e.g., surface area) is obvious if the prior art teaches the parameter and the result is a matter of routine optimization (In re Boesch; In re Applied Materials).

1. The prior-art references (all pre‑June‑7‑2012) and what each teaches

These are analogous art: all are in the field of lignin conversion to carbon fibers/nanofibers and electrospun carbon electrodes, the very field to which the patent is directed.

2. Claim-by-claim obviousness

Claim 2 (and the electrospinning preamble of claim 3): "electrospinning a mixture comprising alkali lignin and a polymer"

Primary combination: P1/P2 + P3 + P4 (with P5/P6 as secondary).

• P1 and P2 teach electrospinning lignin into fibers and converting them to carbon nanofibers. P1 even uses lignin alone via coaxial spinning.
• P3 supplies the motivation to add a polymer: technical/Kraft lignins cannot be electrospun into continuous uniform fibers without a co-polymer. This is an explicit teaching that the blend is the known fix for the known problem (beaded/failed fibers).
• P4 supplies the specific polymer selection (PVA) and the mechanistic reason it will work (strong H-bonding between PVA and lignin), and P5/P6 confirm the same rationale for other water-soluble polyols with kraft lignin.

Motivation to combine (KSR): a PHOSIT seeking a spinnable, uniform lignin fiber as a carbon-fiber precursor would (i) know from P3 that a co-polymer is required and (ii) know from P4/P5 that PVA/PEO form compatible, H-bonded blends with kraft lignin. Selecting PVA from that small, known set is a predictable substitution of one known water-soluble, lignin-compatible polyol for another (In re Fout; KSR). Because P4 expressly characterizes the blend as one in which PVA–lignin interactions are strong, the combination has a reasonable expectation of success.

On the "alkali (Kraft) lignin" limitation: P3, P5, P6, and P8 all expressly name Kraft lignin as the subject lignin. The choice of Kraft/alkali lignin — the dominant, cheapest pulping by-product — is not a patentable distinction; it is the very feedstock the art used.

Potential counter-argument: P1's title emphasizes "without binder polymers." An applicant could argue this teaches away from adding a polymer. However, (i) P1's teaching-away is narrow — it says a binder is not required for organosolv (Alcell) lignin, and Alcell differs from alkali/Kraft lignin in ash/salt content; (ii) P3 affirmatively establishes that Kraft lignin does require a co-polymer, so the two references are reconcilable rather than contradictory (different lignin types); and (iii) under KSR, a teaching-away must be such that a PHOSIT would be dissuaded from the claimed combination, which is not true here for Kraft lignin. The teaching-away defense is weak-to-moderate.

Claim 3(a) and the stabilization limitations of claim 1: "heating in an oxygen-containing atmosphere to at least ~100 °C at ≤2 °C/min (progressively to ≥200 °C at ≤1 °C/min)"

Primary combination: P1 + P8 (with P7).

• P1 discloses the stabilization step in general (thermal stabilization of electrospun lignin fibers before carbonization).
• P8 is a kinetic, quantitative teaching of exactly this step for kraft lignin: thermostabilization in air up to ~340 °C, with a required heating rate of ≈0.06 °C/min or lower to maintain Tg > T and avoid fusion. P8's air atmosphere = the claimed "oxygen-containing atmosphere," and its slow rate sits within/at the low end of the claimed ≤2 °C/min and ≤1 °C/min ranges.
• P7 independently states that "careful control of heating rate was required" during stabilization of lignin-based carbon-fiber precursors.

Motivation: P8 supplies precisely the reason to heat slowly in air (to build Tg via oxidation/crosslinking and prevent the fibers fusing). The claimed ceilings of 2 °C/min and 1 °C/min are not merely disclosed but are subsumed by P8's preferred ≤0.06 °C/min teaching; the specification's own working examples use 0.05 °C/min — squarely within the prior art's range. A PHOSIT following P8 would arrive at the claimed rates as a matter of routine optimization of a disclosed, result-effective variable (heating rate).

Counter-argument: P8 studied lignin powder/"sticks," not electrospun nanofibers. But P8's governing principle (Tg must exceed T during oxidative ramp) is a material property of the lignin and applies equally to fibers; P1/P2/P10 confirm that lignin fibers are the substrate of interest. This is a form-versus-substance distinction that does not defeat obviousness.

Claim 3(c) / claim 1: the pre-carbonization step — "inert atmosphere to ≥400 °C at ≤~0.2 °C/min"

This is the narrowest and most defensible limitation, and the one an IPR would most likely target but a district court might find non-obvious.

Primary combination: P1/P2 + P7 + P8 + routine carbonization practice.

• P1 and P2 perform stabilization then carbonization and thus necessarily pass through an intermediate temperature regime; the concept of a slow, inert-atmosphere compositional transition between stabilization and full carbonization is a known pyrolysis/stabilization continuum in the pitch- and lignin-carbon-fiber arts (P6, P8, P9).
• P7 teaches that a second heat-rate-controlled stage is needed after stabilization, and P8's kinetic modeling (oxygen gain, CO₂/water loss, onset of oxygen loss above 200–250 °C) gives a PHOSIT a reason to continue a slow ramp into the 400–600 °C window in an inert gas, where oxidative reactions give way to pyrolysis/crosslinking.
• P9 (Sudo & Shimizu) and the general carbon-fiber art teach staged thermal pretreatment of lignin before high-temperature carbonization.

Analysis: The claimed pre-carbonization is a temperature-segment within the otherwise-known stabilization→carbonization continuum, distinguished by (i) an inert atmosphere and (ii) a slow rate. Inert atmospheres for carbonization are ubiquitous (P1's carbonization is inert; claim 3(d) itself recites argon). The 0.2 °C/min rate is a result-effective variable — the art (P8) teaches that slower is better for maintaining structural integrity, so a PHOSIT would reasonably optimize downward. There is no teaching of a criticality in the specification for the boundary values (0.2 vs. 0.5 °C/min are given as alternatives), which weakens any non-obviousness argument tied to the specific number.

Strength of this combination: moderate. It is a combination of known steps with a routine-optimization rate; obvious-but-not-a-slam-dunk. The best applicant rebuttal is that no single prior-art reference discloses a distinct, slow pre-carbonization hold in inert gas before the carbonization ramp, i.e., a three-stage rather than two-stage regime — which is the novelty/obviousness battleground the examiner likely addressed during prosecution.

Claim 3(d): carbonization "≥700 °C (700–2200 °C) in inert atmosphere, held to remove non-carbon elements"

Primary combination: P1 + P2 + P6/P9 + P10.

• P1, P2, P6, P9 all disclose carbonization of lignin-derived fibers in an inert atmosphere to carbon fibers/CNFs. P10 discloses the carbon nanofiber mat product. The temperature window (≥700 °C; often 900–1200 °C) and the goal of removing non-carbon elements are standard carbon-fiber processing, taught repeatedly. The 5–10 °C/min carbonization ramp of the working examples is conventional.
• This limitation is plainly obvious over the art.

Claim 4 (product): CNFs with (a) BET SSA ≥500 m²/g (or ≥550), and/or (b) pore volume ≥0.1 cm³/g, and/or (c) average pore size ≤4 nm

Primary combination: P1 (high SSA "similar to activated carbon") + P3/P4 + routine optimization.

• P1 expressly reports carbon nanofibers from electrospun lignin with specific surface areas "similar to values found for active carbon." Activated-carbON SSA typically spans several hundred to >1,000 m²/g, so a PHOSIT would expect electrospun, carbonized lignin nanofibers in the ≥500 m²/g range — the very value claimed.
• The product claim is drafted to a result-effective variable (surface area, pore volume, pore size). Where the prior art discloses the method (P1) and the parameter is a known, result-effective property of the product, the burden falls on the applicant to show unexpected results. The specification's own data show SSA increasing monotonically with lignin content (a predictable, taught trend), reaching ~583 m²/g at 70/30 — consistent with the art's teaching that higher lignin → more porous/disordered carbon.
• Motivation: optimizing lignin:polymer ratio (P3's blend-ratio teaching; P4's PVA content) and carbonization temperature to tune porosity is routine optimization of a disclosed parameter.

Counter-argument (unexpected results): The ~20× SSA increase vs. pure PVA-based CNF could be argued as unexpected. But (i) pure PVA is not the closest art (lignin-based CNFs in P1 achieve high SSA), and (ii) the increase is correlated with, and predictable from, lignin content — so the nexus between the asserted advantage and the claimed invention is weak. This argument is unlikely to succeed.

Claim 5 (EDLC): capacitor comprising the CNF with specific capacitance ≥60 F/g at 400 mA/g

Primary combination: P1 + P10 + P11.

• P11 teaches that electrospun carbon nanofiber webs function as supercapacitor electrodes.
• P10 teaches the electrospun polymer/lignin carbon nanofiber mat.
• A PHOSIT combining P11's known electrode use with P10/P1's known lignin CNF material would predict that a high-SSA lignin CNF mat makes a binder-free EDLC electrode — because supercapacitance is understood to scale with accessible surface area (a proposition the specification itself repeats).
• The numeric threshold (≥60 F/g) is a result-effective variable tied to the same SSA/porosity already addressed in Claim 4; a PHOSIT optimizing SSA and pore size would expect capacitance to follow (as the specification confirms, capacitance rises monotonically with lignin content).

Strength: strong for the article claim; moderate if the claim is construed to require the specific numeric ≥60 F/g as a critical limit, since no pre‑2012 reference reports that exact figure for a lignin-derived CNF. But given the specification's own admission that capacitance is proportional to accessible surface area, the number is a predictable result of the material optimization, not a patentable criticality.

3. Consolidated obviousness combination chart

4. Rebuttal considerations and residual uncertainty

Applicant's best non-obviousness arguments (and my assessment):

1. Three-stage progressive heat treatment with a defined pre-carbonization plateau (weak-to-moderate). The strongest position is that the specific sequence — oxidative stabilization → slow inert pre-carbonization hold → carbonization — is not squarely disclosed in one reference. This succeeds only if the PTAB/court requires the exact three-stage structure and treats the 0.2 °C/min rate as critical (the specification does not establish criticality). Under KSR's "combination of known elements," it likely fails.

2. Teaching away in P1 ("without binder polymers") (weak). As discussed, P1's teaching-away is limited to organosolv lignin; P3 establishes the opposite for Kraft lignin.

3. Unexpected results / high SSA (weak). No well-articulated nexus to the claimed ranges; the trend is predictable from lignin content.

Residual uncertainties I cannot resolve from the provided record:

• I do not have the verbatim issued claims, so I cannot certify the precise boundaries the examiner allowed. The most probable allowance hook was the pre-carbonization step (Claim 3(c) / the method-of-manufacture Claim 1), because that is the element least squarely met by P1/P2/P6/P8. If the issued claims are limited to that step with the recitation of holding at 400–600 °C for a crosslinking-sufficient time, invalidity on the art above is less certain — though still arguable under routine optimization.
• I could not locate any litigation or PTAB challenge to this patent (consistent with the prior Litigation section's negative finding). University-owned materials-science patents of this type are rarely asserted, so no adjudicated obviousness record exists to lean on.
• Publication dates: I verified P3 (2010), P4 (2003), P7 (2005), P8 (2005), P10 (2011), P11 (2003) as pre‑2012. I did not independently re-verify every date to the day; where a reference is dated "2012," the analysis would need its exact publication/priority date against 2012‑06‑07. Conversely, several closely related works (Poursorkhabi 2015; Hu & Hsieh 2013; Lai et al. 2014 J. Power Sources; Dallmeyer et al. 2014 Macromol. Mater. Eng.) are after the priority date and are not usable as § 102/§ 103 art (they are at most evidence of the state of the art at the margin, or the inventors' own later publications).

5. Bottom line

• Claims 2, 3(a)–(b), 3(d), and 4 are very likely obvious over P1/P2 + P3 + P4 + P8 (+P6/P9/P10), with clear motivations (Kraft lignin needs a co-polymer; PVA is the known compatible polymer; slow air oxidation is the known stabilization; carbonization is standard; SSA is a result-effective variable).
• Claim 5 (EDLC) is likely obvious over P1 + P10 + P11.
• The pre-carbonization limitation (Claim 1 / 3(c)) is the only genuinely contestable feature, and even it is vulnerable to a routine-optimization / "slower-is-better" attack grounded in P8's explicit kinetic teaching that heating rate should be minimized to preserve fiber integrity. Its survival depends entirely on the exact issued claim language — which must be pulled directly from USPTO PatentCenter / Google Patents for US 9,190,222 B1 before any validity opinion is finalized.

Caveat, stated plainly: this is an analyst's preliminary § 103 assessment built on the literature that the specification itself relies on, because the "Prior Art section" of the supplied page contained no cited-reference list and the verbatim claims were not available. For a binding validity/FTO conclusion, obtain (i) the issued claims, (ii) the front-page References Cited and any IDS, and (iii) the prosecution history (which will show exactly which references the examiner applied and what distinguished the allowed claims).