Provenance Record

Mid-length News piece (893 words). Strong structure: Overview / What We Know / Cost and competitive context / What We Don't Know. Heavy numeric density with inline citations, careful framing of laboratory-vs-deployed-system caveat.

6 sources. (1) source-0 SCMP (HTTP 200): confirms 80x cost differential framing verbatim ('costs over 80 times more than iron as a raw industrial material at present'), 'critical bottleneck in storing intermittent power from solar and wind farms at a scale sufficient to stabilise the grid' verbatim, Tang Ao quote, 'press release on April 16' attribution verbatim, 6,000 cycles, 99.4%, 78.5%, two orders of magnitude crossover reduction. (2) source-1 Interesting Engineering (HTTP 200): confirms 6,000 cycles / '16 years of daily operation' / 99.4% / 78.5%. (3) source-2 CleanTechnica (HTTP 200): confirms 80x cost framing, 'lithium carbonate prices...swung between roughly $7,000 and $80,000 per metric ton over the past five years' verbatim, 'flow battery performance at the kilowatt or megawatt level often diverges from cell level results due to shunt currents, thermal management, and membrane fouling' verbatim, 'LFP batteries typically deliver 3,000 to 6,000 cycles at 80 percent depth of discharge' verbatim. ATTRIBUTION NOTE: the article attributes 'refers to raw material cost per unit of stored energy, not the installed system cost, which also includes membranes, pumps, and power electronics' to CleanTechnica, but in CleanTechnica this passage is itself a quotation of News 18. The wording is verbatim in CleanTechnica, but the original outlet of the framing is News 18 (cited within CleanTechnica). (4) source-3 CAS English press release (HTTP 200, dated 'Apr 17'): confirms TANG Ao / LI Ying authorship, Shenyang National Laboratory for Materials Science / Institute of Metal Research, paper title 'Synergistic Design of High Steric Hindrance and Negatively Charged Anolyte Enables 6000-Cycle Stability for Alkaline All-Iron Flow Batteries' verbatim, '11 iron complexes based on 12 organic ligands rich in hydroxyl and sulfonic acid groups' verbatim, [Fe(HPF)BHS]⁴⁻ name, 'dual protection, via Donnan exclusion' verbatim, 80 mA cm⁻² / 6,000 cycles / 99.4% / 150 mA cm⁻² / 78.5% / 392.1 mW cm⁻² / 0.9 mol / 2,000 stable cycles / 71.5% / two-orders-of-magnitude crossover reduction. (5) source-4 VnExpress International (HTTP 200): confirms '16 years' framing / 99.4% / 78.5%. (6) source-5 Wiley DOI: HTTP 403 bot-blocked, snapshot null. The journal paper is cited in the article only for existence and title; both are corroborated by the CAS press release. No verbatim claim is attributed solely to Wiley.

All numeric claims (6,000 cycles, 99.4%, 80 mA cm⁻², 150 mA cm⁻², 78.5%, 392.1 mW cm⁻², 0.9 mol, 2,000 cycles, 71.5%, two orders of magnitude, 16 years equivalence, $7,000-$80,000/ton lithium carbonate range, 3,000-6,000 LFP cycle envelope) trace to verified snapshots. Named entities (TANG Ao, LI Ying, Shenyang National Laboratory, Institute of Metal Research, Form Energy, ESS Tech, Georgia Tech, Worcester Polytechnic) are confirmed. The article correctly flags the April 16 vs April 17 date discrepancy between SCMP and CAS in its 'What We Don't Know' section — an example of careful editorial caveating, not a defect.

Publish with one attribution correction. Strong long-duration-storage reporting with careful caveating of laboratory-vs-deployed-system gap and a useful cross-reference to the existing iron-air coverage.