Flow® Series is built on a PAN (polyacrylonitrile) precursor and processed on a continuous line through carbonization, graphitization, activation, and finishing. The product family includes four needle-punched felt grades (Flow-10 / 25 / 45 / 70) and one woven carbon cloth (Flow-CC), covering thicknesses from 0.7 mm to 7.0 mm. Roll width above 1400 mm can be slit to customer-specified dimensions; energy efficiency is ≥83% at 160 mA/cm²; ASR is measured at 0.1 MPa. Grades are available for vanadium, zinc-bromine, all-iron, iron-chromium, and other flow battery chemistries.
Felt and cloth. Two architectures for two stack design philosophies.
Non-woven needle-punched felt offers high porosity (>90%) with moderate resistance, making it a common choice for commercial flow batteries. Woven carbon cloth uses oriented fiber architecture for low through-plane resistance (ASR <50 mΩ·cm²), suited to high-current-density stacks.
Flow® Series Electrode Felt
PAN long-fiber needle-punched non-woven felt, produced on the integrated continuous line. Four standard thickness grades cover use cases from thin-stack high power density to ultra-long-duration low pressure drop. Porosity >90% ensures full electrolyte wetting; roll width >1400mm is cut to customer-specified dimensions. Flow-10, Flow-25, and Flow-45 are delivered activated; Flow-70 is unactivated by default (activated version available on request).
Flow-25 · 2.5mm · Mainstream VRFB commercial standard · Activated
Flow-45 · 4.35mm · Long-duration stacks (>4h) · Activated
Flow-70 · 7.0mm · Ultra-long duration (>8h) · Unactivated by default
Flow-CC Carbon Cloth
PAN-based woven activated carbon cloth, 0.7mm standard thickness. Compared to non-woven felt, the woven structure delivers lower through-plane resistance, higher tensile strength, and better dimensional stability, well-suited to high-power-density stacks targeting current density >200 mA/cm², automated stack assembly lines, and frontier research benchmarks.
Areal weight 240–290 g/m²
Tensile strength ≥10 N · Automation-friendly
Roll width >1200mm
Technical parameters for all five Flow® Series products.
ASR is measured at 0.1 MPa, corresponding to actual commercial stack assembly pressure, which better reflects real operating conditions than the 80% linear compression sometimes used in the industry.
View full specification table (13 parameters × 5 grades) Expand
| Parameter | Unit | Flow-CC0.70mm cloth | Flow-101.0mm thin | Flow-252.5mm standard | Flow-454.35mm long | Flow-707.0mm ultra-long |
|---|---|---|---|---|---|---|
| Precursor | — | PAN woven | PAN needle-punched | PAN needle-punched | PAN needle-punched | PAN needle-punched |
| Nominal thickness | mm | 0.70±0.10 | 0.85–1.10 | 2.5±7.5% | 4.35±7.5% | 7.0±7.5% |
| Bulk density | g/cm³ | 0.29–0.34 | 0.09–0.13 | 0.08–0.11 | 0.08–0.11 | 0.08–0.11 |
| Areal weight | g/m² | 240–290 | 90–140 | 200–250 | 350–480 | 560–770 |
| Porosity | % | > 75 | > 90 | > 90 | > 90 | > 90 |
| Ash content | wt% | < 1.0 | < 0.9 | < 0.5 | < 0.5 | < 0.5 |
| ASR | mΩ·cm² @ 0.1 MPa |
< 50 | < 100 | < 200 | < 200 | < 300 |
| Tensile strength | N | ≥ 10 | ≥ 5 | ≥ 8 | ≥ 8 | ≥ 8 |
| Standard roll width | mm | > 1200 | > 1400 | > 1400 | > 1400 | > 1400 |
| Energy efficiency | % @ 160 mA/cm² |
≥ 83.5 | ≥ 83 | ≥ 83 | ≥ 82 | — |
| Activation | — | Activated | Activated | Activated | Activated | Unactivated default |
| Primary application | — | High power >200 mA/cm² |
Thin-stack flow-through |
Mainstream VRFB commercial standard |
Long-duration low pressure drop |
Ultra-long minimum pressure drop |
Flow-10, Flow-25, Flow-45, and Flow-CC are delivered activated. Flow-70 is unactivated by default (suited to zinc-bromine, ultra-long-duration VRFB, and other applications that do not require activation), with an activated version available on request. ASR test condition: 0.1 MPa per NB/T 42082-2016. Each batch is shipped with a certificate of analysis (thickness, areal weight, ASR, ash). Roll width and thickness can be cut to customer-specified dimensions. Flow-10 and Flow-CC fill thin-grade slots that are not commonly available, supporting high-power-density stack designs at scales above 0.5 m².
Fully integrated continuous line.
From samples to volume orders.
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Continuous Integrated Line
From PAN precursor screening through carbonization, graphitization, activation, inspection, and packaging, the line is managed through continuous process control across key steps. This architecture makes within-batch consistency, surface chemistry uniformity, and roll width stability traceable in-line. Annual capacity: 600,000 m².
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Single-Pass and Double-Pass Activation
Standard stacks use single-pass activation, introducing sufficient hydroxyl (–OH) and carboxyl (–COOH) functional groups. For iron-chromium chemistry or high-current-density stacks (>200 mA/cm²), double-pass activation is available for higher surface activity.
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Custom Width and Thickness
In addition to the five standard grades, intermediate thicknesses or non-standard roll widths can be produced to specific stack designs. R&D customers can request kg-level samples. Volume orders typically ship 3 to 4 weeks to mainstream overseas ports.
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Deep Purification
For applications with stricter ash requirements (such as high-specification VRFB projects sensitive to membrane lifetime), additional high-temperature purification can be added on top of the standard line to further reduce ash content.
Flow Battery Cell Stacks
VRFB, zinc-bromine, all-iron, iron-chromium, and other flow battery chemistries. Flow® Series covers applications from commercial VRFB projects to frontier iron-chromium R&D, from thin-stack high power density to ultra-long-duration low pressure drop designs. The chemistry-thickness-activation matrix is on the Solutions page.
View Full Application CoverageResearch and Benchmark Studies
For universities, research institutes, and start-ups working on electrode materials. Flow-CC and Flow-10 fill thin-grade slots not commonly available, supporting high-power-density stack research, electrode architecture benchmarks, and exploration of new chemistries. Small-batch customization and custom activation parameters supported.
Contact R&D SupportDownloads
Find the right electrode for your stack.
Share your chemistry, stack architecture, target power density, discharge duration, and active area. AYD can recommend thickness, roll width, and activation strategy. Supply ranges from kg-level R&D samples to volume orders, with standard 3 to 4 week lead times to major overseas ports.
