I. Core Advantages (Suitable for Strong Acid and Strong Oxidation Conditions of Flow Batteries)
1. Electrode Application Benefits
| Advantage | Specific Performance | Fluid Battery Value | |
| Three-dimensional porous network, high specific surface area | Carbon felt / carbon cloth has a porosity of 80-95% and a specific surface area of 10-30 m²/g. | Provide a large number of electrochemical reaction active sites, accelerate the transport of vanadium ions, and enhance the power density | |
| Excellent chemical stability | Resistant to sulfuric acid (2-5 M) and strong oxidation by high-valent vanadium (VO₂⁺), does not corrode or dissolve over a long period. | Compatible battery 20 years + Longevity Life Line, no risk of metal ion contamination in the electrolyte solution | |
| Adjustable conductivity Excellent structural resilience | Graphitized carbon fibers have an electrical conductivity of 10³-10⁴ S/cm, while the carbon felt is approximately 10-100 S/cm. | Reduce ohmic polarization, enhance voltage efficiency and energy efficiency | |
| Excellent structural resilience | Flexible and compressible, it fits tightly and seals well during assembly, and does not powder or collapse during the cycle. | High assembly yield of the fuel cell stack, and small degradation in long-term cycling performance (degradation < 1%) after 1000 cycles) | |
| Reactivatable modification | Active sites can be introduced through heat treatment, plasma treatment, doping (N/P/B), etc. | Enhance the redox reactivity of vanadium ions and reduce the overpotential |
2. Advantages of bipolar plate enhancement
- Lightweight and high strength: density is only 1.7-2.0 g/cm³ (much lower than metals), tensile strength can reach 35-50 MPa, enhancing the anti-bending and anti-deformation ability of the bipolar plate
- Conductive network construction: short-cut carbon fibers form continuous conductive pathways, reducing the contact resistance of the composite bipolar plate and improving overall conductivity
- Good thermal stability: wide temperature tolerance, capable of withstanding thermal fluctuations during the charging and discharging process of flow batteries, assisting in uniform heat dissipation
II. Main disadvantages and challenges
1. Shortcomings in basic performance
- Low intrinsic catalytic activity: the surface of raw carbon fibers is inert, and the overpotential of vanadium ion redox reactions is high, requiring complex modifications (such as oxidation, doping, and loading catalysts) to enhance activity
- Insufficient wettability: surface hydrophobicity leads to poor electrolyte wettability, affecting mass transfer efficiency, and surface modification to introduce oxygen-containing functional groups is needed to improve it
- High cost: high-quality PAN-based carbon fibers have a high unit price, especially imported products from Japan's Toray, which restricts large-scale commercial application
Summary and Improvement Directions
Core Value: Carbon fiber, with its four major characteristics of lightweight, high strength, high stability, and porous structure, is an ideal material for the electrodes and composite bipolar plates of flow batteries, especially suitable for the high requirements of long-duration energy storage for lifespan and safety.
Key Bottlenecks: Cost and catalytic activity are the two core challenges that need to be overcome through the following paths:
1. Develop low-cost precursors (such as lignin-based carbon fibers)
2. Optimize modification processes (such as in-situ doping and plasma activation) to reduce overpotential
3. Improve the composite process to enhance the uniformity of carbon fiber dispersion and the interfacial bonding strength
Why choose us?
1. Super high quality: Comprehensive control over every aspect from materials to processes.
2. Core technology fully controllable: Proficient in key processes such as high-temperature graphitization and purification, supporting 72-hour non-standard customization response.
3. Ultimate quality guarantee: High-purity products reach 5N + purity, resistant to 3000℃ high temperature + strong corrosion, with full batch traceable testing.
4. Uninterrupted full-cycle service: Large-scale production + 5-7 days small-batch delivery, 24-hour technical response + on-site support.
