PBI Flow Battery Membrane
A new - generation non-fluorinated ion exchange membrane for flow batteries is developed based on the new modification of the engineering plastic polybenzimidazole (PBI). It breaks through the optimal balance of multiple performance requirements and achieves flow battery performance that surpasses that of perfluorinated proton exchange membranes. It is especially suitable for flow battery technology routes such as vanadium redox and titanium-bromine。
High Selectivity: The proton conductivity reaches the level of commercial perfluorinated sulfonic acid membranes, while the vanadium ion permeability decreases by one order of magnitude.
Ultra-thin and High Strength: The membrane thickness is reduced to 25μm, and the tensile strength and puncture strength are increased by more than 50% compared with commercial perfluorinated sulfonic acid membranes.
High Reliability: It has passed 5000 cycles of accelerated aging test, and the key performance has no attenuation.
SPECIFICATIONS
| Specifications | ||
|---|---|---|
| Performance | Technical Indicator | Test Method |
| Thickness (μm)ⁿ | 25 | NB/T 42080-2023 |
| Ionic Conductivity (mS/cm) | ≥40 | NB/T 42080-2023 |
| Vanadium Ion Diffusion Coefficient (cm²/min) | ≥≤9.0×10-8 | NB/T 42080-2023 |
| Tensile Strength (MPa) | ≥40 | NB/T 42080-2023 |
| Elongation at Break (%) | ≥80 | GB/T 1040.1-2018 |
| Puncture Strength (N) | 6.5 | GB/T 37841-2019 |
| Coulombic Efficiency of Vanadium Batteryᵇ | ≥99% | NB/T 42081-2016 |
| Energy Efficiency of Vanadium Batteryᶜ | ≥83.5% | NB/T 42081-2016 |
ⁿProducts with a thickness of 15-50μm are available;
ᵇ ᶜTested with energy storage batteries, test current density is 180mA/cm².
CORE COMPETITIVENESS
Lower Cost：The price is over 30% lower than that of mainstream perfluorinated membranes, significantly reducing system costs；
Better Performance ：Key indicators (EE/CE) are comprehensively superior to perfluorinated membranes, improving energy efficiency and benefits；
Environmentally Friendly：Fundamentally eliminate perfluorinated compounds (PFCs) pollution, green and biodegradable；
Technological Leadership ：Take the lead in realizing the commercial application and verification of non-fluorinated ion exchange membranes.
TEST PERFORMANCE
Performance Comparison between PBI Flow Battery Membrane and Commercial Perfluorinated Sulfonic Acid Membrane Battery.
| CURRENT DENSITY(mA/cm²) | PBI flow battery membrane | Commercialized PFSA membrane1 | Commercialized PFSA membrane2 | ||||||
|---|---|---|---|---|---|---|---|---|---|
| CE（%） | VE（%） | EE（%） | CE（%） | VE（%） | EE（%） | CE（%） | VE（%） | EE（%） | |
| 120 | 99.6 | 88.9 | 88.5 | 96.2 | 87.8 | 84.4 | 95.6 | 88.4 | 84.6 |
| 150 | 99.7 | 86.6 | 86.1 | 96.0 | 85.1 | 81.7 | 95.8 | 85.6 | 82.0 |
| 180 | 99.6 | 83.9 | 83.5 | 96.2 | 82.4 | 79.2 | 96.0 | 82.8 | 79.5 |
| 210 | 99.6 | 82.3 | 82.0 | 96.2 | 80.7 | 77.6 | 96.0 | 82.7 | 77.5 |
| 240 | 99.6 | 81.3 | 81.0 | 96.2 | 79.0 | 76.0 | 96.1 | 78.7 | 75.7 |
Long-cycle Test of 5000 Cycles for PBI Flow Battery Membrane: A 1kW stack operated at a constant current density of 240mA/cm², where the performance degradation caused by vanadium ion crossover can be restored to the initial state through electrolyte mixing.
SPEEK Flow Battery Membrane
Sulfonated polyetheretherketone (SPEEK) membrane is a high-performance fluorine-free ion exchange membrane prepared by sulfonation modification of polyetheretherketone (PEEK) backbone, specifically designed for flow batteries. Featuring a unique molecular structure, the arrangement of ether bonds, ketone bonds, and benzene rings in SPEEK endows it with exceptional adaptability in flow battery environments. Its swelling resistance outperforms other fluorine-free ion exchange membranes, effectively mitigating performance degradation caused by swelling. The product is suitable for zinc-manganese, zinc-bromine, zinc-iron, all-iron, and other flow battery technology routes, as well as electrodialysis separation.
| Specifications | ||
|---|---|---|
| Item | Technical Indicator | Test Method |
| Appearance | Colorless and Transparent | - |
| Thickness (μm) | 25、50、75 | NB/T 42080-2016 |
| Degree of Sulfonation (%) | 60 | - |
| Ionic Conductivity (mS/cm) | 15-20 | NB/T 42080-2016 |
| Tensile Strength (MPa) | 24-28 | GB/T 1040.3-06 |
| Elongation at Break (%) | 28-32 | GB/T 1040.3-06 |
SPPSU Flow Battery Membrane
Sulfonated polyphenylsulfone (SPPSU) flow battery membrane is a high-performance fluorine-free ion exchange membrane prepared by sulfonation modification of the polyphenylsulfone (PPSU) backbone, specifically designed for flow batteries and suitable for large-scale energy storage systems. This membrane endows polyphenylsulfone materials with excellent ion selectivity and conductivity through sulfonation modification technology, which can efficiently isolate the positive and negative electrolytes and realize the directional transport of protons/ions, ensuring the battery's energy conversion efficiency and cycle stability. Its unique chemical structure enables it to exhibit excellent durability under harsh conditions such as strong acid, strong oxidation, and high potential difference, making it one of the core components for the new generation of flow batteries to achieve long-life and low-cost energy storage.
| Specifications | ||
|---|---|---|
| Item | Technical Indicator | Technical Indicator |
| Appearance | Colorless and Transparent | - |
| Thickness (μm) | 25、50 | NB/T 42080-2016 |
| Degree of Sulfonation (%)） | 30 | - |
| Ionic Conductivity (mS/cm) | 8-10 | NB/T 42080-2016 |
| Tensile Strength (MPa) | 40-45 | GB/T 1040.3-06 |
| Elongation at Break (%) | 4-8 | GB/T 1040.3-06 |