Porimion® High-Current-Density Flow Battery Membrane
PRODUCT OVERVIEW
Developed from an innovative non-fluorinated polybenzimidazole (PBI) resin system, this ion-exchange membrane is specifically engineered for high-current-density flow battery stacks. It offers enhanced mechanical strength and puncture resistance, delivering energy efficiency surpassing that of perfluorinated proton exchange membranes. The membrane is well suited for vanadium, titanium–bromine and acidic flow battery chemistries. Its excellent vanadium-ion blocking capability significantly reduces self-discharge and improves coulombic efficiency during vanadium battery operation, effectively addressing the high self-discharge issue in fast-response frequency-regulation applications. This advancement is expected to accelerate the deployment of vanadium flow batteries in regulation services.
PRODUCT FEATURES
High Strength & Ultra-Thin:Tensile and puncture strength are increased by over 100% compared with perfluorosulfonic membranes, withstanding carbon-fiber penetration. The uniform membrane thickness is reduced to 25 µm for stack use, enabling significantly higher current densities.
High Selectivity:Proton conductivity matches that of perfluorosulfonic membranes, while vanadium-ion permeability is reduced by an order of magnitude, greatly improving coulombic and energy efficiency.
Low Self-Discharge:Extremely low vanadium crossover raises coulombic efficiency to above 99%, substantially reducing self-discharge—ideal for long-duration, uninterrupted frequency-regulation operation.
High Reliability:Validated through 5,000-cycle accelerated aging tests with no performance degradation.
Environmentally Friendly:Eliminates the environmental impact of fluorinated permanent plastics; fully degradable and compliant with EU and North American defluorination requirements.
SPECIFICATION
| Specifications | ||
|---|---|---|
| Performance | Technical Indicator | Test Method |
| Thickness (μm)a | 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) | 7 | 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 |
aProducts with a thickness of 15-50μm are available;
b、cTested with energy storage batteries, test power density is 180mW/cm2.
TEST PERFORMANCE
Performance comparison between the Porimion® flow battery membrane and PFSA membranes in a 1 kW vanadium flow battery stack.
| POWER DENSITY(mW/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 |
Porimion® membrane 5,000-cycle long-term test in a 1 kW vanadium stack:Operated at a constant power density of 240 mW/cm². Performance loss caused by vanadium-ion crossover can be fully restored to the initial level through electrolyte remixing.
