【 Nature Communications Literature Sharing Research 】 Anode pressurization improves the performance of AEM electrolysis water operation
Green hydrogen is a key carrier for decarbonization of new energy, and anion exchange membrane electrolyzed water (AEMWE) is considered one of the core routes for low-cost and large-scale hydrogen production due to its advantages of using non precious metal catalysts and compact equipment structure. However, for a long time, the three major challenges of insufficient water ion transport under high current density, significant hydrogen transmembrane permeation, and poor adaptability to wind solar wave conditions have always constrained the practical application and promotion of AEM WE. Recently, a joint team from Tsinghua University, Hefei University of Technology, Peking University, and Beijing Institute of Technology published a heavyweight study in Nature Communications, proposing an innovative solution of narrow channel anion exchange membrane+anode positive pressure differential coupling, which collaboratively solves industry pain points from the dual dimensions of material design and operating conditions.
1、 The existing core pain points in the industry constrain the scaling up of AEM hydrogen production
There is an irreconcilable contradiction between the current mainstream single-sided anode alkaline and cathode dry state AEM electrolysis configurations:
High current density easily leads to cathode dry film:During the electrolysis process, hydroxide ions migrate towards the anode, and electro osmosis drags water molecules to migrate in the opposite direction, forming a reverse competition with the water source required for hydrogen production at the cathode; The problem of water shortage intensifies under high temperature operation, with a significant increase in tank pressure and difficulty in breaking through current density.
Dual loss of safety and economy in hydrogen transmembrane permeation:The water transport channel inside the membrane will also allow small hydrogen molecules to penetrate the membrane layer, resulting in an increase in the hydrogen in oxygen (HTO) value under low load and wind solar dynamic fluctuation conditions. This not only reduces the purity of hydrogen and causes material loss, but also poses safety hazards such as explosion due to hydrogen oxygen mixing.
Traditional membrane improvement schemes have performance trade-offs:Simply increasing the membrane ion exchange capacity and pore size can improve water transport, but it can lead to increased membrane swelling, decreased mechanical strength, and decreased alkali stability, which cannot meet the three major requirements of high conductivity, long lifespan, and low hydrogen permeability.
2、 Top innovative solution: membrane microstructure regulation+synergistic effect of anode pressure difference
Figure 1 Schematic diagram of anode boosting ET-AEMWE with directional enhancement of H ₂ O/OH ⁻ conduction and inhibition of H ₂ crossover
1. Design logic of new membrane materials
The team independently synthesized Quinocyclonium functionalized rigid poly (terphenyl) AEM (PTPA-6-Kui) and constructed it through polymer phase separationNarrow and continuous hydrophilic nanochannels of 1-2 nmThe narrow pore structure significantly reduces the transmembrane transfer ability of hydrogen molecules, while the rigid non aromatic ether skeleton combined with cage type quinine ring cations endows the membrane with excellent alkali stability, low swelling, and high mechanical strength. After 2000 hours of alkaline aging, the performance does not significantly deteriorate.
2. Positive anode pressure differential operation mechanism (optimal pressure differential of 100 kPa)
Set a positive pressure gradient higher than the cathode on the anode side, introduce pressure driven water permeation flux, and overcome the electroosmotic reverse water transport loss caused by the electric field; On the one hand, it continuously supplies sufficient moisture to the cathode to support ultra-high current density operation, and on the other hand, the pressure difference combined with narrow pores forms a dual barrier, greatly inhibiting hydrogen transmembrane permeation.
The actual measurement of the plan shows impressive data
✅ Paired with low-cost NiFe anode, the current density reaches 11.2 A cm at 90 ℃ and 2V−2；25cm2Large area slots can directly produce 300 kPa pressurized hydrogen gas, saving back-end compression costs;
✅ 2000h long-term operation attenuation<1 μ V h−1Ultra high electrolytic cell stability, suitable for industrial continuous production;
✅ Under wind and solar fluctuation conditions, the Faraday efficiency exceeds 99.9%, and the membrane remains undamaged after 40000 dynamic load changes;
✅ According to the calculation of a 10000 ton hydrogen production station, the cost of hydrogen production is as low as 1.82 $/kg, with outstanding commercial advantages.
3、 Comparison of AEM membrane measurements
Hydrogen barrier performance comparison: PTPA-6-Kui>AEMemr-40>PiperION-A40
Figure 2 Comparison of HTO with and without 100 kPa for three AEM membranes
Among them, AEMemr-40 is the commercial membrane product brand of Anhui Jushi Hydrogen Friend Technology Co., Ltd. Under the same conditions, compared with another commercial AEM membrane, Poly Stone Hydrogen FriendsThe AEMemr-40 product has significant advantagesLow load 0.1 A cm−2Under harsh operating conditions, competitors have higher hydrogen values in their commercial membrane oxygen; After applying a pressure difference of 100 kPa, the decrease in hydrogen permeation of competing commercial membranes is limited, while the hydrogen content in the entire oxygen of AEMemr-40 is lower.
Lower hydrogen content in oxygen will bring three core values to customers
Safer:The transmembrane amount of hydrogen is significantly reduced, avoiding the risk of hydrogen oxygen mixture explosion and adapting to low load scenarios of photovoltaic and wind power fluctuations;
More cost-effective:Less hydrogen loss, higher Faraday efficiency, more hydrogen production with the same power consumption, and lower long-term operating costs;
Higher hydrogen purity:Produce high-purity hydrogen gas, simplify the investment in backend purification equipment, and adapt to diverse scenarios such as hydrogen refueling stations and chemical raw materials.
4、 Choose AEMemr®， Seize the opportunity of green hydrogen industrialization
The top journal research confirms that anode pressurization is one of the effective ways to reduce costs and increase efficiency in AEM water electrolysis, and the self-developed AEMemr-40 by Poly Stone Hydrogen Friend, relying on its excellent micro pore structure, outperforms overseas competitors in core safety indicators.
Polyrocks Hydro-friend are deeply involved in the research and development of anion exchange membranes, AEMemr®Multiple scene tests have confirmed the performance advantage. Polyrocks Hydro-friend will continue to iterate membrane material products, in conjunction with the company's developed anionic polyelectrolyte material (AEMemr)®-PAI provides high-performance and highly stable AEM integrated solutions for hydrogen production equipment manufacturers, working together to accelerate the commercialization of AEMWE green hydrogen production.
Original link
https://www.nature.com/articles/s41467-026-72950-3#ethics
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