Exchange Membrane Electrolysis Cell Research Articles

Strategies for Reducing the Ohmic Resistance in a Proton Exchange Membrane Electrolysis Cell

Ohmic polarization caused by the contact resistance between components and their own bulk resistance is the main polarization loss in proton exchange membrane electrolysis cells. To investigate this, we adopted an electrolysis cell with an active area of 25 cm2 and explored methods of reducing ohmic resistance. First, two kinds of polar plate were designed to investigate the contact area between transport layer and catalytic layer. The results showed that the polar plate with the higher ridge area made the transport layer and catalytic layer achieve good contact, resulting in an ohmic resistance decreases of 17.5 mΩ cm2 when the contact area increases from 16.85 to 21.6 cm2. Second, Pt coating was used to prevent oxidation of the titanium felt and improve electrolytic performance. Sputtering titanium felt exhibits the best performance with the electrolysis voltage of 1.814 V at 2 A cm−2. Finally, we studied different proton exchange membranes and analyzed the performance and hydrogen permeation rate with the self-made membrane electrode, finding that the electrolytic voltage of the Solvay E98–05 S reaches 1.733 V at 2 A cm−2 due to the minimum thickness and the highest conductivity, and the H2 permeation current density is only 2.184 mA cm−2.

Integration of renewable energy sources in tandem with electrolysis: A technology review for green hydrogen production

The global shift toward sustainable energy solutions emphasises the urgent need to harness renewable sources for green hydrogen production, presenting a critical opportunity in the transition to a low-carbon economy. Despite its potential, integrating renewable energy with electrolysis to produce green hydrogen faces significant technological and economic challenges, particularly in achieving high efficiency and cost-effectiveness at scale. This review systematically examines the latest advancements in electrolysis technologies—alkaline, proton exchange membrane electrolysis cell (PEMEC), and solid oxide—and explores innovative grid integration and energy storage solutions that enhance the viability of green hydrogen. The study reveals enhanced performance metrics in electrolysis processes and identifies critical factors that influence the operational efficiency and sustainability of green hydrogen production. Key findings demonstrate the potential for substantial reductions in the cost and energy requirements of hydrogen production by optimising electrolyser design and operation. The insights from this research provide a foundational strategy for scaling up green hydrogen as a sustainable energy carrier, contributing to global efforts to reduce greenhouse gas emissions and advance toward carbon neutrality. The integration of these technologies could revolutionise energy systems worldwide, aligning with policy frameworks and market dynamics to foster broader adoption of green hydrogen.

Ni and Co Catalysts on Interactive Oxide Support for Anion Exchange Membrane Electrolysis Cell (AEMEC)

Ni and Co Catalysts on Interactive Oxide Support for Anion Exchange Membrane Electrolysis Cell (AEMEC)

Research on temperature control of proton exchange membrane electrolysis cell based on MO‐TD3

AbstractTo solve the problem of temperature control in proton exchange membrane electrolytic cell (PEMEC), this paper presents a temperature control method based on multi‐experience pool probability playback and Ornstein‐Uhlenbeck noise‐twin delay depth deterministic strategy gradient. Firstly, considering the influence of water supply, anode and cathode pressure, and natural heat dissipation on temperature, a refined thermal model of PEMEC is established and transformed into a Markov model under the framework of deep reinforcement learning (DRL). Then, to solve the training instability and poor control effect of DRL caused by inertia delay of the PEMEC temperature control system, multi‐empirical pool probability playback and Ornstein‐Uhlenbeck random process noise techniques are introduced on the basis of the traditional DRL method. Finally, the simulation and hardware‐in‐the‐loop experience results show that the proposed method outperforms other advanced methods.

A “Leaf‐Vein” Flow Channel Design for the Improvement of Oxygen Transporting in a Large‐Scale Proton Exchange Membrane Electrolysis Cell

In a proton exchange membrane electrolysis cell (PEMEC), the oxygen generated on the anode side diffuses into the flow channel and forms a gas–liquid two‐phase flow with liquid water. In order to increase the production of hydrogen, larger sized PEMEC would be favorable other than series connection of smaller ones, which can save cost, though the corresponding flow channel design is lacked. Herein, a “leaf‐vein” bionic flow channel for large‐scale PEMEC (the activation area is 1350 cm2) is proposed. A 3D mixture and steady model of the PEMEC is developed to characterize the two‐phase flow in the flow field. Detailed analyses of geometric parameters are conducted through orthogonal test to determine the optimal channel geometry. The numerical results show that the optimized design of PEMEC increases medium and low oxygen gas content, and reduces pressure drop compared to traditional flow channels. An interdigitated leaf‐vein flow field is applied, which effectively alleviates gas blockage problems. This article will provide a theoretical basis for large‐scale PEMEC manufacturing.

Effect of flow channel cross-section shape on the performance of proton exchange membrane electrolysis cell

To study the thermal and mass distribution in proton exchange membrane electrolytic cells (PEMEC), a two-phase numerical model of a single-channel electrolytic cell was established. The polarization performance and gas-heat distribution in a single-channel electrolytic cell under five different flow channel cross-sections (rectangle, trapezoid, inverted trapezoid, triangle, and circle) were studied. The findings indicate that the inverted trapezoidal flow channel’s gas buildup effect is rather severe in both the catalytic and diffusion layers. In the trapezoidal flow channel, the temperature of the proton exchange membrane region is lower, and the electrochemical performance of the rectangular flow channel electrolytic cell is the best, with an improvement rate of up to 11.47%. The electrochemical performance of the triangular and circular flow channels is the worst.

Graphene-based electrochemical system for tritium enrichment

In this study, a tritium enrichment system in the water phase has been developed based on the combination of a proton exchange membrane (PEM) electrolysis cell and a fuel cell. As the PEM, NafionTM and laboratory-synthesized sulfonated poly(ether ether ketone) membranes modified with an additional graphene layer in order to enhance the tritium separation factor were used. Both differences in the kinetics of the hydrogen evolution reaction and transport through the graphene layer of different isotopes are the driving factors expected to affect the separation of hydrogen isotopes. The separation factor was measured both during the electrolysis and fuel cell stage using different membranes. The facilitating effect of the graphene on the separation efficiency was determined during the study. The separation factor obtained by the proposed method was evidently higher than that obtained by other conventional methods.

Pore-scale simulation of oxygen transport in a proton exchange membrane electrolysis cell: Effect of the hydrophilia of porous transport layer and catalytic layer

Proton exchange membrane water electrolysis (PEMWE) shows great potential in coupling fluctuating renewable energy for hydrogen production. In PEMWE, the counter-current transport of oxygen in the porous transport layer (PTL) limits the process of water reaching the catalyst layer (CL), significantly affecting the performance and stability of PEMWE. Herein, a lattice Boltzmann model coupled with a reaction boundary is proposed to consider the mechanism of oxygen expelling due to increased pressure. The model is adopted to study the influence of PTL and CL hydrophilia on the mechanism and pattern of oxygen transport. The results suggest that the PTL hydrophilia results in three different flow patterns before the oxygen breakthrough occurs. After the oxygen breakthrough, the extent of oxygen retreatment is also affected by PTL hydrophilia. Increasing PTL hydrophilia can reduce the oxygen saturation within the PTL, but may increase the saturation on the CL surface. A significant decrease in oxygen saturation at the CL surface can be achieved by increasing the hydrophilia of the CL, and even a minor increase in hydrophilia from 74.5° to 54.9° can lead to a reduction of up to 50 % in oxygen saturation. These findings have implications for rationally designing PTL structures.

An Experimental Investigation of Hydrogen Production through Biomass Electrolysis

This work investigated hydrogen production from biomass feedstocks (i.e., glucose, starch, lignin and cellulose) using a 100 mL h-type proton exchange membrane electrolysis cell. Biomass electrolysis is a promising process for hydrogen production, although low in technology readiness level, but with a series of recognised advantages: (i) lower-temperature conditions (compared to thermochemical processes), (ii) minimal energy consumption and low-cost post-production, (iii) potential to synthesise high-volume H2 and (iv) smaller carbon footprint compared to thermochemical processes. A Lewis acid (FeCl3) was employed as a charge carrier and redox medium to aid in the depolymerisation/oxidation of biomass components. A comprehensive analysis was conducted, measuring the H2 and CO2 emission volume and performing electrochemical analysis (i.e., linear sweep voltammetry and chronoamperometry) to better understand the process. For the first time, the influence of temperature on current density and H2 evolution was studied at temperatures ranging from ambient temperature (i.e., 19 °C) to 80 °C. The highest H2 volume was 12.1 mL, which was produced by FeCl3-mediated electrolysis of glucose at ambient temperature, which was up to two times higher than starch, lignin and cellulose at 1.20 V. Of the substrates examined, glucose also showed a maximum power-to-H2-yield ratio of 30.99 kWh/kg. The results showed that hydrogen can be produced from biomass feedstock at ambient temperature when a Lewis acid (FeCl3) is employed and with a higher yield rate and a lower electricity consumption compared to water electrolysis.

Optimization of power allocation for the multi-stack PEMEC system considering energy efficiency and degradation

With the large-scale application of the proton exchange membrane electrolysis cell (PEMEC), the power allocation of the multi-stack PEMEC system has attracted ever-growing attention. However, fluctuating power significantly affects the lifetime and energy efficiency of the system. In this work, a power allocation strategy of the system is proposed based on detailed modeling and characteristics analysis. A complete model of PEMEC is developed considering bubble coverage for research of operating characteristics. To analyze the energy efficiency characteristics of the system, a power model of the PEMEC stack is established. A mathematical method to real-time obtain the frontier of optimal energy efficiency of stacks is also proposed. The degradation model of the proton exchange membrane is developed to determine the safe operation boundary. And then considering the operating status, voltage degradation is introduced to characterize the degradation of PEMEC dynamically. Finally, a power allocation strategy is proposed considering the system's energy efficiency and degradation. Furthermore, a composite revenue function is presented to compare the performance of different power allocation strategies. The results show that the system has the highest consolidated revenue under the proposed strategy. Current work is conducive to the popularization and generalization of the multi-stack PEMEC system.

Study of optimization and prediction methods for PEMEC performance considering the effects of multiple operating parameters

The influence of operating parameters on the hydrogen production performance of the proton exchange membrane electrolysis cell (PEMEC) is crucial. In this paper, we first investigate the effect of a single operating parameter on the performance of PEMEC, and find the law of single operation effect. After that, the orthogonal experimental methods are used to investigate the effect of cross-coupling of combined operating parameters on the performance of PEMEC and the optimal combination of levels of operating parameters is obtained. Finally, the LSTM neural network is used to predict the PEMEC performance under the multiple operating parameters. The results showed that the weights of voltage, temperature, water flow rate, and bolt torque on PEMEC performance were 68.72 %, 20.63 %, 6.17 %, and 4.48 %, respectively. The optimal combination of operating parameters for the experiment is a torque of 3.5 N m, temperature of 70 °C, voltage of 2.0 V, and the water flow rate of 40 mL/min. It is also found that the long short term mermory (LSTM) neural network is able to predict the performance of PEMEC well, and that the experimental data-driven approach is an effective method for predicting the experimental performance.

Investigation of the degradation of proton exchange membrane water electrolysis cells using electrochemical impedance spectroscopy with distribution of relaxation times analysis

Reduction of catalyst loading on Proton Exchange Membrane (PEM) Electrolysis Cells (EC) is needed because of scarcity and high price of the catalyst. Monitoring the degradation of these cells is important to be able to allocate the different processes taking place. Electrochemical Impedance Spectroscopy (EIS) might be suitable for this purpose, but in its usual implementation, the system and the contribution of its components to the total resistance must be already known to build a suitable equivalent circuit model (ECM). Furthermore, the overlap of different processes in the Nyquist and Bode plots hinders the identification of single components of the system. The Distribution of Relaxation Times (DRT) analysis converts the EIS data into a distribution of time constants of individual processes. The contribution of each component to the full cell resistance can be identified by varying different operation parameters. In this work, a PEMEC with low iridium loading was analyzed by DRT and the faradaic processes were identified. A long-term test was carried out and the degradation of the cell was investigated by DRT analysis, to determine the components and processes which limit the cell performance.

Anode and cathode overpotentials under accelerated stress testing of a PEM electrolysis cell

An in-situ reference electrode was used under accelerated stress testing of a proton exchange membrane electrolysis cell. The reference electrode enabled the measurement of anodic and cathodic overpotentials. The accelerated stress test (dynamic load degradation) was conducted for over 1000 h, and it included half-cell measurements of the known anode and cathode potentials, repeated polarization curves, electron impedance spectroscopy and nano-scale imaging.The experiment had an average full-cell degradation rate of 77 μV/h. The anodic overpotential appears to be the main driver of the full-cell efficiency loss. The cathode EIS measurements indicate catalyst layer degradation despite minimal effect on the full-cell performance. The anodic EIS measurements yielded a resistance double that observed at the cathode. By simultaneously analyzing high frequency resistance, corrected half-cell polarization curves and half-cell EIS measurements, half-cell overpotentials can be attributed with greater confidence.

Optimization assessment and performance analysis of an ingenious hybrid parabolic trough collector: A machine learning approach

Parabolic Trough Collector (PTC) is a solar unit that can convert solar radiation into thermal energy at moderate efficiency. Researchers attempted to increase the output of the PTC units by implementing multiple methods including using helical inserts, transparent aerogel, and reflective mirrors. Nevertheless, the output of this system still is not high enough. The proficiency of the PTC unit can improve by integrating it with Thermoelectric Generator (TEG) and Proton Exchange Membrane (PEM) electrolysis cell, which is studied in the current paper for the first time. In the present study, the efficiency in both PTC-TEG and PTC layouts are poked to demonstrate the consequence of the TEG on the denoted unit efficiency. Besides, the sensitivity study is carried out to assess the influence of operating parameters. Also, extensive data collection is generated and employed to train the designed machine learning models to anticipate the performance of the units in countless operating conditions. Based on the results, the highest accuracy in predicting the performance of the units belongs to the adaptive network-based fuzzy inference system. Also, the results show that the highest entropy generation rate for the PTC and PTC-TEG-PEM units is approximately 11.0 W/m.K and 16.9 W/m.K, respectively. In addition, the highest hydrogen production rate of the PTC-TEG-PEM unit is around 21 mol/h; in fact, the electrical input of the PEM electrolyzer is maintained by the TEG module, which its electrical efficiency calculated to be 3%.

Performance analysis of PEMEC with non-uniform deformation based on a comprehensive numerical framework coupling image recognition and CFD

Proton exchange membrane electrolysis cell (PEMEC) is widely regarded as an efficient device for producing green hydrogen. Proper clamping pressure during cell assembly can reduce contact resistance while ensuring sealing and safety. Meanwhile, the clamping pressure will cause deformation of the cell components, resulting in increasing mass transfer resistance. However, the evolution law of multi-physical parameters under different clamping pressures has not been fully studied. In this study, a comprehensive numerical framework is proposed for non-uniform deformation and performance analysis of PEMEC. The framework includes three parts: non-uniform deformation model, data transmission based on image recognition, and three-dimensional (3D) multi-phase and multi-physical model. The effects of cell component non-uniform deformation on heat and mass transfer, and electrochemical characteristics are studied. The purity of hydrogen production is also fully taken into consideration. Results show that high clamping pressure causes severe deformation of liquid and gas diffusion layers under the land and a significant decrease in porosity and permeability. In addition, the accumulation of oxygen in the flow channel will weaken the liquid water supply rate and form a high oxygen covered region on the membrane. The current density inhomogeneity in this region will increase significantly with clamping pressure. Although high clamping pressure can obtain low contact resistance and high output hydrogen molar fraction, it also increases mass transfer resistance. An appropriate clamping pressure of 3 MPa is recommended with a lower cell voltage of 2.12 V at 2A/cm2 after considering the physical and chemical properties. The present study can provide helpful guidelines on the design of large-scale electrolyzers.

Experimental study of the effect of mechanical vibration and water velocity on bubble management in PEM electrolysis cell

The anode of a proton exchange membrane electrolysis cell (PEMEC) has a complex two-phase flow. Excessive gas concentrations tend to build up on the catalyst layer (CL) surface and inside the porous transport layers (PTLs), inhibiting electrolytic reactions from occurring. Therefore, efficient bubble management methods are required. In this paper, the principle of actions and the effect of mechanical vibration and water velocity as methods of bubble management are investigated. PEMEC bubble kinetic and two-phase flow performance were investigated using high-speed optical imaging at different amplitudes, frequencies and water velocities, and the results were correlated with electrochemical performance. The results show that the vertical sinusoidal vibration can cause cyclic compression of the PTL by the ribs, which promote the discharge of the blocked gas into the flow channel. This effect can be enhanced by increasing the amplitude of the vibration. During vibration, the inertia of the water causes the large bubbles to break up into smaller bubbles and can generate longitudinal shear forces that can promote the bubbles to detach and move. Increasing the frequency can enhance this effect by shortening the period of the action. However, the vertical sinusoidal vibration does not promote the discharge of air bubbles from the flow channel out of the cell, in which the thrust and lateral shear provided by water flow is necessary. Increasing the water velocity can also generate more bubble flow. The combination of vibration and high water velocity can significantly reduce the gas concentration in the cell. Polarization data shows a 7.2% reduction in cell polarization under the experimental conditions (80 mL/min, 1.5 mm, 150 Hz) compared to the normal state. The results of this study can provide theoretical basis and experimental data for the study of bubble management methods, optimization of working conditions and improvement of operating efficiency of PEMEC.

Three-Dimensional CFD Simulation of a Proton Exchange Membrane Electrolysis Cell

The energy shift towards carbon-free solutions is creating an ever-growing engineering interest in electrolytic cells, i.e., devices to produce hydrogen from water-splitting reactions. Among the available technologies, Proton Exchange Membrane (PEM) electrolysis is the most promising candidate for coping with the intermittency of renewable energy sources, thanks to the short transient period granted by the solid thin electrolyte. The well-known principle of PEM electrolysers is still unsupported by advanced engineering practices, such as the use of multidimensional simulations able to elucidate the interacting fluid dynamics, electrochemistry, and heat transport. A methodology for PEM electrolysis simulation is therefore needed. In this study, a model for the multidimensional simulation of PEM electrolysers is presented and validated against a recent literature case. The study analyses the impact of temperature and gas phase distribution on the cell performance, providing valuable insights into the understanding of the physical phenomena occurring inside the cell at the basis of the formation rate of hydrogen and oxygen. The simulations regard two temperature levels (333 K and 353 K) and the complete polarization curve is numerically predicted, allowing the analysis of the overpotentials break-up and the multi-phase flow in the PEM cell. An in-house developed model for macro-homogeneous catalyst layers is applied to PEM electrolysis, allowing independent analysis of overpotentials, investigation into their dependency on temperature and analysis of the cathodic gas–liquid stratification. The study validates a comprehensive multi-dimensional model for PEM electrolysis, relevantly proposing a methodology for the ever-growing urgency for engineering optimization of such devices.

Dynamic modeling and response characteristics of a solar-driven polygeneration system coupled with hydrogen and thermal energy storage

In this paper, a solar-driven polygeneration system integrated with a solid oxide fuel cell, an absorption chiller, hydrogen storage, and thermal energy storage is proposed for maximally utilizing solar energy and addressing the supply–demand mismatch issue on the time scale. The dynamic model and energy management strategy of the proposed system are constructed, and the short- and mid-term dynamic response characteristics against step perturbations are investigated. Based on eco-office load demands during the typical summer and winter solstices, the long-term dynamic response behaviors of the system load-tracking are also studied. The results demonstrate that: the output dynamic response times are less than 1 s for the photovoltaic, 3–22 s for the proton exchange membrane electrolysis cell, and about 25 s for the solid-oxide fuel cell, all demonstrating short-term transient response characteristics in response to step perturbations of external parameters. In contrast, the dynamic response behaviors of the parabolic trough collector and the absorption chiller elapse 10 to 30 min to reach a stable value in response to the step changes, exhibiting typical mid-term dynamic response characteristics. Furthermore, the outputs of the system could fully satisfy the eco-office load demands in summer, while grid electricity is required to supply parts of power or heat for about 11 h in the morning and evening due to the low solar irradiation and short daylight duration in winter.

Safe-efficient operation strategies for integrated system of photovoltaic and proton exchange membrane electrolysis cells

Proton exchange membrane electrolysis cells (PEMEC) can be utilized to produce hydrogen using renewable energy. In this paper, photovoltaic (PV) integrated with PEMEC is developed for hydrogen production. Based on the operation characteristics of PV and PEMEC, two operation strategies (Strategy 1 and Strategy 2) are proposed to regulate membrane temperature lower than 353.15 K under different solar irradiations. For Strategy 1, the water flow rate is firstly increased and then the inlet water temperature is reduced in the morning with increasing irradiation; and only increasing the inlet water temperature in the afternoon. While for Strategy 2, only reducing the inlet water temperature is adopted in the morning, and increasing the inlet water temperature in the afternoon. Results show that Strategy 1 outperforms Strategy 2 in terms of higher energy efficiency of 5.38% and exergy efficiency of 5.46%. However, the specific energy consumption is higher with Strategy 1 owing to higher pump power consumption, which is 6.15 kWh/Nm3.

Hydrogen production in a proton exchange membrane electrolysis cell (PEMEC) with titanium meshes as flow distributors

The proton exchange membrane electrolysis cell (PEMEC) is a green and efficient method for producing hydrogen. The flow field structure is a critical factor affecting the performance of electrolysis. However, conventional processing of flow channels is complex and expensive, a novel PEMEC structure utilizing three-dimensional titanium meshes as flow distributors instead of flow channels is proposed. It is found to exhibit higher current density, pressure, hydrogen concentration, and lower temperature than the traditional parallel flow fields. The current density is improved by 88.2 mA/cm2 and the energy consumption is reduced by 0.15 kW h N−1·m−3 at 1.9 V. Based on the uniformity index, the new structure is found to improve the current and temperature uniformity by 20.6% and 13.4%, respectively, when compared to the parallel flow field structure. Additionally, the physical properties of the mesh layers are studied in terms of their influence on electrolysis performance. The increase in porosity and decrease in thickness can enhance the performance of the cell. The results show that a structure with titanium meshes is more beneficial for improving the heat and mass transfer performance and optimizing uniform distribution than the parallel channels, which provides a new direction for the design of electrolysis cell structures.