{ PEM }

  • Advantages of PEM Pure Water Electrolysis Hydrogen Production Equipment and Methods for Cost Reduction and Efficiency Enhancement

    Given the current situation of PEM electrolyzer, the key to their large - scale application lies in reducing costs and optimizing performance. At present, cost reduction can be achieved by optimizing the catalyst system to reduce costs, using highly conductive support materials, and replacing them with high - performance proton exchange membranes.

    I. Cost Reduction and Optimization of PEM Electrolyzer

    1. Development and Application of Low - Noble - Metal Electrocatalyst 

    ① Reducing Manufacturing Costs
    By reducing the content of noble metals (platinum, iridium, ruthenium) and improving the efficiency of the preparation process, the manufacturing costs of PEM electrolyzer electrocatalysts can be reduced, enhancing the market competitiveness of products.

    ② Improving Stability
    The stability of PEM electrolyzer electrocatalyst can be improved by adding non - metallic element doping and improving the crystal structure, making them more stable and reliable during actual use.

    ③ Enhancing Performance
    The performance of PEM electrolyzer electrocatalysts can be enhanced by adjusting the electrocatalytic activity of non - noble metals and increasing the specific surface area, reducing the activation energy barrier of the reaction and increasing the reaction rate.

    2.Design and Preparation of Highly Conductive Support Materials

    ① Improving Conductivity
    The conductivity of PEM electrolyzer electrocatalysts can be improved by selecting appropriate support materials and increasing the contact area between the catalyst and the support material, reducing the resistance loss during the reaction.

    ② Increasing Support Strength
    The support strength of PEM electrolyzer electrocatalysts can be increased by enhancing the strength and toughness of the support material and improving the preparation process, preventing the catalyst from cracking or detaching during the reaction.

    ③ .Adjusting the Microstructure
    The microstructure of PEM electrolyzer electrocatalysts can be adjusted by regulating the microstructure of the support material and changing the transport path of reactants, further optimizing the transport and reaction processes of reactants.

    3.Optimization and Improvement of Proton Exchange Membrane Structure
    At present, although many domestic manufacturers are researching proton exchange membranes, most industrial - grade applications and industrial projects still rely on products from the United States and other countries. Therefore, it is very important to carry out optimization, upgrading, and transformation of proton exchange membranes.

    ① .Selective Permeable Membrane
    Gas permeation can be reduced by introducing a selective permeable membrane. This membrane only allows the reaction gas to pass through while blocking the permeation of other gases.

    ② Sandwich Structure
    Gas permeation can be reduced by changing the sandwich structure. For example, a porous cushion can be introduced to divide the PEM into multiple small regions, reducing the cross - over of gas products.

    4.Gas Diffusion Coefficient
    Gas permeation can be reduced by lowering the gas diffusion coefficient. This can be achieved by increasing the rigidity of the polymer chain, introducing reinforcing materials, and improving the processing conditions.

    Ⅱ.Optimization of Slurry Composition and Enhancement of Physical Properties

    1.Optimization of Slurry Composition
    Adjust the catalyst, carrier components, ionomers, and other additional materials in the slurry according to requirements to optimize its performance.

    2.Enhancement of Physical Properties
    The quality of the MEA can be improved by enhancing physical properties such as the particle diameter, rheology, and Zeta potential in the slurry.

    3.Introduction of Additional Functions
    The lifespan and reliability of the MEA can be improved by introducing additional functions such as antioxidants and reducing agents.

    Ⅲ.Improvement and Optimization of MEA Processing Technology Measures

    1.Selection of Coating Methods
    Select appropriate coating methods such as electrochemical deposition, ultrasonic spraying, and transfer printing according to requirements to optimize the catalytic performance of the MEA.

    2.Modification of Coating Equipment
    Modify the existing coating equipment according to requirements to achieve roll - to - roll coating, etc., to meet industrial demands.

    3.Monitoring of Coating Film Quality
    Establish a coating film quality inspection system to monitor the quality of the coating film in real - time and implement feedback control to ensure the quality of the MEA.

  • Cooling scheme for thermal management of proton exchange membrane fuel cell (PEMFC)

    Proton Exchange Membrane Fuel Cells (PEMFC) boast advantages such as high efficiency, cleanliness, and zero emissions, making them promising for widespread application. In practical applications, 40% to 60% of the chemical energy from the fuel is converted into electrical energy, while the remaining energy is mostly converted into thermal energy. If heat cannot be promptly dissipated from the cell, the system temperature will continue to rise, leading to localized overheating of individual cells or specific areas within the cell, severely impacting the normal operation of the fuel cell.

    I. Importance of thermal management

    The main heat sources in the process of fuel cell operation are ohmic resistance heating, reaction entropy heat, irreversible electrochemical reaction heat, water vapor condensation heat release, compressed air heat and environmental radiation heat, the latter two can be ignored.

      II. Cooling scheme for fuel cells

    The main heat dissipation pathways for fuel cells are threefold: water vaporization from within the cell, radiative cooling of the stack, and heat removal by circulating cooling media. The latter is the primary method of heat dissipation for fuel cells. For PEMFCs, cooling methods can be broadly categorized into two types: single-phase cooling and phase change cooling.

    1. Single-phase cooling

    Single-phase cooling method is to use the sensible heat of cooling medium to take away the heat generated in the working process of fuel cell. There are two types: air cooling and liquid cooling, which are the most widely used cooling technology at present.

    (1) Air cooling

    Air cooling is the simplest method of cooling, where air passes through cooling plates or cathodes to carry away waste heat generated by fuel cells. The structure of the cooling system is also relatively simple. This type of heat dissipation is commonly used in low-power (≤5kW) PEMFC systems that have fewer components, lower costs, and higher system efficiency, such as in drone power systems and portable power sources.

    Fuel cell system with air cooling

    (2) Liquid cooling

    Liquid cooling is designed to separate the coolant flow path between the cathode and anode plates of the fuel cell, and relies on forced convection heat transfer of the coolant to remove the heat generated during the operation of the fuel cell.

    The coolant can be deionized water or a mixture of water and ethylene glycol. The specific heat capacity of liquids is greater than that of air, making liquid cooling more efficient in terms of heat transfer and lower flow rates compared to air cooling. Using liquid cooling, the temperature distribution in fuel cells becomes more uniform; however, it involves many components and complex structures, with significant power consumption for accessories used in heat dissipation, typically around 10% of the effective output power. For high-power (over 5 kW) fuel cells, such as those used in vehicles, liquid cooling is the most commonly employed method.

    Take the vehicle fuel cell as an example, its thermal management system mainly includes coolant pump, heat exchanger, water tank, fan, pressure sensor and other components.

      III. Phase change cooling

    Phase change cooling is to cool the heat source by using the characteristic of absorbing a large amount of heat when the object changes phase. The commonly used phase change cooling methods in fuel cells are evaporation cooling and heat pipe heat dissipation.

    (1) Evaporative cooling

    The evaporative cooling of fuel cells involves the coolant and air entering the system from the cathode side together. The coolant typically used is deionized water. The coolant can humidify the air, increasing the moisture content in the proton exchange membrane, thereby enhancing the performance of the fuel cell. At the same time, most of the coolant is carried into the core area of the reaction heat source by the air and evaporates, carrying away the heat generated during the reaction. An evaporative cooling fuel cell system does not require a humidifier, as evaporation and condensation heat exchange are more efficient than single-phase convection heat exchange, significantly reducing the load on the cooling water pump and radiator.

    (2) Heat pipe heat dissipation

    Heat pipe cooling involves embedding the heat pipe into a bipolar plate. In the absence of external power, the heat pipe transfers a large amount of heat over long distances through its cross-sectional area for cooling. The material of the heat pipe is typically copper or aluminum alloy, ensuring that the temperature at the heat source remains well-distributed. Research on the application of heat pipe cooling technology in fuel cell applications is still in its early stages and requires further development.

    Thermal management is crucial for the performance of fuel cells, affecting their efficiency, lifespan, and safety. Currently, the most widely used technology in the fuel cell field is single-phase cooling. Phase change cooling technology, with its uniformity and high efficiency, is a highly promising research direction. At the same time, effective thermal management control strategies are key to ensuring the proper operation of fuel cells. For instance, when the temperature of the fuel cell rises and the thermal management system cannot provide sufficient heat dissipation, control strategies on the power system platform should consider measures such as limiting the output power of the fuel cell to enhance its lifespan, safety, and durability. To improve the heat dissipation capability of the fuel cell thermal management system, efforts must also be made to increase the operating temperature of the fuel cell and improve the temperature characteristics of the fuel cell materials. For example, if the operating temperature of the fuel cell is increased to 95℃, the heat dissipation capacity of the thermal management system can be improved by more than 50%.

     

  • How Can PEM Fuel Cells Be Integrated into Commercial and Industrial Applications?

          Integrating Proton Exchange Membrane (PEM) fuel cells into commercial and industrial applications involves several key steps and considerations to ensure efficient, reliable, and cost-effective operation. Here’s a comprehensive guide on how to achieve this integration:

    1.  Application Assessment

    (1)Identify Suitable Applications: Determine where PEM fuel cells can be most beneficial. Common applications include backup power systems, material handling equipment (e.g., forklifts), combined heat and power (CHP) systems, and portable power solutions.

    (2)Load Requirements: Analyze the energy demands of the application to ensure the fuel cell system can meet the required power output and runtime.

    2. System Design and Sizing

    (1)Power Output: Size the fuel cell stack to match the power requirements of the application. Consider peak power demands and average load.

    (2)Balance of Plant (BoP): Design the supporting systems, including air supply, hydrogen storage and delivery, cooling, and humidification systems.

    (3)Integration with Existing Infrastructure: Ensure compatibility with existing electrical and (3)thermal systems. This may involve inverters, transformers, and heat exchangers.

    3. Hydrogen Supply

    (1)Hydrogen Storage: Choose appropriate hydrogen storage methods, such as compressed gas, liquid hydrogen, or metal hydrides, based on the application’s requirements.

    (2)Supply Chain: Establish a reliable hydrogen supply chain, including production, transportation, and refueling infrastructure.

    4. Safety Considerations

    (1)Leak Detection: Implement hydrogen leak detection systems to ensure safety.

    (2)Ventilation: Design proper ventilation systems to prevent hydrogen accumulation.

    (3)Compliance: Ensure compliance with relevant safety standards and regulations, such as NFPA 2 (Hydrogen Technologies Code) and ISO/TS 19880.

    5. Control Systems

    (1)Automation: Develop control algorithms for managing fuel cell operation, including start-up, shutdown, and load following.

    (2)Monitoring: Implement real-time monitoring systems to track performance, detect faults, and optimize operation.

    6. Economic and Environmental Analysis

    (1)Cost-Benefit Analysis: Evaluate the total cost of ownership, including capital expenditure, operating costs, and potential savings from increased efficiency and reduced emissions.

    (2)Environmental Impact: Assess the environmental benefits, such as reduced greenhouse gas emissions and lower noise levels compared to conventional power sources.

    7. Installation and Commissioning

    (1)Site Preparation: Prepare the installation site, ensuring it meets all requirements for safety, accessibility, and environmental conditions.

    (2)Testing: Conduct thorough testing to validate system performance and safety before full-scale operation.

    8. Maintenance and Operation

    (1)Routine Maintenance: Establish a maintenance schedule for inspecting and servicing the fuel cell system and its components.

    (2)Training: Train personnel on proper operation, maintenance, and safety procedures.

    9. Performance Optimization

    (1)Efficiency Improvements: Continuously monitor and optimize system performance to improve efficiency and extend the lifespan of the fuel cell.

    (2)Software Updates: Regularly update control software to incorporate the latest advancements and improvements.

    10. Regulatory and Incentive Programs

    (1)Incentives: Explore available government incentives, grants, and tax credits for fuel cell adoption.

    (2)Regulatory Compliance: Ensure all installations comply with local, national, and international regulations and standards.

    Example Applications

    1.Backup Power: PEM fuel cells can provide reliable backup power for critical infrastructure, such as data centers and hospitals.

    2.Material Handling: Fuel cell-powered forklifts offer longer runtime and faster refueling compared to battery-powered alternatives.

    3.Combined Heat and Power (CHP): PEM fuel cells can be used in CHP systems to provide both electricity and thermal energy for industrial processes or building heating.

    By following these steps, PEM fuel cells can be effectively integrated into various commercial and industrial applications, offering a clean, efficient, and reliable energy solution.

  • Selection of Ion Exchange Membrane for Water Electrolysis

     

    1、Understanding ion exchange membrane An ion exchange membrane (IEM) is a thin barrier that allows ions to be selectively passed from one electrode of an electrochemical device to another, including but not limited to water electrolysis cells and fuel cells. The ion-exchange membrane consists of a three-dimensional polymer matrix functionalized with charged (or ion-exchange) groups. These fixed charge groups completely or partially repel similarly charged ions (isoions) out of the membrane and allow ions with different charges (counterions) to pass through the membrane. In hydroelectrolytic cells and fuel cells, efficient ion transport is important for achieving high performance, reducing overpotential, and ensuring the overall effectiveness of relevant electrochemical processes.

    2、Key considerations when choosing a appropriate IEM

    According to the type of fixed charge group in the polymer backbone, IEM can be divided into two types: cationic (CEM) and anion (AEM) exchange membrane. The cation exchange membranes contain fixed negatively charged ions that allow the cations to move on the membrane. Conversely, AEM carries positively charged groups that selectively allow the transport of anions. In addition to these two basic classifications, the IEM can also be a proton exchange membrane (PEM), a bipolar membrane, an amphotropic membrane, and a mixed matrix membrane. In water electrolytic cells and fuel cells, PEM and AEM are the most useful. PEM is a special CEM that can transport protons (H + ions).

    1. When choosing an ion exchange membrane, the first consideration is the type of fuel cell and water electrolytic tank. The operation of fuel cells and water electrolytic cells involves the transport of ions; the type of ion to be transmitted determines the appropriate type of ion exchange membrane to be used. Polymer electrolyte membrane water electrolytic cell (PEMWE) and fuel cell (PEMFC) operating under acidic conditions are required to transport H + ions. Thus, both PEMFC and PEMWE use the PEM. In contrast, anion exchange membrane fuel cells (AEMFC) and anion exchange membrane water electrolytic cell (AEMWE) operate in alkaline environments. Both AEMFC and AEMWE used the AEM.

    Once the type of IEM suitable for the fuel cell and water electrolytic cell has is identified, it is time to go deeper into the specific characteristics that produce target efficiency and performance.

    2、The IEM performance and the balance between them

    In general, the properties of the IEM are determined by the characteristics of the polymer backbone and the fixed charge that constitutes its structure. In particular, the density, wettability (hydrophobic or hydrophilic) and morphology of the polymer matrix, as well as the type and concentration of charged functional groups, can affect the performance of IEM. The mechanical, chemical and thermal properties of IEM are mainly influenced by the polymer backbone, while the electrochemical properties, conductivity and overselectivity are determined by the concentration of the fixed charge. Click here to learn more about the key IEM features.

    High-performance IEM shall have high ionic conductivity, high ion exchange capacity, near-uniform overselectivity, and excellent dimensional, chemical, mechanical, and thermal stability. However, it is not easy to meet all of these requirements. We can't do everything, and in most cases, we have to find the perfect balance between these features.

    3. Working conditions

    When finding a suitable IEM for your application, you should also consider working conditions, including temperature, pressure, and humidity levels. Working conditions can affect not only IEM performance, but also its stability. Some IEM have the best performance at high temperatures, while others are designed for low temperature applications. Ensure that the selected IEM supports the device usage environment.

    4, the cost of membrane materials

    Suppose that we have found a perfectly optimized membrane with both good performance and stability. Another factor to be considered is the cost. Usually, high requirements for performance and stability require high material costs. Therefore, balancing performance requirements and budget constraints is critical because the cost of IEM affects the overall cost of fuel cells and water systems.

    Choosing the right ion exchange membrane is the key point in the design of efficient and durable hydrolysis cells and fuel cell systems. By carefully considering the above factors and conducting appropriate tests, you can make informed decisions based on the specific application requirements. Please contact us, our application engineers and in-house hydrolysis cell and fuel cell experts will help you select the best product for your application. Let's work together to pave the way for the development of clean and sustainable energy solutions.