The Function of Diaphragm Materials in Hydrogen Production by Water Electrolysis 

The Function of Diaphragm Materials in Hydrogen Production by Water Electrolysis

Under the objectives of "carbon neutrality" and "carbon peaking," the wave of replacing fossil energy with clean energy has fully commenced. Hydrogen energy, with its high calorific value and low pollution and greenhouse gas emissions, is recognized as a crucial pathway toward achieving carbon neutrality.

According to the "Medium- and Long-Term Plan for Hydrogen Industry Development (2021-2035)," by 2025, pilot demonstrations in transportation, industry, energy storage, and power generation will be systematically implemented, with renewable energy hydrogen production reaching 100,000-200,000 tons per year, establishing itself as a significant component of new hydrogen energy consumption. By 2030, China aims to gradually develop a relatively comprehensive clean energy hydrogen production and supply system that supports the attainment of its strategic goal for carbon peaking. As outlined in the "Key to Opening a New Era of Green Hydrogen: China's 2030 'Renewable Hydrogen 100' Development Roadmap," by 2030, the supply of renewable hydrogen will reach 7.7 million tons. Considering regional economic and industrial characteristics, renewable hydrogen will first be widely applied in sectors such as chemicals, transportation, and steel, which have higher technical maturity and application feasibility.

With ongoing economic development and population growth, fossil fuels such as oil and coal-due to their non-renewable nature and finite reserves-pose an imminent risk of severe energy crises. Consequently, there exists an increasingly urgent imperative to advance clean and renewable new energy sources.

Currently, primary methods for hydrogen production include alkaline water electrolysis (ALK), proton exchange membrane electrolysis (PEMD), high-temperature solid oxide electrolysis (SOEO), and solid polymer anion exchange membrane electrolysis (AEM).M).

Water electrolysis for hydrogen production has gained significant popularity in recent years. On one hand, it enables "zero carbon emissions," resulting in the generation of genuinely clean "green hydrogen." On the other hand, water electrolysis can convert intermittent and unstable renewable energy sources (such as wind, solar, and nuclear power) into stored chemical energy, thereby facilitating the utilization of renewable electricity. This process yields substantial ecological and economic benefits.

Alkaline water electrolysis is currently the primary method for green hydrogen production in China. In alkaline electrolysis cells, a diaphragm is essential to separate the cathode and anode electrodes; this prevents short circuits while inhibiting the permeation of H₂ (produced at the cathode) and O₂ (generated at the anode) through the diaphragm. At the same time, the diaphragm acts as a channel for the movement of the electrolyte, allowing OH-ions to be transported from the cathode to the anode.

The function of Diaphragm Materials

Ion Transport: Diaphragms facilitate the transfer of ions (such as hydroxide or hydrogen ions) in the electrolyte.

Safety Barrier for Gases: Diaphragms prevent the crossover or permeation of hydrogen and oxygen between the electrodes.

Electrical Insulation: Diaphragms prevent the transfer of electrons between the two electrodes (preventing electrical conductivity).

Water electrolysis represents a relatively convenient approach to hydrogen production. Within an electrolytic cell filled with electrolyte solution, direct current is applied; consequently, water molecules undergo electrochemical reactions at both electrodes. At the cathode, water molecules are reduced to produce hydrogen gas along with hydroxide ions. These hydroxide ions traverse through the physical diaphragm to reach the anode where oxygen gas is released alongside additional water formation.

In this context, BoLian company has seized the "windfall" of hydrogen industry development. With profound scientific research capabilities, it has innovatively developed "membrane materials for hydrogen production," opening a new market track in the filter cloth industry. In 2024, the company will once again collaborate with Dalian Polytechnic University to jointly launch a research project on composite membrane materials for hydrogen production, including upgrading existing membranes and developing new composite membranes.

The project also completed the pilot testing of existing diaphragm products and can be produced on a large scale. The new composite diaphragm has also achieved a breakthrough on the basis of the original product.