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Background Overview

Since China first proposed the energy-saving and emission reduction goals of "peaking carbon emissions by 2030 and achieving carbon neutrality by 2060" in September 2020, the importance of clean new energy technologies in optimizing China's energy structure has received continuous attention. In the field of energy storage and power battery technology, liquid flow batteries and fuel cells are widely believed to be widely promoted and applied in the future due to their environmentally friendly, long lifespan, high safety, and high energy efficiency characteristics.
In the new battery technology, the flow battery, as a new type of secondary battery, achieves the charging and discharging of the battery through reversible changes in the valence state of chemical active substances, thereby achieving the goal of mutual conversion between chemical energy and electrical energy. Fluid flow batteries play an important role in energy storage for discontinuous renewable energy, with characteristics such as safe operation and long cycle life. They are considered one of the most promising new energy supporting energy storage technologies.
Taking the all vanadium redox flow battery as an example, the battery reaction formula is:
Anode: VO2++H2O==VO2++2H++e-
Cathode: V3++e -=V2+
Total reaction: VO2++H2O+V3+==VO2++2H++V2+

As an energy conversion device that converts chemical energy into electrical energy, fuel cells utilize fuel and oxygen directly, especially hydrogen oxygen fuel cells, whose final product is water molecules that have no impact on the environment. As a representative and hot topic of clean energy power battery technology, fuel cells are considered the most ideal source of vehicle power supply in the future. Taking hydrogen oxygen fuel cells under acidic conditions as an example, their battery reaction formula is:
Anode: H2==2H++2e-
Cathode: 2H++O2+2e -==H2O
Total reaction: H2+O2==H2O

Ion exchange membrane is an important structural component of liquid flow batteries and fuel cell devices. This polymer thin film material with ion groups selectively penetrates ions to achieve the construction of a complete circuit in the battery structure. At present, ion exchange membranes can be mainly divided into two types based on their different functional groups: cation exchange membranes and anion exchange membranes. Cation exchange membranes are mainly composed of negatively charged sulfonic acid groups used for cation transfer, such as proton exchange membranes that transfer H+ions. The negatively charged groups on the cation exchange membrane form a strong negative electric field, which attracts protons to pass through the membrane and repels anions to intercept them; The anion exchange membrane is mainly composed of positively charged functional groups (including quaternary ammonium salts, imidazole salts, quaternary phosphates, etc.), which form a positive electric field to attract OH - and achieve the transfer of OH - ions in the electrolyte, while blocking the passage of cations. The schematic diagram is as follows [1].

Schematic diagram of the working principle of anion and cation exchange membranes [1]

Technical research and analysis

Fuel cell ion exchange membrane

At present, research and application of ion exchange membranes in fuel cells mainly focus on two categories: proton exchange membrane fuel cells and anion exchange membrane fuel cells. The ion exchange membrane is an indispensable component for separating the anode and cathode of fuel cells and achieving specific ion transfer functions.
1. Ion exchange membranes in proton exchange membrane fuel cells (PEMFC)
Proton exchange membrane fuel cells are the most promising clean power source for vehicles, and their working principle is shown in the following figure. At the anode, the incoming hydrogen gas reacts with the catalyst to lose electrons and generate H+. The lost electrons and the generated H+reach the vicinity of the cathode through the external circuit and proton exchange membrane, respectively; At the cathode, the oxygen introduced reacts with H+to generate electrons and water.
At present, the most widely used proton exchange membrane is the perfluorosulfonic acid membrane (Nafion) developed by DuPont, which has excellent chemical stability, high mechanical strength, and outstanding ion conductivity at low temperatures and high humidity. In the field of proton exchange membranes for fuel cell vehicles, Gore Company of the United States is leading the way with expanded polytetrafluoroethylene composite membrane technology (ePTFE). The Nafion membrane is composed of highly hydrophobic semi crystalline polytetrafluoroethylene main chains and perfluorinated side chains containing sulfonic acid groups. The sulfonic acid groups inside the membrane can form continuous nanoscale hydrophilic channels through self-assembly, giving it excellent proton conductivity. However, there are also some drawbacks. Currently, the synthesis and sulfonation of perfluorinated substances are very difficult, and membrane formation is also quite difficult, resulting in high costs. In addition, Nafion membranes have poor proton conductivity at medium and high temperatures, and the selectivity of the membrane still needs further improvement and enhancement.

Chemical structure diagram of Nafion membrane [2]
Schematic diagram of the working principle of PEMFC [3]
2. Ion exchange membranes in anion exchange membrane fuel cells (AEMFC)
Compared with proton exchange membrane fuel cells, anion exchange membrane fuel cells have faster kinetics of oxygen reduction under alkaline conditions and relatively lower dependence on traditional platinum based precious metal catalysts. Non precious metal catalysts such as Ni and Ag can be used to replace them, greatly reducing the cost of fuel cells. The schematic diagram of its working principle [4] is shown below. At the cathode, oxygen and water undergo electron reduction under the action of a catalyst to generate OH -. The generated OH - ions are transported to the vicinity of the anode through an anion exchange membrane (AEM); At the anode, hydrogen gas reacts with OH - under the action of a catalyst to lose electrons and generate water. Electrons are conducted to the cathode through an external circuit, forming a battery circuit.

Schematic diagram of AEMFC working principle [4]
At present, AEMFC ion exchange membranes are composed of polymer frameworks (aromatic polymers such as polyphenylene ether, polyarylethersulfone, and polybenzimidazole, as well as polyolefin polymers) and the main working groups that provide ion conduction (including quaternary ammonium salts, imidazole salts, quaternary phosphine salts, etc.). The ion exchange membrane in AEMFC generally operates in a strong alkaline environment rich in hydroxide ions and has a good vanadium blocking effect. However, its anion exchange groups are gradually deactivated by OH - ions, leading to a continuous decrease in the performance of the exchange membrane.
Ion exchange membrane in all vanadium redox flow batteries

All vanadium redox flow batteries (referred to as all vanadium flow batteries) have always been a focus of attention in the layout of intermittent new energy storage equipment, and can be used as supporting energy storage technologies for renewable energy such as solar and wind energy. The all vanadium flow battery was first proposed by Maria Kacos from the University of New South Wales in Australia in 1985. In the 1980s, Sumitomo Electric and Kansai Electric successfully prepared all vanadium flow battery packs. In 2003, VRB Power System, a Canadian company, developed an all vanadium flow battery energy storage system based on wind power generation and successfully commercialized it. In 2005, Dalian Institute of Chemical Physics successfully developed a 10kW all vanadium flow battery energy storage system, marking an important beginning for the application of flow battery energy storage in China. In 2014, Rongke Energy Storage and Bosch from Germany jointly designed and constructed a commercial all vanadium flow battery energy storage system based on wind farms, with a capacity of 250kW/1MWh. The schematic diagram of the working principle of the ion exchange membrane in the all vanadium redox flow battery is as follows [5]:
Schematic diagram of the working principle of ion exchange membrane in all vanadium flow battery [5]
The ideal all vanadium flow battery separator needs to have:
Low vanadium ion permeability reduces pollution caused by transmembrane transport of vanadium ions;

Excellent chemical stability and high mechanical strength enable the film to have a long lifespan under acidic conditions, thereby increasing battery life;
High ion conductivity and good ion selectivity result in high battery efficiency;
Low water flux, during the charging and discharging process, keeps the electrolyte at the anode and cathode balanced;
(5) Low processing and production costs are conducive to the widespread application of diaphragms.
1. Cation exchange membrane for all vanadium flow battery
The cation exchange membrane of all vanadium flow battery refers to the membrane containing cation exchange groups (such as sulfonic acid groups, phosphate groups, carboxylic acid groups, etc.), among which the sulfonic acid group (- SO3H) is more acidic and easier to dissociate H+, thereby improving the conductivity of the membrane. At present, the proton exchange membrane represented by Nafion membrane is widely used in the commercial field, which uses sulfonic acid groups as exchange groups as the standard separator for all vanadium redox flow batteries. It has high stability in the electrolyte, but due to its high vanadium ion permeability, difficulty in degradation, and high cost, it has to some extent limited the further development of flow batteries. Although there has been continuous research on modifying Nafion membranes to reduce their vanadium ion permeability, the cost has not decreased.
2. Anion exchange membrane for all vanadium flow battery

The all vanadium flow battery anion exchange membrane refers to the membrane containing quaternary amine groups (- NR3X), tertiary amine groups (- NR2) and other anion exchange groups, which can allow sulfate ions and hydrogen sulfate ions to pass through the film, reducing the vanadium ion passing rate and the oxidation of the membrane surface caused by adsorption on the film, thereby improving the film's lifespan. At present, the main problem is focused on its low ion conductivity, which leads to low efficiency of flow batteries. Further research is needed to achieve large-scale applications.
3. Amphoteric ion membrane for all vanadium flow batteries
A zwitterionic membrane refers to a membrane that contains both anion and cation exchange groups. It is hoped to combine the low vanadium ion transmittance of the anion exchange membrane and the high conductivity of the cation exchange membrane to improve the service life and efficiency of the flow battery. However, the synthesis process of this membrane is complex, costly, and has low stability, and further development is needed.
Market research and analysis
Main types and current status of ion exchange membranes
1. Proton Exchange Membrane (PEM)
Proton exchange membranes, as a current research hotspot in liquid flow batteries and fuel cells, have been developed for over 60 years, as shown in Table [5]. During this period, the energy density and service life of thin films have continuously improved and improved.
At present, the production process of proton exchange membranes includes fluorite basic materials, which first react with sulfuric acid to obtain hydrofluoric acid as an intermediate product, and then react with chloroform to generate the raw material difluorochloromethane (R22) required for subsequent resin preparation. According to the specific requirements of different types of membranes produced, R22 is processed into various perfluorinated, non perfluorinated, and special resin materials. The proton exchange membrane obtained through further processing can be widely used in fields such as fuel cells, flow batteries, water electrolysis, and chlor alkali industry.
2. Perfluorosulfonic acid proton exchange membrane (PFSA membrane)
Perfluorosulfonic acid proton exchange membrane is currently a commercialized fuel cell membrane material. Due to its complex preparation process and high technical requirements, it has long been monopolized by American and Japanese companies such as DuPont and Asahi. In 2009, DuPont, a leading enterprise in perfluorosulfonic acid proton exchange membranes in the United States, produced the Nafion Ⓡ series of membranes (Nafion Ⓡ 112, Nafion Ⓡ 115, Nafion Ⓡ 117, etc.), Solvay in Belgium produced Aquivion Ⓡ membranes, while Asahi and Asahi Chemicals in Japan produced Flemion Ⓡ membranes and Acrylex Ⓡ membranes, respectively. The domestic market started relatively late, and currently Shandong Dongyue Group and Kerun Group are well-known in China. Dow Group in the United States once produced an XUS-B204 membrane. The main difference between it and three perfluorosulfonic acid proton exchange membranes, Flemion Ⓡ, Acidex Ⓡ, and Nafion Ⓡ, is the length of its fluorinated side chains (as shown in the figure) [6]. Dow Group's XUS-B204 membrane has a z-value of 0, which results in a lower equivalent weight EW value (referring to the mass of resin containing 1mol ion exchange group - SO3H) and a significant increase in conductivity. However, due to the short side chains, the synthesis difficulty is high, and the cost is also high. Finally, production was discontinued. The Aquivion membrane, which is also a short branched chain membrane, is still in production due to its higher sulfonic acid content to maintain the water content inside the membrane, resulting in better battery performance.
Chemical structures of four perfluorosulfonic acid proton exchange membrane substrates in 2009 [6]
By 2011, as shown in the table, the main production of perfluorosulfonic acid proton membranes was still dominated by several major enterprises, and product parameters were constantly improving to give them better performance. Shandong Dongyue Group has also achieved success in the preparation of perfluorinated sulfonic acid membranes, using short chain sulfonic acid resin to prepare high-performance, suitable for high-temperature PEMFC short chain perfluorinated sulfonic acid membranes. The single cell output performance at 95 ℃ and 30% relative humidity is superior to that of Nafion Ⓡ 112 membrane and Suwei Company E97-03S membrane under the same conditions.
At present, looking at the downstream market of perfluorosulfonic acid proton exchange membranes, fuel cells are still the main application and commercialization field of proton exchange membranes. According to statistics from E4tech, the global shipment volume of PEM fuel cells exceeded 934MW in 2019, an increase of nearly 20 times compared to the same period in 2011, mainly sold to Asia and North America.
3. Partially fluorinated, non fluorinated composite membranes and other membranes
At present, some enterprises and experts have also conducted research on porous proton exchange membranes (referred to as porous membranes), partially fluorinated proton exchange membranes, and fluorine-free proton exchange membranes, mainly through the modification of commercial films or the regulation of production conditions for exchange membranes. Part of the fluorinated proton membrane is mainly used to ensure a longer service life by changing the introduction method of sulfonic acid groups, such as grafting sulfonic acid branched chains after main chain polymerization, copolymerizing main chains first followed by sulfonic acid branched chains, and direct polymerization of sulfonic monomers, while ensuring a fluorinated main chain. The BAM3G (sulfonated or phosphated trifluoromethylene proton exchange membrane) produced by Ballad Company shows a cost of $50-150/m2, which is much lower than that of perfluorosulfonic acid proton exchange membrane manufacturers, but has a shorter lifespan than perfluorosulfonic acid proton exchange membranes.
Due to the low cost of raw materials and environmental friendliness, non fluorinated thin films are considered as proton exchange membranes with broad prospects in the future. Non fluorinated thin films are still in the research stage, and further development is needed in terms of conductivity, chemical stability, and service life. The sulfonated styrene butadiene/styrene block copolymer film developed by DAIS in the United States can achieve conductivity comparable to Nafion films when the sulfonation degree is above 50%. Its service life is 2500 hours at 60 ℃ and 4000 hours at room temperature, and it is expected to be applied in low-temperature fuel cells in the future. In addition, porous membranes have shown superior low vanadium ion transmittance and proton conductivity in experimental research compared to commercial membranes, and are expected to be applied in liquid flow batteries with further improvements in the future.
4 Anion Exchange Membrane (AEM)
Accompanied by the use of non precious metal catalysts in fuel cells is the anion exchange membrane. The biggest limitation of fuel cell vehicles and applications is the high cost and high price brought by platinum metal. Therefore, the development of anion exchange membranes is of great significance for the widespread application of fuel cells in the future. At present, anion exchange membranes are mainly used in other electrochemical fields, such as electrodialysis, and there are few reports on their application in fuel cells and flow cells. The production companies are mainly foreign companies, such as Tokuyama in Japan and Solvay in Belgium. Dongshan Company in Japan mainly produces anion exchange membranes with quaternary amine groups, such as AHA, AMX, A-006, etc.
Main production methods
At present, the main method for producing perfluorosulfonic acid proton exchange membranes in industry is to make membranes from perfluorosulfonic acid resin through melt extrusion and solution casting (casting method) [8]. The production of perfluorosulfonic acid resin is generally achieved through the use of suitable initiators and dispersants, using monomers containing sulfonyl fluorine groups and multi suspension copolymerization with tetrafluoroethylene and hexafluoropropylene.
Melt extrusion method
Perfluorosulfonic acid resin is a raw material for preparing perfluorosulfonic acid proton membranes, with thermoplastic properties. Its initial decomposition temperature is about 310 ℃, which is much higher than its melting temperature by about 200 ℃. Therefore, the resin can be extruded into a thin film by melt extrusion without causing its decomposition. The thin film produced by melt extrusion does not have ion exchange function and requires hydrolysis transformation. The industrial process diagram of hydrolysis transformation is shown in the following figure [7]. The melt extrusion method is suitable for large-scale continuous film production, with high preparation efficiency and uniform thickness. However, there are often "pinhole" defects, and maintaining flatness during the hydrolysis transformation process requires high equipment and technical requirements. Currently, it is almost monopolized by American and Japanese enterprises.
Industrial process diagram of perfluorosulfonic acid exchange membrane hydrolysis transformation [8]
2. Solution casting method (flow casting method)
The solution casting method is different from the melt extrusion method. Its core processes are resin transformation, resin dissolution, and mold casting, which first undergo resin transformation and then flow onto the template to form a film. In the process, the - SO2F type resin needs to be converted to the - SO3M ion type using MOH first, then dissolved in a low boiling solvent in the reactor, replaced with hyperbranched polymer (HBPS), removed from the solvent, and finally cast into the mold for molding. This process can directly obtain ionic products and obtain high-strength, high flatness perfluorosulfonic acid proton exchange membranes.
3. Steel strip casting method
The steel strip casting method has certain similarities with the solution casting method, mainly reflected in the need to first transform perfluorosulfonic acid resin into - SO3Na ion type, obtain film making liquid through low boiling solvent dissolution and high boiling solvent replacement, and then cast into film on the steel strip casting machine, which is conducive to the continuous production of thin films. At present, Kerun New Materials mainly adopts this film-forming method.
Analysis of Major Enterprises
1. Gore Corporation in the United States
Gore Company was founded in 1958. Gore Company first discovered expanded polytetrafluoroethylene (ePTFE) and, based on the production of DuPont Nafion membranes, combined perfluorosulfonic acid resin with heat-resistant and corrosion-resistant expanded polytetrafluoroethylene polymer through impregnation drying to produce an enhanced perfluorosulfonic acid Gore Select composite membrane, which reduces thickness to up to 5 μ m. Currently, it has achieved mass production with a thickness of 8 μ m, while reducing the amount of perfluorosulfonic acid resin and achieving cost reduction. In terms of performance, it is superior to DuPont's second-generation membranes in terms of conductivity, chemical stability, and mechanical strength. The implementation of ultra-thin proton exchange membranes can effectively reduce ion conduction resistance, reduce Ohmic polarization, improve water vapor conductivity, increase proton conductivity, and enhance stack power density. This has also enabled Gore Company to quickly occupy the global market and become a leading enterprise in fuel cell vehicle proton exchange membranes.
As early as the first generation Gore Select proton exchange membrane was launched, it became the core component of the fuel cell pack in Toyota MIRAI in 2014. The enhanced version of the second generation Gore Select proton exchange membrane has helped MIRAI-2021 achieve better performance of 152 kilometers per kilogram hydrogen fuel, with reduced stack volume, increased lifespan, and lower costs.
According to relevant reports, Gore Company's sales in 2018 were about 3.7 billion US dollars, and the world's first proton exchange membrane production line for fuel cell vehicles with a scale of one million square meters began production in Okayama, Japan in 2019. Its 5 μ m ultra-thin proton exchange membrane has exceeded 80000 cycles, showing an improvement in durability. According to relevant data, as of 2019, Gore's proton exchange membrane is used by most domestic membrane electrode manufacturers, with a market share of over 90%.
2. DuPont and Chemous in the United States
The development of DuPont's perfluorosulfonic acid proton membranes can be traced back to the introduction of the first generation membranes N111 and N112 in the 1990s, followed by the second generation NRE211 and NRE212. The main changes in production technology and process are from initial melt extrusion to solution casting, which enhances the conductivity of proton membranes, significantly reduces fluoride ion release rate, and reduces manufacturing costs. By 2006, DuPont had launched the Nafion XL-100, which incorporated membrane chemical stability improvement technology and mechanical reinforcement technology. Compared to the second-generation membrane, its stability was improved by 8 times, the hydration expansion rate was reduced by 50%, and the mechanical strength was increased by 1.5 times.
In order to meet the needs of the development of fuel cell business, DuPont's subsidiary Kemou Chemical was independently launched in 2015. The current Nafion perfluorosulfonic acid membrane is a polymer membrane formed by copolymerization with polytetrafluoroethylene. At present, DuPont's main products are D520/521, D1020/1021, D2020/2021, N1110, N115, and N117. Among them, NR211 and NR212 are used in the fuel cell field through solution casting method, with membrane thicknesses of 50 μ m and 100 μ m, respectively. Currently, their market competitiveness is limited, but with DuPont's long-term research and accumulation of Nafion membranes and the absolute leading advantage of perfluorosulfonic acid resins, the prospects are still promising. The main parameters of its Nafion series perfluorosulfonic acid resin are shown in the table below. At present, the main products sold by Kemu in China are N115 and N117, with retail prices of 13500 yuan/square meter and 15000-19000 yuan/square meter. Its fuel cell proton exchange membrane is relatively rare to sell in China.
3. Solvay, Belgium
Solvay's perfluorosulfonic acid proton membrane changed its name from Hyflon Ion to Aquavion in 2008, and its production method is melt extrusion. Before 2008, the company mainly produced the E83 model. After 2008, the company launched E87 and E79 with membrane exchange capacities of 1.14 mmol/g and 1.26 mmol/g, respectively, with thicknesses of 30, 50, and 100 μ m. At present, Suwei mainly produces Equivion models E87-05, E98-05, E98-05S, and E98-09S, which can be applied in the fields of fuel cells and hydrogen production. The main parameters of its E87-05 are shown in the table below. Currently, it is not very popular in the domestic Suwei market and there are almost no related prices.
Table 4 Main Parameters of E87-05
4. China Dongyue Group
(1) Overview
Dongyue Group, founded in 1987, mainly engages in the research and production of new environmentally friendly refrigerants, fluorinated polymer materials, organosilicon materials, chlor alkali ion membranes, and hydrogen fuel proton exchange membranes. Dongyue has invested heavily in technology research and development, ranking among the top 2500 global industrial research and development investments released by the European Commission in 2021 (a total of 123 chemical companies worldwide and 28 Chinese chemical companies). Its subsidiary Shandong Dongyue Future Hydrogen Materials Co., Ltd. was established in 2017, mainly engaged in high-performance hydrogen materials such as fuel cell membranes, high-performance fluorinated polymers, and high-end fluorinated fine chemicals. The company has formed a complete industrial chain from raw materials, intermediates, monomers, polymers, to film-forming technology and functionalization technology. Currently, some high functional fluorinated polymers and fluorinated fine chemicals are the only products in China that have achieved industrialization, with more than 150 authorized patents at home and abroad. The high-performance fuel cell membranes produced have passed Mercedes Benz's 6000 hour test, freeing China from dependence on proton exchange membrane imports.
Due to its mastery of the core component of hydrogen fuel cells - fuel cell proton exchange membranes, it has become the only enterprise to simultaneously enter the five major fuel cell vehicle demonstration city clusters of Beijing Tianjin Hebei, Shanghai, Guangzhou, Hebei, and Henan. At present, Dongyue Future Hydrogen Energy is the only enterprise in China with a mass production foundation for the entire fuel cell membrane industry chain. The first phase of its annual production of 1.5 million square meters of proton exchange membrane production line has been officially put into operation, and a new generation of higher operating conditions, higher exchange capacity, higher strength, longer lifespan, and superior high-temperature and low-humidity working environment performance fuel cell membranes are also about to be launched to meet the requirements of the next generation of fuel cell stack systems for membranes and promote the further development of fuel cells. Dongyue Future Hydrogen has reached strategic cooperation with Shanghai Shenli Technology Co., Ltd. (a core enterprise of automotive fuel cell stacks), Shanghai Yihydrogen Technology Co., Ltd. (a leader in the research and development of hydrogen fuel cell membrane electrodes), and Beijing Yihuatong Technology Co., Ltd. (a pioneer in the domestic hydrogen energy industry) on the process of technological autonomy in the hydrogen and fuel cell industries. At present, the company is preparing to build a second proton membrane production line, striving to become the world's largest proton membrane production base, and the listing of Dongyue Future Hydrogen Energy Science and Technology Innovation Board has entered the coaching stage.
(2) Sales and revenue of the company
According to the 2021 interim financial report of Dongyue Group, its total revenue in the first half of 2021 was approximately 6.471 billion yuan, an increase of 39.57% compared to the same period last year of 4.636 billion yuan. Among them, the revenue from fluorinated polymer materials was 1.942 billion yuan, an increase of 28.92% compared to the same period last year, accounting for 30.02% of the group's total external sales. Its profit was 413 million yuan, an increase of 63.44% compared to the revenue of 252 million yuan in the same period last year. However, according to the 2020 annual financial report of Dongyue Group, the impact of the epidemic has had a certain impact on its supply chain and sales. Its annual revenue was RMB 10.044 billion, a year-on-year decrease of 22.49% compared to RMB 12.959 billion in 2019. The annual revenue of polymer materials was RMB 3.192 billion, a decrease of 7.02% compared to the same period last year, which was RMB 3.433 billion.
main products
The perfluorosulfonic acid series products produced by Dongyue Future Hydrogen Energy Materials Co., Ltd. mainly include perfluorosulfonic acid fuel cell proton membranes, flow cell membranes, and water electrolysis hydrogen production membranes. The proton membrane of perfluorosulfonic acid fuel cells produced by Dongyue Future Hydrogen Energy has excellent heat resistance, mechanical performance, electrochemical performance, and chemical stability. It can be used under harsh conditions such as strong acid, strong alkali, and strong oxidant media. The main technical indicators are shown in the table below.
At the same time, the liquid flow battery membrane produced by future hydrogen energy is a composite film DMV850 composed of perfluorosulfonic acid resin and reinforcement materials, which has the characteristics of unidirectional cation passing, thin thickness, high strength, low swelling, high dimensional stability, and good durability. It can be widely used in all vanadium liquid flow batteries, iron chromium liquid flow batteries, and other fields. The main technical parameter indicators are shown in Table 6. And in the future, hydrogen energy has also achieved the production of perfluorosulfonic acid resin as an important intermediate material for the production of perfluorosulfonic acid proton exchange membranes. The main models include DHS093 and DHS103, and their main technical parameters are shown in Table 7. But currently, its market share in the domestic market is not large, with a significant competitive gap compared to Gore, but it has a certain price advantage of about 2000 yuan/square meter.
5. Suzhou Kerun New Materials Co., Ltd