Academician Yi Baolian: Fuel cell vehicles are a breakthrough in hydrogen energy applications

Production | NetEase Technology's "Smart Interview"Author | Zhao FuyaoEditor | Ding GuangshengHow long has it been since you saw the blue sky?With global climate change, rising fuel prices, and increasingly severe environmental pollution, the demand for cleaner, safer, and more efficient energy by humans is increasing day by day. Faced with this urgent demand, fuel cells, as a new energy source with great development prospects, have attracted much attention

Production | NetEase Technology's "Smart Interview"

Author | Zhao Fuyao

Editor | Ding Guangsheng

How long has it been since you saw the blue sky?

With global climate change, rising fuel prices, and increasingly severe environmental pollution, the demand for cleaner, safer, and more efficient energy by humans is increasing day by day. Faced with this urgent demand, fuel cells, as a new energy source with great development prospects, have attracted much attention.

Fuel cells, with their clean and efficient characteristics, are becoming the star of the future in the energy field. It not only provides clean energy supply, reduces environmental pollution and greenhouse gas emissions, but also has higher energy utilization efficiency. With the continuous innovation of technology and the gradual reduction of costs, fuel cells are expected to provide sustainable energy solutions for humanity, assisting in the transformation and upgrading of energy structure.

As the fuel of fuel cell, hydrogen energy is a kind of secondary energy with rich sources, environmental protection, low carbon and wide application. It plays an important role in building a clean, low-carbon, safe and efficient energy system and achieving the goals of carbon peaking and carbon neutrality.

In 2022, the National Development and Reform Commission and the National Energy Administration jointly issued the "Medium and Long Term Plan for the Development of the Hydrogen Energy Industry (2021-2035)", which proposed the goals for each stage of the development of the hydrogen energy industry: by 2025, the basic mastery of core technologies and manufacturing processes will be achieved, and the number of fuel cell vehicles will be about 50000, which is sufficient to demonstrate the importance that the country attaches to the hydrogen and fuel cell industries.

So what is the current development status of fuel cells? What measures should we take in the face of the high cost of hydrogen transportation and the lack of hydrogen refueling stations? How should we catch up in technology compared to developed countries?

In this interview, NetEase Technology invited Yi Baolian, a fuel cell expert and academician of the CAE Member, through the secretariat of the Science and Technology Committee of the World New Energy Automobile Conference. A few years ago, by chance, I accompanied the Secretary of the Institute to a meeting in Beijing and took on the space fuel cell mission, thus forming a bond with fuel cells. How does he view the above issues after years of deep cultivation in the field of fuel cells? The following is an interview transcript.

Hydrogen refueling stations can only compete with gasoline vehicles by reducing prices

Fuel cell vehicles alleviate "mileage anxiety"

NetEase Technology:You have been focusing on fuel cell research for over fifty years. What do you think is the value of hydrogen fuel cell vehicles and hydrogen energy industry applications?

Yi Baolian:To achieve the dual carbon goal, it is necessary to vigorously develop renewable energy and achieve energy transformation. Due to the volatility and seasonality of renewable energy, in order to achieve safe grid access of renewable energy, it is necessary to vigorously develop energy storage.

Hydrogen energy storage, that is, using renewable energy to electrolyze water to produce hydrogen, can not only achieve renewable energy storage, but also achieve the redistribution of renewable energy, eliminate the ceiling of renewable energy development, achieve energy supply for the hydrogen electricity system, and ensure national energy security.

Fuel cell vehicles are a breakthrough point in the application of hydrogen energy. In theory, hydrogen energy can be used instead of fuel to drive various transportation vehicles such as various vehicles. A significant reduction in oil imports can not only achieve carbon reduction in the transportation sector, but also improve national energy security.

NetEase Technology:What is the difference between hydrogen oxygen fuel cells and ordinary batteries? What are the existing advantages of China's development of fuel cell vehicles? What do you think are the main shortcomings reflected in?

Yi Baolian:Fuel cells and secondary batteries such as lithium-ion batteries convert chemical energy into electrical energy based on electrochemical principles. But their working methods are different. Fuel cells work in the same way as internal combustion engines, that is, they must form a system to generate electricity: fuel hydrogen supply, oxygen (air) supply, removal of hydrogen oxygen reaction product water, thermal management and electrical management of the fuel cell stack, and other subsystems.

In the 15th Five Year Plan, the Ministry of Science and Technology established an expert group for electric vehicles, with Wan Gang serving as the team leader and establishing a special project for electric vehicles. The expert group proposed a development strategy for electric vehicles with three aspects: lithium-ion battery vehicles, hybrid electric vehicles, and fuel cell vehicles. Three horizontal: batteries and fuel cells, motors and propulsion systems, and electronic control systems. After the industrialization of lithium-ion battery vehicles, a city cluster demonstration plan for fuel cell vehicles was proposed, and two batches of five city clusters have been approved to promote the development of fuel cell vehicles with incentives instead of subsidies.

The advantages of hydrogen fuel cells include the following points. Firstly, the specific energy of the battery system can reach 0.5-1.0kw hr/kg per kilogram, which is several times that of lithium-ion batteries. Therefore, fuel cell vehicles are particularly suitable for long-distance and heavy-duty vehicles, without mileage anxiety. Secondly, the hydrogen tank and stack of the fuel cell system are separate. Once an accident occurs in the stack, such as membrane gas leakage, the voltage of the inspection battery rapidly decreases, and the solenoid valve of the hydrogen supply circuit is closed, so the stack will not burn or explode. At present, there are nearly 70000 fuel cell vehicles in operation worldwide, and over 12000 vehicles in China are in operation. No vehicle has experienced combustion or explosion accidents. Thirdly, in severe cold regions, the driving range of fuel cell vehicles is not shortened, and the waste heat generated by fuel cells can also provide heating for the vehicle, highlighting its advantages. Fourthly, the range, refueling time, and driving comfort of fuel cell vehicles are comparable to those of gasoline powered vehicles. Replacing oil with hydrogen as fuel has no impact on drivers.

Of course, fuel cell vehicles also have obvious shortcomings, such as the high cost of fuel cell engines, which leads to fuel cell vehicle costs being 2-3 times higher than fuel vehicles and 1.5-2.0 times higher than lithium-ion battery vehicles. In addition, the construction cost of a hydrogen refueling station is about 15 million yuan, which is several times that of a charging station. In my opinion, there is no subsidy for refueling at hydrogen refueling stations, with around 60 yuan per kilogram of hydrogen. Only by reducing it to 30-20 yuan can they compete with gasoline powered vehicles.

NetEase Technology:Do you agree with the view that hydrogen fuel cell vehicles will replace diesel vehicles more in the future, while pure electric vehicles will replace gasoline vehicles more? To what extent will there be a competitive relationship between pure electric vehicles and hydrogen fuel cell vehicles in the future?

Yi Baolian:Due to the current mileage anxiety of lithium-ion battery vehicles. In winter, especially in snowy weather, the temperature drops to tens of degrees below zero, the battery capacity decreases, and the driving distance is shortened. Occasionally, combustion and explosion accidents occur. I believe that with the advancement of fuel cell vehicle technology, fuel cell vehicles can enter the field of passenger vehicles, especially in the northern winter, where their advantages are more prominent. For example, in this Beijing Winter Olympics, fuel cell vehicles are the main vehicles used. Fuel cell vehicles in the south have advantages in intercity operation. Overall, these two types of cars complement each other more than compete.

NetEase Technology:Can hydrogen fuel cell vehicles replace traditional fuel vehicles and pure electric vehicles as the main force of new energy vehicles? What do you think of its future development trend?

Yi Baolian:In the future, with technological progress, various powered cars will complement each other, and the applicable testing standards will be carbon emissions and environmental adaptability. There will be no problem of who replaces who. If the fuel used in fuel vehicles is prepared from recycled carbon dioxide and green hydrogen, it also has advantages, especially for military vehicles.

Urgent Development of Pure Hydrogen Pipeline for Hydrogen Transmission

Demonstration city clusters provide a market for fuel cells

NetEase Technology:The storage and transportation of hydrogen energy currently faces significant technical challenges and relatively high costs. Do you think that in terms of hydrogen storage and transportation, in what areas do you need to strengthen technological breakthroughs in the future?

Yi Baolian:The storage and transportation of hydrogen in China requires the development of pure hydrogen pipelines, which are particularly suitable for producing hydrogen from offshore wind power and transporting pure hydrogen to land for storage. It is also suitable for factories that use green hydrogen to prepare green ammonia, methanol, synthetic oil, etc. For short distances within a hundred kilometers, pipeline vehicles are used for transportation. But it is necessary to gradually increase the pressure of containers, improve transportation efficiency, and reduce shipping costs based on technological progress.

The optimal long-distance transportation is through the use of weather network for hydrogen. The international standard for hydrogen concentration is 20%, while in China it reaches 24%. In places where hydrogen is used, membrane separation is used to extract pure hydrogen.

Hydrogen can also be liquefied and transported as liquid hydrogen. But hydrogen liquefaction consumes high energy. Marine transportation uses liquid hydrogen, ammonia, and liquid hydrogen storage such as toluene hydrogenation to methylcyclohexane. The liquid is loaded onto the ship and then converted into pure hydrogen and toluene at the site of use.

NetEase Technology:In terms of fuel cell technology and research and development, there is still a significant gap between China and countries such as Japan. What is the core issue of this gap? How to solve this problem and promote the large-scale implementation of hydrogen fuel cell vehicles?

Yi Baolian:It has been over a century since the discovery of fuel cells. China started researching fuel cells based on the national demand that they have a higher specific energy ratio and are particularly suitable for power sources on spacecraft. The overall work is to build a fuel cell power generation system based on the needs, with the stack as the core. Therefore, research on materials and mechanisms started late.

Overall, compared to Japan, we have slightly lower power and reliability in terms of fuel cell stacks. In terms of systems, we have advantages in low-temperature startup, waste heat utilization, and high-temperature heat removal. But there are gaps in key components such as air compressors, hydrogen compressors, and hydrogen circulation pumps.

At the same time as demonstrating, we need to emphasize strengthening basic research and eliminating deep-seated bottleneck technologies such as plastic liner resin, high-strength carbon fiber, and bottle mouth combination valve for preparing high-pressure hydrogen four type bottles. Reinforced composite membranes with low hydrogen permeability, high strength, and high conductivity used in batteries.

The cost reduction of fuel cell engines relies on two technological breakthroughs: firstly, achieving mass production, but currently local governments' finances are difficult to support the purchase of large quantities of fuel cell vehicles! The country should expand demonstration city clusters and promote mass production of key materials and components for fuel cells! The second is technological progress, mainly improving the specific power of the fuel cell stack and enhancing and extending the reliability and lifespan of fuel cell engines!

The current density of fuel cell stacks is currently around two amperes, and efforts are being made to gradually increase it to four amperes. Therefore, it is necessary to improve the flow field, increase the operating temperature of the battery, thin the diffusion layer, use thin reinforced composite membranes, reduce the oxygen mass transfer resistance of the catalytic layer, and improve the utilization rate of platinum. It is also possible to further increase the current density to over five amperes and lower the selling price of the stack to below 500 yuan.

NetEase Technology:On March 23, 2022, the National Development and Reform Commission and the National Energy Administration jointly issued the "Medium and Long Term Plan for the Development of Hydrogen Energy Industry (2021-2035)", clarifying the three "strategic positioning" of hydrogen energy. More than 20 cities, including Beijing, Shanghai, and Guangzhou, have formulated development plans for the hydrogen energy industry, all of which are trying to seize the commanding heights of its development. How do you view the enthusiasm for developing hydrogen energy in various regions?

Yi Baolian:A large number of cities have formulated hydrogen energy development plans, reflecting their ability to closely follow the central government in achieving the dual carbon goals and have ideas. But it should be noted that the current production cost of green hydrogen is still high, and whether product sales can keep up. For example, fuel cell vehicles are being developed, and with a large amount of government subsidies to promote development, can they be sustainable.

I suggest that the country expand demonstration city clusters to provide a market for mass production of fuel cell components and materials. There is a division of labor for key materials and components in each urban agglomeration to conquer deep level bottleneck materials.

NetEase Technology:From the perspective of sustainable development, do you have any suggestions for the current demonstration and promotion of fuel cell vehicles?

Yi Baolian:Firstly, we will focus on demonstration city clusters and appropriately expand them to promote mass production of key materials and components.

The second is to strengthen basic research and further improve the specific power of the stack and the specific energy of the fuel cell engine. Strengthen research on basic materials and tackle deep-seated bottleneck problems. Develop high-temperature membrane, raise the operating temperature of hydrogen fuel cell to more than 100, eliminate two-phase flow, and improve the consistency of single cell in the stack. Develop hydrogen storage materials with high hydrogen storage capacity to replace high-pressure hydrogen storage bottles, further improving the safety of fuel cell vehicles.

NetEase Technology:At present, the domestic automotive industry, from commercial vehicle companies to passenger vehicle companies, is actively developing hydrogen fuel cell vehicles. How can automotive companies do better in this regard?

Yi Baolian:It is possible to intervene, but it is necessary to combine the production of complete vehicles with technological research and development, gradually improving the level of vehicles. It is best to collaborate with research institutes or universities.

NetEase Technology:At first, the path of fuel cell research and development was not smooth. During this period (1978), it was forced to be interrupted due to adjustments in major national projects, until research and development resumed again. Have you ever considered giving up? What motivates you to persist in this research for decades?

Yi Baolian:At that time, the American Apollo spacecraft, which used fuel cells as its onboard power, had already landed on the moon, and the German AIP submarine, which used fuel cells as its auxiliary power, had successfully tested and could dive underwater for half a month.

Our mission has developed a kilowatt level alkaline asbestos membrane fuel cell system and completed space environment simulation experiments through 1000 hours of unmanned stable operation. I thought at the time that fuel cells were a new technology that was useful to the country, and we should keep a small number of personnel to continue working on them.

In short, I believe that fuel cells have a good foundation and are useful to the country, and should be persisted.

NetEase Technology:What qualities and spirit do you think a scientific researcher should possess?

Yi Baolian:Select tasks based on the needs of the country and one's own foundation, do not retreat when encountering difficulties, persist until success.