Hydrogen fuel cell vehicles still have a long way to go before they can be industrialized

At the 2008 Beijing Olympics, six hydrogen fuel cell buses led the way for marathon runners. The futuristic, clean and pollution-free buses became a moving landscape at the time. Chen Quanshi, an electric vehicle expert and professor at Tsinghua University, presided over the construction of Beijing's first standardized hydrogen refueling station on Beiqing Road, 50 kilometers away from Tiananmen Square, to provide hydrogen refueling services for these six vehicles.

12 years have passed. What is the current status of hydrogen fuel cell vehicle technology? When will it be truly industrialized? What are the current development bottlenecks? In response to these questions, Auto-First recently conducted an exclusive interview with Professor Chen Quanshi.

Professor Chen introduced that fuel cells still have a long way to go before they can be industrialized on a large scale. According to Academician Yi Baolian of the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences, the originator of China's hydrogen fuel cell vehicles, "the current situation of hydrogen fuel cells is superficially a problem of excessively high manufacturing and use costs, but in fact the fundamental reason is that further technological breakthroughs are needed."

The basic principle of hydrogen fuel cell stack is that hydrogen is decomposed into hydrogen ions and electrons under the action of platinum catalyst. The hydrogen ions pass through the proton exchange membrane to reach the cathode and react with the oxygen atoms that have been catalyzed on the cathode side to generate water, while the electrons flow from the external circuit to the cathode to form current. Multiple battery stacks are connected in series to make fuel cells through management systems such as humidity, pressure, and thermal balance to provide electric drive for the car.

Professor Chen said that of the six buses running during the Beijing Olympics, three were Mercedes-Benz and the other three were domestically produced. The domestically produced battery stacks were mainly from the Dalian Institute of Chemical Physics, and the operating life was 700 hours. Previously, Honda announced that the battery it developed could operate for 5,000 hours under laboratory conditions. At present, the operating life of battery stacks in domestic research institutes has not been announced, but there has been little breakthrough. Although domestic battery stacks can be produced at present, the consistency is poor. When used, complete fuel cells and systems are often imported from abroad, or membrane electrodes are imported from abroad, and humidity, pressure and thermal balance systems are matched in China. When domestic hydrogen fuel cells are matched to cars, imported batteries are often needed as backup.

The three methods to decompose hydrogen molecules into hydrogen ions are high temperature, high pressure or strong catalysts. It is obviously unrealistic to use high temperature and high pressure in automobiles. Currently, only strong catalysts can be used, and platinum is the most effective, but it is expensive. It is understood that the annual output of platinum in the world is about 400 tons, of which 70% is used to make jewelry, and the other 30% is mainly provided for high-precision and cutting-edge industrial use. It is obviously unrealistic to use platinum as a catalyst in automobiles for large-scale industrialization.

Professor Chen introduced that currently, 0.3-0.5 grams of platinum are used for each kilowatt-hour of the battery stack. Most domestic research institutions are in this level range. Japan is doing better. They can grind the platinum very finely and apply it evenly on the carbon plate. Currently, only 0.25 grams of platinum are used for each kilowatt-hour. The price of a 1 kilowatt-hour battery stack is 10,000 yuan. When matched with a fuel cell that can generate electricity, the price of a 1 kilowatt-hour battery stack is 20,000 yuan. The cost of matching a car with a 30-50 degree battery is 600,000 to 1 million yuan.

In addition to the high price of platinum as a catalyst, the material used in the proton exchange membrane also requires scientific and technological breakthroughs. Professor Chen introduced that the technical problem of whether the proton exchange membrane is made of carbon plate, metal plate or carbon plate attached to metal plate has not been fundamentally solved. The carbon plate is not rigid enough and the metal is not corrosion-resistant. If the metal plate is used as the substrate and the carbon plate is attached to it, but the expansion coefficient of the metal plate is greater than that of the carbon plate, the two will separate after being heated several times. At present, the material technology of the proton exchange membrane still needs to be greatly improved.

Professor Chen introduced that the hydrogen added to the anode of the battery stack needs to be of high purity, at least 99.99%, or even 99.999%. Low-purity hydrogen will cause catalyst poisoning and failure. Currently, 99% pure hydrogen costs about 1 yuan per cubic meter, 99.9% costs 5 yuan per cubic meter, and when the purity reaches 99.99%, the price of hydrogen soars to 11 yuan per cubic meter. Japanese media have previously calculated that the hydrogen refueling cost of hydrogen fuel cell vehicles is comparable to that of gasoline vehicles, and even has some advantages, but the purity of hydrogen obviously cannot be sloppy.

It is understood that there are about 60 hydrogen refueling stations in my country, mainly distributed in Beijing, Dalian, Zhangjiakou, and some economically developed cities in the Yangtze River Delta and the Pearl River Delta. According to Professor Chen, the equipment and devices such as pipelines, hydrogen storage tanks, and hydrogen refueling guns of hydrogen refueling stations are currently mainly imported.

The hydrogen refueling station built in Rugao, Jiangsu Province previously invested about 120 million yuan. As the relevant equipment has not been industrialized, enterprises are unwilling to produce equipment without a market, and domestic related materials and technologies have not achieved breakthroughs. For example, hydrogen pipelines require special technology. Under high pressure, hydrogen molecules will penetrate into metals, and metal materials will change, hydrogen embrittlement will occur, and cracks will leak hydrogen. In addition, high-pressure hydrogenation also requires specialized talents. Professor Chen introduced that during the Olympic Games, the Beiqing Road hydrogenation station borrowed aerospace-related personnel. Ordinary hydrogenation workers need to undergo special training before they can take up their posts. Due to the characteristics of hydrogen molecules, problems are prone to occur in preparation, transportation, storage, etc. If the operation is not careful. In particular, the pressure of the hydrogen tank must reach 70-90Mpa. Once an explosion occurs, the area within a radius of several hundred meters will be in a mess.

Previously, a hydrogen fuel storage tank exploded in Gangwon Province, South Korea in May 2019. A hydrogen storage tank leaked and exploded in Santa Clara, California, in June 2019. On June 10, 2019, an explosion occurred at a hydrogen refueling station near a subway station in Oslo, Norway.

The development of hydrogen fuel cell vehicles is inseparable from the construction of hydrogen refueling facilities. Like hydrogen fuel cell stacks, the related facilities and operations of hydrogen refueling stations also require technological breakthroughs, especially the construction of hydrogen refueling stations needs to be carried out cautiously.

Recently, the Ministry of Finance, the Ministry of Industry and Information Technology, the Ministry of Science and Technology, the National Development and Reform Commission, and the National Energy Administration jointly issued the "Notice on the Demonstration Application of Fuel Cell Vehicles". In view of the current development status of the industry, the five departments will adjust the purchase subsidy policy for fuel cell vehicles to a support policy for the demonstration application of fuel cell vehicles, and provide rewards to eligible urban clusters that carry out industrial research and demonstration applications of key core technologies for fuel cell vehicles, forming a new model for the development of fuel cell vehicles with a reasonable layout, different focuses, and coordinated promotion.

Professor Chen explained that the policy is to some extent cooling down the industrialization of hydrogen fuel cell vehicles. At present, hydrogen fuel cell vehicles have not really reached the stage of industrial development. Cities without economic and scientific research conditions have hastily launched them, which cannot achieve the expected results. Professor Chen said that the hydrogen fuel industrial parks launched in some regions are not worthy of their names. If they only buy equipment and materials from abroad without investment and breakthroughs in key technologies, it will be the same whether they make 10 or 1,000 vehicles for promotion.

Toyota's hydrogen fuel cell car Marai was launched as early as 2014. By the end of June 2019, less than 9,000 units had been sold worldwide. It is understood that in 10 years, Toyota has invested 1.5 trillion yuan in the field of fuel cells and obtained 16,000 patents. The second-generation Toyota Marai concept car was unveiled at this year's Beijing Auto Show. It is understood that the new car will be equipped with a new hydrogen fuel cell system, and the cruising range has increased by 30% to 650 kilometers. Professor Chen introduced that there is no essential breakthrough in the battery stack catalyst and proton exchange membrane technology of the car. In addition, the problem of difficult and expensive hydrogenation has not been fundamentally solved. There is still a long way to go before large-scale promotion and application.