Li Keqiang, premier of the State Council, visited the hydrogen fuel cell vehicle at TOYOTA motor factory in Hokkaido some time ago. This move has been interpreted as a good signal for the hydrogen fuel cell vehicle industry.
According to the 14 day of science and technology daily, one of the embarrassing realities is that the foreign fuel cell vehicles have been produced, but the fuel cells in our country are still in the technical verification stage. Wang Haijiang, a professor of the Department of mechanical and energy engineering at the South University of science and technology, pointed out that the current status of vehicle fuel cells in China is that there are almost no parts manufacturers, car - free reactor production companies, and only a small amount of commercial fuel cell vehicles.
Hydrogen fuel cell car
Fuel cell is a "team"
In general, the single - node fuel cell has a low voltage and a large current. In practical applications, a multi - section fuel cell is needed to form a reactor in series to improve the output voltage.
The power source of a hydrogen fuel cell is hydrogen and oxygen, both of which start their "fantasy" journey in fuel cells: hydrogen is oxidized by anodic catalysis to generate protons and electrons; electrons do work to reach the cathode; protons are transmitted to the cathode through a proton exchange membrane from the inside of the electric pool, protons and electricity. It reacts with oxygen to form water under the catalysis of the cathode.
It seems to be only a junior high school chemistry knowledge. But in fact, the operation of fuel cells is a systematic project.
Instead of ordinary batteries, fuel cells are more like generators -- "fuel" and "oxidant" to drink, and send electricity out. Therefore, in addition to electric reactors, fuel cell and fuel supply subsystem, oxidant supply subsystem, hydrothermal management subsystem and thermal management and control system... In a word, people are team fighting.
"Fuel cell vehicle is a new energy vehicle, it is one of the future development directions." Shao Zhigang, Minister of the fuel cell research department of the CAS Dalian Chemical Institute, told the science and Technology Daily that at the end of 2014, the Japanese Toyota Corporation announced the commercialization of fuel cell vehicles; in the country, everything was still in its infancy.
Key materials are still short of mass production lines
Vehicle fuel cells are generally proton exchange membrane fuel cells.
It has two key components, one is membrane electrode assembly and one is bipolar plate. The former is composed of three brothers: proton exchange membrane, catalytic layer and gas diffusion layer.
The main function of proton exchange membrane is to transport protons, separate reaction gases and electronic insulation. It is responsible for the "door", putting the protons in the past and blocking the electrons; the catalytic layer mainly carries the catalyst. The catalyst can promote the oxidation and reduction process of hydrogen and oxygen on the electrode and produce the current; the gas diffusion layer is composed of the basement layer and the microporous layer, which requires high conductivity, thermal conductivity and hydrophobicity.
These key materials determine the life and performance of fuel cells.
"A clever woman is hard to cook for no rice." Our key materials depend on foreign countries for a long time. Once foreign countries are banned from sale, China's fuel cell industry will have no material basis. " Wang Cheng, director of the hydrogen fuel cell laboratory at Tsinghua University, said.
In fact, these materials are not completely absent in our country, and some laboratory achievements have even reached the international level. However, without the mass production line, the fuel cell industry chain is still obstructed. Especially in the gas diffusion layer mass production technology, our country is still blank. "This is because the graphite chemical order of the gas diffusion layer needs to be prepared through the high temperature above 2000 degrees centigrade, but the key equipment of the high temperature furnace is still in the hands of the foreign countries." Wang Cheng explained.
To achieve mass production of materials, consistency and cost control must be solved. It is not the same as laboratory preparation. Taking the catalyst as an example, Wang Cheng told sci-tech daily that the commercial fuel cell catalyst is still a platinum based catalyst, and the laboratory preparation level is generally milligram, and the production technology needs a kilogram level. The batch production should break through three key technologies: one is the uniformity of the reaction conditions, and the stability of batch is ensured; the two is the nano size control of the platinum particles to ensure the specific surface area of the catalytic activity; the three is to improve the stability of the carbon carrier and reach the service life of the vehicle.
The industrialization of laboratory results is a key technology and requires enterprise intervention. "For a long time, the research and development of fuel cells in China is mainly carried out by universities and research institutes. Enterprises take a wait-and-see attitude, participate less and join late. Shao Zhigang's Dalian Chemical Institute started research on vehicle fuel cell since 1994. However, the breakage between basic research and application has made the industrialization of key materials a barrier.
To be commercialized, we have to strengthen the chain and make up the chain
When Wang Haijiang returned home, he wanted to bring years of experience in the field of fuel cells and build a fuel cell industrial chain in Shenzhen.
First, Nan Ke fuel cell Co., Ltd. is mainly used for the production of key parts, stack integration and testing. But if the heap of raw materials need to be imported from abroad, the cost is too high. So the team set up a company that focused on the localization of three key materials, such as gas diffusion layer, proton exchange membrane and catalyst. "At that time, the cost of fuel cells can be reduced by 1/3." Wang Haijiang said.
At present, the number of China's stack and industrial chain enterprises is increasing. It is estimated that the domestic stack capacity will exceed 400 thousand kW in 2018. "Pure electric vehicles have made great progress in recent years, creating a very good condition for the application of fuel cells." Wang Cheng said, "at this point, we need to focus more on fuel cell core innovation."
To break the long-term technological monopoly of developed countries, we must increase investment in the industrialization of fuel cell core materials. The experts interviewed pointed out that the fuel cell industry chain is "very long", which involves hydrogen energy system, fuel cell power generation system and automobile terminal products. "Domestic spare parts, hydrogen infrastructure and standard specifications are not sound. We need strong chain and supplement chain to promote the growth of new materials, new energy and high end equipment of automobile, so as to promote the speed of commercialization of fuel cells." Wang Cheng stressed.
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