The spiral evolution and development of lithium batteries and fuel cells

If we carefully analyze the changes in the basic research and industrial policies of the European Union (EU) and the US Department of Energy (DOE) in the field of lithium and fuel cells over the past 20 years, it can be clearly seen that lithium batteries and fuel cells are actually one "happy family". In fact, lithium batteries and fuel cells have not really been "cold" in the past few decades, but the degree of attention is different. They are all ups and downs, and you sing to our side, the chemical power industry is so spirally developed. This article reviews the development of lithium batteries and fuel cells. Let’s discuss: Why do China and Japan choose different technical routes in developing pure electric vehicles? Or what kind of power system is more suitable for pure electric vehicles?

New energy vehicles are emerging industries that have been developed in China in recent years. In January 2009, the Ministry of Science and Technology, the Ministry of Finance, the National Development and Reform Commission, and the Ministry of Industry and Information Technology jointly launched the “Ten Thousands of Energy Saving and New Energy Vehicle Demonstration and Application Projects”, marking the new The energy auto industry officially rose to a national strategy.

In 2012, the State Council issued the “Energy Conservation and New Energy Vehicle Industry Development Plan (2012-2020)”, which defined the definition of energy-saving vehicles and new energy vehicles, and determined the path and objectives of the realization. The plan clarifies that the development of new energy vehicles in China will focus on lithium-ion battery pure electric vehicles (LIB-EV).

In recent years, lithium-ion battery pure electric vehicles have become the mainstream route of new energy vehicles in China. At present, China's pure electric vehicles are basically passenger cars with ternary power batteries, while commercial vehicles mainly use lithium iron phosphate power batteries development pattern.

Japan, which is the world leader in the development and industrialization of electric vehicles, is inconsistent with China in the electric vehicle technology route. In December 2014, Toyota, the world's largest auto company, officially launched Mirai, the world's first mass-produced fuel cell electric vehicle. The price of this car in Japan was 7.236 million yen (equivalent to RMB 383,000). The subsidy price is 275,000 Yuan). Following this, Honda also released its new generation fuel cell vehicle FCV Clarity in the second half of 2015. In fact, as early as May 2014, the Ministry of Economy, Trade and Industry of Japan issued the “Promoting Strategy for the Promotion of Hydrogen Fuel Cell Vehicles”, which established the domestic industry standard for hydrogen fuel cell vehicles. Afterwards, the Japanese government proposed specific targets for hydrogen fuel cell vehicles and policy support programs in the “Implementation of Hydro-Social Policy Recommendations”. In addition, Japan's Nissan, Hyundai, General Motors (GM), BMW and Volkswagen (VW) have also released their own fuel cell electric vehicle industrialization plans in the past two years. .

We can see that China and Japan (actually including Korean and European mainstream car companies) have chosen different technical routes in the development direction of pure electric vehicles. The news of the mass production of fuel cells for two fields (Toyota and Honda) sparked heated discussions in the domestic electric vehicle industry and formed two perspectives:

One view is that the Japanese auto industry is wrong in taking fuel cell routes on pure electric vehicles (route error theory). The example is the current hot international Tesla electric vehicle in the United States. Another point of view is that Japan's development of fuel cell vehicles is more for its military industry services, and misleading the direction of China's electric vehicles (conspiracy theory).

These different viewpoints are temporarily put down. Facing the reality of small-scale commercial production of Toyota and Honda fuel cell vehicles, the first thing we need to seriously consider now is why China and Japan have chosen different technical routes in developing pure electric vehicles. Or what kind of power system is more suitable for pure electric vehicles?

Whether it is a lithium-ion battery (Li-ion battery, LIB) or a proton exchange membrane fuel cell (Proton Exchange Membrane Fuel Cell, PEMFC), it is a highly specialized high-tech field involving multidisciplinary integration. The author has a fairly good understanding of these two chemical power systems. In this paper, the author will abandon the profound scientific principles of electrochemistry, solid chemistry and electro catalysis, and stand on the macroscopic point of view. The chemical power system is analyzed and compared, and it is hoped that the readers can provide some different perspectives and angles on the issue of pure electric vehicle power source.

Before comparing the two power systems, we must first understand the most essential characteristics of LIB and PEMFC, so as to understand the respective applicable fields of these two chemical power sources.

Fundamentally, a secondary battery is an energy storage device that stores and releases electrical energy through a reversible electrochemical reaction. The basic measure of the ability of a secondary battery to store electrical energy is the energy density (WH/Kg or WH/L). The fuel cell is an electric energy production device that converts chemical energy in the fuel into electrical energy by electro catalytic reaction. Although the fuel cell is also called "battery" (the reason for Chinese translation), its basic working mode is somewhat similar to that of an internal combustion engine, which is essentially different from a conventional secondary battery. The basic measure of fuel cell power production capacity is power density (W/Kg or W/L). The different natures of the two electrochemical power systems work will directly determine their different positioning at the application level, which I will discuss in detail later.

Research and development of lithium-ion batteries and fuel cells

Before comparing and analyzing the application prospects of lithium ion batteries (LIB) and proton exchange membrane fuel cells (PEMFC) in the field of pure electric vehicles, it is necessary to briefly review the development of the two so that readers can be more intuitive Awareness. If we carefully analyze the changes in the basic research and industrial policies of the European Union (EU) and the US Department of Energy (DOE) in the field of lithium and fuel cells over the past 20 years, it can be clearly seen that lithium batteries and fuel cells are actually one "happy family".

In fact, at the end of the nineteenth century, cars were first developed from battery vehicles. The production of lead-acid battery cars reached their peak in the early 20th century. However, with the innovative use of the production line to produce the T-car in 1908 (substantially reducing the cost), and the emergence of the electric ignition of the gasoline car in 1912 (more convenient use), it caused a fatal blow to the lead-acid battery car. The electric car has since retired from the historical stage. Until the end of the last century, due to technological advances in high-energy chemical power sources (secondary batteries and fuel cells), electric vehicles have once again received attention. The international first round of research on fuel cells occurred in the 1970s. Due to the demand of the US space industry, the use of alkaline fuel cells (AFC) was promoted. Later, GM also produced the world's first AFC fuel cell car. Since AFC must use pure oxygen and cannot directly use air, AFC cannot be used in the civilian field, but many AFC technologies were later transplanted to PEMFC.

In the 1970s, the two international oil crises caused by the Arab-Israeli war not only had a profound impact on the global political and economic structure, but also prompted Western countries to profoundly recognize the importance of finding new energy sources and thus the new high energy. The study of chemical power has produced an unprecedented boost. It is during this period that people have made great progress in basic research on organic electrolytes, solid electrode materials, proton exchange membranes, and electrode process kinetics. The sodium-sulfur battery and lithium-ion battery are the basic principles built during this period. .

Thanks to research progress in the field of transition metal oxides, graphite lithium intercalation compounds and organic electrolytes in the 1980s, Japan's SONY Corporation successfully commercialized lithium-ion batteries for the first time in 1991. The initial lithium-ion battery has a low energy density due to the use of pyrolyzed polyacetal hard carbon anode material. Since the Osaka City Gas Company industrialized MCMB in 1994, the performance of lithium-ion battery has been greatly improved to quickly occupy the mobile phone battery. The market developed rapidly, and at the end of the last century, the first wave of lithium battery industrialization was launched on a global scale. Corresponding to this is the first round of international lithium battery research from 1995 to 2002. The development of lithium-ion power batteries also began to emerge in the beginning of this century (represented by the French SAFT), but it did not attract widespread attention around the world.

In 1996, the Clinton administration of the United States opened the prelude to the basic research and industrialization of the "hydrogen economy" (hydrogen energy and fuel cells), followed by the EU. In the eight years of President Bush’s administration, the “hydrogen economy” research reached its peak in western developed countries, especially the United States, and this is the basic research of lithium-ion batteries from 2002 to 2007. In the past six years, it has fallen into a trough. Of course, the industrialization of lithium battery is still developing rapidly.

The second round of fuel cell research/industrialization wave has gradually cooled down after 2007. The details will be discussed in detail in later chapters. Since Obama was elected president of the United States in 2008, the US government has shifted from hydrogen and fuel cells to lithium-ion batteries in the strategic direction of electric vehicles, which is the second round of lithium battery research and industrialization in the world. This change is not the willingness of DOE. The main reason behind it is the industrial production and storage of hydrogen and the technical challenges of fuel cell in terms of technology, cost and longevity. These problems have seriously hindered the industrialization of fuel cell electric vehicles.

Japan’s new energy research and industrialization policy is mainly formulated by the New Energy Industry Technology Development Agency (NEDO). Unlike the rollercoaster of lithium and fuel cells in the US and Europe, Japan has not been far behind in its support over the past few decades. There is not much difference in support between the two fields. This is mainly because Japan is in a leading position in global industrialization in both fields, and the lithium battery industry in Europe and the United States has not developed.

If we carefully study the DOE's annual reports on lithium batteries (BATT and ABR projects), the EU ALISTORE project, and the NEDO lithium-related projects in Japan, we can see that compared with the fruitful first-round lithium battery research boom at the end of the last century, This round of lithium-based basic research has basically not made any breakthrough progress, but has obvious academic "foaming" characteristics (expressed in "nano-lithium" and lithium iron phosphate), the next stage of DOE in high-energy Changing the funding direction in the chemical power sector will be a matter of time. In fact, the technical route and development goals of the US DOE have always been the basic reference for the Ministry of Science and Technology and the Ministry of Industry and Information Technology to formulate research and industrialization policies for new energy vehicles. So, what is the next round of DOE research and industrialization of new high-energy chemical power sources? Let us wait and see.

In fact, readers who understand the history of chemical power development should understand that secondary batteries and fuel cells have not been really "cold" in the past few decades, but the degree of attention is different. They have gone through ups and downs, and that's how the chemical power industry got started.

The page contains the contents of the machine translation.