Metal-air battery drawing attention
Q: I'd like to ask about the batteries first.
Hirota: Fuel cell vehicles feature longer driving distances and were expected to be commercialized at an early date. However, the introduction of FC vehicles into the market has been substantially delayed due to some unsolved issues including their high costs.
Hybrid vehicles with nickel-metal hydride (NiMH) batteries have already been commercialized, and electric vehicles incorporating lithium ion (Li-ion) secondary batteries are expected to debut within 2009. Driving distances of electric vehicles are short, though, because the energy density of the batteries is still low.
Li-ion secondary batteries with a higher energy density are being developed so as to improve driving distances of electric vehicles. At the same time, fuel cells and air batteries including metal-air batteries are under development.
NiMH batteries and Li-ion batteries, commonly-used high-performance batteries, use oxidizers for their cathodes and are similar to rocket engines. The batteries have a high instantaneous force (power density) while they are heavy because of the oxidizers and low in energy density. Though some improvements have been made, we are beginning to see technological limits.
On the other hand, metal-air batteries, which use zinc, magnesium, lithium, etc, as fuel, as well as hydrogen-oxygen fuel cells, which oxidize hydrogen and metals by using oxygen in the air, are similar to jet engines. These batteries do not need an oxidizer, one of the materials necessary for redox reaction in batteries, resulting in possible weight reduction.
Airplanes that fly in the atmosphere carry jet engines, not rocket engines. I think automotive engineers have big expectations for metal-air batteries similar to jet engines in this respect.
Based on these perspectives, electric vehicles with zinc-air batteries, etc, are being actively developed in the US, Europe and China.
For commercialization of metal-air batteries, we should utilize technologies for Li-ion batteries and zinc-air batteries as well as air electrode technologies advanced through the development of fuel cells. Japan will continue to lead the world in the development of batteries if we take advantage of our advanced atomic level observation technologies and elementary reaction analysis technologies and if the industry, government and academia join forces on projects, such as the one being promoted by NEDO.
Electronics/Electrochemistry Fusion Expected
Q: Is the development of automotive batteries progressing smoothly?
Hirota: A variety of research institutes and corporations in Japan have been developing batteries. However, to develop batteries appropriate for automotive use, it is necessary to enhance collaboration of battery developers and automobile developers who specialize in machines and electricity.
Though mechatronics, a synergetic combination of mechanical engineering and electronic engineering, has a history of more than 30 years, there were disputes arising from differences in thinking patterns and cultures between machine-oriented engineers and electronics-oriented engineers in development sites at an early stage of its history. Fortunately, as time went by, the two parties came to cooperate with each other.
Batteries are developed by "electrochemistry engineers." The key to open the electric vehicle era lies in "chemtronics," the fusion of electronics and electrochemistry, as well as mechatronics, but we have to wait some time for this fusion to occur.
For example, battery characteristics are provided from manufacturers in the form of charts rather than mathematical models or equivalent circuit models, making it difficult to design charge/discharge systems.
The Japanese battery industry is ranked number one in the world in terms of batteries themselves. So, I believe we have the capability to be the number one in system technologies including the use of batteries. The competitiveness of Japanese automotive manufacturers may decline if they don't see a vehicle and batteries as an integrated system.
Q: What can be done to solve that issues?
Hirota: The ideal way would be that engineers for electronic circuits learn about electrochemistry and those for electrochemistry learn about electronic circuits. But they will have a hard time understanding unfamiliar fields especially when they are busy with their own jobs.
When we look at actual job sites from the perspective of understanding unfamiliar fields, circuit designers don't always understand the principles of semiconductor engineering. But they can fully utilize, for example, power devices.
Semiconductor manufacturers provide equivalent circuit models of power devices, so it is possible to know operating margin, calorific value and changes in characteristics due to temperature increase of power devices by using a circuit simulator. Mechanical engineers can also fully utilize semiconductor devices by using the circuit simulator.
I think equivalent circuit models for batteries should also be created as soon as possible so that electronics engineers and mechanical engineers can handle batteries. Such models are needed not only for batteries but also for various other fields, and I believe they are essential for electric vehicle system integration.
Source: Tech-On!
Q: I'd like to ask about the batteries first.
Hirota: Fuel cell vehicles feature longer driving distances and were expected to be commercialized at an early date. However, the introduction of FC vehicles into the market has been substantially delayed due to some unsolved issues including their high costs.
Hybrid vehicles with nickel-metal hydride (NiMH) batteries have already been commercialized, and electric vehicles incorporating lithium ion (Li-ion) secondary batteries are expected to debut within 2009. Driving distances of electric vehicles are short, though, because the energy density of the batteries is still low.
Li-ion secondary batteries with a higher energy density are being developed so as to improve driving distances of electric vehicles. At the same time, fuel cells and air batteries including metal-air batteries are under development.
NiMH batteries and Li-ion batteries, commonly-used high-performance batteries, use oxidizers for their cathodes and are similar to rocket engines. The batteries have a high instantaneous force (power density) while they are heavy because of the oxidizers and low in energy density. Though some improvements have been made, we are beginning to see technological limits.
On the other hand, metal-air batteries, which use zinc, magnesium, lithium, etc, as fuel, as well as hydrogen-oxygen fuel cells, which oxidize hydrogen and metals by using oxygen in the air, are similar to jet engines. These batteries do not need an oxidizer, one of the materials necessary for redox reaction in batteries, resulting in possible weight reduction.
Airplanes that fly in the atmosphere carry jet engines, not rocket engines. I think automotive engineers have big expectations for metal-air batteries similar to jet engines in this respect.
Based on these perspectives, electric vehicles with zinc-air batteries, etc, are being actively developed in the US, Europe and China.
For commercialization of metal-air batteries, we should utilize technologies for Li-ion batteries and zinc-air batteries as well as air electrode technologies advanced through the development of fuel cells. Japan will continue to lead the world in the development of batteries if we take advantage of our advanced atomic level observation technologies and elementary reaction analysis technologies and if the industry, government and academia join forces on projects, such as the one being promoted by NEDO.
Electronics/Electrochemistry Fusion Expected
Q: Is the development of automotive batteries progressing smoothly?
Hirota: A variety of research institutes and corporations in Japan have been developing batteries. However, to develop batteries appropriate for automotive use, it is necessary to enhance collaboration of battery developers and automobile developers who specialize in machines and electricity.
Though mechatronics, a synergetic combination of mechanical engineering and electronic engineering, has a history of more than 30 years, there were disputes arising from differences in thinking patterns and cultures between machine-oriented engineers and electronics-oriented engineers in development sites at an early stage of its history. Fortunately, as time went by, the two parties came to cooperate with each other.
Batteries are developed by "electrochemistry engineers." The key to open the electric vehicle era lies in "chemtronics," the fusion of electronics and electrochemistry, as well as mechatronics, but we have to wait some time for this fusion to occur.
For example, battery characteristics are provided from manufacturers in the form of charts rather than mathematical models or equivalent circuit models, making it difficult to design charge/discharge systems.
The Japanese battery industry is ranked number one in the world in terms of batteries themselves. So, I believe we have the capability to be the number one in system technologies including the use of batteries. The competitiveness of Japanese automotive manufacturers may decline if they don't see a vehicle and batteries as an integrated system.
Q: What can be done to solve that issues?
Hirota: The ideal way would be that engineers for electronic circuits learn about electrochemistry and those for electrochemistry learn about electronic circuits. But they will have a hard time understanding unfamiliar fields especially when they are busy with their own jobs.
When we look at actual job sites from the perspective of understanding unfamiliar fields, circuit designers don't always understand the principles of semiconductor engineering. But they can fully utilize, for example, power devices.
Semiconductor manufacturers provide equivalent circuit models of power devices, so it is possible to know operating margin, calorific value and changes in characteristics due to temperature increase of power devices by using a circuit simulator. Mechanical engineers can also fully utilize semiconductor devices by using the circuit simulator.
I think equivalent circuit models for batteries should also be created as soon as possible so that electronics engineers and mechanical engineers can handle batteries. Such models are needed not only for batteries but also for various other fields, and I believe they are essential for electric vehicle system integration.
Source: Tech-On!
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