[:en]
Mr. Ryota Katsumi
Hometown in Japan: Tokyo
Home University in Japan: University of Tokyo
Major & School Year: Physics, B4
Research Host at Rice: Prof. P.M. Ajayan, Materials Science & Nanoengineering
Research Project Title: Supercapacitors (PDF)
Why TOMODACHI STEM @ Rice University?
I have a strong interest in nanotechnology. Materials science at Rice University has a history of discovery and innovation, such as the discovery of the spherical fullerene and materials research in carbon nanotubes. I think Rice University has traditionally been a strong force in nanotechnology. Since my area is related to nano-electronics, I’m eager to conduct most-advanced experiences in the Department of Materials Science and Nano Engineering.
Another season is to improve my English skill. As the world is becoming more international, skill in English is becoming more important because most people in the world speak English. Not only is such skill essential for many jobs, but it is also useful for cross-cultural communication. In this program, I would like to blush up my English ability by speaking English to many students and researchers in Rice University.
Goals
- Personal goals: Interact with many students and researchers in Rice University.
- Language goals: Brush up my English skills.
- Research goals: Enjoy my research theme.
Questions I have About Research or Life in the U.S. – Prior to Departure
- Is there any activity like club activity?
- How do they spend their weekend?
Excerpts from Ryota’s Weekly Reports
- Week 01: Arrival in the U.S.
- Week 02: Critical Incident Analysis
- Week 03: Research in the U.S. vs. Research in Japan
- Week 04: Final Week at Rice University
- Final Research Project Presentation
- Week 05: Science & Technology Policy Study Tour in Washington, DC
- Final Report
Week 01: Arrival in the U.S.
Welcome party at Prof. Kono’s home.
This is the first time to come to the U.S, so I was really excited.
One of the most amazing things in the U.S was the scale. When we arrived at Houston airport, I found out that the aiport is way larger than that of Japan. And when we ate dinner, the meat was so big that I had a hard time eating it. It is true I expected that the scale here would be bigger than that of Japan, but it was much bigger than I expected.
Another amazing thing was the population of the Chinese students. When I visited Rice University, there were a lot of Chinese students or researchers in the buildings. Before I came here, I had thought that there were a variety of people, but not more than Americans. I was surprised to know that Rice University had so many Chinese students.
During the first week of the program we had many events and activities. One of the most helpful activities was the workshop with Professor Kono. In the workshop, he provided us much information about graduate schools in the U.S. as there were few opportunities to know how American graduate schools are, it was really helpful.
One of the most helpful people is Ms. Keiko Kato the graduate student assistant. She not only gives me tips about research but also supports our daily life. As she is Japanese as well, she tells us what makes Japanese people in trouble or how we should do here. It really helps.
Research Project Overview
Working in the Ajayan Lab.
My research topic is supercapacitors in Prof. Ajayan’s lab in the Department of Materials Science & NanoEngineering. These days, we can’t do without smart phones or computers. They need energy, so energy storage is necessary in the modern society. The most famous energy storage is a battery. It has high energy densities, so it is applied to many devices.
However, there is another up-and-coming energy storage. This is a supercapacitor. Supercapacitors are capacitors whose capacitance is much higher than that of normal capacitors. By using electrodes which have many pores and choosing proper electrolyte, we can get higher surface area and lower distance between electrodes.
This week I decided my research topic (see above). Before I came here, I got in touch with Ms. Kato, who also is a graduate student in Prof. Ajayan’s lab. I was interested in batteries, so I read some papers about Li battery. But because I major in physics, Dr. Robert Vajtai, a assistant professor in the Ajayan Group, advised me that it was difficult for me to deal with many complicated chemicals. That’s why I chose supercapacitors.
After I decided my topic, I read some papers to understand what supercapacitors are. Reading papers before experiment is important to conduct better experiments.
My mentor is Kaushik Kalaga. He is PhD student in the Ajayan Lab. There are so many topic and so many people in the Ajayan Lab, so I often interact with people of the energy storage group. They are so kind that when I’m in trouble, they teach me what I do or how I do my experiments.
Question of the Week
In this county, food is not healthy compared to Japan. How do you keep your health?
- It really depends on the person but typically people who want to be healthy will cook most meals at home on their own, not eat out very often (especially fast food) and will regularly exercise either at the gym or outdoors by running or joining some sort of sports team. At Rice it is very convenient since there is a nice running/walking track all around campus and there is a very good gym on campus so it is easy to exercise/work-out if you would like.
Week 02: Critical Incident Analysis
The example of cross-cultural communication is “politeness”.
When I was conducting my experiment, the group member told me some tips about experiments. It was really helpful, and he was so kind. I said to him “Thank you so much”, with bowing.
Then he suddenly laughed at me, saying “Japanese people often bow”. Although he didn’t seem to get disgusted, it is true that bowing or apologizing too many times is not familiar to him or people from abroad.
However, we don’t have to quit bowing. Emphasizing politeness is one of Japanese culture. When we interact with people abroad, what we should do is not to adjust to them, but to accept them and have a confidence in my own culture.
Research Project Update
Working on my experiment.
My project is focusing on supercapacitors, especially Electrochemical double-layer capacitors (EDLCs). They are constructed from two carbon-based electrodes, an electrolyte and a separator.
How does it work? As voltage is applied, charge accumulates on the electrode surfaces. Because of this, ions in the electrolyte diffuse across the separator into the pores of electrode of opposite charge. However, electrodes are designed to prevent the recombination of ions, so a double-layer of charge is produced at each electrode.
What is the advantage of this? As there are lots of pores, we can get an increase in surface area and a decrease in the distance between electrodes. These allows EDLCs to achieve higher energy densities than conventional capacitors.
Because there is no transfer of charge between electrolyte and electrode, there are no chemical reactions. For this reason, charge storage in EDLCs is highly reversible, which allow them to achieve very high cycling stabilities.
My research topic is supercapacitors, so I need the electrodes. This week I did experiments of deposition. I won’t mention about the details of my experiment, but by using these electrodes, I can get capacitors which have much higher capacitance than normal capacitors.
When doing experiments, it was difficult to make enough deposition on the surface of stainless. I had little knowledge about organic chemistry, but Ms. Kato provided me some tips and I managed to complete my first experiment.
Visiting NASA Johnson Space Center.
Question of the Week
This week is Spring Break and many Rice undergraduate students are not on campus. What are the students doing during their vacations?
- Many places. They may take a trip to beaches in the U.S., Mexico, or the Caribbean; they may take a trip with friends somewhere else in the U.S. or abroad; they may participate in a volunteer program such as Rice’s Alternative Spring Break program; they may stay at school and work if they have a part-time job; they may go home to visit family; or something else entirely. It all depends on the student and what they want, and can afford, to do.
Week 03: Research in the U.S. vs. Research in Japan
In Rice University, there are so many kinds of people. In my lab, there are a lot of Indian people, Chinese people, and European people. This is similar to what I expected.
But equipment of here is not as good as that of Japan. The measuring machine sometimes doesn’t work well and most equipment is shared with each labs. This is different from my expectation.
What is different from Japan is that many labs cooperate with each other in the U.S. For example, some labs make samples and others measure their property. It’s very efficient and powerful.
On the other hand, there is little collaboration between labs in Japan. I believe collaborative research is valued in terms of academic research.
Research Project Update
There was no change in my project. This week I conducted my experiment as before.
Generally, any capacitor has some resistance, and that have a bad influence on the energy densities. So it is important to choose proper materials of electrodes.
To decrease the resistance, I used conductive polymer, specifically poly-pyrrole. Poly-pyrrole has conductivity and low resistance. Moreover, poly-pyrrole is light. Poly-pyrrole is easy to synthesize and very cheap. If we applied it to smartphones, we can get very light and reasonable smartphones. This is why I used poly-pyrrole as electrodes.
Why does poly-pyrrole have conductivity? Let’s see its energy band. The valance band is full of electron, but conduction band is vacant. In that case, like p-type semiconductor, poly-pyrrole gets conductivity by adding the “acceptor” to add hole to poly-pyrrole
And on Friday, I learned the impedance spectroscopy. By using it, I can get its impedance, and from this I can get the capacitance or the resistance of the supercapacitors.
Attending the Houston Rodeo on Rice Night at the Rodeo!
Question of the Week
How many students go to the Rodeo?
- The Houston Rodeo does not report attendance by whether you are a student or not, but here is a link to the 2016 attendance records. Total attendance for this year was 2,462,030 so the Houston Rodeo is very popular! Also here’s a fun video of the Rice Night at the Rodeo from the night you went.
Celebrating Rice at the Houston Rodeo
Week 04: Final Week at Rice University
At the final research presentation. From left to right, Ryota Katsumi, Dr. Robert Vajtai, Yoko Tomo, and Keiko Kato.
This week I measured the capacitance of my supercapacitors. The result was not so bad. But because there is no theoretical model, I was not able to evaluate this result properly.
All the research members were so kind that when I was in trouble, they helped me. Because I’m a physicist, I didn’t know about organic chemistry or chemical substance. They taught me how to conduct the experiments. So I miss people in my laboratory.
Before I came here, I had decided to go on to the graduate school in Japan and get PhD. If we finish what we do, we can get PhD in Japan. But after visiting here, I changed my mind. The students here have a solid goal and they are eager to do their projects. I realized this attitude is important in order to become one of the best scientists in the world.
I’m not sure whether I stay in Japan or move to the U.S., but I don’t have to be in a hurry deciding what I do. I would like to have many choices. By doing things at hand, I will know what I truly want to do.
Week 05: Final Week at Rice University
On Friday, March 18 all TOMODACHI STEM students gave a research project presentation at Rice University. Click on the project title to view a PDF of their presentation.
Research Host at Rice
Prof. P.M. Ajayan, Materials Science & Nanoengineering
Research Project Title
Supercapacitors (PDF)
Week 05: Science & Technology Policy Study Tour in Washington, DC
Lunch at a Chinese restaurant after our visit to the Japan Society for the Promotion of Science (JSPS).
The most helpful program event that I participated in this week was visiting many monuments. We could learn a lot of historic things from them.
We met with the other TOMODACHI students participating in the Met Life Women’s Leadrship Program on Thursday, March 24. At first, I was surprised because most members were female. They listened to the guest talks eagerly and asked good questions to presenters.
Visiting the White House!
During my free sight-seeing time, I went to the Smithsonian Museums, specifically the Air and Space museum. The Smithsonian’s National Air and Space Museum collects, preserves, and exhibits artifacts, archival materials, and works of art related to the history, culture, and science of aviation and spaceflight and the study of the universe. They really helped us understand the importance of flight to humanity and know about the difficulty of spaceflight.
Question of the Week?
Should I have a car if I go on to the graduate school?
- The best way to find out if a car is needed is to ask other graduate students at the school you are planning to attend. It will depend on what city you are living in as some do have good public transportation and where you live in relation to campus. Many graduate students have very limited budgets so try to save money by biking, walking or taking the bus to/from school.
Final Report
This is the first time to come to the U.S, so I was really excited. One of the most surprising things in the U.S was its scale. When I arrived at Houston airport, I found out that the air station is way larger than that of Japan. And when we ate the dinner, the meat was so big that I had a hard time eating it. It is true I expected that the scale here is bigger than that of Japan, but it was much bigger than I expected.
Another amazing thing was the population of the Chinese students. When I visited Rice University, there were a lot of Chinese students or researchers in the buildings. Before I came here, I had thought that there were a variety of people, but not more than Americans. I was surprised to know that Rice University had so many Chinese students.
I found out that there are some differences between Japan and U.S. In Rice University, there are so many kinds of people. In my lab, there are a lot of Indian people, Chinese people, and European people.
But equipment of here is not as good as that of Japan. The measuring machine sometimes doesn’t work well and most equipment is shared with each labs.
The different approach from Japan is that many labs cooperate with each other in the U.S. For example, some labs make samples and others measure their property. It’s very efficient and powerful.
On the other hand, there is little collaboration between labs in Japan. I believe Collaborative research is valued in terms of academic research.
My research topic is supercapacitors. These days, we can’t do without smart phones or computers. They need energy, so energy storage is necessary in the modern society. Most famous energy storage is battery. It has high energy densities, so it is applied to many devices.
However, there is another up-and-coming energy storage. This is supercapacitor. Supercapacitors are capacitors whose capacitance is much higher than that of normal capacitors. By using electrodes which have many pores and choosing proper electrolyte, we can get higher surface area and lower distance between electrodes.
In the first week I decided my research topic. Before I came here, I got in touch with Ms. Kato, the graduate student in Ajayan’s lab. I was interested in batteries, so I read some papers about Li battery. But because I major in physics, Dr. Robert, assistant professor, advised me that it was difficult for me to deal with many complicated chemicals. That’s why I chose supercapacitors.
After I decided my topic, I read some papers to understand what supercapacitors are. Reading papers before experiment is important to conduct better experiments.
My project is focusing on supercapacitors, especially Electrochemical double-layer capacitors (EDLCs). They are constructed from two carbon-based electrodes, an electrolyte and a separator.
How does it work? As voltage is applied, charge accumulates on the electrode surfaces. Because of this, ions in the electrolyte diffuse across the separator into the pores of electrode of opposite charge. However, electrodes are designed to prevent the recombination of ions, so a double-layer of charge is produced at each electrode.
What is the advantage of this? As there are lots of pores, we can get an increase in surface area and a decrease in the distance between electrodes. These allow EDLCs to achieve higher energy densities than conventional capacitors.
Because there is no transfer of charge between electrolyte and electrode, there are no chemical reactions. For this reason, charge storage in EDLCs is highly reversible, which allow them to achieve very high cycling stabilities.
In the second week I synthesized polymer which was used as the electrodes. By using these electrodes, I can get capacitors which have much higher capacitance than normal capacitors. When doing experiments, it was difficult to make enough deposition on the surface of stainless. I had little knowledge about organic chemistry, but Ms. Kato provided me some tips and I managed to complete my first experiment.
In the third week I measured the capacitance of my supercapacitors. The result was not so bad. But because there is no theoretical model, I was not able to evaluate this result properly.
Before I came here, I had decided to go on to the graduate school in Japan and get PhD. If we finish what we do, we can get PhD in Japan. But after visiting here, I changed my mind. The students here have a solid goal and they are eager to do their projects. I realized this attitude is important in order to become one of the best scientists in the world.
I’m not sure whether I stay in Japan or move to the U.S., but I don’t have to be in a hurry deciding what I do. I would like to have many choices. By doing things at hand, I will know what I truly want to do.