11/01/2016 HYU News > Academics Important News
[Researcher of the Month] Professor Paik Un-gyu
Making sodium-ion batteries applicable for use
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Professor Paik Un-gyu of the Department of Energy Engineering is November's Researcher of the Month for his active role in exploring the field of energy engineering. Recently, he has led a research team in developing significant improvement of sodium-ion batteries (SIBs), explained in the paper, 'SB@C coaxial nanotubes as a superior long-life and high-rate anode for sodium ion batters'. This specific study focuses on ways to increase the efficiency of the sodium-ion battery, which can possibly replace the popular lithium-ion batteries. Paik spoke about his study as well as his experience as a professor. “There are other excellent professors who deserve this honor for than me. Yet, I am still very thankful for it,” said Paik. “The research was about sodium-ion batteries, which is rarely known to the public. The main objective was to reduce problems and improve effectiveness of sodium-ion batteries to replace lithium-ion batteries in the future.” Currently, lithium-ion batteries are commonly used in various electronic devices including smartphones. However, the main problem of lithium-ion batteries is the cost of lithium itself. There are certain limits for the Korean government to secure enough lithium mines from overseas. Therefore, a more parallel, affordable solution is to replace lithium with sodium in making ion batteries.
Similar to lithium-ion batteries, sodium-ion batteries have issues of rapid operating-capacity fading due to large volume expansion during sodiation. Sodiation is the process of using sodium for a battery. Smartphone batteries bubbling up like a balloon is an example of volume expansion in lithium-ion batteries. “To reduce volume expansion, we tuned the morphology and structure at the nanoscale using carbonaceous materials as the buffer layer,” explained Paik. “Hence, a carbon-coating with a thermal reduction strategy was developed to create a unique tube-like structure, known as Sb@C coaxial nanotubes.” In other words, the hollow space within the specially-created tube can make space available for the accommodation of volume expansion.
Another way to increase sodium-ion batteries' efficiency is to improve the charge and discharge system. The charging speed of a battery depends on electron conduction; how fast electrons move within its electric field. Carbon-coated nanotube, a conduction material, allows the conduction of electrons to quicken and enables diffusion to take place, making both sides of the tubes accessible for the charging system. Therefore, by reducing the risk of volume expansion and enhancing the charge system, sodium-ion batteries can be applicable in replacing lithium-ion batteries.
Other than this specific study, Paik has contributed immensely in researching applicable, practical studies of nanoparticles and nanodevices used in semiconductors. Most of his studies focus on what can be done to improve technology by working with industries in various sectors. “I personally believe that the reason why I am a researcher is to find practical ways to help the society. The fundamental studies are also important, but I tend to use the basic principles to apply them to real and effective technology,” said Paik. His passion for energy engineering has led him to become one of the professors to have published the most research papers at Hanyang University.
Like his accomplishment in energy engineering research, Paik emphasized the need for passion for students who strive for success. “Today, we are facing a more skill-intensified society where work requires advanced expertise in an area. As learners, students must have passion for studying,” said Paik. “Even though the society is rapidly changing at each moment, if students take consistent steps through learning, it can be a strong benefit for them once they have amassed required knowledge.” As a professor, Paik has guided many students in taking the same steps that he himself has gone through for the past 24 years of learning and researching. “In science, understanding the boundaries of each important experiment is necessary, which must be overcome to produce an outcome. Likewise, I hope my role as a professor can assist students to overcome those limitations.”
Park Min-young email@example.com