Research Field 1:
Direct Borohydride Feul Cell
2002 ~ 2007, LG Electronics Inc., Korea
2007 ~ Present, Nuclear, Plasma and Radiology Department, University of Illinois at Urbana-Champaign, IL
The DBFC has been the subject of his research since I started working as the chief research engineer in the digital appliance lab at LG Electronics, South Korea in 2002.
The DBFC is relatively new types of fuel cells that are currently in the developmental stage, compared to the hydrogen fuel cells that have been introduced and utilized for several scores of years. The DBFC uses borohydride, which is a water soluble chemical compound in solid form and abundant natural resources in US, as the fuel.
The designing of DBFC is much different from other types of fuel cells due to the electro-chemical reaction that requires direct contact of fuel and catalytic electrode, which directly generates electrical energy. The DBFC has multiple advantages; borohydride can be stored as a chemically stable solid matter and be dissolved in water when they are used for making the fuel on
demand, the DBFC has higher energy density due to its double higher voltage, twice stronger than the fuel cells using methanol or natural gas and twenty times stronger than the wet cells largely used for automobiles.
As a researcher, Dr. Kim has been dedicated to developing the DBFC for three significant reasons. First, it is a relatively new field that has a lot of potential and challenges. Second, Dr. Kim could utilize his previous knowledge and experience on the metal hydride application technology that Dr. Kim has obtained throughout his doctoral research. Third, the DBFC is highly
competitive fuel cell in the mass production perspective because non-precious metal hydride base catalyst can be utilized, unlike other fuel cells using platinum or gold catalyst.
His research experience on the development of DBFC includes with an international collaborative efforts with research teams of Kogakum University in Japan, the Korea Advanced Institute of Science and Technology in Korea, Kurchatov institute in Russia. The collaborative work yielded a notable accomplishment of introducing 1 kW power level of portable DBFC system in 2004. This
result granted the research team forty two patents as well as confidence as one of the founders in the field. The work is published as:
C.H.Kim, K.J.Kim, M.Y.Ha, “Investigation of the characteristics of a stacked direct borohydride fuel cell for portable applications.” Journal of Power Sources, Volume 180, Pages 114-121, 2008, USA
C.H.Kim, K.J.Kim, M.Y.Ha, “Performance enhancement of a direct borohydride fuel cell in practical running conditions.” Journal of Power Sources, Volume 180, Pages 154-161, 2008, USA
During his research on DBFC, Dr. Kim found the fact that the fuel as an aqueous solution of Borohydride is an electrolyte that conducts ions and electrons which has to be significantly considered to design the electrode, fuel channels and fuel distribution manifolds. This discovery has made the DBFC design uniquely different from any other types of fuel cells and brought considerable
number of patent ideas. One of the idea is to build its anode electrode can be designed with corrugated shape to extend its fuel and catalyst contact surface area and eliminates complex fuel channel structure. The idea is applied to patent and issued as:
US 7318975, “Membrane electrode assembly of fuel cell,” Jan. 15, 2008
KR 0806101, “Fuel cell,” Feb. 15, 2008
Besides, many other discoveries from his BDFC research have resulted to apply 46 more patents and 7 of them have issued in USA and Korea until now. The relate patents are:
US 731658, “Fuel cell system,” Jan. 8, 2008
US 7691501, “Fuel cell system and controlling method thereof,” Apr. 6, 2010
US 7700206, “Fuel cell system,” Apr. 20, 2010
US 7910251, “Fuel cell system,” Mar. 22, 2011
KR 0565224, “Electrochemical battery, electrode thereof and method for manufacturing the same,” Mar. 22, 2006
KR 0606978, “Fuel cell,” Jul. 24, 2006
KR 0823924, “Structure for reducing internal circuit of fuel cell,,” Apr. 15, 2008
Dr. Kim firmly believe that the purpose of conducting research is not just to publish articles in a science journal but also to make innovation that can benefit the lives of people. With this conviction in mind, Dr. Kim started looking for opportunities that could allow me to continue the research, while the company turned its intention to have a business in hydrogen fuel cell
using the reforming of natural gas.
While Dr. Kim was looking for the further opportunities of DBFC research in 2006, Dr. Kim encountered the research team lead by Prof. Miley in University of Illinois at Urbana-Champaign, which is the only DBFC research team in the U.S. in those days. Therefore Dr. Kim joined the team in 2007 under mutual agreement. From that time on, Dr. Kim has been active as a visiting research
professor for the development of DBFC in special application where it may maximize its competitiveness. Dr. Kim participated in the Wearable Power Pack Competition in 2008 held by the Defense Research and Engineering of the Department of Defense. Currently, Dr. Kim is working on developing the specialized DBFC system for unmanned underwater vehicle (UUV), which is sponsored by ‘the Mission and Unmanned System of Lockheed and Martin Corporation.’
The performance and characteristics of direct borohydride / hydrogen-peroxide (NaBH4 / H2O2) fuel cells are studied in the context
of potential applications for air independent propulsion for outer space and underwater. Due to the existence of ocean (sea) water as a natural heat sink, this new fuel cell technology is best suited for underwater propulsion / power systems for small scale high performance marine vehicles. The characteristics of such a power system are compared to other options, specifically for the underwater scenario. The potential of this fuel cell is demonstrated in laboratory experiments. Power density over 1.5W/cm2, at 65°C and ambient pressure, have been achieved with the help of some unique treatments of the fuel cell. One such treatment is an in-situ electroplating technique, which results in electrodes with power density 20~40% higher, than that of the electrodes produced by the ordinary ex-situ electroplating method. This unique process also makes repair or reconditioning of the fuel cell possible and convenient. The related paper is:
N.Luo, G.Miley, K.J.Kim, R.Burton, X.Huang, “NaBH4/H2O2 fuel cells for air independent power systems.” Journal of Power Sources, Volume 185, Pages
685–690, 2008, USA
Dr. Kim is confident that his expertise that Dr. Kim have been accumulated for ten years is beneficial for various areas; especially, it is an important technology for the power source of robotic system that will be largely adapted to the national defense system in the future.
Research Field 2:
Metal Hydride Thermal Energy Conversion System
1993 ~ 2000, Luikov Heat and Mass Transfer Institute, National Academy of Sciences, Belarus
2001 ~ 2002, DAC Lab of LG Electronics Inc., Korea
His expertise is not just limited to fuel cells; it includes metal hydride application as a thermal energy conversion technology. Dr. Kim had conducted research on metal hydride application technology, which is a thermal energy conversion system, for nine years throughout his doctoral study at National Academy of Sciences and as a visiting researcher in Luikov heat and Mass
Transfer Institute in Belarus, as well as a senior research engineer of LG Electronics. Metal hydride application technology can allow us to utilize low-level thermal energy of waste heat for cooling and heat-upgrading, while refrigerators and air conditioners consume the electrical energy. Therefore, the technology provides a double benefit as 1) economical advantages; waste heat from chemical process or food process industries can be utilized to operate refrigeration cycle without electric power, 2) ecological
advantage; the global use of chlorofluorocarbon (CFC), which is the main cause of ozone layer depletion, can be reduced because the technology is using the hydrogen instead of CFC.
A method of metal-hydride thermal energy conversion that is an alternative to the traditional vapor compression method is proposed and investigated. The poles of metal-hydride thermal energy converters with the different thermo-physical properties are distributed in pairs inside parallel channels. The channels are blown through with a heat-transfer agent. Thermal
energy conversion develops as a set of propagating heat waves. By a numerical-modeling method it is shown that the maximum thermal effect is attained in synchronous motion of the heat wave and the heat source (or sink) that accompanies the phase transition in the propagation of metal-hydride thermal energy converter poles. The paper and issued patent about the research efforts is:
K.J.Kim, “Propagation of waves of metal-hydride thermal conversion in blown-through porous media.” Journal of Engineering Physics and Thermophysics, Vol.71, No.1, pp51~61, Minsk, Belarus, 1998
G.A.Fateyev, M.A.Silenkov, K.J.Kim, “Experimental study of propagation of waves of energy conversion in blown- through porous media.” Journal of Engineering Physics and Thermo-physics, Vol.73, No.5, pp1093~1108, Minsk, Belarus, 2000
KR 0442274, “Relief valve for airconditioner performing airconditioning by transmitting hydrogen,” Jul. 20, 2004
Research Field 3:
Thermo-Dynamic Modeling of Internal Combustion Engine
1989 ~ 1991, Graduate school of INHA University, Korea
1991 ~ 1992, Korea Institute of Industrial Technology, Korea
Dr. Kim's journey as a scientific and engineering researcher started out with his passion to understand the physicochemical mechanism of internal combustion engine from his graduate school days. The engine is a mechanical system, which converts chemical energy directly to mechanical energy. Especially Dr. Kim was very interested in Wankel type rotary engine that provides
both advantages of 2 cycle engine as mechanical perspective and 4 cycle engine as chemical perspective, and moreover its unique geometrical structure offers a lesser friction loss than the reciprocation type engine. Dr. Kim could successfully establish a numerical modeling of the complex epitrochoidal motion of the engine that generates exact numerical value of engine displacement versus eccentric shaft angle. The modeling is linked to the thermo-dynamic modeling of the internal combustion engine that Dr. Kim
developed later. The model is utilized not only to predict the engine performance based on the design parameters but also to design and program the electronic engine management system. His research and development experience of the thermo-dynamic modeling of internal combustion engine is contributed to develop electronic engine management system and to evaluate of rotary engine performance in submarine application during his career in Korea Institute of Industrial Technology. The efforts is introduced as:
K.J.Kim, J.O.Chae, “A performance simulation of spark ignition Wankel type rotary engine.” The sixth international pacific conference of automotive engineers, Paper No. 912479, Seoul, Korea, 1991