Design Current Collector of Different Cell Size Metal Foam for Lithium-ion Batteries ; 리튬이온전지를 위한 다양한 셀 사이즈 발포금속인 집전체의 설계

학위논문 (석사)-- 서울대학교 대학원 : 재료공학부, 2017. 2. 주승기. ; Abstract Design Current Collector of Different cell size Metal Foam Cathode for Lithium-ion Batteries JIN TAO Department of Materials Science and Engineering The Graduate School Seoul National University In the last two decades, Lithium-ion batteries could be considered to be the most impressive success story of modern electrochemistry. Among rechargeable batteries, because Lithium-ion batteries have high energy density and high power performance, they are key components of the portable, entertainment, computing and telecommunication equipment. However, the energy density and electrochemical performance are still required to be further improved for more applications. The most important problem is that there are 50-100 ㎛ thick active materials on the foil-type current collector, and to sustain high power performance, the thickness of active materials is only 20-60 ㎛. In this way, to obtain large-scale capacity, the batteries become heavy and large. It is also caused by increased inactive materials, such as separator, current collector and so on. Moreover, one of the big issues for application is high production cost due to the increasing of materials and workload. To solve these problems, three- dimensional structure material – metal foams have been used for Lithium-ion battery electrodes instead of commercial foil-type current collectors in this study. In the condition of same volume, the cathodes using 450 ㎛ cell size metal foam and 3000 ㎛ cell size metal foam are compared in electrochemical performances. According to the charge-discharge test, cyclic voltammetric (CV) analysis, better kinetic performance is obtained for the 450 ㎛ cell size metal foam cathode due to the more triple junctions (junction of active material, metal frame, and electrolyte). But the electrode density of 3000 ㎛ metal foam cathode is higher than 450 ㎛ metal foam cathode, because the weight of active materials of 3000 ㎛ cell size metal foam cathode is more than 450 ㎛ metal foam cathode. It ...