Layered LiNi1/2Mn1/2O2materials used as the cathode active material for Li-ion secondary battery were synthesized by sol-gel and molten-salt methods, and their structural and electrochemical properties were investigated by the implementation of FE-SEM, XRD and Charge/Discharge cycler. It was identified from Rietveld refinement of XRD data that layered LiNi1/2Mn1/2O2materials were synthesized and the Li ions and Ni ions were co-existed in 3a and 3b sites, respectively. Electrochemical cells using LiNi1/2Mn1/2O2were tested at the voltage range between 2.0 and 4.8 V and at the specific current density of 40 mA g-1. To elute the effects of electrical conductor, the amounts of acetylene black were changed from 15 wt% to 40 wt% in cathode. It was found that the discharge capacity of electrochemical cell with layered LiNi1/2Mn1/2O2cathode increased with increasing the amount of acetylene black. It was also found that LiNi1/2Mn1/2O2cathode B included acetylene black of 40 wt% showed higher discharge capacity of approximately 220 mAh g-1than cathode A included acetylene black of 15 wt%

졸-겔법과 용융염법으로 제조한 층상구조의 LiNi1/2Mn1/2O2계 정극 활물질의 구조 및 전기화학적 특성을 FE-SEM, XRD및 충ㆍ방전기를 사용하여 조사하였다. 합성된 시료를 Rietveld 프로그램을 이용해서 XRD pattern을 분석한 결과, 3a와 3b 위치에 리튬과 니켈이 서로 공존하는 층상구조를 갖는 LiNi1/2Mn1/2O2가 생성되는 것을 확인할 수 있었다. LiNi1/2Mn1/2O2계 정극 활물질과 도전체로 사용되는 acetylene black의 양을 무게비 15%와 40%로 변화시켜 전지를 제조한 다음 2.0~4.8 V의 전압범위와 40 mA g-1의 전류밀도에서 충ㆍ방전 실험을 실시하였다. LiNi1/2Mn1/2O2계층상 양극 활물질을 사용한 전지의 방전용량은 첨가한 acetylene black의 양이 증가할수록 증가하는 경향을 나타내었다. Acetylene black이 40% 포함된 양극 B에서 15% 포함된 양극 A보다 높은 방전용량(220 mAh g-1)을 얻을 수 있었다.