Energy storage systems should address issues such as power fluctuations and rapid charge-discharge; to meet this requirement, CoFe2O4 (CFO) spinel nanoparticles with a suitable electrical conductivity and various redox states are synthesized and used as electrode materials for supercapacitors. In particular, CFO electrodes combined with carbon nanofibers (CNFs) can provide long-term cycling stability by fabricating binder-free three-dimensional electrodes. In this study, CFO-decorated CNFs are prepared by electrospinning and a low-cost hydrothermal method. The effects of heat treatment, such as the activation of CNFs (ACNFs) and calcination of CFO-decorated CNFs (C-CFO/ACNFs), are investigated. The C-CFO/ACNF electrode exhibits a high specific capacitance of 142.9 F/g at a scan rate of 5 mV/s and superior rate capability of 77.6% capacitance retention at a high scan rate of 500 mV/s. This electrode also achieves the lowest charge transfer resistance of 0.0063 Ω and excellent cycling stability (93.5% retention after 5,000 cycles) because of the improved ion conductivity by pathway formation and structural stability. The results of our work are expected to open a new route for manufacturing hybrid capacitor electrodes containing the C-CFO/ACNF electrode that can be easily prepared with a low-cost and simple process with enhanced electrochemical performance.

코발트 폴리사이드 게이트 전극을 형성할 때, 원주형(columnar)과 입자형(granular)다결정 Si 및 비정질 Si 기판위에 Co 단일막(Co monolayer)또는 Co/Ti 이중막(Co/Ti bilayer)을 사용하여 형성한 CoSi2의 열정안정을 비교하여 기판의 결정성과 CoSi/ sub 2/ 형성방법이 열적안정성에 미치는 영향을 연구하였다. 900˚C에서 600초까지 급속열처리하였을 때 , 기판을 비정질을 사용하거나 기판에 관계없이 Co/Ti 이중막을 사용하면 열적안정성이 향상되었다, 이는 평탄하고 깨끗한 기판 Si표면과 지연된 Co확산으로 인해,조성이 균일하고 계면이 평탄한 CoSi2가 형성되었기 때문이다. CoSi2의 열적안정성에 가장 중요한 인자는 열처리 초기 처음 형성된 실리사이드의 조성 균일성과 기판과의 계면 평탄성이었다.