| Hard carbon(HC) has attracted great attention in electrochemical energy storage for its low cost and environmental friendliness. However, the limitation of theoretical capacity has limited the application of HC electrode. Cooperating with metal oxide is an effective method to increase the capacity of HC and nickel oxide(Ni O) is a suitable component for composite electrode.In this paper, we prepared nano HC particles via hydrothermal method and then combined HC with Ni O via impregnation and calcination. Hydrothermal temperature, hydrothermal time and solution concentration for hydrothermal reaction and calcination temperature were optimized for the preparation of HC. Contents of nickel and carbon, calcination atmosphere and calcination process were adjusted for the preparation of HC-Ni O. Furthermore, the electrochemical perforamce of the obtained products were tested as lithium ion battery and supercapacitor electrode.The results show that the obtained HC has a typical morphology of sphere with numerous functional groups on the surface and micropores inside, and with a narrow diameter distribution of 90-130 nm. After impregnation in Ni2+ and calcination, a unique structure of uniform Ni O nanoparticles with a size of a few nanometers embedded in porous hard carbon spheres were obtained.The specific capacities at the 100 th cycle of the HC and HC-Ni O as lithium ion battery(LIB) anode materials are 390 m Ah/g and 777 m Ah/g, respectively. The specific capacitances at 2000 th cycle of the HC and HC-Ni O as supercapacitor(SC) electrodes are 122.4 and 193.8 F/g, respectively. Compared to HC electrode, the energy density of HC-Ni O electrode has been greatly improved. Besides, both HC and HC-Ni O have achieved good rate performance. The HC-Ni O composite electrode has achieved much higher energy and power density, owing to the synergistic effects between the hard carbon and the homogeneous dispersed Ni O nanoparticles. |
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