Effect of slurry preparation duration on electrochemical performance of raspberry-like NiO@C

초록

Raspberry-like hybrid metal oxides or metal oxide-carbon composites are widely used as supercapacitor electrodes due to their morphology, which promotes diffusion of electrolyte ions. This study examines how the slurry preparation time affects the morphology and electrochemical performance of a nickel oxide-carbon composite (NiO@C) synthesized via solvothermal methods. The structural changes during preparation increase the average pore diameter, leading to significant electrochemical improvements. Notably, the specific capacitance rises from 797 to 1022 F g(-1 )at a current density of 0.5 A g(-1). In addition, at a high current density of 5 A g(-1), capacitance retention exceeds 70% after 1000 cycles. The experimental results reveal that both the morphology and electrochemical properties of NiO@C change progressively with increasing preparation time. However, extended preparation times beyond a 12-h threshold do not result in further improvements in the electrochemical properties of the material. This method of investigating and optimizing electrochemical performance through mechanical structural modifications can be applied to other raspberry-like metal oxide-carbon composites or hybrid metal oxides.

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