| 초록 |
Supercapacitors have intrigued researchers because of their greater energy density compared to conventional capacitors and their greater power density than batteries, as well as their long cycle life. However, for high power applications, a major disadvantage is that they have unsatisfactory energy density compared to batteries. To increase the energy density of supercapacitors, increasing the potential range is an effective approach. Carbon can complement or replace batteries in electrical energy storage and harvesting applications, where high power delivery and wide potential range are needed. Among them, CNTs are an attractive solution for energy storage devices due to their unique properties such as high chemical stability, high aspect ratio, strong mechanical strength, and high activated surface area. Alternative pseudocapacitive materials have proven to be promising materials for supercapacitor applications. Among these other metal oxides/hydroxides, nickel- and cobalt-based materials are considered the most promising for the next generation of supercapacitors because of their high specific capacitances, cost effectiveness, and natural abundance. Herein, multi-walled carbon nanotube (MWCNT) and nickel-cobalt binary metal hydroxide nanorod hybrids have been developed through the chemical synthesis of binary metal hydroxide on a MWCNT surface. These hybrids show enhanced supercapacitive performance and cycling ability. In this study, we report on the synthesis of nickel–cobalt hydroxide and CNT composites on a stainless steel substrate with promising charge storage performance. These electrodes yield a significantly high capacitance of 502 F/g with a high energy density of 69 Wh/kg at a scan rate of 5 mV/s. The film is stable up to 5000 cycles with greater than 80% capacitance retention. |
