Carbon cloth supported flower-like porous nickel-based electrodes boosting ion/charge transfer characteristics of flexible supercapacitors. (31st October 2022)

• Record Type: Journal Article
• Authors: Fu, Min; Zhu, Zitong; Chen, Wei; Yu, Hao; Lv, Ruitao
• Is Part Of: Carbon. Volume 199(2022)
• Page Start: 520
• Page End: 528
• Publication Date: 2022-10-31
• Subjects: Nickel-based electrodes -- NiS2 -- Flower-like -- Flexible supercapacitors; Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2022.07.032
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: Despite low cost and high theoretical specific capacitances, nickel-based compounds still suffer from poor conductivity, limited redox active sites and sluggish ion and charge transfer for their applications in flexible supercapacitors (FSCs). The rational structural control of nickel-based compound electrodes is vital but very challenging. Herein, a series of flower-like nickel-based compound electrodes are grown on carbon cloth (CC) by a general synthetic method, including Ni(OH)2 /CC, NiS2 /CC, NiO/CC and Ni2 P/CC hybrid electrodes. The formation mechanism of such flower-like structure is investigated in-depth. Benefiting from the fibrous structure of flexible carbon cloth and flower-like porous structure of NiS2, the NiS2 /CC hybrid electrodes are more accessible for the electrolyte ions, which facilitates their electrochemical kinetics and capacitive performances. The maximum specific capacitance of the NiS2 /CC electrode is 1166.3 F/g at 0.4 A/g. Moreover, flexible asymmetric supercapacitors (FASCs) are assembled using NiS2 /CC and activated carbon/CC (AC/CC) as positive and negative electrodes, respectively. Such FASCs exhibit an energy density of 34.1 Wh/kg at a power density of 561.3 W/kg, a long lifetime stability (96% retention after 8, 000 cycles), and excellent mechanical stability. These superior electrochemical characteristics make the flower-like porous NiS2 /CC hybrid a good candidate for next-generation flexible and high-performance electrode in FSCs. Graphical abstract: A series of flower-like nickel-based electrodes are developed as high performance free-standing electrodes for flexible supercapacitors (FSCs). The flower-like porous structure, high specific surface area and porous structure can render electrolyte ions free access to electrodes and provide abundant active sites for redox reactions, thereby promoting their capacitive performances. The assembled FSCs exhibit an energy density of 34.1 Wh/kg (51.1 μWh/cm 2 ) at a power density of 561.3 W/kg (841.2 μW/cm 2 ), 96% capacitance retention after 8, 000 cycles and excellent mechanical stability. Image 1