Template-free synthesis of β-NiS ball-in-ball microspheres for a high-performance asymmetrical supercapacitor. Issue 33 (4th August 2021)

• Record Type: Journal Article
• Authors: Hu, Qin; Zhang, Shengtao; Li, Wenpo; Hao, Jiangyu; Zhang, Lulu; Yan, Lijin; Zou, Xuefeng
• Is Part Of: Dalton transactions. Volume 50:Issue 33(2021)
• Page Start: 11512
• Page End: 11520
• Publication Date: 2021-08-04
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d1dt01687c
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : In this work, single-component β-NiS ball-in-ball microspheres has been easily obtained by the unique use of 2-mercaptopropionic acid (2-MPA) as the sulfur source and ethanol as the solvent. Abstract : While significant advances have been made in the synthesis of core–/multi-shell materials, the synthetic process usually involves a soft/hard template and complicated procedures. In particular, it is extremely difficult to fabricate single-component core–shell structures for nickel sulfides (NSs) with a controlled phase. In this work, we demonstrate a novel facile method to synthesize a single-component β-NiS ball-in-ball microsphere. The ball-in-ball structure is easily obtained by uniquely employing 2-mercaptopropionic acid (2-MPA) as the sulfur source and ethanol as the solvent based on the Ostwald ripening process. In particular, our work demonstrates that the chemical structure of sulfur sources and solvents plays a key role in the formation of the pure β-NiS ball-in-ball structure. When used as an electrode active material, the β-NiS ball-in-ball microspheres exhibit two times stronger specific capacity and three times higher rate performance than NSs produced by a hydrothermal method. The fabricated NS-2//rGO asymmetrical supercapacitor (ASC) displays an energy density of 46.4 W h kg −1 at a power density of 799.0 W kg −1 and good cycling performance. Thus, this study provides a new method for controlling the phase and morphology of NSs.