Rational Design of Hierarchically Core–Shell Structured Ni3S2@NiMoO4 Nanowires for Electrochemical Energy Storage

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 14; no. 27
• Main Authors: Chen, Fangshuai, Ji, Shan, Liu, Quanbing, Wang, Hui, Liu, Hao, Brett, Dan J. L., Wang, Guoxiu, Wang, Rongfang
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 05.07.2018
• Subjects: Activated carbon; binder‐free electrodes; Core-shell structure; core–shell; Electric contacts; Electrical resistivity; Electrochemical analysis; Electrodes; Energy storage; Flux density; hierarchical structures; Molybdates; Nanostructured materials; Nanotechnology; Nanowires; Nickel compounds; Nickel sulfide; Structural hierarchy; Supercapacitors; Synthesis
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201800791

Rational design and controllable synthesis of nanostructured materials with unique microstructure and excellent electrochemical performance for energy storage are crucially desired. In this paper, a facile method is reported for general synthesis of hierarchically core–shell structured Ni3S2@NiMoO4 nanowires (NWs) as a binder‐free electrode for asymmetric supercapacitors. Due to the intimate contact between Ni3S2 and NiMoO4, the hierarchical structured electrodes provide a promising unique structure for asymmetric supercapacitors. The as‐prepared binder‐free Ni3S2@NiMoO4 electrode can significantly improve the electrical conductivity between Ni3S2 and NiMoO4, and effectively avoid the aggregation of NiMoO4 nanosheets, which provide more active space for storing charge. The Ni3S2@NiMoO4 electrode presents a high areal capacity of 1327.3 µAh cm−2 and 67.8% retention of its initial capacity when current density increases from 2 to 40 mA cm−2. In a two‐electrode Ni3S2@NiMoO4//active carbon cell, the active materials deliver a high energy density of 121.5 Wh kg−1 at a power density of 2.285 kW kg−1 with excellent cycling stability. A facile method for general synthesis of core–shell structured Ni3S2@NiMoO4 nanowires as a binder‐free electrode for asymmetric supercapacitors is described in this study. Due to the intimate contact between the materials, core–shell structured Ni3S2@NiMoO4 binder‐free electrodes provide a promising target structure for energy storage.