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MoS 2 /NiS Yolk–Shell Microsphere‐Based Electrodes for Overall Water Splitting and Asymmetric Supercapacitor
Author(s) -
Qin Qing,
Chen Lulu,
Wei Tao,
Liu Xien
Publication year - 2019
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201803639
Subject(s) - supercapacitor , materials science , capacitance , electrochemistry , current density , electrode , chemical engineering , power density , energy storage , electrolysis , nanotechnology , chemistry , electrolyte , power (physics) , physics , quantum mechanics , engineering
Abstract Rational designing of the composition and structure of electrode material is of great significance for achieving highly efficient energy storage and conversion in electrochemical energy devices. Herein, MoS 2 /NiS yolk–shell microspheres are successfully synthesized via a facile ionic liquid‐assisted one‐step hydrothermal method. With the favorable interface effect and hollow structure, the electrodes assembled with MoS 2 /NiS hybrid microspheres present remarkably enhanced electrochemical performance for both overall water splitting and asymmetric supercapacitors. In particular, to deliver a current density of 10 mA cm −2 , the MoS 2 /NiS‐based electrolysis cell for overall water splitting only needs an output voltage of 1.64 V in the alkaline medium, lower than that of Pt/C–IrO 2 ‐based electrolysis cells (1.70 V). As an electrode for supercapacitors, the MoS 2 /NiS hybrid microspheres exhibit a specific capacitance of 1493 F g −1 at current density of 0.2 A g −1 , and remain 1165 F g −1 even at a large current density of 2 A g −1 , implying outstanding charge storage capacity and excellent rate performance. The MoS 2 /NiS‐ and active carbon‐based asymmetric supercapacitor manifests a maximum energy density of 31 Wh kg −1 at a power density of 155.7 W kg −1 , and remarkable cycling stability with a capacitance retention of approximately 100% after 10 000 cycles.