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Study on Electrochemical Properties of MnO 2 /MoS 2 composites
Author(s) -
YANG Yang,
CHUAN Xiuyun
Publication year - 2017
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/1755-6724.13241
Subject(s) - materials science , composite material , electrochemistry , chemistry , electrode
Supercapacitor also called electrochemical capacitor, has become one of the most promising energy storage devices due to its long service life, great power density, high energy density, green environmental protection (Simon et al, 2008; Ma et al, 2013). Based on the charge storage mechanisms, Supercapacitors can be divided into electrical double-layer capacitor (EDLC) and pseudo-capacitor according to the charge storage mechanism. The energy storage of EDLCs is the accumulation of ionic charges which occur at the interface between the electrode and electrolyte. For the pseudo-capacitor, it is produced by the fast reversible faradic transitions of active materials, e.g., transition metal oxides, conducting electric polymers (Lu et al, 2015; Huang et al, 2013). Among these active materials, manganese oxides (MnO2) are the most potential one because of their low cost, natural abundance, high theoretical capacity (1370 F/g), nontoxicity and wide operating potential window in mild electrolyte. However, bulk MnO2 suffers from low electronic conductivity (10-10 S/cm), low ionic diffusion constant and structural susceptibility which limit their applications as active materials for supercapacitor (Zhang et al, 2014). Therefore, MnO2 is usually mixed with other materials to prepare composite materials with better cycling, specific capacitance and mechanical stability. As a graphene-like material, MoS2 crystals are composed of the metal Mo layers sandwiched between two sulfur layers and stacked together by weak van der Waals interactions (He et al, 2016). Because of the intrinsic ionic conductivity higher than that of the metal oxide and the theoretical specific capacitance than graphite, the electrode material used as the capacitor has been deeply studied. However, there are still a lot of limitations when MoS2 is used as electrode material alone (Ma et al, 2013; Huang et al, 2013; Firmiano et al, 2013). This article is mainly study the electrochemical properties of MnO2/MoS2 composites.