Electrochemical performance of interspace-expanded molybdenum disulfide few-layer
Interspace-expanded molybdenum disulfide (IE-MoS2) has been designed as a supercapacitor electrode material to improve the cycling stability. IE-MoS2 was formed through the ultrasound exfoliation of the interspace-compacted molybdenum disulfide (IC-MoS2), which was initially prepared through hydrothermal synthesis using Na2MoO4 as molybdenum source and CH4N2S as sulfur source. As-formed IE-MoS2 shows a few-layer structure with approximate 8–16 monolayer packing and monolayer distance of 0.83 nm. The MoS2 few-layer distance increased from 12 nm of IC-MoS2 to 20 nm for IE-MoS2. The specific capacitance was determined to be 108 F g−1 for IC-MoS2 to 192 F g−1 for IE-MoS2 at 0.5 A g−1. The improved specific capacitance was ascribed to more active sulfur atom exposed at the edges of IE-MoS2 few-layer to conduct the promoted proton attachment reaction. IE-MoS2 showed the capacity retention of 42% when the current density increased from 0.5 to 10 A g−1, presenting the high-rate capability. IE-MoS2 achieved the capacity retention of 116% at 10 A g−1 after 5000 charge-discharge cycles, which was ascribed to the electro-activation of the few-layer expanded MoS2 in proton acid electrolyte solution. IE-MoS2 exhibited the obviously improved cycling stability in comparison with IC-MoS2. All solid-state IE-MoS2 supercapacitor based on two symmetric IE-MoS2 electrodes and H2SO4-PVA gel electrolyte exhibited the energy density of 18.75 Wh kg−1 and power density of 375 W kg−1 at 0.5 A g−1 and high voltage window of 1.5 V. IE-MoS2 supercapacitor also exhibited the improved capacity retention of 110% after 1000 charge-discharge cycles. Such well-designed IE-MoS2 few-layer with highly improved cycling stability performance presented the promising energy storage application.
KeywordsMolybdenum disulfide Ultrasound exfoliation Cycling stability Electrode material Supercapacitor
The work was supported by National Natural Science Foundation of China (No. 21373047), Graduate Innovation Program of Jiangsu Province, the Fundamental Research Funds for the Central Universities (2242018K41024) and the Priority Academic Program Development of Jiangsu Higher Education Institutions.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Cunningham G, Lotya M, Cucinotta CS, Sanvito S, Bergin SD, Menzel R, Shaffer MSP, Coleman JN (2012) Solvent exfoliation of transition metal dichalcogenides: dispersibility of exfoliated nanosheets varies only weakly between compounds. ACS Nano 6:3468–3480. https://doi.org/10.1021/nn300503e CrossRefGoogle Scholar
- Koroteev VO, Kuznetsova IV, Kurenya AG, Kanygin MA, Fedorovskaya EO, Mikhlin YL, Chuvilin AL, Bulusheva LG, Okotrub AV (2016) Enhanced supercapacitance of vertically aligned multi-wall carbon nanotube array covered by MoS2nanoparticles. Phys Status Solidi B 253:2451–2456. https://doi.org/10.1002/pssb.201600366 CrossRefGoogle Scholar
- Liu AP, Zhao L, Zhang JM, Lin LX, Wu HP (2016) Solvent-assisted oxygen incorporation of vertically aligned MoS2 ultrathin nanosheets decorated on reduced graphene oxide for improved electrocatalytic hydrogen evolution. ACS Appl Mater Interface 8:25210–25218. https://doi.org/10.1021/acsami.6b06031 CrossRefGoogle Scholar
- Mahmood Q, Park SK, Kwon KD, Chang SJ, Hong JY, Shen G, Jung YM, Park TJ, Khang SW, Kim WS, Kong J, Park HS (2016) Transition from diffusion-controlled intercalation into extrinsically pseudocapacitive charge storage of MoS2 by nanoscale heterostructuring. Adv Energy Mater 6. https://doi.org/10.1002/aenm.201501115
- Xiao H, Wang S, Zhang S, Wang Y, Xu Q, Hu W, Zhou Y, Wang Z, An C, Zhang J (2017) Interlayer expanded molybdenum disulfide nanosheets assembly for electrochemical supercapacitor with enhanced performance. Mater Chem Phys 192:100–107. https://doi.org/10.1016/j.matchemphys.2017.01.077 CrossRefGoogle Scholar
- Zhang P, Qin F, Zou L, Wang M, Zhang K, Lai Y, Li J (2017a) Few-layered MoS2/C with expanding d-spacing as a high-performance anode for sodium-ion batteries. NanoscaleGoogle Scholar