MoS2-coated vertical graphene nanosheet for high-performance rechargeable lithium-ion batteries and hydrogen production

Abstract

Hybrid nanostructures composed of vertical graphene nanosheet (VGNS) and MoS 2 nano-leaves are synthesized by the chemical vapor deposition method followed by a solvothermal process. The unique three-dimensional nanostructures of MoS 2 /VGNS arranged in a vertically aligned manner can be easily constructed on various substrates, including Ni foam and graphite paper. Compared with MoS 2 /carbon black, MoS 2 /VGNS nanocomposites grown on Ni foam exhibit enhanced electrochemical performance as the anode material of lithium-ion batteries, delivering a specific capacity of 1277 mAh g − 1 at a current density of 100 mA g − 1 and a high first-cycle coulombic efficiency of 76.6%. Moreover, the MoS 2 /VGNS nanostructures also retain a capacity of 1109 mAh g − 1 after 100 cycles at a current density of 200 mA g − 1 , suggesting excellent cycling stability. In addition, when the MoS 2 /VGNS nanocomposites grown on graphite paper are applied in the hydrogen evolution reaction, a small Tafel slope of 41.3 mV dec − 1 and a large double-layer capacitance of 7.96 mF cm − 2 are obtained, which are among the best values achievable by MoS 2 -based hybrid structures. These results demonstrate the potential applications of MoS 2 /VGNS hybrid materials for energy conversion and storage and may open up a new avenue for the development of vertically aligned, multifunctional nanoarchitectures.

MoS2/C/C nanofiber with double-layer carbon coating for high cycling stability and rate capability in lithium-ion batteries

“…Two peaks are observed at 228.6 and 231.9 eV, which can be attributed to the Mo 3d 5/2 and Mo 3d 3/2 binding energies, respectively, and are ascribed to the characteristic peaks of Mo 4+ in MoS 2 flakes [40]. The peaks at 232.1 and 235.3 eV are related to the Mo 3d 5/2 and 3d 3/2 of Mo 6+ (typical of the Mo-O-C bond) [26]. The peaks at 162.5 and 161.3 eV are attributed to the S 2p 1/2 and S 2p 3/2 peaks, which are related to the sulfur in MoS 2 [13].…”

“…The peaks at 162.5 and 161.3 eV are attributed to the S 2p 1/2 and S 2p 3/2 peaks, which are related to the sulfur in MoS 2 [13]. The C 1s spectra can be decomposed into a dominant peak at 284.7 eV for C=C/C−C, and another broad peak related to oxygen-containing functional groups, which include C-O-Mo bonds [26]. The C-O-Mo bonds can be formed by bonding Mo atoms to oxygen-containing functional groups of the carbon precursor.…”

“…In order to ameliorate the electrical conductivity and structural stability of MoS 2 electrodes during cycling, carbonaceous materials, such as amorphous carbon, carbon fibers, porous carbon, carbon spheres, carbon nanotubes, and graphene, have been employed to form hybrid MoS 2 -carbon systems [13,25,26]. The carbon component can enhance the electronic conductivity and concurrently buffer the volume changes of MoS 2 during the lithiation/delithiation reaction.…”

Vertically Aligned Graphene Nanosheet Arrays: Synthesis, Properties and Applications in Electrochemical Energy Conversion and Storage

“…Interestingly, MoS 2 nanosheets could be easily assembled on the surfaces of graphene nanosheets in VAGNAs through solvothermal or hydrothermal methods. [118,119] The MoS 2 /VAGNAs/Ni-foam anode exhibited a high specific capacity of 1277 mA h g −1 at current density of 100 mA g −1 , a first Coulombic efficiency of 76.6%, and high capacity of 818 mA h g −1 at an elevated current density of 2000 mA g −1 . Such a composite structure enabled an much improved capacity as compared with that of MoS 2 /GFs [120] synthesized by CVD (less than 600 mA h g −1 at a current density of 2000 mA g −1 ).…”

Low‐Cost Metallic Anode Materials for High Performance Rechargeable Batteries

“…Therefore, developing highcapacity anode and cathode materials or new battery systems have drawn extensive attentions. [6,[21][22][23][24][25][26][27][28] Metal anodes, especially those with high-capacity and low-cost are promising alternative anode materials for LIBs in replace of graphite anode. [29][30][31][32][33][34] Generally, the metal anodes electrochemically alloy/ de-alloy with Li + to complete the battery reaction, which can store more energy than the intercalation/deintercalation mechanism in graphite.…”