Construction of MoS2/Mxene heterostructure on stress-modulated kapok fiber for high-rate sodium-ion batteries

Porous graphene-like MoS2/carbon hierarchies for high-performance pseudocapacitive sodium storage

“…5a shows the cyclic voltammetry (CV) curves of MoS 2 /C100 in the first five cycles, in which two peaks in the first cathodic scan appear at 1.20 and 0.43 V, corresponding to the intercalation reaction of 2H-MoS 2 (2H-MoS 2 + x Na + + x e − → 1T-Na x MoS 2 ) and the conversion reaction from Na x MoS 2 to Mo and Na 2 S (1T-Na x MoS 2 + (4 − x )Na + + (4 − x )e − → 2Na 2 S + Mo), as well as the formation of the solid electrolyte interface (SEI) film, respectively. 55,56 The oxidation peak at 0.42 V might be ascribed to the formation of Na x MoS 2 , and the peaks at 1.59, 1.85 and 2.14 V are related to the stepwise oxidation of Mo to MoS 2 . 42,56–58 From the second CV cycle onward, two reduction peaks appear at 1.50 and 0.73 V with good overlapping, confirming the high reversibility of MoS 2 /C100 upon cycling.…”

“…55,56 The oxidation peak at 0.42 V might be ascribed to the formation of Na x MoS 2 , and the peaks at 1.59, 1.85 and 2.14 V are related to the stepwise oxidation of Mo to MoS 2 . 42,56–58 From the second CV cycle onward, two reduction peaks appear at 1.50 and 0.73 V with good overlapping, confirming the high reversibility of MoS 2 /C100 upon cycling. For comparison, the CV curves of MoS 2 , MoS 2 /C50 and MoS 2 /C150 are also provided in Fig.…”

“…Note that all the MoS 2 -based electrodes show much smaller R ct values, which may be related to the formation of the high conductivity 1T-MoS 2 phase upon cycling. 56 Furthermore, the inclined line in the low-frequency region relates to the Warburg impedance ( Z w ), which determines the ion diffusion coefficient according to eqn (3) and (4): 63 …”

Recent Research Progress in the Structure, Fabrication, and Application of MXene-Based Heterostructures

“…MXene-based heterostructures can integrate the merits of different materials to achieve enhanced mechanical properties with isotropic characteristics, which is able to ensure the structure stability, as well as provide a new idea and paradigm for the construction of flexible electrodes. Zhang et al [ 105 ] constructed the MoS 2 /MXene heterostructure based on MoS 2 nanoflowers, MXene micro-nano materials, and hollow carbonized kapok fibers (CKFs) for a high-speed sodium-ion battery by the hydrothermal method. The MoS 2 /MXene heterostructure made full use of the advantages of MoS 2 and MXene, showing excellent coulomb efficiency and high capacitance thanks to the layered, hollow, and porous heterostructure.…”

A photolithography tailored undulating configuration to confine nanostructures on microtubes via a “stress-induced” effect for boosting sodium ion storage

“…40,41 In addition, nanomaterials in close contact can crush and fracture each other, resulting in poor structural integrity of the electrode. For example, Xu 42 found that kapok fibers, as biomass-based carbon fibers, have a relatively stable three-dimensional structure that can withstand a certain level of external attack. The removal of easily degradable components creates multiple channels and pores in the resulting matrix, enabling the formation of natural structures that facilitate subsequent steps.…”