RESUMEN
Zn anodes suffer from the formation of uncontrolled dendrites aggravated by the uneven electric field and the insulating by-product accumulation in aqueous zinc-ion batteries (AZIBs). Here, an effective strategy implemented by 1-butyl-3-methylimidazolium hydrogen sulfate (BMIHSO4) additive is proposed to synergistically tune the crystallographic orientation of zinc deposition and suppress the formation of zinc hydroxide sulfate for enhancing the reversibility on Zn anode surface. As a competing cation, BMI+ is proved to preferably adsorb on Zn-electrode compared with H2O molecules, which shields the "tip effect" and inhibits the Zn-deposition agglomerations to inducing the horizontal growth along Zn (002) crystallographic texture. Simultaneously, the protonated BMIHSO4 additives could remove the detrimental OH- in real-time to fundamentally eliminate the accumulation of 6Zn(OH)2·ZnSO4·4H2O and Zn4SO4(OH)6·H2O on Zn anode surface. Consequently, Zn anode exhibits an ultra-long cycling stability of one year (8762 h) at 0.2 mA cm-2/0.2 mAh cm-2, 3600 h at 2 mA cm-2/2 mAh cm-2 with a high plating cumulative capacity of 3.6 Ah cm-2, and a high average Coulombic efficiency of 99.6 % throughout 1000 cycles. This work of regulating Zn deposition texture combined with eliminating notorious by-products could offer a desirable way for stabilizing the Zn-anode/electrolyte interface in AZIBs.
RESUMEN
Two-dimensional (2D) layered MoSe2 has been demonstrated to be a promising electrode material for new energy storage systems. However, its nature of poor conductivity and the undesirable interlayer spacing hinder its further application. In this paper, a general and simple plasma-enhanced chemical vapor deposition method is proposed to produce 2D heterolayer-structured MoSe2-carbon (MoSe2/C) with carbon atoms inserted in the MoSe2 layers. After morphology optimization, when applying flat-type MoSe2/C-200 nanosheets with an enlarged interlayer spacing of 0.79 nm as the anode and activated carbon as the cathode, the assembled sodium-ion hybrid capacitors can reach a maximum energy/power density of 116.5 W h kg-1/107.5 W kg-1 and exhibit superior cycling durability (91.3% capacitance retention after 4000 cycles at 1 A g-1). The good electrochemical property can be ascribed to the enlarged interlayer spacing that can offer fast diffusion channels for Na ions, and the carbon layer sandwiched in the MoSe2 layer can not only enhance the electron transfer, accelerating the reaction kinetics, but also alleviate the volume change of MoSe2, ensuring the good stability of the electrode. The proposed approach can also be extended to other 2D transition metal chalcogenide (TMC) materials for constructing the TMC/C heterostructures for the application in energy storage systems.