Hierarchical carbon nanosheet confined defective MoSx cathode towards long-cycling zinc-ion-battery

Aqueous zinc-ion batteries (ZIBs) have attracted increasing attention due to their low cost and high safety. MoS2 is a promising cathode material for aqueous ZIBs due to its favorable Zn2+ accommodation ability. However, the structural strain and large volume changes during intercalation/deintercalation lead to exfoliation of active materials from substrate and cause irreversible capacity fading. In this work, a highly stable cathode was developed by designing a hierarchical carbon nanosheet-confined defective MoSx material (CNS@MoSx). This cathode material exhibits an excellent cycling stability with high capacity retention of 88.3% and ∼ 100% Coulombic efficiency after 400 cycles at 1.2 A·g−1, much superior compared to bare MoS2. Density functional theory (DFT) calculations combined with experiments illustrate that the promising electrochemical properties of CNS@MoSx are due to the unique porous conductive structure of CNS with abundant active sites to anchor MoSx via strong chemical bonding, enabling MoSx to be firmly confined on the substrate. Moreover, this unique hierarchical complex structure ensures the fast migration of Zn2+ within MoSx interlayer.