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 MoS_x material (CNS@MoS_x). 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@MoS_x are due to the unique porous conductive structure of CNS with abundant active sites to anchor MoS_x via strong chemical bonding, enabling MoS_x to be firmly confined on the substrate. Moreover, this unique hierarchical complex structure ensures the fast migration of Zn²⁺ within MoS_x interlayer. [ABSTRACT FROM AUTHOR]