3D Interconnected MoS₂ with Enlarged Interlayer Spacing Grown on Carbon Nanofibers as a Flexible Anode Toward Superior Sodium-Ion Batteries

Molybdenum disulfide (MoS2) has attracted extensive research interest as a fascinating anode for sodium-ion batteries (SIBs) because of its high specific capacity of 670 mA h g–1. However, unsatisfied cycling durability and poor rate performance are two barriers that hinder MoS2 for practical application in SIBs. Herein, 3D interconnected MoS2 with enlarged interlayer spacing epitaxially grown on 1D electrospinning carbon nanofibers (denoted as MoS2@CNFs) was prepared as a flexible anode for SIBs via l-cysteine-assisted hydrothermal method. Benefitting from the C–O–Mo bonding between the CNFs and MoS2 as well as the rational design with novel structure, including the well-retained 3D interconnected and conductive MoS2@CNFs networks and expanded (002) plane interlayer space, the flexible MoS2@CNFs electrode achieves a remarkable specific capacity (528 mA h g–1 at 100 mA g–1), superior rate performance (412 mA h g–1 at 1 A g–1), and ultralong cycle life (over 600 cycles at 1 A g–1 with excellent Coulombic efficiencies exceeding 99%). The elaborate strategy developed in this work opens a new avenue to prepare highly improved energy storage materials, especially suitable for flexible electronics.