Inner–outer dual space protection of free-standing MoS2 anodes via electrospinning for stable lithium-ion storage

Abstract

Although significant achievements in improving the stability of MoS2 anodes have been made, the cycling life in most studies is still less than 1000 cycles. This is because MoS2 anodes directly contact the electrolyte and generate byproducts, leading to the loss of active mass and capacity decay. Herein, the inner–outer dual space protection of MoS2 fibers is realized by regulating the surface and interface structure of electrospinning precursors (noted as X-MoS2/CNFs). Inside the fibers, Mo–N covalent bond is constructed to anchor the active material, preventing MoS2 from falling off the matrix after multiple cycles. Simultaneously, surface of the fibers, a stable solid electrolyte interface layer is induced to prevent contact between active materials and electrolytes. In addition, the initial Coulombic efficiency is enhanced as high as 84.4%. The profound investigations of morphological evolution and internal real-time resistance confirm the double structural protection of 800-MoS2/CNFs. As a result, a decent cycling performance (408.9 mAh g−1 at 1000 mA g−1 for 2000 cycles) and the satisfied rate capacities (100–1000 mA g−1) are achieved. This work provides a new idea for the preparation of stable anodes for alkali metal ion secondary batteries.