Inner-outer dual space protection of free-standing MoS2anodes via electrospinning for stable lithium-ion storage

Abstract

Although significant achievements in improving the stability of MoS₂anodes have been made, the cycling life in most studies is still less than 1000 cycles. This is because MoS₂anodes 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 MoS₂fibers 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 MoS₂from 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^-1at 1000 mA g^-1for 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.

Keywords: MoS2; electrospinning; high ICE; lithium-ion batteries; surface/interface regulation.