Ultrathin MoS2 nanosheets anchored on carbon nanofibers as free-standing flexible anode with stable lithium storage performance

Abstract

Lithium-ion batteries have high potential to be used as energy storage devices for wearable electronics due to their high energy density, high output voltage and environmental benignity. The increasing demand to develop wearable electronics has aroused great interests for flexible anode of lithium-ion batteries. However, the traditional rigid anode severely hiders further development of lithium-ion batteries in flexible wearable devices. Herein, we demonstrated a flower-like architecture material, in which the layered MoS2 nanosheets are anchoring on 3D porous carbon nanofibers (CNFs), serving as free-standing anode for LIBs, and this material can be wound at will. The free-standing CNFs were prepared through a facile electrospinning and carbonization process, the MoS2 nanosheets consist of few MoS2 ≤ 5 layers and were prepared through a hydrothermal process. Time-dependent experiment illustrated that the flower-like architecture was transformed from bare fibers and tiny particles. Although the polymers were stretched, shrank and covered by MoS2 nanosheets in the fabrication proess, the membrane still retained excellent flexible from beginning to end. Benefiting from the coaxial structure and synergistic effect, the flexible anode delivered an initial high discharge capacity (938.8 mAh g−1, 0.2 A g−1) and outstanding capacity retention rate at high current density (457.2 mAh g−1, 2 A g−1, 276.3 mAh g−1 after 1000 cycles). Its stability can surpass other flexible MoS2-based anodes. Furthermore, the hybrid electrode can maintain superior flexibility and mechanical stability after experiments, guaranteeing a promising future in wearable electronics. This work indicates that the flexible MoS2 @CNFs can be used as anode for flexible batteries, flexible capacitors and other wearable applications.