A facile electrospinning and electrospraying synchronization technique for preparation of high performance MnO/C@rGO composite anodes for lithium storage

Abstract

A three-dimensional (3D) composite film has become one of the most attractive candidates for energy-storage systems owing to its simple design and fast charge-transportation network. In this study, novel electrospinning and electrospraying synchronization technologies were combined to achieve manganese oxide/carbon nanofibers@reduced graphene oxide composite film electrodes [MnO/CNFs@rGO, (MCG)] for lithium-ion batteries (LIBs). In such an electrode structure, the as-prepared CNFs/MnO nanowires successively dispersed on the 2D reduced graphene oxide (rGO) sheets to build a 3D composite flexible film, forming an especially stable, freestanding, and binder-free structure. In this film, the rGO sheets and carbon coating can accommodate the huge volume expansion from MnO after lithiation, improve the electronic conductivity, and further increase lithium ion diffusion. Remarkably, the MCG electrodes exhibited a reversible capacity of 1148 mA h g⁻¹ at a current density of 0.1 A g⁻¹ and retained a capacity of 332 mA h g⁻¹ at a current density of 5 A g⁻¹ even after 4500 cycles. More interestingly, the MnO₂ powder (Mn source) used as the raw material in this work was the recovery product from spent Zn/MnO₂ batteries. The present work also demonstrates a new approach to utilize the MnO₂ from spent Zn/MnO₂ batteries to make high value Li-ion battery electrodes.