High-performance cathode promoted by reduced graphene oxide nanofibers with well-defined interconnected meso-/micro pores for rechargeable Li-Se batteries

Abstract

Highly conductive nanostructures comprising one-dimensional (1D) reduced graphene oxide (rGO) nanofibers (NFs) and bimodal pores i.e., meso-/micropores, as efficient cathode hosts (Bi-P-rGO) for Li–Se batteries were prepared. The highly conductive rGO matrix acts as a self-supporting skeleton to enhance the structural integrity of the nanostructure besides providing numerous conducting pathways for rapid charge transfer. Moreover, highly interconnected chain-like mesopores guarantee efficient electrolyte percolation, whereas the micropores offer highly active material impregnation. Correspondingly, Bi-P-rGO@Se as a high-performance cathode was visualized, which demonstrated an overall enhanced electrochemical performance such as excellent rate capability (up to 20.0C) and overwhelming long-term cycling stability (73% capacity retention at the end of 800cycles with an average capacity decay rate of just 0.03% per cycle at 0.5C rate). The exceptional electrochemical performance of the Bi-P-rGO@Se cathode can be attributed to its highly porous structure, which promises efficient electrolyte infiltration and diffusion of charged species, high active material utilization within micropores, availability of conductive pathways for fast charge transfer, and high structural integrity. Therefore, we anticipate that the structural and electrochemical results presented in this work will provide significant insights into the synthesis of high-performance porous and conductive nanostructures for a wide range of applications.