摘要：SummaryLithium selenium (Li-Se) batteries have attracted increasing interest for its high theoretical volumetric capacities up to 3,253 Ah L−1. However, current studies are largely limited to electrodes with rather low mass loading and low areal capacity, resulting in low volumetric performance. Herein, we report a design of covalent selenium embedded in hierarchical nitrogen-doped carbon nanofibers (CSe@HNCNFs) for ultra-high areal capacity Li-Se batteries. The CSe@HNCNFs provide excellent ion and electron transport performance, whereas effectively retard polyselenides diffusion during cycling. We show that the Li-Se battery with mass loading of 1.87 mg cm−2displays a specific capacity of 762 mAh g−1after 2,500 cycles, with almost no capacity fading. Furthermore, by increasing the mass loading to 37.31 mg cm−2, ultra-high areal capacities of 7.30 mAh cm−2is achieved, which greatly exceeds those reported previously for Li-Se batteries.Graphical AbstractDisplay OmittedHighlights•The CSe@HNCNFs were used as flexible and free-standing cathode for Li-Se battery•The CSe@HNCNFs effectively retard polyselenides diffusion during cycling•The CSe@HNCNFs delivered high areal capacity of 7.30 mAh cm−2•The CSe@HNCNFs displayed excellent cyclic stability and rate performanceEnergy Storage; Materials Characterization Techniques; Nanostructure
