▎ 摘　　要

In this study, we introduced a facile and single-step synthetic protocol for the scalable synthesis of tetra germanium nonaselenide (Ge4Se9) and it's composite with reduced graphene oxide (RG). The physicochemical properties of the samples were studied systematically, and their electrochemical performances for energy storage in supercapacitors were explored. Herein, the weight percentage of graphene oxide in the composite played a vital role in the enhancement of charge storage. Among other composites, the Ge4Se9/RG1 composite showed an enhanced specific capacitance (220 F g(-1)) with a higher specific energy (12 W h kg(-1)) as well as power (4.6 kW kg(-1)). Moreover, the composite showed excellent cycling stability (with 91% of capacitance retention after 10 000 repeated cycles) and reversibility (similar to 98% coulombic efficiency). Furthermore, the robustness of the composite was accessed via the post-stability analysis.