Dandelion-Like Bi₂S₃/rGO hierarchical microspheres as high- performance anodes for potassium-ion and half/full sodium-ion batteries

Sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs) have been considered as attractive alternatives for next-generation battery systems, which have promising application potential due to their earth abundance of potassium and sodium, high capacity and suitable working potential, however, the design and application of bi-functional high-performance anode still remain a great challenge up to date. Bismuth sulfide is suitable as anode owing to its unique laminar structure with relatively large interlayer distance to accommodate larger radius ions, high theoretical capacity and high volumetric capacity etc. In this study, dandelion-like Bi₂S₃/rGO hierarchical microspheres as anode material for PIBs displayed reversible capacity, and 206.91 mAh·g^–1 could be remained after 1, 200 cycles at a current density of 100 mA·g^–1. When applied as anode materials for SIBs, 300 mAh·g^–1 could be retained after 300 cycles at 2 A·g^–1 and its initial Coulombic efficiency is as high as 97.43%. Even at high current density of 10 A·g^–1, 120.3 mAh·g^–1 could be preserved after 3, 400 cycles. The Na₃V₂(PO₄)₃@rGO//Bi₂S₃/rGO sodium ion full cells were successfully assembled which displays stable performance after 60 cycles at 100 mA·g^–1. The above results demonstrate that Bi₂S₃/rGO has application potential as high performance bi-functional anode for PIBs and SIBs.