固体润滑国家重点实验室（LSL）知识库

Three dimensional (3D) hierarchical structures have attracted rapidly increasing attention in the energy storage field because they can facilitate electron and ion transport and electrolyte/electrode contact which results in full utilization of active materials. Here, a series of 3D hierarchical bismuth (Bi)-based compounds with different sizes and morphologies have been controllably synthesized by adjusting the Bi³⁺/urea molar ratio. Electrochemical characterizations indicated that the prepared Bi-based compounds exhibit high specific capacitance and superior rate capability in aqueous alkaline electrolyte (832 F g⁻¹ at 1 A g⁻¹, and still maintained 90% of the initial level at 20 A g⁻¹), which can be attributed to their novel hierarchical structure.