Controllable synthesis of 3D hierarchical bismuth compounds with good electrochemical performance for advanced energy storage devices

Abstract

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.