Three-Dimensional Hierarchical Ternary Nanostructures Bismuth/Polypyrrole/CNTs for High Performance Potassium-Ion Battery Anodes

Comprehensive Summary In recent years, the anode materials of bismuth(Bi)-based potassium ion batteries with high theoretical capacity and suitable potassium ion insertion potential have attracted extensive attention. However, due to the volume expansion of Bi, the performance of Bi-based anode materials is not ideal during potassium ion (de)intercalation. In order to solve these problems, we report a three-dimensional (3D) ternary bismuth nanoparticles/conductive polymers/carbon nanotubes (Bi/PPy/CNT) hybrid anode material for K-ion batteries. At a current density of 100 mA·g –1 , its reversible capacity reaches 302 mAh·g –1 after 200 cycles, while it reaches 195.7 mAh·g –1 after 600 cycles at 1 A·g –1 . Its excellent performance is attributed to the hydrogel network which provides a range of electron transport networks and high porosity. Carbon nanotubes are used as electron enhancers to reduce the volume expansion of Bi particles during the reaction. This study provides a prerequisite for expanding the application of 3D ternary materials.