Nitrogen-doped three-dimensional porous carbon anode derived from hard halloysite template for sodium-ion batteries

Halloysite nanotubes were investigated as a hard template for the preparation of multi-functional porous carbon due to their one-dimensional ordered structures and the composition of aluminosilicate. Herein, a novel N-doped three-dimensional porous carbon nanofiber (3D PCN) was obtained following electrospinning, pyrolysis and demineralization of natural halloysite. When used as anodes in Na+-batteries, the obtained 3D PCN exhibited a high specific capacity of 266 mAh·g−1 at a current density of 100 mA·g−1 and super cycling stability with a capacity retention of 91.1% after 5000 cycles at 1 A·g−1. This work can not only extend the application of halloysite in energy storage but also provide a low-cost and promising three-dimensional porous carbon material for advanced Na+ batteries.