In Situ Growth of a Feather-like MnO₂ Nanostructure on Carbon Paper for High-Performance Rechargeable Sodium-Ion Batteries

Recently, sodium-ion batteries have attracted great attention, owing to the rich resource and low cost. In the present work, a feather-like MnO₂ nanostructure was prepared directly on carbon paper by using a rapid and simple hydrothermal route for the first time. The formation mechanism was proposed by investigating the intermediate products during the reaction. When applied as an anode for a sodium-ion battery, the feather-like MnO₂ nanostructure on carbon paper exhibited a high discharge capacity, good rate reversibility, and long-term cycling stability. A high specific capacity of approximately 300 mAh g⁻¹ could be obtained even after cycling 400 times with a current density of 0.1 A g⁻¹. Furthermore, the Na⁺ storage mechanism of MnO₂ on carbon paper in the sodium-ion battery was also investigated in this work. Such high performance can be attributed to the porous structure of the substrate and high specific surface area of the feather-like nanostructure.