MoS2 Nanosheets Vertically Aligned on Carbon Paper: A Freestanding Electrode for Highly Reversible Sodium-Ion Batteries

The development of sodium‐ion batteries for large‐scale applications requires the synthesis of electrode materials with high capacity, high initial Coulombic efficiency (ICE), high rate performance, long cycle life, and low cost. A rational design of freestanding anode materials is reported for sodium‐ion batteries, consisting of molybdenum disulfide (MoS2) nanosheets aligned vertically on carbon paper derived from paper towel. The hierarchical structure enables sufficient electrode/electrolyte interaction and fast electron transportation. Meanwhile, the unique architecture can minimize the excessive interface between carbon and electrolyte, enabling high ICE. The as‐prepared MoS2@carbon paper composites as freestanding electrodes for sodium‐ion batteries can liberate the traditional electrode manufacturing procedure, thereby reducing the cost of sodium‐ion batteries. The freestanding MoS2@carbon paper electrode exhibits a high reversible capacity, high ICE, good cycling performance, and excellent rate capability. By exploiting in situ Raman spectroscopy, the reversibility of the phase transition from 2H‐MoS2 to 1T‐MoS2 is observed during the sodium‐ion intercalation/deintercalation process. This work is expected to inspire the development of advanced electrode materials for high‐performance sodium‐ion batteries. MoS2 nanosheets vertically aligned on paper towel derived carbon paper are fabricated as freestanding electrodes for sodium‐ion batteries. Benefiting from the 3D hierarchical structure, the as‐prepared electrodes exhibited high initial Coulombic efficiency, high reversible capacity, high‐rate charging, and a long cycle life. In situ Raman electrospectroscopy is employed to investigate the sodiation/desodiation process.