Hierarchical Nanoarchitectured Hybrid Electrodes Based on Ultrathin MoSe2 Nanosheets on 3D Ordered Macroporous Carbon Frameworks for High-Performance Sodium-Ion Batteries
Sodium-ion batteries (SIBs) have been considered as a promising alternative to lithium-ion batteries for large-scale stationary energy storage due to their low cost and abundant resource of sodium. Nevertheless, lack of high capacity, long cycling stability anodes seriously hinders the commercialization of SIBs. Herein, ultrathin 2D MoSe2 nanosheets strongly bonded on 3D ordered macroporous (3DOM) carbon are designed to greatly improve sodium storage. The resulting MoSe2@C composite delivers high capacities (410 mAh g-1 at 0.5 A g-1 after 100 cycles, considering total weight of all active MoSe2@C), superior rate capability (249 mAh g-1 at 10 A g-1), and long-term cycling stability (384 mAh g-1 at 5 A g-1 after 2000 cycles). The enhanced electrochemical performance can be ascribed to synergistic effects between the hybrid structures constructed from 2D MoSe2 nanosheets and 3DOM carbon architecture, which can provide expended interlayer spacing (0.76 nm for single layer) facilitating Na+ insertion/extraction, strong electronic coupling of Mo-C bonding boosting the fast electron/ion transfer, and ordered stereoscopic cavity accommodating the volume expansion and preventing the stacking of MoSe2 nanosheets upon cycling.