Boosting Na+ Storage Ability of Bimetallic MoxW1−xSe2 with Expanded Interlayers.

In spite of the valuable advancements in the fabrication of transition‐metal selenides (TMSs)‐based hybrid structures, only single‐metal selenides have been obtained through most of the present methods. Herein, a facile room‐temperature self‐polymerization and subsequent selenization strategy is proposed for the synthesis of bimetallic MoxW1−xSe2 nanosheets with expanded interlayers decorated with N‐doped carbon‐matrix assembled flowerlike hierarchical microspheres (MoxW1−xSe2/NC). Depending on the excellent coordination ability of dopamine with metal ions, self‐formed flowerlike single precursors are harvested. The unique hybrid architecture benefits the penetration of the electrolyte, accelerates Na+ insertion/extraction kinetics, enhances electron‐transfer ability, and alleviates the volume expansion and aggregation during cycling processes. Therefore, the bimetallic MoxW1−xSe2/NC electrode delivers high reversible capacities of 264 mA h g−1 at 1 A g−1 for 700 cycles, 204.4 mA h g−1 at 4 A g−1 for 1400 cycles, and 153.3 mA h g−1 at 8 A g−1 for 2000 cycles, as well as an excellent rate capability up to 10 A g−1 with a capacity of 188.9 mA h g−1. Our study offers an effective strategy to boost sodium storage performance through elaborate structural engineering. [ABSTRACT FROM AUTHOR]