Controlled assembly of MoSe2/N-doped carbon nanoflower spheres via coordination-induced precursor for superior sodium-ion storage

Molybdenum diselenide (MoSe 2 ) suffers from poor conductivity and structural degradation for sodium storage, which hinders its electrochemical performance. Herein, a coordination-induced precursor strategy is proposed to construct three-dimensional MoSe 2 /nitrogen-doped carbon (MoSe 2 -NC) nanoflowers, in which MoSe 2 nanosheets are tightly embedded within a nitrogen-doped carbon matrix via dopamine-assisted self-assembly. The dopamine content regulates the structural evolution from solid to hollow flower-like spheres with tunable shell thickness, enabling uniform carbon incorporation and effective suppression of MoSe 2 aggregation. Strong Mo–C/N interfacial coupling enhances structural stability and charge transfer, while the carbon framework accommodates volume variation during cycling. Consequently, the optimized MoSe 2 -NC-2 anode delivers a high reversible capacity of 335.4 mAh g −1 at 0.5 A g −1 , along with excellent rate capability and cycling stability (232.35 mAh g −1 after 800 cycles at 2 A g −1 ). When coupled with a NaNi 1/3 Fe 1/3 Mn 1/3 O 2 cathode, the assembled full cell exhibits stable cycling performance (106.3 mAh g −1 after 90 cycles at 1C), demonstrating its potential for practical applications. The enhanced electrochemical performance can be attributed to the conductive carbon framework, strengthened interfacial interactions, and efficient accommodation of volume variation. This work provides insights into the rational design of metal selenide/carbon composites for sodium-ion batteries.