Mo2C nanoparticles anchored on Ti3C2Tx MXene assembled hierarchical architecture for anodic applications in advanced sodium-ion battery

Transition metal carbides (M x C y ) have recently emerged as promising candidates for sodium-ion battery (SIB) anodes, among which Mo 2 C stands out due to its metallic conductivity and favorable Na  +  migration characteristics. Nevertheless, substantial volume expansion and severe particle agglomeration during cycling impair structural integrity and cycling stability, thereby hindering its practical application. To tackle these intrinsic limitations, we synthesized morphology-modulated Mo 2 C/MXene composites by adjusting the mass ratio of Mo source to MXene precursors. One of these composites forms a 3D hierarchical porous framework, in which Mo 2 C nanocrystals are uniformly anchored on conductive Ti 3 C 2 T x MXene sheets, and is named Mo 2 C / MXene-S. MXene acts as an effective electron-transport network and mechanical buffer to alleviate volume fluctuation of Mo 2 C and suppress structural pulverization. Benefiting from the synergistic effect, the Mo 2 C/MXene-S anode exhibits reversible capacities of 406.5/143.6 mA h g −1 at 0.1/2 A g −1 and retains 296.1 mA h g −1 at 1 A g −1 after 1500 cycles. Kinetic analysis shows that Na  +  storage is dominated by surface-controlled pseudocapacitance. Density Functional Theory (DFT) calculations demonstrate that the composite optimizes Na  +  adsorption and reduces the diffusion energy barrier. The Na 3 V 2 (PO 4 ) 3 //Mo 2 C/MXene full cell displays stable cycling, offering an effective strategy for developing high-performance SIB anodes.