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High-performance flexible sodium-ion batteries based on carbon sphere-supported hierarchical Nb2CTx MXene/MoS 2 composites, which excellent specific capacity, cycle stability and rate performance. It has a specific capacity of 196 mAh g-1 at a current density of 20 A g-1. In addition, this design scheme can also be extended to other application scenarios. [Display omitted] • Hollow carbon sphere could make electrode three-dimensional. • MXene-bonded 3D hierarchical structure could reduce the charge transfer path. • Nb 2 CT x /MoS 2 @CS anode have outstanding cycle stability for Na ion storage. • MXene-bonded electrode have certain flexibility. Hand-made Nb 2 CT x /MoS 2 @CS//NVP full battery could reach to 90° bending. Sodium-ion batteries, as a promising alternative to the lithium-ion battery, have attracted extensive attention. However, due to the larger ion radius and higher standard reduction potential, the sodium-ion batteries still face poor cycle stability and relatively low energy density problems. In this work, a carbon sphere-supported Nb 2 CT x MXene/MoS 2 hierarchical structure has been designed and synthesized through hydrothermal and electrostatic self-assembly methods. The design strategy successfully improves the utilization efficiency of the MoS 2 carbon sphere as a support skeleton and reducing the diffusion path length of Na ions, leading to an improved specific capacity and rate performance. Moreover, Nb 2 CT x sheets also effectively inhibit the capacity attenuation caused by MoS 2 shedding, thus achieving the long cycle life of the sodium-ion battery. As a result, the carbon-supported MXene/MoS 2 anode delivers an ultrahigh reversible capacity, long cycling stability, and superior capacity retention rate. Notably, the carbon-supported MXene/MoS 2 anode can also obtain a considerable capacity of 196 mAh g−1 at a current density of 20 A g−1. The full cell of SIBs was assembled, and the flexibility of the battery was tested. The density functional theory simulation results show that the sodium ion has a smaller diffusion barrier under this material design strategy. [ABSTRACT FROM AUTHOR]