Carbon-coated MoS_(2) nanosheets@CNTs-Ti_(3)C_(2) MXene quaternary composite with the superior rate performance for sodium-ion batteries

The exploration of advanced MoS_(2)-based electrode materials overcoming their inherent low conductivity and large volume changes is of importance for next-generation energy storage.In this work,we report a simple and high-efficient one-pot hydrothermal approach to prepare a unique and stable 1D/2D heterostructure.In the architecture,ultrathin carbon layer-coated MoS_(2) nanosheets with large expanded interlayer of 1.02 nm are vertically grown onto the Ti_(3)C_(2) MXene and cross-linked carbon nanotubes(CNTs),giving rise to a highly conductive 3D network.The interlayer expanded MoS_(2) nanosheets can greatly facilitate the Na ions/electrons transmission.Meanwhile,the N-doped 1D/2D CNTs-Ti_(3)C_(2) matrix can be used as a strong mechanical support to well relieve the large volume expansion upon cycles.As a combination result of several advantages,the developed quaternary C-MoS_(2)/CNTs-Ti_(3)C_(2) composite anode shows an excellent sodium storage performance(562 mA h g^(-1) at 100 mA g^(-1) after 200 cycles)and rate capability(475 mA h g^(-1) at 2000 mA g^(-1)).The density functional theory calculations further prove that the full combination of layer-expanded MoS_(2) nanosheets and N-doped Ti_(3)C_(2) matrix can significantly enhance the adsorption energy of Na ions,further resulting in the enhancement of sodium storage capabilities.