Spray pyrolysis-derived W-doped MoSe₂/rGO paper-like microspheres: optimization of microstructure and mesostructure for enhanced lithium storage

Two-dimensional MoSe₂ is a promising candidate for lithium-ion battery anodes. However, its conductivity and lithium storage volumetric effect still need to be optimized. In this work, W-doped MoSe₂/rGO paper-like microspheres are successfully prepared through ultrasonic spray pyrolysis, achieving optimization at both the microstructure and mesostructure to enhance the lithium storage performance of the material. Firstly, by utilizing the similar two-dimensional structure between MoSe₂ and rGO, self-assembly is achieved through spray pyrolysis, resulting in a well-defined van der Waals heterostructure at the interface on the microscale, enhancing the electron and ion transfer capability of the composite. Secondly, the mesoscale paper-like microsphere morphology provides additional volume expansion buffering space. Moreover, W-doping not only increases the interlayer spacing of MoSe₂ (0.73 nm), thereby reducing the diffusion resistance of Li⁺, but also allow for the modulation of the energy band structure of the material. Density functional theory (DFT) calculations confirm that W-doped MoSe₂/rGO exhibits the narrowest bandgap (0.892 eV). Therefore, the composite demonstrates excellent lithium storage performance, maintaining a specific capacity of 732.9 mAh·g⁻¹ after 300 cycles at a current density of 1 A·g⁻¹.