Porous MoS_2/Carbon Spheres Anchored on 3D Interconnected Multiwall Carbon Nanotube Networks for Ultrafast Na Storage

摘要

The performance of lithium and sodium-ion batteries is partly determined by the microstructures of the active materials and anodes. Much attention has been paid to the construction of various nanostructured active materials, with emphasis on optimizing the electronic and ionic transport kinetics, and structural stability. However, less attention has been given to the functionalization of electrode microstructure to enhance performance. Therefore, it is significant to study the effect of optimized microstructures of both active materials and electrodes on the performance of batteries. In this work, porous MoS2/carbon spheres anchored on 3D interconnected multiwall carbon nanotube networks (MoS2/C-MWCNT) are built as sodium-ion battery anodes to synergistically facilitate the sodium-ion storage process. The optimized MoS2/C-MWCNT possesses favorable features, namely few-layered, defect-rich, and interlayer-expanded MoS2 with abundant mesopores/macropores and carbon incorporation. Notably, the presence of 3D MWCNT network plays a critical role to further improve interparticle and intraparticle conductivity, sodium-ion diffusion, and structural stability on the electrode level. As a result, the electrochemical performance of optimized MoS2/C-MWCNT is significantly improved. This study suggests that rational design of microstructures on both active material and electrode levels simultaneously might be a useful strategy for designing high performance sodium-ion batteries.