3D Printing of Tungstate Anion Modulated 1T-MoS2 Composite Cathodes for High-Performance Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) batteries can offer high capacity and energy-density, but face challenges like low conductivity, lithium polysulfides (LiPSs) shuttling, and limited reaction kinetics. In this study, the electronic configuration of Mo 4d orbital in MoS2 is modulated through a one-step method involving tungstate anion (WO42-) modulation to form a stable 1T-MoS2/carbon composite (1T-W-MoS2/C). When WO42- is introduced, it causes a transfer of electrons to Mo in 2H-MoS2, resulting in the generation of a stable 1T phase. In the composite, 1T-MoS2 nanosheets exhibit remarkable electronic conductivity, hydrophilicity, and catalytic activity, facilitating the LiPSs adsorption and Li+ transport. Meanwhile, the WO42- modulation can create abundant adsorption/catalytic sites with defects on the basal surface and edges of MoS2, facilitating the efficient catalysis of LiPSs conversion. Furthermore, the 3D-printed electrodes without utilization of binders and current collectors can ensure high mass loading and promote ion diffusion and electrolyte penetration. Theoretical and experimental results confirm that 1T-W-MoS2/C can catalyze LiPSs conversion, suppress LiPSs shuttling, and enhance sulfur reaction kinetics. Therefore, the 3D-printed 1T-W-MoS2/C/S cathode exhibits a high initial capacity and excellent rate capability, achieving an areal capacity of 7.37 mAh cm(-2) with a sulfur loading of 8.89 mg cm(-2).