Atomic-Scale Laminated Structure of O-Doped WS2 and Carbon Layers with Highly Enhanced Ion Transfer for Fast-Charging Lithium-Ion Batteries

WS2 anode materials show huge potential for fast-charging lithium-ion batteries (LIBs) due to the naturally good 2D diffusion pathways but suffer from large Li+ diffusion barrier energy and poor intrinsic electrical conductivity. Here, a defect-rich atomic-scale laminated structure of WS2 and C (D-WS2-C) with O doping and enlarged interlayer distance from 0.62 to 1.06 nm of WS2 is first fabricated, which is assembled into micron-sized spheres to prepare WS2/C composite microspheres. D-WS2-C with maximized molecular layer contact area between WS2 and carbon and large interlayer spacing greatly enhances the electrical conductivity of WS2 and reduces Li-ion diffusion energy barrier, confirmed by density functional theory calculations. Besides, the unique D-WS2-C enables the formation of vast superfine W nanoparticles (1-2 nm) during the conversation reaction, resulting in the construction of a space charge zone on W surface. Based on these characteristics of D-WS2-C, the prepared WS2/C composite microspheres show superior fast-charging capability with a high capacity of 647.8 mAh g(-1) at 20 C in half cells. For full cells, a high-energy density of 100.9 Wh kg(-1) is achieved at a charge time of only 8.5 min at 5 C, representing the best fast-charging performances in WS2-based anode materials to date.