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.
Keywords: O atom doping; WS 2/C anodes; atomic-scale laminated structure; enlarged interlayer distance; fast-charging lithium-ion batteries.
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