Monolayer MoS2 Fabricated by In Situ Construction of Interlayer Electrostatic Repulsion Enables Ultrafast Ion Transport in Lithium-Ion Batteries

Highlights: In-situ construction of electrostatic repulsion between MoS interlayers is first proposed to successfully prepare Co-doped monolayer MoS under high vapor pressure.The doped Co atoms radically decrease bandgap and lithium ion diffusion energy barrier of monolayer MoS and can be transformed into ultrasmall Co nanoparticles (~2 nm) to induce strong surface-capacitance effect during conversion reaction.The Co doped monolayer MoS shows ultrafast ion transport capability along with ultrahigh capacity and outstanding cycling stability as lithium-ion-battery anodes. Abstract: High theoretical capacity and unique layered structures make MoS a promising lithium-ion battery anode material. However, the anisotropic ion transport in layered structures and the poor intrinsic conductivity of MoS lead to unacceptable ion transport capability. Here, we propose in-situ construction of interlayer electrostatic repulsion caused by Co+ substituting Mo between MoS layers, which can break the limitation of interlayer van der Waals forces to fabricate monolayer MoS, thus establishing isotropic ion transport paths. Simultaneously, the doped Co atoms change the electronic structure of monolayer MoS, thus improving its intrinsic conductivity. Importantly, the doped Co atoms can be converted into Co nanoparticles to create a space charge region to accelerate ion transport. Hence, the Co-doped monolayer MoS shows ultrafast lithium ion transport capability in half/full cells. This work presents a novel route for the preparation of monolayer MoS and demonstrates its potential for application in fast-charging lithium-ion batteries.[MediaObject not available: see fulltext.]