Single-Layered MoS 2 Fabricated by Charge-Driven Interlayer Expansion for Superior Lithium/Sodium/Potassium-Ion-Battery Anodes.

Single-layered MoS 2 is a promising anode material for lithium-ion batteries (LIBs), sodium-ion batteries (SIBs), and potassium-ion batteries (PIBs) due to its high capacity and isotropic ion transport paths. However, the low intrinsic conductivity and easy-agglomerated feature hamper its applications. Here, a charge-driven interlayer expansion strategy that Co 2+ replaces Mo 4+ in the doping form to endow MoS 2 layers with negative charges, thus inducing electrostatic repulsion, together with the insertion of gaseous groups, to drive interlayer expansion which once breaks the confinement of interlayer van der Waals force, single-layered MoS 2 is obtained and uniformly dispersed into carbon matrix arising from the transformation of carbonaceous gaseous groups under high vapor pressure, is proposed. Co atom doping helps enhance the intrinsic conductivity of single-layered MoS 2 . Carbon matrix effectively prevents agglomeration of single-layered MoS 2 . The doped Co atoms can be fully transformed into ultrasmall Co nanoparticles during conversion reaction, which enables strong spin-polarized surface capacitance and thus significantly boosts ion transport and storage. Consequently, the prepared material delivers superb Li/Na/K-ion storage performances, which are best in the reported MoS 2 -based anodes. The proposed charge-driven interlayer expansion strategy provides a novel perspective for preparing single-layered MoS 2, which shows huge potential for energy storage.