Nitrogen-Doped Metallic MoS2 Derived from a Metal-Organic Framework for Aqueous Rechargeable Zinc-Ion Batteries.

Abstract

Molybdenum disulfide (MoS2) has been extensively studied as a potential storage material for batteries. However, the electrochemical performance of MoS2 is far from ideal, and it exhibits severe activity fading resulting from its low electronic conductivity. The present work synthesizes nitrogen (N)-doped 1T MoS2 nanoflowers made of ultrathin nanosheets via the one-step hydrothermal sulfurization of a molybdenum-based metal-organic framework precursor. The resulting metallic phase shows improved conductivity and hydrophilicity, and characterization demonstrates that N doping effectively expands the interlayer spacing and increases the concentration of sulfur vacancies serving as defects. This material demonstrates high rate performance and good cycling stability when used as the cathode in an aqueous rechargeable zinc-ion battery (ARZIB). Its performance is superior to those of pure 1T MoS2 and 2H MoS2 synthesized with MoO3 as the molybdenum source. Ex situ X-ray photoelectron spectroscopy and X-ray diffraction analyses are performed to explore the reaction mechanism during charging and discharging of the N-doped 1T MoS2. A three-cell series ARZIB system containing this material is used to power five light-emitting diodes to confirm the possible practical applications of this technology.