Novel Designed MnS-MoS2 Heterostructure for Fast and Stable Li/Na Storage:Insights into the Advanced Mechanism Attributed to Phase Engineering

Combining 2D MoS2 with other transition metal sulfide is a promising strategy to elevate its electrochemical performances. Herein, heterostructures constructed using MnS nanoparticles embedded in MoS2 nanosheets (denoted as MnS-MoS2) are designed and synthesized as anode materials for lithium/sodium-ion batteries via a facile one-step hydrothermal method. Phase transition and built-in electric field brought by the heterostructure enhance the Li/Na ion intercalation kinetics, elevate the charge transport, and accommodate the volume expansion. The sequential phase transitions from 2H to 3R of MoS2 and alpha to gamma of MnS are revealed for the first time. As a result, the MnS-MoS2 electrode delivers outstanding specific capacity (1246.2 mAh g(-1) at 1 A g(-1)), excellent rate, and stable long-term cycling stability (397.2 mAh g(-1) maintained after 3000 cycles at 20 A g(-1)) in Li-ion half-cells. Superior cycling and rate performance are also presented in sodium half-cells and Li/Na full cells, demonstrating a promising practical application of the MnS-MoS2 electrode. This work is anticipated to afford an in-depth comprehension of the heterostructure contribution in energy storage and illuminate a new perspective to construct binary transition metal sulfide anodes.