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 α to γ 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. A heterostructure composed of MnS and MoS2 (denoted as MnS‐MoS2) possesses a uniform sheet structure. The MnS‐MoS2 heterostructure undergoes phase transition from 2H to 3R of MoS2 and α to γ of MnS during the electrode reaction. A built‐in electric field is introduced to enhance the electrochemical performance. Superior cycling and rate performance are achieved.