Controlling structure and morphology of MoS2 via sulfur precursor for optimized pseudocapacitive lithium intercalation hosts

Molybdenum disulfide (MoS2)-based electrode materials can exhibit a pseudocapacitive charge storage mechanism induced by nanosized dimension of the crystalline domains. This effect is achievable through hydrothermal synthesis of MoS2, which often yields different properties of the final material, thereby affecting its electrochemical lithium intercalation behavior. In this study, we investigate how the use of different sulfide precursors, specifically thiourea (TU), thioacetamide (TAA), and L-cysteine (LC), during the hydrothermal synthesis of MoS2, affects its physicochemical, and consequently, electrochemical properties. The three materials obtained exhibit distinct morphologies, ranging from micron-sized architectures (MoS2 TU), to nanosized flakes (MoS2 TAA and LC), which influence their available specific surface area and tortuosity. Consequently, the choice of hydrothermal synthesis parameters allows to control the resulting electrochemical signature. The individual charge storage properties are analyzed by operando X-ray diffraction, dilatometry, and 3D Bode analysis, revealing a correlation between the morphology, porosity, and the electrochemical intercalation behavior of the obtained electrode materials. The results demonstrate a facile strategy to control MoS2 structure and related functionality by choice of hydrothermal synthesis precursors.