2D interspace confined growth of ultrathin MoS2-intercalated graphite hetero-layers for high-rate Li/K storage

Herein, a two-dimensional (2D) interspace-confined synthetic strategy is developed for producing MoS2-intercalated graphite (G-MoS2) hetero-layers composite through sulfuring the pre-synthesized stage-1 MoCl5-graphite intercalation compound (MoCl5-GIC). The in situ grown MoS2 nanosheets (3–7 layers) are evenly encapsulated in graphite layers with intimate interface thus forming layer-by-layer MoS2-intercalated graphite composite. In this structure, the unique merits of MoS2 and graphite components are integrated, such as high capacity contribution of MoS2 and the flexibility of graphite layers. Besides, the tight interfacial interaction between hetero-layers optimizes the potential of conductive graphite layers as matrix for MoS2. As a result, the G-MoS2 exhibits a high reversible Li+ storage of 344 mAh·g−1 even at 10 A·g−1 and a capacity of 539.9 mAh·g−1 after 1,500 cycles at 5 A·g−1. As for potassium ion battery, G-MoS2 delivers a reversible capacity of 377.0 mAh·g−1 at 0.1 A·g−1 and 141.2 mAh·g−1 even at 2 A·g−1. Detailed experiments and density functional theory calculation demonstrate the existence of hetero-layers enhances the diffusion rates of Li+ and K+. This graphite interspace-confined synthetic methodology would provide new ideas for preparing function-integrated materials in energy storage and conversion, catalysis or other fields.