Freestanding nanosheets of 1T-2H hybrid MoS2 as electrodes for efficient sodium storage

Molybdenum disulfide (MoS2) is a promising electrode material for sodium-ion batteries as it offers a large capacity through a distinct conversion reaction. However, the electrochemical potential of MoS2 is often restrained by the poor conductivity as the dominant 2H phase is a semiconductor while the metallic 1T phase is thermodynamically unstable. In this work, we report a hybrid design and material preparation of freestanding nanosheets of MoS2 composed of both 1T and 2H phases based on mild hydrothermal reaction. The introduction of the metallic 1T-MoS2 phase into 2H-MoS2 and their intimate hybridization enable a significant improvement in electronic conductivity, while the freestanding architecture avoids possible electrochemical aggregation. When used as electrodes for sodium storage, such a hybrid MoS2 affords a high capacity of ∼500 mA h g−1 at 0.5 A g−1 after 300 cycles, and retains capacity of ∼200 mA h g−1 at a high current rate of 4 A g−1, thus demonstrating their potential in high-performance battery applications.