Metallic 1T phase MoS2/MnO composites with improved cyclability for lithium-ion battery anodes

Abstract

Transition metal oxides, such as manganese monoxide (MnO), have the potential to provide higher reversible capacities via conversion reactions than carbon-based anodes. However, one issue hindering MnO's use in lithium ion batteries is its low electrical conductivity. Here, we fabricate a metallic 1T phase MoS2 by molten lithium salts assisted method and describe a simple and effective ball-milling strategy to form a composite lithium ion battery anode consisting of two-dimensional metallic 1T phase MoS2 single crystal nanosheets and MnO nanoparticles. The nanocomposite electrode initially delivers 729.8 mAh g−1 and 493.7 mAh g−1 at 0.5 C and 10 C, respectively. At 2000th cycled at 0.5 C, charge/discharge capacities of electrode delivered 584.8 mAh g−1 and 589.6 mAh g−1. Even at the 2020th cycle, the charge/discharge capacities of electrode present 583.9 mAh g−1 and 588.2 mAh g−1, respectively, which still are more than 80% retention of the initial charge/discharge capacities. The good rate performance could be attributed to the improved electrical conductivity provided by the 1T MoS2. In the composite, there appears to the formation of Mo–O bonds between the 1T MoS2 and MnO. Such bonding may be the reason for the cyclability.