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Metal sulfides are regarded as promising anode materials for developing high-performance lithium-ion batteries (LIBs) due to their high theoretical specific capacity and intrinsic safety. However, poor electrical conductivity and drastic volume change during lithiation hamper their practical application. This study reports the synthesis of hollow cube-like composites consisting of heterostructured MnS/Co1−xS nanoparticles embedded in electrically conductive carbon@reduced graphene oxide (MnS/Co1−xS@C@rGO) obtained from a GO-coated mixed metal-cyanide coordination polymer precursor. Benefiting from the synergistic effect of different components and the unique hierarchically hollow architecture, the MnS/Co1−xS@C@rGO-600 composites evaluated as anode materials exhibited a high reversible capacity of 1018 mA h g−1 after 500 cycles at a current density of 1 A g−1 and 723 mA h g−1 after 1000 cycles at a high current density of 5 A g−1. The combination of the convenient synthesis strategy and excellent lithium storage performance makes MnS/Co1−xS@C@rGO-600 composites a promising anode material for high-performance LIBs. [ABSTRACT FROM AUTHOR]

Transition metal sulfides are of great interest as anodes for lithium-ion batteries (LIBs) due to their high theoretical capacity and low cost. However, the poor cycling stability and rate performance are the critical problems that hinder their practical applications. In this work, a unique hybrid nanocomposite constructed from starfish-like ZnxCo1−xS rooted in porous carbon and strongly coupled carbon nanotubes (ZnxCo1−xS@C–CNTs) is demonstrated to address this concern. The designed nanocomposite integrates the high theoretical capacity of ZnxCo1−xS and the excellent conductivity as well as the excellent mechanical stability of CNTs. When evaluated as anode materials for LIBs, ZnxCo1−xS@C–CNTs exhibited a high reversible capacity of 635 mA h g−1 at a current density of 1.2 A g−1 after 1000 cycles and excellent high-rate capability (890 mA h g−1 and 750 mA h g−1 at current densities of 3.2 and 6.4 A g−1, respectively). The excellent electrochemical performance of ZnxCo1−xS@C–CNTs can be ascribed to its hierarchically porous structure design and the synergistic effect between ZnxCo1−xS@C and CNTs. [ABSTRACT FROM AUTHOR]

The high conductivity of bimetallic thiospinel NiCo2S4 endows energy storage devices with very fascinating performance. However, the unsatisfactory rate capability and long-term cyclability of this material series significantly limit their large-scale practical applications such as in electric vehicles and hybrid electric vehicles. Herein, we successfully synthesized NiCo2S4 hexagonal nanosheets with a large lateral dimension of ∼1.35 μm and a thickness of ∼30 nm through a vapor transformation method. The dynamic transformation process of the NiCo2S4 polycrystalline nanosheets from NiCo-hydroxide has been revealed in detail. Originating from their two-dimensional thin-sheet structure with a high aspect ratio, the induced extrinsic capacitive contribution as high as 91% makes them an ideal candidate for high-capacity and high-rate lithium-ion anodes. The NiCo2S4 nanosheets deliver a reversible capacity of 607 mA h g−1 upon 800 cycles at a current density of 2 A g−1. This outstanding long cycle performance sheds light on the structural design of electrode materials for high-rate lithium-ion batteries. [ABSTRACT FROM AUTHOR]