Hollow carbon spheres supporting nitrogen-doped carbon–coated (Co0.67Ni0.33)9S8/NiCoLDH nanosheets with enhanced performance for lithium-ion batteries

Nickel–cobalt sulfides and nickel–cobalt hydroxides are outstanding anode materials for lithium-ion batteries (LIBs), but their commercial applications are restricted by poor conductivity and severe cyclic expansion. In this article, we report a structure in which nitrogen-doped carbon layers are compactly coated on nanosheets of (Co0.67Ni0.33)9S8/NiCoLDH that are supported by hollow carbon spheres (HCS). The HCS@(Co0.67Ni0.33)9S8/NiCoLDH@NC was synthesized by hydrothermal reactions and calcination with SiO2 as hard templates. The hollow structure reduces the severe capacity attenuation caused by volume expansion, and the nanosheets covered with carbon have a huge specific surface area and significantly enhanced electrical conductivity. The HCS@(Co0.67Ni0.33)9S8/NiCoLDH@NC exhibits excellent cycle capacity (615 mAh g−1 at 0.2 A g−1 after 150 cycles) and rate performance depending on the structural preponderances and the synergistic interaction between (Co0.67Ni0.33)9S8 and NiCoLDH. This research provides a unique route for the synthesis of anode materials for high-performance LIBs.