Porous hollow composites assembled by NiCoSe nanosheets rooted on carbon polyhedra for superior lithium storage capability.

Transition metal chalcogenides (TMCs) have attracted considerable interest owing to their satisfied theoretical capacity, good safety and environmentally benign nature in lithium-ion batteries (LIBs). However, the poor conductivity as well as the severe volume changes during the discharge-charge process cause capacity fading rapidly, which severely impede the practical applications of TMCs. To address this challenge, a hollow hybrid architecture assembled by NiCoSe nanosheets and strongly coupled porous carbon have been rational designed. Within this structure, the integration of nanosheets rooted on the surface of porous carbon not only provide three-dimensional conductive network but also offer plentiful pathways and active sites for electrolyte penetration and Li storage, and buffer a large volume expansion/contraction caused by lithium intercalation/deintercalation. As evidenced by electrochemical measurements, the NiCoSe/C composites used as anodes in LIBs exhibit a superior reversible high capacity of 1667 mA h g at current density of 2.0 A g over 600 cycles and an outstanding rate capability (1580 and 1093 mA h g at 3.2 and 6.4 A g, respectively).