Designed synthesis of NiO@polypyrrole hollow spheres for long-life lithium storage

A novel type of NiO-based anodes, i.e., NiO@polypyrrole hollow spheres (NiO@PPy HSs), has been constructed by using SiO 2 spheres as templates. The PPy component serves as an ideal supporting matrix for NiO anodes owing to its high structural stability and electrical conductivity. Thus, the NiO@PPy HSs demonstrate markedly enhanced lithium storage capabilities in terms of cycling stability compared with bare NiO spheres. For example, a high reversible capacity of 520.0 mA h g −1 can be delivered after 200 cycles in NiO@PPy anode at a current density of 100 mA g −1 . The superior cycling stability of NiO@PPy HSs makes it an ideal anodic candidate for long-life lithium-ion batteries.