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 SiO2 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.