Self-supported porous CoO semisphere arrays as binder-free electrodes for high-performance lithium ion batteries

[Display omitted] •CoO semisphere arrays are prepared by a template-assisted electrodeposition method.•Interconnected semisphere arrays are favorable for fast ion/electron transfer.•CoO semisphere arrays show excellent Li ion storage performance. Construction of hierarchical porous metal oxides arrays is critical for the development of high-performance electrochemical energy storage devices. Herein we report porous CoO semisphere arrays using an electrodeposited polystyrene template method. Interestingly, the as-prepared porous CoO semisphere arrays consist of bowl-like semispheres with diameters of ∼500nm and show highly porous structure. As a preliminary test as anode for lithium ion batteries (LIBs), the porous CoO semispheres arrays exhibit superior electrochemical performances with good cyclability (695.5mAhg−1 after 150 cycles at 0.5Ag−1) and high-rate capability. The porous semispherical architecture provides positive roles in the enhancement of electrochemical properties, including fast electronic transportation path, short diffusion of Li ion and high sufficient interfacial contact area between the active material and the electrolyte. The developed methodology enables a new fabrication of porous metal oxides with applications in electro-catalysis, optical and electrochemical devices.