CuO powders composed of different rod-like clusters or dandelion-like nanospheres are prepared by a low-temperature thermal decomposition process of Cu(OH)2 precursors, which are obtained via a catalytic template method. A tentative mechanism is proposed to explain the formation and transformation of different Cu(OH)2 nanostructures. X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, field-emission scanning electron microscopy, transmission electron microscopy, infrared spectra analysis, Brunauer-Emmett-Teller measurements, and galvanostatic cell cycling are employed to characterize the structures and electrochemical performance of these CuO samples. The results show that these CuO samples obtained after 500 °C calcination have a stable cycling performance with a reversible capacity of over 587 mA h g-1 after 50 cycles. The dandelion-like CuO electrode shows the best rate performance with a high capacity of 511 mA h g-1 at 4C.