Novel secondary assembled micro/nano porous spheres ZnCo 2 O 4 with superior electrochemical performances as lithium ion anode material.

In this work, novel secondary assembled micro/nano porous spheres ZnCo2 O4 were firstly prepared by combining the hydrothermal method with post-synthesis calcinations. The structure and morphology of the obtained powder were characterized by x-ray powder diffraction and field emission-scanning electron microscopy. As the anode material of lithium-ion half-cells, the as-prepared ZnCo2 O4 delivered a very high capacity, extra cycling stability and excellent rate capability. A discharge capacity of 950 mAh g-1 with up to 99.7% retention corresponding to the second cycle at 0.1 C was achieved after 90 cycles, which was an improved cyclability over previous reports. The higher current charge-discharge and electrochemical impedance spectroscopy data indicate that the material's integrity was maintained. Therefore constructing the secondary assembled 3D micro/nano structure is an effective strategy to obtain the superior electrochemical performances.