Synthesis and electrochemical performances of ZnO/MnO2 sea urchin-like sleeve array as anode materials for lithium-ion batteries.

Abstract: MnO2 is electrodeposited onto ZnO nanorod array grown on Ni foil, forming a binder-free ZnO/MnO2 composited electrode. XRD, EDS, SEM and TEM are used to analyze the phase and microstructure of this composite. Burr-like MnO2 nanoflakes grows on ZnO nanorod array, the top of the composite is hollow and at the bottom exists ZnO large block core as an internal support, forming ZnO/MnO2 sea urchin-like sleeve array. As anode material for lithium ion batteries, ZnO/MnO2 sleeve array exhibits higher discharge capacity and coulombic efficiency, better rate performance and cycling stability than single ZnO nanorod array or directly electrodepsited MnO2, and the composite effect is very remarkable. After 100 cycles, the discharge capacity of ZnO/MnO2 still reaches 1259mAhg−1, and coulombic efficiency surpasses 98%, higher than those of ZnO nanorod array (111mAhg−1) and directly electrodeposited MnO2 (507mAhg−1). The improvement of the electrochemical performances is due to the unique sea urchin-like sleeve array architecture. MnO2 burr tube shell structure leads to high electrochemical activity while the internal ZnO core support ensures good structure stability. The gradually opening of sea urchin-like sleeve during the cycling further enhances the electrochemical activity of MnO2, stabilizing and increasing electrochemical performances of the ZnO/MnO2 composite. [Copyright &y& Elsevier]