Structure, morphology and electrochemical performance of Zn-doped [Ni4Al(OH)10]OH

A layered double hydroxide [Ni4Al(OH)10]OH was doped with different amounts of Zn2+ by coprecipitation and subsequent hydrothermal treatment. The structures of the samples were investigated by XRD, which showed that all are layered double hydroxides with very similar lattice parameters; and samples treated hydrothermally have better crystallinity with ZnO phase. The ZnO exists in rods of several micrometers long, while the [Ni4Al(OH)10]OH in disks of various sizes as shown in SEM images. It has been found that samples treated hydrothermally have higher discharge capacity and better cyclic stability, the maximum discharge capacities are 315 mAh g−1 and 300 mAh g−1 at discharge current densities of 400 mA g−1 and 2000 mA g−1, respectively.