The incorporation of Cr ions into the framework of ZnO for stable electrochemical performance in a membrane free alkaline Ni/Zn redox

ZnO and Cr-incorporated ZnO (CrxZnO, x = 0.001, 0.005, and 0.01 moles) crystalline particles are synthesized using a solvothermal method for use as an anode material in membrane free alkaline Ni/Zn batteries. Both types of particle showed a wurtzite-type structure with spherical shapes, however the peak widths of <20 nm in the XRD patterns of the CrxZnO particles were broader. Cr0.005ZnO displayed a high power, higher capacity and longer life cycle for rechargeable membrane-free alkaline Ni/Zn batteries than the other particles. The capacity of 136 mA h g (1) for the Ni/Cr0.005ZnO battery was higher than that (49 mA h g (1)) of the Ni/ZnO battery after cycling at a current density of 30 mA cm (2). When Cr0.005ZnO was used as an anodic material, the growth of zinc dendrites on the Ni-plate anodic electrode was suppressed during 50 charge-discharge cycles. These results indicate that the proper insertion of Cr into the lattice of the ZnO framework enhances the electrochemical performance in a membrane free alkaline Ni/Zn battery. (C) 2016 Elsevier Ltd. All rights reserved.