Durability of nickel-metal hydride (Ni-MH) battery cathode using nickel-aluminum layered double hydroxide/carbon (Ni-Al LDH/C) composite

We report the durability of the optimized nickel aluminum layered double hydroxide/carbon (Ni-Al LDH/C) composite prepared by liquid phase deposition (LPD) as cathode active materials in nickel metal hydride (Ni-MH) secondary battery. The positive electrode was used for charge discharge measurements under two different current: 5 mA for 300 cycles in half-cell conditions, and 5.8 mA for 569 cycles in battery regime, respectively. The optimized Ni-Al LDH/C composite exhibits a good lifespan and stability with the capacity retention above 380 mA h g(comp)(-1) over 869 cycles. Cyclic voltammetry shows that the alpha-Ni(OH)(2)/gamma-NiOOH redox reaction is maintained even after 869 cycles, and the higher current regime is beneficial in terms of materials utilization. X-ray diffraction (XRD) patterns of the cathode after charge and discharge confirms that the alpha-Ni(OH)(2)/gamma-NiOOH redox reaction occurs without any intermediate phase. (C) 2013 Elsevier B.V. All rights reserved.