Electrochemical properties of nickel-aluminum layered double hydroxide/carbon composite fabricated by liquid phase deposition

Nickel-aluminum layered double hydroxide/carbon (Ni-Al LDH/C) composites have been fabricated using a mixed solution of {Al(NO3)(3)center dot 9H(2)O and H3BO3} as fluoride scavengers in the liquid phase deposition (LPD) process. The amount of divalent Ni2+ substituted by trivalent Al3+ within the lattice of alpha-Ni(OH)(2) was controlled by the concentration of Al(NO3)(3)center dot 9H(2)O solution. X-ray diffraction studies reveal pure phase Ni-Al LDH, isostructural and isomorphic to alpha-Ni(OH)(2) with higher interlayer distance. The electrochemical properties of the cathode materials containing 0, 8.6, 13.8, 17.8, 21.3 and 23.4 Al% were evaluated by the means of charge-discharge and cyclic voltammetry measurements. The overall comparison indicates that Ni-Al LDH/C composites have higher electrochemical performance than pure alpha-Ni(OH)(2)/C composite. The cathode with 17.8 Al% exhibits the best performance at 1 C compared to other Al3+ contents: a much lower voltage plateau, well separated from the oxygen evolution at the end of the charging as well as a single flat and high discharge plateau with a discharge capacity of 376.9 mAh g(comp)(-1). Short term durability test for 80 cycles showed that the electrode containing 13.8 Al% has the highest discharge rate at 2 C. The range of Al substitution 13.8-17.8 Al% provides a good electrochemical response. (C) 2010 Elsevier B.V. All rights reserved.