The impact of drying temperature on the crystalline domain and the electrochemical performance of NiCoAl-LDH

Abstract

This work has investigated the effect of drying temperature on the crystallite size and lattice strain of NiCoAl-LDH using the Williamson–Hall (W–H) method and tracked the impact of the changes thereof on the electrochemical properties. During the experiments, the drying time was kept unchanged, while the temperature was varied from 70 °C, 80 °C to 90 °C. From the X-ray diffractometer (XRD), Fourier-transform infrared spectroscopy (FTIR), Cyclic voltammetry (CV), and Electrochemical impedance spectroscopy (EIS) results, it was found that the drying temperature had greatly influenced the crystalline structure, the interlamellar domain as well as the electrochemical properties of NiCoAl-LDH. An increment in the crystallite sizes was observed from 4.971 to 12.334 nm as the drying temperature increased from 70 to 80 °C and dropped to 7.681 nm when it reached 90 °C. Similarly, an increase in the specific capacitance was recorded from 1158.26 to 4180.16 Fg−1 at 10 mVs −1 as the drying temperature went up from 70 to 80 °C and dropped to 3775.77 Fg −1 at 10 mVs −1 when the drying temperature increased to 90 °C. Moreover, the sample dried at 80 °C exhibited low internal resistance compared to its counterpart. The best electrochemical performance of the sample dried at 80 °C could be attributed to the larger size of its crystallite. This leads to the conclusion that the electrochemical performance of NiCoAl-LDH could be crystallite size-dependent. Finally, it was proved that the drying temperature (80 °C-12 h) is the best for the drying stage of NiCoAl-LDH.

Keywords

• Williamson–Hall analysis
• Crystallite size
• Drying temperature
• Cyclic voltammetry