Electrochemical Assessment of As-Deposited Co(OH)₂ by Electrochemical Synthesis: The Effect of Synthesis Temperature on Performance

Abstract

In this paper, the influence of an electrolytic temperature bath was used in the electrodeposition process on the size, color, and shape of the as-deposited Co(OH)2, and the electrochemical performance was investigated. Three different temperatures of 25, 60, and 95 °C were evaluated for the electrodeposition of Co(OH)2 on stainless steel plates (SSP). The electrochemical performance of the as-deposited electrodes (SSP) was measured in a symmetric electrochemical cell (EC) arrangement. XRD, SEM, and N2 physisorption analyses were carried out to evaluate the structure and morphological composition, along with the textural properties. Results showed that the hexagonal platelet micro-clusters of Co(OH)2 are formed in a mixed composition of both α-Co(OH)2 and β-Co(OH)2 phases, with the α-Co(OH)2 phase being the major phase formed in the electrodeposition process at temperatures below 95 °C, as suggested by the XRD analysis. Electrochemical cell performances were evaluated by galvanostatic cycling, results showed maximum areal capacity values of 1.97, 2.69, and 4.34 mA h cm−2 at a charge/discharge current of 6.25 mA cm−2, for the as-deposited materials at 25, 60 and 95 °C, respectively. The specific power of the EC reached up to 19 kW kg−1 for the EC obtained material at 60 °C, with a specific energy of 2.8 W h kg−1. The maximum specific energy was reached at a current density of 6.25 mA cm−2, with a value of 10.79 W h kg−1 for the EC at 60 °C. These results offer some insight into how the morphology and composition of thin films can be tuned by the electrochemical synthesis temperature, yielding different electrochemical performances and areal capacity behaviors.

Keywords

• electrochemical synthesis
• cobalt hydroxide
• morphology control
• electrochemical performance
• energy storage devices