Preparation and the Electrochemical Properties of Monolithic Porous Carbon as a Substrate for Nickel Hydroxide Electrode

Abstract

Phenolic-resin-based monolithic porous carbon (MPC) with large pores of about 2 μm in diameter has been prepared and evaluated as a possible substrate for the nickel hydroxide electrode. It has been observed that the MPC is basically electrochemically stable in the voltage range in which the nickel hydroxide electrodes operate. The Ni(OH)2 materials are loaded into the MPC using cathodic electrodeposition from the nickel nitrate solutions. This is performed by pulsing square-wave electrodeposition at room temperature. The ohmic drop of the MPC-Ni(OH)2/NiOOH electrodes during the charge-discharge process is largely due to their relatively low conductivity. The initial charge-discharge characterization of the MPC-Ni(OH)2/NiOOH electrodes shows that the specific capacity of the electrode material (SCEM) reaches 115 mAh·g−1 in terms of the total electrode weight. The above mentioned value is considerably higher than that of state-of-the-art sintered Ni-Ni(OH)2/NiOOH electrodes. Thus, it can be suggested that the MPC is a promising lightweight matrix for the Ni(OH)2/NiOOH electrodes with a focus on acquiring high weight specific energy for application in nickel-based alkaline batteries.