A new application for nickel foam in alkaline fuel cells

The use of nickel foam as an electrode substrate in alkaline fuel cells (AFCs) has been investigated for bi-polar cells incorporating an electrically conducting gas diffusion layer. This contribution focuses on the cathode, and draws comparisons between nickel foam and nickel mesh substrates. One of the principal electrocatalysts for the cathodic reduction of oxygen is silver, so an improvement in electrochemical performance was obtained by electroplating the nickel foam with silver. The electrodeposition process was optimised to maximise electrochemical performance with a minimum of silver deposited. Nickel foam, which is less expensive than the usual nickel mesh, appears to be a good substrate for AFC electrode fabrication, especially when incorporating a conducting gas diffusion layer. Silver deposited by electroplating onto the nickel foam was found to result in significantly enhanced electrochemical performance, with a reduction in both the Ohmic resistance of the electrode, as well as the oxygen reduction reaction charge transfer resistance.