Development and experimental investigation of direct urea fuel cells

Abstract

This thesis study considers the development and experimental investigation of Direct Urea-Hydrogen Peroxide Fuel Cells (DUHPFC). The research focuses on preparing electrodes using nickel zinc iron oxide on stainless steel foil and evaluates single cells and stacks under varying conditions. Optimal single-cell performance is achieved at 65°C with 9 M KOH and 0.5 M urea, yielding a peak power density of 46.38 mW/cm². The stack shows improved performance at 65°C, with a power output of 0.307 kW. The single cell attains an open circuit voltage (OCV) of 0.72 V, while the stack reaches 8.8 V. The energy and exergy efficiencies are 58% and 24% at 5 M KOH for single cells, and 48% and 41% at 65°C for stack, respectively. The electrochemical impedance spectroscopy (EIS) shows impedance reduction from 30 ohm.cm² at 25°C to 15 ohm.cm² at 65°C, indicating enhanced ionic conductivity and reduced resistance. These findings provide insights for advancing DUHPFC technology.