A thin-layer fuel cell is described that is simple and easy to set up and is particularly useful for teaching and classroom demonstrations. The cell is both an electrolyzer and a fuel cell and operates using a thin layer of electrolyte with a thickness of approximately 127 micrometers and a volume of approximately 40 microliters. As an electrolyzer, an external power source such as a photovoltaic array drives the cell to generate hydrogen and chlorine gas bubbles at the cathode and anode, respectively. As a fuel cell, the cell utilizes the stored hydrogen and chlorine to generate electricity. The cell design exploits the phenomenon of gas bubble coalescence to suppress the occurrence of bubble-induced turbulence mixing in the system during electrolysis. The cell design minimizes the level of fuel crossover and cell depolarization and eliminates the need for a cathode-anode separator. (Contains 4 figures.)