A hydrogen battery is an electrochemical device that can convert the chemical energy of hydrogen and oxygen into electrical energy without polluting and emitting harmful substances. A PEM fuel cell (proton exchange membrane fuel cell) consists of two electrodes (a cathode and an anode) connected by a polymer membrane. eous hydrogen is sent to the anode of the membrane, and air is sent to the cathode. Hydrogen atoms are stripped by electrons on the anode side, and positively charged protons pass through the membrane to reach the cathode. A platinum catalyst must be used for this reaction to occur. Hydrogen electrons flow from the anode to the cathode through an external circuit to generate electric current. The electrons, protons and oxygen in the air combine at the cathode to produce water, which is the main by-product of fuel cells. Used for teaching, classroom demonstration, high school physics experiment science and education equipment.