A fuel cell is a kind of energy conversion device, which must have energy (fuel) input when it is working in order to produce electricity. Once the technical performance of the fuel cell is determined, the electrical energy it can generate is only related to the supply of fuel. As long as the fuel is supplied, electrical energy can be generated, and its discharge characteristics are continuous.
Fuel cells convert chemical energy into electrical energy. Ordinary batteries also convert chemical energy into electrical energy. This is what they have in common. However, when the fuel cell generates electrical energy, the reacting substances participating in the reaction will continue to be consumed after the reaction. Repeated use, therefore, requires continuous input of reaction substances.
The fuel cell inputs hydrogen from the hydrogen electrode (fuel electrode) on the negative side of the battery and air or oxygen from the oxidation electrode (air or oxygen) on the positive side of the battery. There is no electrolyte between the positive and negative electrodes, and the electrolyte separates the two electrodes.
According to different types of fuel cells, different electrolytes are used, including acidic, alkaline, molten salt, or solid electrolyte. In the fuel cell, the fuel and oxidant are used as catalysts. During the energy conversion process, electricity, and water (H2O) are generated through electrochemical reactions. Therefore, nitrogen oxides (NOX) and hydrocarbons (HC) are not produced. The atmospheric environment causes polluting gas emissions.
The mass and volume of the fuel cell body are not large, but the fuel cell requires a set of fuel storage device or fuel conversion device and auxiliary equipment to obtain hydrogen, and the mass and volume of these fuel storage devices or fuel conversion device and auxiliary equipment are far Exceeding the fuel cell itself, during the working process, the fuel will gradually be consumed as the fuel cell generates electricity, and the quality will gradually decrease (referring to the limited fuel on-board).
An ordinary battery is an energy storage device that must first store electrical energy in the battery. It can only output electrical energy during work and does not need to input energy or generate electrical energy during work. This is the essential difference between fuel cells and ordinary batteries.
After the technical performance of an ordinary battery is determined, it can only output electrical energy within its rated range, and it must be recharged before it can be reused. Its discharge characteristics are intermittent.
Ordinary storage batteries have no other auxiliary equipment. After the technical performance is determined, the quality and volume of the storage batteries remain basically the same whether they are fully charged or discharged.
The active material of ordinary battery changes with the charge and discharge of the battery and the active material undergoes reversible chemical changes repeatedly. The active material is not consumed, and only some electrolytes and other substances need to be added.