What is a key difference between a fuel cell and a battery?

A fuel cell generates electrical energy through an electrochemical reaction that typically involves hydrogen and oxygen, producing electricity, water, and heat as by-products. While it is accurate that fuel cells operate primarily through chemical reactions, they do generate heat as a result of these reactions. Therefore, stating that no heat is generated by a fuel cell is not correct.

The key distinguishing characteristic between a fuel cell and a battery lies in the continuous nature of a fuel cell's operation. Fuel cells generate electricity as long as there is a supply of fuel (e.g., hydrogen) and oxidant (e.g., oxygen), constantly converting those reactants into usable energy without storing it. In contrast, batteries store energy chemically and provide it when required. This stored chemical energy can be replenished by recharging the battery, whereas fuel cells must be continuously supplied with fresh reactants to function.

The option that states batteries can be recharged accurately highlights a significant difference, as it emphasizes the energy storage capability of batteries, which is not a characteristic of fuel cells. In summary, fuel cells do generate heat during their operation and their primary feature is the continuous production of electrical energy from reactants, distinguishing them from traditional batteries.