| − | A type of [[battery|electrochemical cell]] where [[hydrogen]] and [[oxygen]] combine to make [[water]] and energy. Scientists discovered fuel cells in the early 1900s, and they will be important in establishing the [[hydrogen economy]]. | + | A '''fuel cell''' is a type of [[battery|electrochemical cell]] where [[hydrogen]] and [[oxygen]] combine to make [[water]] and energy. Scientists discovered fuel cells in the early 1900s, and they will be important in establishing the [[hydrogen economy]]. |