Exxon Mobil said it will develop fuels for the partnership's vehicles. Financial terms and Exxon Mobil's stake in the partnership weren't released. Company officials couldn't immediately be reached for comment.
Fuel cells generate electricity by combining hydrogen with oxygen from the air.
Under ideal conditions, they emit nothing more than water vapor. Automakers, power companies and others are working on ways to use fuel cells to meet stricter air-quality laws.