429 / | HD | CHEMISTRY: ELECTRICAL CURRENT PRODUCING APPARATUS, PRODUCT, AND PROCESS |
12 | DF | FUEL CELL, SUBCOMBINATION THEREOF OR METHODS OF OPERATING {10} |
19 | .~ Having means for active material generation or regeneration {2} | |
20 | DF | .~.~> By heating or cooling |
21 | DF | .~.~> By electrical current |