| 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 |