Conversely, zinc air primary cells are also used as pressure actuators. Don't have a link handy, but Big Clive on YouTube did a series of videos a while back on

Conversely, zinc air primary cells are also used as pressure actuators. Don't have a link handy, but Big Clive on YouTube did a series of videos a while back on some industrial air fresheners and grease dispensers that use one of these cells to very slowly create a large amount of air pressure to squeeze out viscous liquid over time. The amount of gas released can be controlled with the current through the cell. Very interesting technology!