Not sure why you'd want to do that. Many use CO2 because it's faster for airing up tires and using air tools. I just don't see a need to use a CO2 tank for lockers. A tiny inexpensive air compressor is going last a long time and work well.
I carry a CO2 tank and use it most of the time. That is, until it's empty. Then I use my air compressor. With your idea, when the tank goes empty, now you don't have functioning lockers.