I was doing some searching for the batteries that the Apollo Hasselblad cameras used. I couldn't find a direct article, but IIRC they were either Zinc or Silver nicades. Is this correct ? If anyone has a link bookmarked, please provide.
I think every flight battery used in the Apollo program was silver-zinc. I know that to be true for all stages of the Saturn V, the LM, the CSM and the PLSS. So I assume it was true for the cameras as well.
Silver/zinc is more accurately described as silver oxide/zinc. The anode (negative plate) is zinc, just as in ordinary alkaline batteries. The cathode (positive plate) is silver oxide. It should be fairly obvious why this is not more widely used despite substantially outperforming the manganese dioxide in the cathodes of ordinary alkaline batteries.
A "nicad" is a completely different type of battery. It uses cadmium anodes and nickel oxy-hydroxide cathodes. It has lower energy density but works well as a secondary (rechargeable) battery.
Silver-zinc can be recharged, but with a very poor cycle life measured in the single digits. The only batteries recharged in Apollo were the entry batteries in the CM; all the others were primaries (non-rechargeables).