Zinc and Alkaline are two different types of batteries. Zinc batteries are known to have been around for a longer period of time. The Zinc batteries right now are considered to be the updated versions of the old zinc batteries but if the capacity will be compared to the alkaline batteries, the alkaline batteries can still be considered to be far better and more superior in providing the right amount of energy for a longer period of time.
Obviously, when it comes to price, Zinc batteries will be considered cheaper but if you would like to have batteries that will last for longer periods of time even if they are more expensive, alkaline batteries are the better option.