All of these alkaline batteries are now either made in China, or are assembled from crap materials bought from China. Chinese manufacturing materials are almost universally crap.  Any part made with  plastics from China is going to break within a couple of years, and any polymer barriers in any of those batteries are going to break down in a couple of years. The stabilizing chemicals for plastics are expensive so the Chinese just leave them out, grab the quick money and let you deal with the breakdowns.