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Zinc carbon primary cell - What is the alternate to Hg?

In case of Zinc carbon dry cells, mercury is used to prevent zinc can corrosion. Chemistry behind how mercury prevent Zinc from corrosion is well known.

But, now-a-days, for environmental reasons, many companies are forced to make Hg free batteries. So,what are the alternatives to Hg in Zinc-carbon battery. Do these really substitute Hg from all angle?

PRASAD TANTRY
Novino Batteries - Baroda, Gujatat, India
2004

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Zinc-carbon batteries are based on the Leclanche Cell; this was first invented in the mid C19. Mercury was added to the zinc to reduce the chemical dissolution of zinc by the electrolyte and hence reduce the amount of hydrogen gassing. In the west, mercury has been eliminated from consumer dry cells since about 2001, but many countries stopped using it as far back as 1990. Since its withdrawal, battery technology has progressed and it is not required. To overcome the problems it was originally used for, the formaulation of the electrolytes have been changed; for instance the pH of them has been brought closer to neutral. Furthermore, additives such as polyethylene glycol have been used to "protect" the zinc. There are numerous patents on organic inhibitors for zinc-carbon cells, so it will be worth doing a search. Other improvements include better separator technologies and materials. As far as I am aware, there has been no reduction in the characteristics of the zinc-carbon cell, so I can only surmise that there has been no reduction in the electrochemical performance of the system.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2004