All those cells have a zinc anode, which used to be amalgamated with a small amount of mercury to prevent corrosion and leakage[1]. (Mercuric oxide batteries ce

All those cells have a zinc anode, which used to be amalgamated with a small amount of mercury to prevent corrosion and leakage[1]. (Mercuric oxide batteries certainly contain even more.) [1] https://www.epa.gov/mercury/mercury-batteries https://www.epa.gov/mercury/mercury-batteries