Dry Cell
A primary cell using a moist paste rather than a liquid electrolyte, so it can be used in any orientation.
Formula / equation
Zn + 2MnO₂ + 2NH₄⁺ → Zn²⁺ + Mn₂O₃ + 2NH₃ + H₂O
Unit
V
In depth
In the Leclanché design a zinc case acts as the anode and a carbon rod surrounded by manganese dioxide as the cathode, with ammonium chloride paste as electrolyte. It delivers about 1.5 V but polarises under heavy load and eventually leaks as the zinc case is consumed.
Examples in the real world
The traditional zinc–carbon torch battery; the alkaline version replaces the paste with potassium hydroxide.