Leclanché cell

[1][2][3] The battery contained a conducting solution (electrolyte) of ammonium chloride, a cathode (positive terminal) of carbon, a depolarizer of manganese dioxide (oxidizer), and an anode (negative terminal) of zinc (reductant).

In 1866, Georges Leclanché invented a battery that consisted of a zinc anode and a manganese dioxide cathode wrapped in a porous material, dipped in a jar of ammonium chloride solution.

[7] This cell achieved very quick success in telegraphy, signalling and electric bell work.

The redox reaction in a Leclanché cell involves the two following half-reactions: The chemical process which produces electricity in a Leclanché cell begins when zinc atoms on the surface of the anode oxidize, i.e. they give up both their valence electrons to become positively charged Zn2+ ions.

A variety of factors, such as internal resistance, lower this output value to the 1.4 volts measured from these cells in practice.

As the current travels around the circuit, when the electrons enter the cathode (carbon rod), they combine with manganese dioxide (MnO2) and water (H2O), which react with each other to produce manganese oxide (Mn2O3) and negatively charged hydroxide ions.