Metal–air electrochemical cell

A metal–air electrochemical cell is an electrochemical cell of which the anode is a made from pure metal and the cathode connects to an inexhaustible supply of air.[1][2]

Contents

Types

Properties of metal–air batteries

Of the various metal–air battery chemical couples (Table 1), the Li–air battery is the most attractive since the cell discharge reaction between Li and oxygen to yield Li2O, according to 4Li + O2 → 2Li2O, has an open-circuit voltage of 2.91 V and a theoretical specific energy of 5210 Wh/kg. In practice, oxygen is not stored in the battery, and the theoretical specific energy excluding oxygen is 11140 Wh/kg (40.1 MJ/kg). Compare this to the figure of 44 MJ/kg for gasoline (see petrol energy content).

Metal–air battery Calculated open-circuit voltage, V Theoretical specific energy, Wh/kg
(including oxygen)
Theoretical specific energy, Wh/kg
(excluding oxygen)
Li–O2 2.91 5210 11140
Na–O2 1.94 1677 2260
Ca–O2 3.12 2990 4180
Mg–O2 2.93 2789 6462
Zn–O2 1.65 1090 1350

Advantages

References