Studies of Zn/X-/Polyaniline Batteries:Part 2. X=I

The characteristics of a Zn/ZnI2/polyaniline battery have been examined. It is demonstrated that the polymer has a charge storage capacity of 143 A h kg-~ and an energy efficiency above 70%. The battery has an open circuit voltage of 1.2 V and polarization during charges and discharges at 30-120mA were low. Self discharge is low compared to the chloride and bromide electrolyte batteries and charge recovery was 60% after 12 days stored on open circuit. It is shown that these promising characteristics may be interpreted in terms of a system where the polyaniline largely acts as a current collector and the I3-/I- couple is rapid within the film. The kinetics of the system are determined by a.c. impedance.