Polypyrrole-silver Chloride Composite as Energy Storage Materials

Abstract

Over the last decades we are witnesses of astonishing development of different electrode materials for alkali-ion and metal-air batteries [1] supercapacitors [2] and supercapattery [3]. Even so, some rather old electrochemical systems have still space for further improvement. Seawater-activated primary battery, as another example of the old systems, discovered in 1878 [4] and developed by Bell Telephone Laboratories in 1945 as the power source for electric torpedoes, are used for a wide range of applications. [5]. Among many different cathode materials, silver chloride (AgCl) and lead chloride (PbCl2) are most widely applied [5]. An improvement of AgCl synthesis is reported in our previous work [6] in which the fast and low-cost modified process of successive ion layer adsorption and reaction (SILAR) is effectively applied to form carbon felt-silver chloride cathode materials for primary cell. In this work we investigated electrochemical synthesis of polypyrrole on a carbon felt (CF/PPy) electrode. Further, the CF/PPy electrode is modified by AgCl by applying modified SILAR method. Using the cyclic voltammetry and charge discharge techniques, it is shown superior behavior of composite CF/PPy-AgCl electrode. For the possible rechargeable aqueous based magnesium alloy AZ63 |3.5% NaCl | CF/PPy-AgCl cell in the current range of 135 to 1350 A g-1 the specific capacity in the range of 35-25 Ah kg-1 , energy of 45-25 Wh kg-1 and power of 100 to 1600 W kg-1 are obtained. Also the cyclic stability is determined, and concluded that such a simple cell using small photovoltaic cell could be charged at least 100 times, depending of Mg-alloy mass. The possibilities of further improvement of the system is considered.