Carbon felt-polypyrrole-silver chloride composite as a rechargeable positive electrode for the seawater magnesium cell

In the paper, for the first time, the new concept of rechargeable cathode for Mg-based seawater cells is demonstrated. The pristine carbon felt (CF) is functionalized with electrodeposited polypyrrole (PPy), and the composite with silver chloride (AgCl) is prepared by the modified successive ion layer adsorption and reaction (SILAR) method. Pristine carbon felt – polypyrrole (CF/PPy) and carbon felt - polypyrrole - silver chloride (CF/PPy-AgCl) are investigated as potential rechargeable positive electrodes for the magnesium seawater cell. During charge, which can be accomplished with small photovoltaic cells, polypyrrole, and silver are oxidized while on Mg hydrogen is evolved. During discharge dissolution of Mg alloy, and reduction of doped polypyrrole and silver chloride occurred. The specific capacity, energy, and power of the cell, as well as cyclic stability, are estimated. The possible application of the cell is also proposed. [Display omitted] •PPy is successfully electrodeposited on carbon felt (CF).•CF/PPy composite with AgCl is prepared by the modified SILAR method.•CF/PPy-AgCl composite is investigated as the rechargeable cathode for seawater Mg cells.•Promising results concerning specific capacity, energy, and power are obtained.