Rechargeable aluminum batteries with conducting polymers as positive electrodes

Abstract

This report is a summary of research results from an Early Career LDRD project conducted from January 2012 to December 2013 at Sandia National Laboratories. Demonstrated here is the use of conducting polymers as active materials in the positive electrodes of rechargeable aluminum-based batteries operating at room temperature. The battery chemistry is based on chloroaluminate ionic liquid electrolytes, which allow reversible stripping and plating of aluminum metal at the negative electrode. Characterization of electrochemically synthesized polypyrrole films revealed doping of the polymers with chloroaluminate anions, which is a quasi-reversible reaction that facilitates battery cycling. Stable galvanostatic cycling of polypyrrole and polythiophene cells was demonstrated, with capacities at near-theoretical levels (30-100 mAh g -1 ) and coulombic efficiencies approaching 100%. The energy density of a sealed sandwich-type cell with polythiophene at the positive electrode was estimated as 44 Wh kg -1 , which is competitive with state-of-the-art battery chemistries for gridscale energy storage. 4 ACKNOWLEDGMENTS

Recent advances in cathode engineering to enable reversible room-temperature aluminium–sulfur batteries

“… 44 )), titanium dioxide, 45 and conductive polymers. 46 Although the abovementioned cathode materials have brought obvious advantages, certain disadvantages have been brought by the traditional insertion-type cathode compounds. For instance, the energy density of such batteries fades quickly due to depletion in the electrolyte concentration.…”