An Aluminum-Sulfur Battery with a Fast Kinetic Response

The electrochemical performance of the aluminum-sulfur (Al-S) battery has very poor reversibility and a low charge/discharge current density owing to slow kinetic processes determined by an inevitable dissociation reaction from Al2Cl7- to free Al3+center dot Al2Cl6Br- was used instead of Al2Cl7- as the dissociation reaction reagent. A 15-fold faster reaction rate of Al2Cl6Br- dissociation than that of Al2Cl7- was confirmed by density function theory calculations and the Arrhenius equation. This accelerated dissociation reaction was experimentally verified by the increase of exchange current density during Al electro-deposition. Using Al2Cl6Br- instead of Al2Cl7- , a kinetically accelerated Al-S battery has a sulfur utilization of more than 80%, with at least four times the sulfur content and five times the current density than that of previous work.