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 Al 2 Cl 7 - to free Al 3+ . Al 2 Cl 6 Br - was used instead of Al 2 Cl 7 - as the dissociation reaction reagent. A 15-fold faster reaction rate of Al 2 Cl 6 Br - dissociation than that of Al 2 Cl 7 - 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 Al 2 Cl 6 Br - instead of Al 2 Cl 7 - , 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.