An Aluminum–Sulfur Battery with a Fast Kinetic Response. Issue 7 (16th January 2018)

• Record Type: Journal Article
• Authors: Yang, Huicong; Yin, Lichang; Liang, Ji; Sun, Zhenhua; Wang, Yuzuo; Li, Hucheng; He, Kuang; Ma, Lipo; Peng, Zhangquan; Qiu, Siyao; Sun, Chenghua; Cheng, Hui‐Ming; Li, Feng
• Is Part Of: Angewandte Chemie international edition. Volume 57:Issue 7(2018)
• Page Start: 1898
• Page End: 1902
• Publication Date: 2018-01-16
• Subjects: aluminum–sulfur battery -- electrochemistry -- energy storage -- ionic liquid electrolytes -- kinetics; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201711328
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: 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 Al2 Cl7 − to free Al 3+ . Al2 Cl6 Br − was used instead of Al2 Cl7 − as the dissociation reaction reagent. A 15‐fold faster reaction rate of Al2 Cl6 Br − dissociation than that of Al2 Cl7 − 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 Al2 Cl6 Br − instead of Al2 Cl7 −, 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. Abstract : A major hindrance of Al‐S batteries is slow kinetics, leading to a low charge/discharge current density and low sulfur content. The relationship between the electrochemical kinetics and the electrolyte was explored, focusing on accelerating the rate‐determining step (dissociation of Al2 X7 − anions in ionic‐liquid electrolyte). Using Al2 Cl6 Br − instead of Al2 Cl7 − led to faster dissociation and an improvement of electrochemical performance.