Rechargeable Aluminium–Sulfur Battery with Improved Electrochemical Performance by Cobalt‐Containing Electrocatalyst

• Published in: Angewandte Chemie International Edition Vol. 59; no. 51; pp. 22963 - 22967
• Main Authors: Guo, Yue, Hu, Zhiqiu, Wang, Jiawei, Peng, Zhangquan, Zhu, Junfa, Ji, Hengxing, Wan, Li‐Jun
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 14.12.2020
• Edition: International ed. in English
• Subjects: aluminium–sulfur battery; Aluminum; catalyst; Catalysts; Cathodes; Chemical reactions; Cobalt; Cobalt sulfide; Discharge; Electric potential; Electrocatalysts; Electrochemical analysis; Electrochemistry; Electrode materials; Flux density; Hysteresis; kinetic response; Lithium; Lithium-ion batteries; Product safety; Reaction kinetics; Rechargeable batteries; Specific capacity; Sulfur; Valence; Voltage
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.202008481

The rechargeable aluminium–sulfur (Al–S) battery is regarded as a potential alternative beyond lithium‐ion battery system owing to its safety, promising energy density, and the high earth abundance of the constituent electrode materials, however, sluggish kinetic response and short life‐span are the major issues that limit the battery development towards applications. In this article, we report CoII,III as an electrochemical catalyst in the sulfur cathode that renders a reduced discharge–charge voltage hysteresis and improved capacity retention and rate capability for Al–S batteries. The structural and electrochemical analysis suggest that the catalytic effect of CoII,III is closely associated with the formation of cobalt sulfides and the changes in the valence states of the CoII,III during the electrochemical reactions of the sulfur species, which lead to improved reaction kinetics and sulfur utilization in the cathode. The Al–S battery, assembled with the cathode consisting of CoII,III decorated carbon matrix, demonstrates a considerably reduced voltage hysteresis of 0.8 V, a reversible specific capacity of ≈500 mAh g−1 at 1 A g−1 after 200 discharge–charge cycles and of ≈300 mAh g−1 at 3 A g−1. The catalytic effect of CoII,III on the electrochemical conversion reactions of sulfur in a rechargeable Al–S battery is demonstrated, which is associated with the changes in the valence states of the CoII,III during the discharge–charge cycles, rendering a reduced discharge–charge voltage hysteresis and improved capacity retention and rate capability.