A Versatile Halide Ester Enabling Li‐Anode Stability and a High Rate Capability in Lithium–Oxygen Batteries. (30th January 2019)

• Record Type: Journal Article
• Authors: Wang, Di; Zhang, Fan; He, Ping; Zhou, Haoshen
• Is Part Of: Angewandte Chemie. Volume 131:Number 8(2019)
• Page Start: 2377
• Page End: 2381
• Publication Date: 2019-01-30
• Subjects: Elektrolytaddivita -- Entladungsrate -- Lithiummetall -- Li-O2-Batterien; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201813009
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Li‐O2 batteries are promising candidates for next‐generation high‐energy‐density battery systems. However, the main problems of Li–O2 batteries include the poor rate capability of the cathode and the instability of the Li anode. Herein, an ester‐based liquid additive, 2, 2, 2‐trichloroethyl chloroformate, was introduced into the conventional electrolyte of a Li–O2 battery. Versatile effects of this additive on the oxygen cathode and the Li metal anode became evident. The Li–O2 battery showed an outstanding rate capability of 2005 mAh g −1 with a remarkably decreased charge potential at a large current density of 1000 mA g −1 . The positive effect of the halide ester on the rate capacity is associated with the improved solubility of Li2 O2 in the electrolyte and the increased diffusion rate of O2 . Furthermore, the ester promotes the formation of a solid–electrolyte interphase layer on the surface of the Li metal, which restrains the loss and volume change of the Li electrode during stripping and plating, thereby achieving a cycling stability over 900 h and a Li capacity utilization of up to 10 mAh cm −2 . Abstract : Ester‐Batterie : Die Verwendung von 2, 2, 2‐Trichlorethylchlorformiat als Elektrolyt‐Additiv in einer Li‐O2 ‐Batterie führt zu einer hervorragenden Entladungsrate (2005 mAh g −1 ) mit deutlich verringertem Ladungspotential bei einer Stromdichte von 1000 mA g −1 . Dem positiven Effekt liegen die verbesserte Löslichkeit von Li2 O2 im Elektrolyten und die erhöhte Diffusionsrate von O2 zugrunde.