An Intrinsically Non‐flammable Electrolyte for High‐Performance Potassium Batteries. Issue 9 (29th January 2020)

• Record Type: Journal Article
• Authors: Liu, Sailin; Mao, Jianfeng; Zhang, Qing; Wang, Zhijie; Pang, Wei Kong; Zhang, Lei; Du, Aijun; Sencadas, Vitor; Zhang, Wenchao; Guo, Zaiping
• Is Part Of: Angewandte Chemie international edition. Volume 59:Issue 9(2020)
• Page Start: 3638
• Page End: 3644
• Publication Date: 2020-01-29
• Subjects: batteries -- non-flammable materials -- phosphates -- potassium -- solvents; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201913174
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Potassium‐ion batteries are promising for low‐cost and large‐scale energy storage applications, but the major obstacle to their application is the lack of safe and effective electrolytes. A phosphate‐based fire retardant such as triethyl phosphate is now shown to work as a single solvent with potassium bis(fluorosulfonyl)imide at 0.9 m, in contrast to previous Li and Na systems where phosphates cannot work at low concentrations. This electrolyte is optimized at 2 m, where it exhibits the advantages of low cost, low viscosity, and high conductivity, as well as the formation of a uniform and robust salt‐derived solid‐electrolyte interphase layer, leading to non‐dendritic K‐metal plating/stripping with Coulombic efficiency of 99.6 % and a highly reversible graphite anode. Abstract : A phosphate‐based fire retardant such as triethyl phosphate (TEP) is shown to work as a single solvent with potassium bis(fluorosulfonyl)imide (KFSI). This electrolyte forms a uniform and robust salt‐derived solid‐electrolyte interphase layer, leading to non‐dendritic K‐metal plating/stripping with Coulombic efficiency of 99.6 % with a highly reversible graphite anode.