Additives Engineered Nonflammable Electrolyte for Safer Potassium Ion Batteries. (6th September 2020)

• Record Type: Journal Article
• Authors: Liu, Gang; Cao, Zhen; Zhou, Lin; Zhang, Jiao; Sun, Qujiang; Hwang, Jang‐Yeon; Cavallo, Luigi; Wang, Limin; Sun, Yang‐Kook; Ming, Jun
• Is Part Of: Advanced functional materials. Volume 30:Number 43(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-09-06
• Subjects: additives -- nonflammable electrolytes -- potassium ion batteries -- solid electrolyte interfaces -- solvation structures; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202001934
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Potassium ion batteries (KIBs) are attracting great attention as an alternative to lithium‐ion batteries due to lower cost and better global sustainability of potassium. However, designing electrolytes compatible with the graphite anode and addressing the safety issue of highly active potassium remains challenging. Herein, a new concept of using additives to engineer non‐flammable electrolytes for safer KIBs is introduced. It is discovered that the additives, such as the ethylene sulfate (i.e., DTD), can make the electrolyte of 1.0 m potassium bis(fluorosulfonyl) imide in trimethyl phosphate compatible with graphite anode for the first time, without the need of concentrated electrolyte strategies. A new coordination mechanism of additives in the electrolyte is presented. It is shown that the additive can change the K + solvation structure and then determine the interfacial behaviors of K + ‐solvent on electrode interface, which are critical to affect the graphite performance (i.e., K + ‐solvent co‐insertion, or K + (de‐)intercalation). Then, an extremely high potassium storage capability is obtained in graphite electrode for potassium (ion) batteries, particularly the presented high‐performance graphite|K0.69 CrO2 full battery fully demonstrates the practical application of this newly designed electrolyte. This additive‐based strategy can offer more opportunities to tune the electrolyte properties and then serve for the more mobile ion battery system. Abstract : A new concept of using additives to engineer electrolyte is introduced in potassium (ion) batteries (KIBs), successfully addressing the great issue of electrolytes: their incompatibility with graphite for storing K + reversibly. A new coordination mechanism of additives in the electrolyte is presented. Thus, high potassium storage capability in the graphite electrode is demonstrated in graphite|K0.69 CrO2 full KIBs.