Cyclic-anion salt for high-voltage stable potassium-metal batteries

Yanyao Hu; Ling Fan; Apparao M Rao; Weijian Yu; Caixiang Zhuoma; Yanhong Feng; Zhihui Qin; Jiang Zhou; Bingan Lu

doi:10.1093/nsr/nwac134

Cyclic-anion salt for high-voltage stable potassium-metal batteries

Natl Sci Rev. 2022 Jul 9;9(10):nwac134. doi: 10.1093/nsr/nwac134. eCollection 2022 Oct.

Authors

Yanyao Hu¹, Ling Fan¹, Apparao M Rao², Weijian Yu¹, Caixiang Zhuoma¹, Yanhong Feng¹, Zhihui Qin¹, Jiang Zhou³, Bingan Lu¹

Affiliations

¹ School of Physics and Electronics, Hunan University, Changsha 410083, China.
² Department of Physics and Astronomy, Clemson Nanomaterials Institute, Clemson University, Clemson, SC 29634, USA.
³ School of Materials Science and Engineering, Central South University, Changsha 410083, China.

Abstract

Electrolyte anions are critical for achieving high-voltage stable potassium-metal batteries (PMBs). However, the common anions cannot simultaneously prevent the formation of 'dead K' and the corrosion of Al current collector, resulting in poor cycling stability. Here, we demonstrate cyclic anion of hexafluoropropane-1,3-disulfonimide-based electrolytes that can mitigate the 'dead K' and remarkably enhance the high-voltage stability of PMBs. Particularly, even using low salt concentration (0.8 M) and additive-free carbonate-based electrolytes, the PMBs with a high-voltage polyanion cathode (4.4 V) also exhibit excellent cycling stability of 200 cycles with a good capacity retention of 83%. This noticeable electrochemical performance is due to the highly efficient passivation ability of the cyclic anions on both anode and cathode surfaces. This cyclic-anion-based electrolyte design strategy is also suitable for lithium and sodium-metal battery technologies.

Keywords: additive-free electrolyte; cyclic anion; high-voltage; low concentration; potassium-metal batteries; solid–electrolyte interface.