An all-organic aqueous potassium dual-ion battery

Abstract

An all-organic aqueous potassium dual-ion full battery was assembled with polytriphenylamine cathode, 21 M Potassium bis(fluoroslufonyl)imide water-in-salt electrolyte and 3,4,9,10-perylenetetracarboxylic diimide anode for the first time. • The advanced all organic aqueous potassium dual-ion full battery (APIB) is assembled. • The reaction mechanism of APIB is verified by X-ray spectroscopy and scanning electron microscopy. • The solvation structures of different concentration electrolytes are investigated. Benefiting from the environmental friendliness of organic electrodes and the high security of aqueous electrolyte, an all-organic aqueous potassium dual-ion full battery (APDIB) was assembled with 21 M potassium bis(fluoroslufonyl)imide (KFSI) water-in-salt as the electrolyte. The APDIB could deliver a reversible capacity of around 50 mAh g −1 at 200 mA g −1 (based on the weight of total active materials), a long cycle stability over 900 cycles at 500 mA g −1 and a high coulombic efficiency of 98.5%. The reaction mechanism of APDIB during the charge/discharge processes is verified: the FSI − could associate/disassociate with the nitrogen atom in the polytriphenylamine (PTPAn) cathode, while the K + could react with C O bonds in the 3,4,9,10-perylenetetracarboxylic diimide (PTCDI) anode reversibly. Our work contributes toward the understanding the nature of water-into-salt electrolyte and successfully constructed all-organic APDIB.