11,11,12,12-tetracyano-9,10-anthraquinonedimethane as a high potential and sustainable cathode for organic potassium-ion batteries

We fabricated a potassium-ion battery by using 11,11,12,12-tetracyano-9,10-anthraquinonedimethane (TCAQ) as the cathode for the first time. Owing to the unique molecular structure and configuration of ionic liquid electrolytes, TCAQ shows a high redox potential of 2.6 V vs. K + /K while delivering a capacity of 88 mAh g −1 at a current density of 17 mA g −1 and a capacity retention of 61% after 50 cycles. The mechanism of the reaction of TCAQ with K was investigated. The results prove that TCAQ holds great promise for broad applications in potassium-ion batteries while revealing new scientific insights into K + -organic cathode batteries.