Octahydroxytetraazapentacenedione: New organic electrode material for fast and stable potassium batteries

Abstract

We report the synthesis and electrochemical characterization of octahydroxytetraazapentacenedione (OHTAPQ). The potassium batteries using OHTAPQ as electrode material delivered the specific capacity of 190 mAh g −1 at the current density of 0.6 A g −1 . The use of the concentrated (2.2 M KPF 6 ) diglyme-based electrolyte suppressed significantly the capacity fading of the potassium half-cells with OHTAPQ electrodes thus enabling their stable operation for 1200 charge-discharge cycles. Furthermore, OHTAPQ delivered the specific discharge capacity of 82–103 mAh g −1 at high current densities of 9–21 A g −1 , which leads to high power densities approaching 41000 W kg −1 . Thus, we demonstrate that the rationally designed organic electrode material enables high-capacity and high-power potassium batteries, which can be considered as a more environment-friendly and scalable alternative to the mainstream lithium-ion battery technology. • A promising organic redox-active material OHTAPQ is introduced. • OHTAPQ//K cells demonstrated specific capacities of >200 mAh g −1 at 0.6 A g −1 • Potassium battery with OHTAPQ cathode showed good stability for >1200 cycles. • The specific power of >41000 W kg −1 is demonstrated for OHTAPQ-based electrodes. • Redox transformations of OHTAPQ were modeled using DFT calculations.