Dihydrophenazine-Based Copolymers As Promising Cathode Materials For Dual-Ion Batteries

Herein, two novel copolymers of dihydrophenazine with diphenylamine (PDPAPZ) and phenothiazine (PPTZPZ) are synthesized and investigated as cathode materials for dual-ion batteries. Both polymers demonstrate high average discharge potentials (3.5-3.6 V) in lithium cells. The PDPAPZ//Li cells demonstrate impressive rate capability: specific capacities of 101 and 82 mAh g(-1) are reached under galvanostatic charging and discharging at the high current densities of 5 and 20 A g(-1), respectively. The capacity retention of 86% and 34% after 100 and 25 000 cycles, respectively, features decent operational stability of the batteries. Furthermore, an encouraging energy density of 398 Wh kg(-1) is achieved in potassium PDPAPZ//K cells. The obtained values place PDPAPZ on par with the best organic cathode materials for fast lithium and potassium batteries.