Anion-Dependent Redox Chemistry of p-Type Poly(vinyldimethylphenazine) Cathode Materials

Metal-free organic electrode materials have attracted vast research attention owing to their designable structures and tunable electrochemical properties. Although n-type cathode materials could be used in various metal-ion batteries, p-type ones with high potential can deliver high energy density. Herein, we report a new p-type polymeric cathode material, poly(2-vinyl-5,10-dimethyl-dihydrophenazine) (PVDMP), with a theoretical capacity of 227 mAh g(-1). PVDMP featuring two-step redox reaction will be doped by two anions to maintain electroneutrality during oxidation, which resulted in an anion-dependent electrochemical behavior of PVDMP-based cathode. The suitable dopant anion for PVDMP was selected and the doping mechanism was confirmed. Under the optimized condition, PVDMP cathode can deliver a high initial capacity of 220 mAh g(-1) at 5 C and even remains 150 mAh g(-1) after 3900 cycles. This work not only provides a new kind of p-type organic cathode materials but also deepens the understanding of its anion-dependent redox chemistry.

Automated summary

Metal-free organic electrode materials have been widely studied due to their designable structures and tunable electrochemical properties. This article introduces a new p-type polymeric cathode material, poly(2-vinyl-5,10-dimethyl-dihydrophenazine) (PVDMP), with a theoretical capacity of 227 mAh g(-1). The study investigates the electrochemical behavior of PVDMP-based cathode, which depends on the doping of two anions to maintain electroneutrality during oxidation. The optimal conditions for PVDMP cathode are identified, resulting in high initial capacity and excellent cycling stability.