Molecular Tailoring of p–type Organics for Zinc Batteries with High Energy Density

Abstract

AbstractP‐type organic electrode materials are known for their high redox voltages and fast kinetics. However, single‐electron p‐type organic materials generally exhibit low capacity despite high operating voltage and stability, while some multi‐electron p‐type organic materials have high theoretical capacity but low stability. To address this challenge, we explore the possibility of combining single‐electron and multi‐electron units to create high‐capacity and stable p‐type organic electrodes. We demonstrate the design of a new molecule, 4,4′‐(10H‐phenothiazine‐3,7‐diyl) bis (N,N‐diphenylaniline) (PTZAN), which is created by coupling the triphenylamine molecule and the phenothiazine molecule. The resulting PTZAN||Zn battery shows excellent stability (2000 cycles), high voltage (1.3 V), high capacity (145 mAh g−1), and energy density of 187.2 Wh kg−1. Theoretical calculations and in/ex situ analysis reveal that the charge storage of the PTZAN electrode is mainly driven by the redox of phenothiazine heterocycles and triphenylamine unit, accompanied by the combination/release of anions and Zn2+.